Commit Graph

5139 Commits

Author SHA1 Message Date
Stefan Hajnoczi
cbc20bfb8f block: move block exports to libblockdev
Block exports are used by softmmu, qemu-storage-daemon, and qemu-nbd.
They are not used by other programs and are not otherwise needed in
libblock.

Undo the recent move of blockdev-nbd.c from blockdev_ss into block_ss.
Since bdrv_close_all() (libblock) calls blk_exp_close_all()
(libblockdev) a stub function is required..

Make qemu-nbd.c use signal handling utility functions instead of
duplicating the code. This helps because os-posix.c is in libblockdev
and it depends on a qemu_system_killed() symbol that qemu-nbd.c lacks.
Once we use the signal handling utility functions we also end up
providing the necessary symbol.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20200929125516.186715-4-stefanha@redhat.com
[Fixed s/ndb/nbd/ typo in commit description as suggested by Eric Blake
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
3a213f83d9 util/vhost-user-server: use static library in meson.build
Don't compile contrib/libvhost-user/libvhost-user.c again. Instead build
the static library once and then reuse it throughout QEMU.

Also switch from CONFIG_LINUX to CONFIG_VHOST_USER, which is what the
vhost-user tools (vhost-user-gpu, etc) do.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-14-stefanha@redhat.com
[Added CONFIG_LINUX again because libvhost-user doesn't build on macOS.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
80a06cc52b util/vhost-user-server: move header to include/
Headers used by other subsystems are located in include/. Also add the
vhost-user-server and vhost-user-blk-server headers to MAINTAINERS.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-13-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
90fc91d50b block/export: convert vhost-user-blk server to block export API
Use the new QAPI block exports API instead of defining our own QOM
objects.

This is a large change because the lifecycle of VuBlockDev needs to
follow BlockExportDriver. QOM properties are replaced by QAPI options
objects.

VuBlockDev is renamed VuBlkExport and contains a BlockExport field.
Several fields can be dropped since BlockExport already has equivalents.

The file names and meson build integration will be adjusted in a future
patch. libvhost-user should probably be built as a static library that
is linked into QEMU instead of as a .c file that results in duplicate
compilation.

The new command-line syntax is:

  $ qemu-storage-daemon \
      --blockdev file,node-name=drive0,filename=test.img \
      --export vhost-user-blk,node-name=drive0,id=export0,unix-socket=/tmp/vhost-user-blk.sock

Note that unix-socket is optional because we may wish to accept chardevs
too in the future.

Markus noted that supported address families are not explicit in the
QAPI schema. It is unlikely that support for more address families will
be added since file descriptor passing is required and few address
families support it. If a new address family needs to be added, then the
QAPI 'features' syntax can be used to advertize them.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20200924151549.913737-12-stefanha@redhat.com
[Skip test on big-endian host architectures because this device doesn't
support them yet (as already mentioned in a code comment).
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
0534b1b227 block/export: report flush errors
Propagate the flush return value since errors are possible.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-11-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
7185c85776 util/vhost-user-server: rework vu_client_trip() coroutine lifecycle
The vu_client_trip() coroutine is leaked during AioContext switching. It
is also unsafe to destroy the vu_dev in panic_cb() since its callers
still access it in some cases.

Rework the lifecycle to solve these safety issues.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-10-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
47ba680466 util/vhost-user-server: drop unused DevicePanicNotifier
The device panic notifier callback is not used. Drop it.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Stefan Hajnoczi
df6af7ce77 block/export: consolidate request structs into VuBlockReq
Only one struct is needed per request. Drop req_data and the separate
VuBlockReq instance. Instead let vu_queue_pop() allocate everything at
once.

This fixes the req_data memory leak in vu_block_virtio_process_req().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Coiby Xu
3578389bcf block/export: vhost-user block device backend server
By making use of libvhost-user, block device drive can be shared to
the connected vhost-user client. Only one client can connect to the
server one time.

Since vhost-user-server needs a block drive to be created first, delay
the creation of this object.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20200918080912.321299-6-coiby.xu@gmail.com
[Shorten "vhost_user_blk_server" string to "vhost_user_blk" to avoid the
following compiler warning:
../block/export/vhost-user-blk-server.c:178:50: error: ‘%s’ directive output truncated writing 21 bytes into a region of size 20 [-Werror=format-truncation=]
and fix "Invalid size %ld ..." ssize_t format string arguments for
32-bit hosts.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Philippe Mathieu-Daudé
f25e7ab2b0 block/nvme: Add driver statistics for access alignment and hw errors
Keep statistics of some hardware errors, and number of
aligned/unaligned I/O accesses.

QMP example booting a full RHEL 8.3 aarch64 guest:

{ "execute": "query-blockstats" }
{
    "return": [
        {
            "device": "",
            "node-name": "drive0",
            "stats": {
                "flush_total_time_ns": 6026948,
                "wr_highest_offset": 3383991230464,
                "wr_total_time_ns": 807450995,
                "failed_wr_operations": 0,
                "failed_rd_operations": 0,
                "wr_merged": 3,
                "wr_bytes": 50133504,
                "failed_unmap_operations": 0,
                "failed_flush_operations": 0,
                "account_invalid": false,
                "rd_total_time_ns": 1846979900,
                "flush_operations": 130,
                "wr_operations": 659,
                "rd_merged": 1192,
                "rd_bytes": 218244096,
                "account_failed": false,
                "idle_time_ns": 2678641497,
                "rd_operations": 7406,
            },
            "driver-specific": {
                "driver": "nvme",
                "completion-errors": 0,
                "unaligned-accesses": 2959,
                "aligned-accesses": 4477
            },
            "qdev": "/machine/peripheral-anon/device[0]/virtio-backend"
        }
    ]
}

Suggested-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20201001162939.1567915-1-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-23 13:42:16 +01:00
Claudio Fontana
9b1c911654 replay: do not build if TCG is not available
this fixes non-TCG builds broken recently by replay reverse debugging.

Stub the needed functions in stub/, splitting roughly between functions
needed only by system emulation, by system emulation and tools,
and by everyone.  This includes duplicating some code in replay/, and
puts the logic for non-replay related events in the replay/ module (+
the stubs), so this should be revisited in the future.

Surprisingly, only _one_ qtest was affected by this, ide-test.c, which
resulted in a buzz as the bh events were never delivered, and the bh
never executed.

Many other subsystems _should_ have been affected.

This fixes the immediate issue, however a better way to group replay
functionality to TCG-only code could be developed in the long term.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20201013192123.22632-4-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-22 11:53:54 -04:00
Daniel P. Berrangé
e1c4269763 block: deprecate the sheepdog block driver
This thread from a little over a year ago:

  http://lists.wpkg.org/pipermail/sheepdog/2019-March/thread.html

states that sheepdog is no longer actively developed. The only mentioned
users are some companies who are said to have it for legacy reasons with
plans to replace it by Ceph. There is talk about cutting out existing
features to turn it into a simple demo of how to write a distributed
block service. There is no evidence of anyone working on that idea:

  https://github.com/sheepdog/sheepdog/commits/master

No real commits to git since Jan 2018, and before then just some minor
technical debt cleanup.

There is essentially no activity on the mailing list aside from
patches to QEMU that get CC'd due to our MAINTAINERS entry.

Fedora packages for sheepdog failed to build from upstream source
because of the more strict linker that no longer merges duplicate
global symbols. Fedora patches it to add the missing "extern"
annotations and presumably other distros do to, but upstream source
remains broken.

There is only basic compile testing, no functional testing of the
driver.

Since there are no build pre-requisites the sheepdog driver is currently
enabled unconditionally. This would result in configure issuing a
deprecation warning by default for all users. Thus the configure default
is changed to disable it, requiring users to pass --enable-sheepdog to
build the driver.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20201002113243.2347710-3-berrange@redhat.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-15 16:06:28 +02:00
Elena Afanasova
5b4c95d0a3 block/blkdebug: fix memory leak
Spotted by PVS-Studio

Signed-off-by: Elena Afanasova <eafanasova@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1e903f928eb3da332cc95e2a6f87243bd9fe66e4.camel@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-10-13 13:33:46 +02:00
Christian Borntraeger
cd466702f0 vmdk: fix maybe uninitialized warnings
Fedora 32 gcc 10 seems to give false positives:

Compiling C object libblock.fa.p/block_vmdk.c.o
../block/vmdk.c: In function ‘vmdk_parse_extents’:
../block/vmdk.c:587:5: error: ‘extent’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  587 |     g_free(extent->l1_table);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~
../block/vmdk.c:754:17: note: ‘extent’ was declared here
  754 |     VmdkExtent *extent;
      |                 ^~~~~~
../block/vmdk.c:620:11: error: ‘extent’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  620 |     ret = vmdk_init_tables(bs, extent, errp);
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../block/vmdk.c:598:17: note: ‘extent’ was declared here
  598 |     VmdkExtent *extent;
      |                 ^~~~~~
../block/vmdk.c:1178:39: error: ‘extent’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
 1178 |             extent->flat_start_offset = flat_offset << 9;
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
../block/vmdk.c: In function ‘vmdk_open_vmdk4’:
../block/vmdk.c:581:22: error: ‘extent’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  581 |     extent->l2_cache =
      |     ~~~~~~~~~~~~~~~~~^
  582 |         g_malloc(extent->entry_size * extent->l2_size * L2_CACHE_SIZE);
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../block/vmdk.c:872:17: note: ‘extent’ was declared here
  872 |     VmdkExtent *extent;
      |                 ^~~~~~
../block/vmdk.c: In function ‘vmdk_open’:
../block/vmdk.c:620:11: error: ‘extent’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  620 |     ret = vmdk_init_tables(bs, extent, errp);
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../block/vmdk.c:598:17: note: ‘extent’ was declared here
  598 |     VmdkExtent *extent;
      |                 ^~~~~~
cc1: all warnings being treated as errors
make: *** [Makefile.ninja:884: libblock.fa.p/block_vmdk.c.o] Error 1

fix them by assigning a default value.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Message-Id: <20200930155859.303148-2-borntraeger@de.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-10-13 13:33:45 +02:00
Vladimir Sementsov-Ogievskiy
99d72dba1c block/nbd: nbd_co_reconnect_loop(): don't connect if drained
In a recent commit 12c75e20a2 we've improved
nbd_co_reconnect_loop() to not make drain wait for additional sleep.
Similarly, we shouldn't try to connect, if previous sleep was
interrupted by drain begin, otherwise drain_begin will have to wait for
the whole connection attempt.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200903190301.367620-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-10-09 15:04:32 -05:00
Vladimir Sementsov-Ogievskiy
46f56631b5 block/nbd: fix reconnect-delay
reconnect-delay has a design flaw: we handle it in the same loop where
we do connection attempt. So, reconnect-delay may be exceeded by
unpredictable time of connection attempt.

Let's instead use separate timer.

How to reproduce the bug:

1. Create an image on node1:
   qemu-img create -f qcow2 xx 100M

2. Start NBD server on node1:
   qemu-nbd xx

3. On node2 start qemu-io:

./build/qemu-io --image-opts \
driver=nbd,server.type=inet,server.host=192.168.100.5,server.port=10809,reconnect-delay=15

4. Type 'read 0 512' in qemu-io interface to check that connection
   works

Be careful: you should make steps 5-7 in a short time, less than 15
seconds.

5. Kill nbd server on node1

6. Run 'read 0 512' in qemu-io interface again, to be sure that nbd
client goes to reconnect loop.

7. On node1 run the following command

   sudo iptables -A INPUT -p tcp --dport 10809 -j DROP

This will make the connect() call of qemu-io at node2 take a long time.

And you'll see that read command in qemu-io will hang for a long time,
more than 15 seconds specified by reconnect-delay parameter. It's the
bug.

8. Don't forget to drop iptables rule on node1:

   sudo iptables -D INPUT -p tcp --dport 10809 -j DROP

Important note: Step [5] is necessary to reproduce _this_ bug. If we
miss step [5], the read command (step 6) will hang for a long time and
this commit doesn't help, because there will be not long connect() to
unreachable host, but long sendmsg() to unreachable host, which should
be fixed by enabling and adjusting keep-alive on the socket, which is a
thing for further patch set.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200903190301.367620-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-10-09 15:04:32 -05:00
Vladimir Sementsov-Ogievskiy
8a509afd72 block/nbd: correctly use qio_channel_detach_aio_context when needed
Don't use nbd_client_detach_aio_context() driver handler where we want
to finalize the connection. We should directly use
qio_channel_detach_aio_context() in such cases. Driver handler may (and
will) contain another things, unrelated to the qio channel.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200903190301.367620-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-10-09 15:04:32 -05:00
Vladimir Sementsov-Ogievskiy
8c517de24a block/nbd: fix drain dead-lock because of nbd reconnect-delay
We pause reconnect process during drained section. So, if we have some
requests, waiting for reconnect we should cancel them, otherwise they
deadlock the drained section.

How to reproduce:

1. Create an image:
   qemu-img create -f qcow2 xx 100M

2. Start NBD server:
   qemu-nbd xx

3. Start vm with second nbd disk on node2, like this:

  ./build/x86_64-softmmu/qemu-system-x86_64 -nodefaults -drive \
     file=/work/images/cent7.qcow2 -drive \
     driver=nbd,server.type=inet,server.host=192.168.100.5,server.port=10809,reconnect-delay=60 \
     -vnc :0 -m 2G -enable-kvm -vga std

4. Access the vm through vnc (or some other way?), and check that NBD
   drive works:

   dd if=/dev/sdb of=/dev/null bs=1M count=10

   - the command should succeed.

5. Now, kill the nbd server, and run dd in the guest again:

   dd if=/dev/sdb of=/dev/null bs=1M count=10

Now Qemu is trying to reconnect, and dd-generated requests are waiting
for the connection (they will wait up to 60 seconds (see
reconnect-delay option above) and than fail). But suddenly, vm may
totally hang in the deadlock. You may need to increase reconnect-delay
period to catch the dead-lock.

VM doesn't respond because drain dead-lock happens in cpu thread with
global mutex taken. That's not good thing by itself and is not fixed
by this commit (true way is using iothreads). Still this commit fixes
drain dead-lock itself.

Note: probably, we can instead continue to reconnect during drained
section. To achieve this, we may move negotiation to the connect thread
to make it independent of bs aio context. But expanding drained section
doesn't seem good anyway. So, let's now fix the bug the simplest way.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200903190301.367620-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-10-09 15:04:32 -05:00
Peter Maydell
f2687fdb75 * Reverse debugging (Pavel)
* CFLAGS cleanup (Paolo)
 * ASLR fix (Mark)
 * cpus.c refactoring (Claudio)
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Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging

* Reverse debugging (Pavel)
* CFLAGS cleanup (Paolo)
* ASLR fix (Mark)
* cpus.c refactoring (Claudio)

# gpg: Signature made Tue 06 Oct 2020 07:35:09 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini-gitlab/tags/for-upstream: (37 commits)
  tests/acceptance: add reverse debugging test
  replay: create temporary snapshot at debugger connection
  replay: describe reverse debugging in docs/replay.txt
  gdbstub: add reverse continue support in replay mode
  gdbstub: add reverse step support in replay mode
  replay: flush rr queue before loading the vmstate
  replay: implement replay-seek command
  replay: introduce breakpoint at the specified step
  replay: introduce info hmp/qmp command
  qapi: introduce replay.json for record/replay-related stuff
  migration: introduce icount field for snapshots
  qcow2: introduce icount field for snapshots
  replay: provide an accessor for rr filename
  replay: don't record interrupt poll
  configure: don't enable ASLR for --enable-debug Windows builds
  configure: consistently pass CFLAGS/CXXFLAGS/LDFLAGS to meson
  configure: do not clobber environment CFLAGS/CXXFLAGS/LDFLAGS
  dtc: Convert Makefile bits to meson bits
  slirp: Convert Makefile bits to meson bits
  accel/tcg: use current_machine as it is always set for softmmu
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-10-06 15:04:10 +01:00
Pavel Dovgalyuk
b39847a505 migration: introduce icount field for snapshots
Saving icount as a parameters of the snapshot allows navigation between
them in the execution replay scenario.
This information can be used for finding a specific snapshot for proceeding
the recorded execution to the specific moment of the time.
E.g., 'reverse step' action (introduced in one of the following patches)
needs to load the nearest snapshot which is prior to the current moment
of time.
This patch also updates snapshot test which verifies qemu monitor output.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>

--

v4 changes:
 - squashed format update with test output update
v7 changes:
 - introduced the spaces between the fields in snapshot info output
 - updated the test to match new field widths
Message-Id: <160174518865.12451.14327573383978752463.stgit@pasha-ThinkPad-X280>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06 08:34:49 +02:00
Pavel Dovgalyuk
bbacffc5f7 qcow2: introduce icount field for snapshots
This patch introduces the icount field for saving within the snapshot.
It is required for navigation between the snapshots in record/replay mode.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>

--

v7 changes:
 - also fix the test which checks qcow2 snapshot extra data
Message-Id: <160174518284.12451.2301137308458777398.stgit@pasha-ThinkPad-X280>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06 08:34:49 +02:00
Vladimir Sementsov-Ogievskiy
b33b354f3a block/io: refactor save/load vmstate
Like for read/write in a previous commit, drop extra indirection layer,
generate directly bdrv_readv_vmstate() and bdrv_writev_vmstate().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200924185414.28642-8-vsementsov@virtuozzo.com>
2020-10-05 10:59:42 +01:00
Vladimir Sementsov-Ogievskiy
fae2681add block: drop bdrv_prwv
Now that we are not maintaining boilerplate code for coroutine
wrappers, there is no more sense in keeping the extra indirection layer
of bdrv_prwv().  Let's drop it and instead generate pure bdrv_preadv()
and bdrv_pwritev().

Currently, bdrv_pwritev() and bdrv_preadv() are returning bytes on
success, auto generated functions will instead return zero, as their
_co_ prototype. Still, it's simple to make the conversion safe: the
only external user of bdrv_pwritev() is test-bdrv-drain, and it is
comfortable enough with bdrv_co_pwritev() instead. So prototypes are
moved to local block/coroutines.h. Next, the only internal use is
bdrv_pread() and bdrv_pwrite(), which are modified to return bytes on
success.

Of course, it would be great to convert bdrv_pread() and bdrv_pwrite()
to return 0 on success. But this requires audit (and probably
conversion) of all their users, let's leave it for another day
refactoring.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200924185414.28642-7-vsementsov@virtuozzo.com>
2020-10-05 10:59:42 +01:00
Vladimir Sementsov-Ogievskiy
9bb4b066cc block: generate coroutine-wrapper code
Use code generation implemented in previous commit to generated
coroutine wrappers in block.c and block/io.c

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200924185414.28642-6-vsementsov@virtuozzo.com>
2020-10-05 10:59:42 +01:00
Vladimir Sementsov-Ogievskiy
aaaa20b69b scripts: add block-coroutine-wrapper.py
We have a very frequent pattern of creating a coroutine from a function
with several arguments:

  - create a structure to pack parameters
  - create _entry function to call original function taking parameters
    from struct
  - do different magic to handle completion: set ret to NOT_DONE or
    EINPROGRESS or use separate bool field
  - fill the struct and create coroutine from _entry function with this
    struct as a parameter
  - do coroutine enter and BDRV_POLL_WHILE loop

Let's reduce code duplication by generating coroutine wrappers.

This patch adds scripts/block-coroutine-wrapper.py together with some
friends, which will generate functions with declared prototypes marked
by the 'generated_co_wrapper' specifier.

The usage of new code generation is as follows:

    1. define the coroutine function somewhere

        int coroutine_fn bdrv_co_NAME(...) {...}

    2. declare in some header file

        int generated_co_wrapper bdrv_NAME(...);

       with same list of parameters (generated_co_wrapper is
       defined in "include/block/block.h").

    3. Make sure the block_gen_c declaration in block/meson.build
       mentions the file with your marker function.

Still, no function is now marked, this work is for the following
commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924185414.28642-5-vsementsov@virtuozzo.com>
[Added encoding='utf-8' to open() calls as requested by Vladimir. Fixed
typo and grammar issues pointed out by Eric Blake. Removed clang-format
dependency that caused build test issues.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-05 10:59:06 +01:00
Vladimir Sementsov-Ogievskiy
21c2283ebc block: declare some coroutine functions in block/coroutines.h
We are going to keep coroutine-wrappers code (structure-packing
parameters, BDRV_POLL wrapper functions) in separate auto-generated
files. So, we'll need a header with declaration of original _co_
functions, for those which are static now. As well, we'll need
declarations for wrapper functions. Do these declarations now, as a
preparation step.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200924185414.28642-4-vsementsov@virtuozzo.com>
2020-10-05 09:35:52 +01:00
Vladimir Sementsov-Ogievskiy
f9e694cb32 block/io: refactor coroutine wrappers
Most of our coroutine wrappers already follow this convention:

We have 'coroutine_fn bdrv_co_<something>(<normal argument list>)' as
the core function, and a wrapper 'bdrv_<something>(<same argument
list>)' which does parameter packing and calls bdrv_run_co().

The only outsiders are the bdrv_prwv_co and
bdrv_common_block_status_above wrappers. Let's refactor them to behave
as the others, it simplifies further conversion of coroutine wrappers.

This patch adds an indirection layer, but it will be compensated by
a further commit, which will drop bdrv_co_prwv together with the
is_write logic, to keep the read and write paths separate.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200924185414.28642-3-vsementsov@virtuozzo.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
eefffb0244 block/nvme: Replace magic value by SCALE_MS definition
Use self-explicit SCALE_MS definition instead of magic value
(missed in similar commit e4f310fe7f).

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-7-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
fad1eb6886 block/nvme: Use register definitions from 'block/nvme.h'
Use the NVMe register definitions from "block/nvme.h" which
ease a bit reviewing the code while matching the datasheet.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-6-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
9406e0d97e block/nvme: Drop NVMeRegs structure, directly use NvmeBar
NVMeRegs only contains NvmeBar. Simplify the code by using NvmeBar
directly.

This triggers a checkpatch.pl error:

  ERROR: Use of volatile is usually wrong, please add a comment
  #30: FILE: block/nvme.c:691:
  +    volatile NvmeBar *regs;

This is a false positive as in our case we are using I/O registers,
so the 'volatile' use is justified.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-5-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
37d7a45abd block/nvme: Reduce I/O registers scope
We only access the I/O register in nvme_init().
Remove the reference in BDRVNVMeState and reduce its scope.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-4-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
f68453237b block/nvme: Map doorbells pages write-only
Per the datasheet sections 3.1.13/3.1.14:
  "The host should not read the doorbell registers."

As we don't need read access, map the doorbells with write-only
permission. We keep a reference to this mapped address in the
BDRVNVMeState structure.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-3-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Philippe Mathieu-Daudé
b02c01a513 util/vfio-helpers: Pass page protections to qemu_vfio_pci_map_bar()
Pages are currently mapped READ/WRITE. To be able to use different
protections, add a new argument to qemu_vfio_pci_map_bar().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200922083821.578519-2-philmd@redhat.com>
2020-10-05 09:35:52 +01:00
Alberto Garcia
c508c73dca qcow2: Use L1E_SIZE in qcow2_write_l1_entry()
We overlooked these in 02b1ecfa10

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200928162333.14998-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
30dbc81d31 block/export: Move writable to BlockExportOptions
The 'writable' option is a basic option that will probably be applicable
to most if not all export types that we will implement. Move it from NBD
to the generic BlockExport layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-26-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
8cade320c8 block/export: Add query-block-exports
This adds a simple QMP command to query the list of block exports.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-25-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
331170e073 block/export: Create BlockBackend in blk_exp_add()
Every export type will need a BlockBackend, so creating it centrally in
blk_exp_add() instead of the .create driver callback avoids duplication.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-24-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
37a4f70cea block/export: Move blk to BlockExport
Every block export has a BlockBackend representing the disk that is
exported. It should live in BlockExport therefore.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-23-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
1a9f7a804f block/export: Add BLOCK_EXPORT_DELETED event
Clients may want to know when an export has finally disappeard
(block-export-del returns earlier than that in the general case), so add
a QAPI event for it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200924152717.287415-22-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
3c3bc462ad block/export: Add block-export-del
Implement a new QMP command block-export-del and make nbd-server-remove
a wrapper around it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-21-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
3859ad36f0 block/export: Move strong user reference to block_exports
The reference owned by the user/monitor that is created when adding the
export and dropped when removing it was tied to the 'exports' list in
nbd/server.c. Every block export will have a user reference, so move it
to the block export level and tie it to the 'block_exports' list in
block/export/export.c instead. This is necessary for introducing a QMP
command for removing exports.

Note that exports are present in block_exports even after the user has
requested shutdown. This is different from NBD's exports where exports
are immediately removed on a shutdown request, even if they are still in
the process of shutting down. In order to avoid that the user still
interacts with an export that is shutting down (and possibly removes it
a second time), we need to remember if the user actually still owns it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-20-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
d53be9ce55 block/export: Add 'id' option to block-export-add
We'll need an id to identify block exports in monitor commands. This
adds one.

Note that this is different from the 'name' option in the NBD server,
which is the externally visible export name. While block export ids need
to be unique in the whole process, export names must be unique only for
the same server. Different export types or (potentially in the future)
multiple NBD servers can have the same export name externally, but still
need different block export ids internally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-19-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
bc4ee65b8c block/export: Add blk_exp_close_all(_type)
This adds a function to shut down all block exports, and another one to
shut down the block exports of a single type. The latter is used for now
when stopping the NBD server. As soon as we implement support for
multiple NBD servers, we'll need a per-server list of exports and it
will be replaced by a function using that.

As a side effect, the BlockExport layer has a list tracking all existing
exports now. closed_exports loses its only user and can go away.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-18-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
a6ff798966 block/export: Allocate BlockExport in blk_exp_add()
Instead of letting the driver allocate and return the BlockExport
object, allocate it already in blk_exp_add() and pass it. This allows us
to initialise the generic part before calling into the driver so that
the driver can just use these values instead of having to parse the
options a second time.

For symmetry, move freeing the BlockExport to blk_exp_unref().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-17-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
b6076afcab block/export: Add node-name to BlockExportOptions
Every block export needs a block node to export, so add a 'node-name'
option to BlockExportOptions and remove the replaced option 'device'
from BlockExportOptionsNbd.

To maintain compatibility in nbd-server-add, BlockExportOptionsNbd needs
to be wrapped by a new type NbdServerAddOptions that adds 'device' back
because nbd-server-add doesn't use the BlockExportOptions base type at
all (so even without changing it to a 'node-name' option in
block-export-add, this compatibility code would be necessary).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-16-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
8612c68673 block/export: Move AioContext from NBDExport to BlockExport
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-15-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
c69de1bef5 block/export: Move refcount from NBDExport to BlockExport
Having a refcount makes sense for all types of block exports. It is also
a prerequisite for keeping a list of all exports at the BlockExport
level.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-14-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
1c8222b014 nbd: Add max-connections to nbd-server-start
This is a QMP equivalent of qemu-nbd's --shared option, limiting the
maximum number of clients that can attach at the same time.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-9-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
9b562c646b block/export: Remove magic from block-export-add
nbd-server-add tries to be convenient and adds two questionable
features that we don't want to share in block-export-add, even for NBD
exports:

1. When requesting a writable export of a read-only device, the export
   is silently downgraded to read-only. This should be an error in the
   context of block-export-add.

2. When using a BlockBackend name, unplugging the device from the guest
   will automatically stop the NBD server, too. This may sometimes be
   what you want, but it could also be very surprising. Let's keep
   things explicit with block-export-add. If the user wants to stop the
   export, they should tell us so.

Move these things into the nbd-server-add QMP command handler so that
they apply only there.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-8-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
56ee86261e block/export: Add BlockExport infrastructure and block-export-add
We want to have a common set of commands for all types of block exports.
Currently, this is only NBD, but we're going to add more types.

This patch adds the basic BlockExport and BlockExportDriver structs and
a QMP command block-export-add that creates a new export based on the
given BlockExportOptions.

qmp_nbd_server_add() becomes a wrapper around qmp_block_export_add().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200924152717.287415-5-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
143ea7670c qapi: Rename BlockExport to BlockExportOptions
The name BlockExport will be used for the struct containing the runtime
state of block exports, so change the name of export creation options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-4-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Kevin Wolf
5daa6bfd8e qapi: Create block-export module
Move all block export related types and commands from block-core to the
new QAPI module block-export.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924152717.287415-3-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Philippe Mathieu-Daudé
74f2e02766 block/sheepdog: Replace magic val by NANOSECONDS_PER_SECOND definition
Use self-explicit NANOSECONDS_PER_SECOND definition instead
of magic value.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200921110145.520944-1-philmd@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-10-02 15:46:40 +02:00
Philippe Mathieu-Daudé
f68c01470b qapi: Restrict query-uuid command to machine code
Only qemu-system-FOO and qemu-storage-daemon provide QMP
monitors, therefore such declarations and definitions are
irrelevant for user-mode emulation.

Restricting the query-uuid command to machine.json pulls less
QAPI-generated code into user-mode.

Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200913195348.1064154-6-philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 15:41:35 +02:00
Stefan Hajnoczi
d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Daniel P. Berrangé
b18a24a9f8 block/file: switch to use qemu_open/qemu_create for improved errors
Currently at startup if using cache=none on a filesystem lacking
O_DIRECT such as tmpfs, at startup QEMU prints

qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: file system may not support O_DIRECT
qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: Could not open '/tmp/foo.img': Invalid argument

while at QMP level the hint is missing, so QEMU reports just

  "error": {
      "class": "GenericError",
      "desc": "Could not open '/tmp/foo.img': Invalid argument"
  }

which is close to useless for the end user trying to figure out what
they did wrong.

With this change at startup QEMU prints

qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: Unable to open '/tmp/foo.img': filesystem does not support O_DIRECT

while at the QMP level QEMU reports a massively more informative

  "error": {
     "class": "GenericError",
     "desc": "Unable to open '/tmp/foo.img': filesystem does not support O_DIRECT"
  }

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-09-16 10:33:48 +01:00
Daniel P. Berrangé
448058aa99 util: rename qemu_open() to qemu_open_old()
We want to introduce a new version of qemu_open() that uses an Error
object for reporting problems and make this it the preferred interface.
Rename the existing method to release the namespace for the new impl.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-09-16 10:33:48 +01:00
Stefano Garzarella
7bae7c805d block/rbd: add 'namespace' to qemu_rbd_strong_runtime_opts[]
Commit 19ae9ae014 ("block/rbd: Add support for ceph namespaces")
introduced namespace support for RBD, but we forgot to add the
new 'namespace' options to qemu_rbd_strong_runtime_opts[].

The 'namespace' is used to identify the image, so it is a strong
option since it can changes the data of a BDS.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1821528
Fixes: 19ae9ae014 ("block/rbd: Add support for ceph namespaces")
Cc: Florian Florensa <fflorensa@online.net>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20200914190553.74871-1-sgarzare@redhat.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:31:10 +02:00
Alberto Garcia
bfd0989acf qcow2: Convert qcow2_alloc_cluster_offset() into qcow2_alloc_host_offset()
qcow2_alloc_cluster_offset() takes an (unaligned) guest offset and
returns the (aligned) offset of the corresponding cluster in the qcow2
image.

In practice none of the callers need to know where the cluster starts
so this patch makes the function calculate and return the final host
offset directly. The function is also renamed accordingly.

See 388e581615 for a similar change to qcow2_get_cluster_offset().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <9bfef50ec9200d752413be4fc2aeb22a28378817.1599833007.git.berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:31:10 +02:00
Alberto Garcia
8e958260c5 qcow2: Make preallocate_co() resize the image to the correct size
This function preallocates metadata structures and then extends the
image to its new size, but that new size calculation is wrong because
it doesn't take into account that the host_offset variable is always
cluster-aligned.

This problem can be reproduced with preallocation=metadata when the
original size is not cluster-aligned but the new size is. In this case
the final image size will be shorter than expected.

   qemu-img create -f qcow2 img.qcow2 31k
   qemu-img resize --preallocation=metadata img.qcow2 128k

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <adeb8b059917b141d5f5b3bd2a016262d3052c79.1599833007.git.berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
[mreitz: Mark compat=0.10 unsupported for iotest 125]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:30:36 +02:00
John Snow
c1dadda02c block/qcow: remove runtime opts
Introduced by d85f4222b4,
These were seemingly never used at all.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20200806211345.2925343-3-jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
John Snow
30b70f070f block/rbd: remove runtime_opts
This saw its last use in 4bfb274165.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20200806211345.2925343-2-jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
580384d637 qcow2: Return the original error code in qcow2_co_pwrite_zeroes()
This function checks the current status of a (sub)cluster in order to
see if an unaligned 'write zeroes' request can be done efficiently by
simply updating the L2 metadata and without having to write actual
zeroes to disk.

If the situation does not allow using the fast path then the function
returns -ENOTSUP and the caller falls back to writing zeroes.

If can happen however that the aforementioned check returns an actual
error code so in this case we should pass it to the caller.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200909123739.719-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
3fec237fca qcow2: Make qcow2_free_any_clusters() free only one cluster
This function takes an L2 entry and a number of clusters to free.
Although in principle it can free any type of cluster (using the L2
entry to determine its type) in practice the API is broken because
compressed clusters have a variable size and there is no way to free
more than one without having the L2 entry of each one of them.

The good news all callers are passing nb_clusters=1 so we can simply
get rid of that parameter.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <77cea0f4616f921d37e971b3c5b18a2faa24b173.1599573989.git.berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
1a52b73dba qcow2: Handle QCowL2Meta on error in preallocate_co()
If qcow2_alloc_cluster_offset() or qcow2_alloc_cluster_link_l2() fail
then this function simply returns the error code, potentially leaking
the QCowL2Meta structure and leaving stale items in s->cluster_allocs.

A second problem is that this function calls qcow2_free_any_clusters()
on failure but passing a host cluster offset instead of an L2 entry.
Luckily for normal uncompressed clusters a raw offset also works like
a valid L2 entry so it works just the same, but we should be using
qcow2_free_clusters() instead.

This patch fixes both problems by using qcow2_handle_l2meta().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <cd3a6b9abd43f9c0b60be413d760f0cacc67eb66.1599573989.git.berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Swapnil Ingle
83a6a90009 block/vhdx: Support vhdx image only with 512 bytes logical sector size
block/vhdx uses qemu block layer where sector size is always 512 bytes.
This may have issues  with 4K logical sector sized vhdx image.

For e.g qemu-img convert on such images fails with following assert:

$qemu-img convert -f vhdx -O raw 4KTest1.vhdx test.raw
qemu-img: util/iov.c:388: qiov_slice: Assertion `offset + len <=
qiov->size' failed.
Aborted

This patch adds an check to return ENOTSUP for vhdx images which
have logical sector size other than 512 bytes.

Signed-off-by: Swapnil Ingle <swapnil.ingle@nutanix.com>
Message-Id: <1596794594-44531-1-git-send-email-swapnil.ingle@nutanix.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
2b60c5b996 qcow2: Rewrite the documentation of qcow2_alloc_cluster_offset()
The current text corresponds to an earlier, simpler version of this
function and it does not explain how it works now.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <bb5bd06f07c5a05b0818611de0d06ec5b66c8df3.1599150873.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
f7bd5bba1b qcow2: Don't check nb_clusters when removing l2meta from the list
In the past, when a new cluster was allocated the l2meta structure was
a variable in the stack so it was necessary to have a way to tell
whether it had been initialized and contained valid data or not. The
nb_clusters field was used for this purpose. Since commit f50f88b9fe
this is no longer the case, l2meta (nowadays a pointer to a list) is
only allocated when needed and nb_clusters is guaranteed to be > 0 so
this check is unnecessary.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <ab0b67c29c7ba26e598db35f12aa5ab5982539c1.1599150873.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
184581fa4d qcow2: Fix removal of list members from BDRVQcow2State.cluster_allocs
When a write request needs to allocate new clusters (or change the L2
bitmap of existing ones) a QCowL2Meta structure is created so the L2
metadata can be later updated and any copy-on-write can be performed
if necessary.

A write request can span a region consisting of an arbitrary
combination of previously unallocated and allocated clusters, and if
the unallocated ones can be put contiguous to the existing ones then
QEMU will do so in order to minimize the number of write operations.

In practice this means that a write request has not just one but a
number of QCowL2Meta structures. All of them are added to the
cluster_allocs list that is stored in BDRVQcow2State and is used to
detect overlapping requests. After the write request finishes all its
associated QCowL2Meta are removed from that list. calculate_l2_meta()
takes care of creating and putting those structures in the list, and
qcow2_handle_l2meta() takes care of removing them.

The problem is that the error path in handle_alloc() also tries to
remove an item in that list, a remnant from the time when this was
handled there (that code would not even be correct anymore because
it only removes one struct and not all the ones from the same write
request).

This can trigger a double removal of the same item from the list,
causing a crash. This is not easy to reproduce in practice because
it requires that do_alloc_cluster_offset() fails after a successful
previous allocation during the same write request, but it can be
reproduced with the included test case.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <3440a1c4d53c4fe48312b478c96accb338cbef7c.1599150873.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:13 +02:00
Alberto Garcia
02b1ecfa10 qcow2: Use macros for the L1, refcount and bitmap table entry sizes
This patch replaces instances of sizeof(uint64_t) in the qcow2 driver
with macros that indicate what those sizes are actually referring to.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200828110828.13833-1-berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:12 +02:00
Lukas Straub
5eb9a3c7b0 block/quorum.c: stable children names
If we remove the child with the highest index from the quorum,
decrement s->next_child_index. This way we get stable children
names as long as we only remove the last child.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Fixes: https://bugs.launchpad.net/bugs/1881231
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <5d5f930424c1c770754041aa8ad6421dc4e2b58e.1596536719.git.lukasstraub2@web.de>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:05:12 +02:00
Peter Maydell
2499453eb1 Block layer patches:
- qemu-img create: Fail gracefully when backing file is an empty string
 - Fixes related to filter block nodes ("Deal with filters" series)
 - block/nvme: Various cleanups required to use multiple queues
 - block/nvme: Use NvmeBar structure from "block/nvme.h"
 - file-win32: Fix "locking" option
 - iotests: Allow running from different directory
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qemu-img create: Fail gracefully when backing file is an empty string
- Fixes related to filter block nodes ("Deal with filters" series)
- block/nvme: Various cleanups required to use multiple queues
- block/nvme: Use NvmeBar structure from "block/nvme.h"
- file-win32: Fix "locking" option
- iotests: Allow running from different directory

# gpg: Signature made Thu 10 Sep 2020 10:11:19 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (65 commits)
  block/qcow2-cluster: Add missing "fallthrough" annotation
  block/nvme: Pair doorbell registers
  block/nvme: Use generic NvmeBar structure
  block/nvme: Group controller registers in NVMeRegs structure
  file-win32: Fix "locking" option
  iotests: Allow running from different directory
  iotests: Test committing to overridden backing
  iotests: Add test for commit in sub directory
  iotests: Add filter mirror test cases
  iotests: Add filter commit test cases
  iotests: Let complete_and_wait() work with commit
  iotests: Test that qcow2's data-file is flushed
  block: Leave BDS.backing_{file,format} constant
  block: Inline bdrv_co_block_status_from_*()
  blockdev: Fix active commit choice
  block: Drop backing_bs()
  qemu-img: Use child access functions
  nbd: Use CAF when looking for dirty bitmap
  commit: Deal with filters
  backup: Deal with filters
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-11 14:47:49 +01:00
Thomas Huth
b9be6faed1 block/qcow2-cluster: Add missing "fallthrough" annotation
When compiling with -Werror=implicit-fallthrough, the compiler currently
complains:

../../devel/qemu/block/qcow2-cluster.c: In function ‘cluster_needs_new_alloc’:
../../devel/qemu/block/qcow2-cluster.c:1320:12: error: this statement may fall
 through [-Werror=implicit-fallthrough=]
         if (l2_entry & QCOW_OFLAG_COPIED) {
            ^
../../devel/qemu/block/qcow2-cluster.c:1323:5: note: here
     case QCOW2_CLUSTER_UNALLOCATED:
     ^~~~

It's quite obvious that the fallthrough is intended here, so let's add
a comment to silence the compiler warning.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200908070028.193298-1-thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-10 11:11:13 +02:00
Philippe Mathieu-Daudé
e5ff22ba9f block/nvme: Pair doorbell registers
For each queue doorbell registers are paired as:
- Submission Queue Tail Doorbell
- Completion Queue Head Doorbell

Reflect that in the NVMeRegs structure, and adapt
nvme_create_queue_pair() accordingly.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200904124130.583838-4-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-10 11:11:13 +02:00
Philippe Mathieu-Daudé
c7100f0a0b block/nvme: Use generic NvmeBar structure
Commit f3c507adcd ("NVMe: Initial commit for new storage interface")
introduced the NvmeBar structure. Unfortunately in commit bdd6a90a9e
("block: Add VFIO based NVMe driver") we duplicated it.

Apparently in commit a3d9a352d4 ("block: Move NVMe constants to
a separate header") we tried to unify headers but forgot to remove
the structure declared in the block/nvme.c source file.

Do it now, and remove the structure size check which is redundant
with the header check added in commit 74e18435c0 ("hw/block/nvme:
Align I/O BAR to 4 KiB").

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200904124130.583838-3-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-10 11:11:13 +02:00
Philippe Mathieu-Daudé
0ea32f34ce block/nvme: Group controller registers in NVMeRegs structure
We want to use the NvmeBar structure from "block/nvme.h" in the
next commit. As a preliminary step, group all the NVMe controller
registers in the 'ctrl' field, keeping the doorbells registers
out of it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200904124130.583838-2-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-10 11:11:12 +02:00
Kevin Wolf
3b079ac0ff file-win32: Fix "locking" option
The intended behaviour was that locking=off/auto work and have no
effect (to remain compatible with file-posix), whereas locking=on would
return an error. Unfortunately, the code forgot to remove "locking" from
the options QDict, so any attempt to use the option would fail.

Replace the option parsing code for "locking" with something that is
part of the raw_runtime_opts QemuOptsList (so it is properly removed
from the QDict) and looks more like file-posix.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200907092739.9988-1-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-10 11:11:12 +02:00
Markus Armbruster
b15e402fc8 trace-events: Fix attribution of trace points to source
Some trace points are attributed to the wrong source file.  Happens
when we neglect to update trace-events for code motion, or add events
in the wrong place, or misspell the file name.

Clean up with help of scripts/cleanup-trace-events.pl.  Funnies
requiring manual post-processing:

* accel/tcg/cputlb.c trace points are in trace-events.

* block.c and blockdev.c trace points are in block/trace-events.

* hw/block/nvme.c uses the preprocessor to hide its trace point use
  from cleanup-trace-events.pl.

* hw/tpm/tpm_spapr.c uses pseudo trace point tpm_spapr_show_buffer to
  guard debug code.

* include/hw/xen/xen_common.h trace points are in hw/xen/trace-events.

* linux-user/trace-events abbreviates a tedious list of filenames to
  */signal.c.

* net/colo-compare and net/filter-rewriter.c use pseudo trace points
  colo_compare_miscompare and colo_filter_rewriter_debug to guard
  debug code.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200806141334.3646302-5-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-09-09 17:17:58 +01:00
Markus Armbruster
6ec9379870 trace-events: Delete unused trace points
Tracked down with the help of scripts/cleanup-trace-events.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20200806141334.3646302-4-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-09-09 17:17:02 +01:00
Max Reitz
0b877d09df block: Leave BDS.backing_{file,format} constant
Parts of the block layer treat BDS.backing_file as if it were whatever
the image header says (i.e., if it is a relative path, it is relative to
the overlay), other parts treat it like a cache for
bs->backing->bs->filename (relative paths are relative to the CWD).
Considering bs->backing->bs->filename exists, let us make it mean the
former.

Among other things, this now allows the user to specify a base when
using qemu-img to commit an image file in a directory that is not the
CWD (assuming, everything uses relative filenames).

Before this patch:

$ ./qemu-img create -f qcow2 foo/bot.qcow2 1M
$ ./qemu-img create -f qcow2 -b bot.qcow2 foo/mid.qcow2
$ ./qemu-img create -f qcow2 -b mid.qcow2 foo/top.qcow2
$ ./qemu-img commit -b mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b $PWD/foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find '[...]/foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'

After this patch:

$ ./qemu-img commit -b mid.qcow2 foo/top.qcow2
Image committed.
$ ./qemu-img commit -b foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b $PWD/foo/mid.qcow2 foo/top.qcow2
Image committed.

With this change, bdrv_find_backing_image() must look at whether the
user has overridden a BDS's backing file.  If so, it can no longer use
bs->backing_file, but must instead compare the given filename against
the backing node's filename directly.

Note that this changes the QAPI output for a node's backing_file.  We
had very inconsistent output there (sometimes what the image header
said, sometimes the actual filename of the backing image).  This
inconsistent output was effectively useless, so we have to decide one
way or the other.  Considering that bs->backing_file usually at runtime
contained the path to the image relative to qemu's CWD (or absolute),
this patch changes QAPI's backing_file to always report the
bs->backing->bs->filename from now on.  If you want to receive the image
header information, you have to refer to full-backing-filename.

This necessitates a change to iotest 228.  The interesting information
it really wanted is the image header, and it can get that now, but it
has to use full-backing-filename instead of backing_file.  Because of
this patch's changes to bs->backing_file's behavior, we also need some
reference output changes.

Along with the changes to bs->backing_file, stop updating
BDS.backing_format in bdrv_backing_attach() as well.  This way,
ImageInfo's backing-filename and backing-filename-format fields will
represent what the image header says and nothing else.

iotest 245 changes in behavior: With the backing node no longer
overriding the parent node's backing_file string, you can now omit the
@backing option when reopening a node with neither a default nor a
current backing file even if it used to have a backing node at some
point.

273 also changes: The base image is opened without a format layer, so
ImageInfo.backing-filename-format used to report "file" for the base
image's overlay after blockdev-snapshot.  However, the image header
never says "file" anywhere, so it now reports $IMGFMT.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
549ec0d978 block: Inline bdrv_co_block_status_from_*()
With bdrv_filter_bs(), we can easily handle this default filter behavior
in bdrv_co_block_status().

blkdebug wants to have an additional assertion, so it keeps its own
implementation, except bdrv_co_block_status_from_file() needs to be
inlined there.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
9a71b9de3f commit: Deal with filters
This includes some permission limiting (for example, we only need to
take the RESIZE permission if the base is smaller than the top).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
2b088c60bb backup: Deal with filters
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
3f072a7fb7 mirror: Deal with filters
This includes some permission limiting (for example, we only need to
take the RESIZE permission for active commits where the base is smaller
than the top).

base_overlay is introduced so we can query bdrv_is_allocated_above() on
it - we cannot do that with base itself, because a filter's block_status
is the same as its child node, so if there are filters on base,
bdrv_is_allocated_above() on base would return information including
base.

Use this opportunity to rename qmp_drive_mirror()'s "source" BDS to
"target_backing_bs", because that is what it really refers to.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
c6f6d8462c block-copy: Use CAF to find sync=top base
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
0a7585dbba block: Use child access functions for QAPI queries
query-block, query-named-block-nodes, and query-blockstats now return
any filtered child under "backing", not just bs->backing or COW
children.  This is so that filters do not interrupt the reported backing
chain.  This changes the output for iotest 184, as the throttled node
now appears as a backing child.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
3f26191c73 block: Report data child for query-blockstats
It makes no sense to report the block stats of a purely metadata-storing
child in query-blockstats.  So if the primary child does not have any
data, try to find a unique data-storing child.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
07cd7b659a block/null: Implement bdrv_get_allocated_file_size
It is trivial, so we might as well do it.

Remove _filter_actual_image_size from iotest 184, so we get to see the
result in its reference output.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
c8af87573f block/snapshot: Fix fallback
If the top node's driver does not provide snapshot functionality and we
want to fall back to a node down the chain, we need to snapshot all
non-COW children.  For simplicity's sake, just do not fall back if there
is more than one such child.  Furthermore, we really only can fall back
to bs->file and bs->backing, because bdrv_snapshot_goto() has to modify
the child link (notably, set it to NULL).

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
c4db2e25df block: Use CAF in bdrv_co_rw_vmstate()
If a node whose driver does not provide VM state functions has a
metadata child, the VM state should probably go there; if it is a
filter, the VM state should probably go there.  It follows that we
should generally go down to the primary child.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
66b129ac5e block: Iterate over children in refresh_limits
Instead of looking at just bs->file and bs->backing, we should look at
all children that could end up receiving forwarded requests.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
fb787f02a6 vmdk: Drop vmdk_co_flush()
Before HEAD^, we needed this because bdrv_co_flush() by itself would
only flush bs->file.  With HEAD^, bdrv_co_flush() will flush all
children on which a WRITE or WRITE_UNCHANGED permission has been taken.
Thus, vmdk no longer needs to do it itself.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
883833e29c block: Flush all children in generic code
If the driver does not support .bdrv_co_flush() so bdrv_co_flush()
itself has to flush the children of the given node, it should not flush
just bs->file->bs, but in fact all children that might have been written
to (judging from the permissions taken on them).

This is a bug fix for qcow2 images with an external data file, as they
so far did not flush that data_file node.

In any case, the BLKDBG_EVENT() should be emitted on the primary child,
because that is where a blkdebug node would be if there is any.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
23b93525a2 block: Use bdrv_cow_child() in bdrv_co_truncate()
The condition modified here is not about potentially filtered children,
but only about COW sources (i.e. traditional backing files).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
67acfd2188 stream: Deal with filters
Because of the (not so recent anymore) changes that make the stream job
independent of the base node and instead track the node above it, we
have to split that "bottom" node into two cases: The bottom COW node,
and the node directly above the base node (which may be an R/W filter
or the bottom COW node).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
cb8503159a block: Use CAFs in block status functions
Use the child access functions in the block status inquiry functions as
appropriate.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
93393e698c block: Use bdrv_filter_(bs|child) where obvious
Places that use patterns like

    if (bs->drv->is_filter && bs->file) {
        ... something about bs->file->bs ...
    }

should be

    BlockDriverState *filtered = bdrv_filter_bs(bs);
    if (filtered) {
        ... something about @filtered ...
    }

instead.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
4935e8be22 copy-on-read: Support compressed writes
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
e7e754aec3 throttle: Support compressed writes
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:31 +02:00
Max Reitz
8b8277cdb0 block: Drop bdrv_is_encrypted()
The original purpose of bdrv_is_encrypted() was to inquire whether a BDS
can be used without the user entering a password or not.  It has not
been used for that purpose for quite some time.

Actually, it is not even fit for that purpose, because to answer that
question, it would have recursively query all of the given node's
children.

So now we have to decide in which direction we want to fix
bdrv_is_encrypted(): Recursively query all children, or drop it and just
use bs->encrypted to get the current node's status?

Nowadays, its only purpose is to report through bdrv_query_image_info()
whether the given image is encrypted or not.  For this purpose, it is
probably more interesting to see whether a given node itself is
encrypted or not (otherwise, a management application cannot discern for
certain which nodes are really encrypted and which just have encrypted
children).

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
b111b3fcde block/nvme: Use an array of EventNotifier
In preparation of using multiple IRQ (thus multiple eventfds)
make BDRVNVMeState::irq_notifier an array (for now of a single
element, the admin queue notifier).

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-16-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
7a1fb2ef40 block/nvme: Extract nvme_poll_queue()
As we want to do per-queue polling, extract the nvme_poll_queue()
method which operates on a single queue.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-15-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
0a28b02ef9 block/nvme: Simplify nvme_create_queue_pair() arguments
nvme_create_queue_pair() doesn't require BlockDriverState anymore.
Replace it by BDRVNVMeState and AioContext to simplify.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-14-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
073a06978c block/nvme: Replace BDRV_POLL_WHILE by AIO_WAIT_WHILE
BDRV_POLL_WHILE() is defined as:

  #define BDRV_POLL_WHILE(bs, cond) ({          \
      BlockDriverState *bs_ = (bs);             \
      AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
                     cond); })

As we will remove the BlockDriverState use in the next commit,
start by using the exploded version of BDRV_POLL_WHILE().

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-13-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
3a6d34d066 block/nvme: Simplify nvme_init_queue() arguments
nvme_init_queue() doesn't require BlockDriverState anymore.
Replace it by BDRVNVMeState to simplify.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-12-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
38e1f8186f block/nvme: Replace qemu_try_blockalign(bs) by qemu_try_memalign(pg_sz)
qemu_try_blockalign() is a generic API that call back to the
block driver to return its page alignment. As we call from
within the very same driver, we already know to page alignment
stored in our state. Remove indirections and use the value from
BDRVNVMeState.
This change is required to later remove the BlockDriverState
argument, to make nvme_init_queue() per hardware, and not per
block driver.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-11-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
2ed846930d block/nvme: Replace qemu_try_blockalign0 by qemu_try_blockalign/memset
In the next commit we'll get rid of qemu_try_blockalign().
To ease review, first replace qemu_try_blockalign0() by explicit
calls to qemu_try_blockalign() and memset().

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-10-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:31:30 +02:00
Philippe Mathieu-Daudé
7d3b214ae4 block/nvme: Use union of NvmeIdCtrl / NvmeIdNs structures
We allocate an unique chunk of memory then use it for two
different structures. By using an union, we make it clear
the data is overlapping (and we can remove the casts).

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-9-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:24:53 +02:00
Philippe Mathieu-Daudé
4d98093937 block/nvme: Rename local variable
We are going to modify the code in the next commit. Renaming
the 'resp' variable to 'id' first makes the next commit easier
to review. No logical changes.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-8-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
c8edbfb2cc block/nvme: Use common error path in nvme_add_io_queue()
Rearrange nvme_add_io_queue() by using a common error path.
This will be proven useful in few commits where we add IRQ
notification to the IO queues.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-7-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
bf6ce5ec6d block/nvme: Improve error message when IO queue creation failed
Do not use the same error message for different failures.
Display a different error whether it is the CQ or the SQ.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-6-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
73159e52e6 block/nvme: Define INDEX macros to ease code review
Use definitions instead of '0' or '1' indexes. Also this will
be useful when using multi-queues later.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-5-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
0ea45f76eb block/nvme: Let nvme_create_queue_pair() fail gracefully
As nvme_create_queue_pair() is allowed to fail, replace the
alloc() calls by try_alloc() to avoid aborting QEMU.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-4-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
e266f52cfb block/nvme: Avoid further processing if trace event not enabled
Avoid further processing if TRACE_NVME_SUBMIT_COMMAND_RAW is
not enabled. This is an untested intend of performance optimization.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-3-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Philippe Mathieu-Daudé
e4f310fe7f block/nvme: Replace magic value by SCALE_MS definition
Use self-explicit SCALE_MS definition instead of magic value.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200821195359.1285345-2-philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-09-07 12:23:55 +02:00
Peter Maydell
df8176274a nbd patches for 2020-09-02
- fix a few iotests affected by earlier nbd changes
 - avoid blocking qemu by nbd client in connect()
 - build qemu-nbd for mingw
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 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2020-09-02' into staging

nbd patches for 2020-09-02

- fix a few iotests affected by earlier nbd changes
- avoid blocking qemu by nbd client in connect()
- build qemu-nbd for mingw

# gpg: Signature made Wed 02 Sep 2020 22:52:31 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2020-09-02:
  nbd: disable signals and forking on Windows builds
  nbd: skip SIGTERM handler if NBD device support is not built
  block: add missing socket_init() calls to tools
  block/nbd: use non-blocking connect: fix vm hang on connect()
  iotests/259: Fix reference output
  iotests/059: Fix reference output

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-03 21:35:01 +01:00
Vladimir Sementsov-Ogievskiy
1dc4718d84 block/nbd: use non-blocking connect: fix vm hang on connect()
This makes nbd's connection_co yield during reconnects, so that
reconnect doesn't block the main thread. This is very important in
case of an unavailable nbd server host: connect() call may take a long
time, blocking the main thread (and due to reconnect, it will hang
again and again with small gaps of working time during pauses between
connection attempts).

Realization notes:

 - We don't want to implement non-blocking connect() over non-blocking
 socket, because getaddrinfo() doesn't have portable non-blocking
 realization anyway, so let's just use a thread for both getaddrinfo()
 and connect().

 - We can't use qio_channel_socket_connect_async (which behaves
 similarly and starts a thread to execute connect() call), as it's relying
 on someone iterating main loop (g_main_loop_run() or something like
 this), which is not always the case.

 - We can't use thread_pool_submit_co API, as thread pool waits for all
 threads to finish (but we don't want to wait for blocking reconnect
 attempt on shutdown.

 So, we just create the thread by hand. Some additional difficulties
 are:

 - We want our connect to avoid blocking drained sections and aio context
 switches. To achieve this, we make it possible to "cancel" synchronous
 wait for the connect (which is a coroutine yield actually), still,
 the thread continues in background, and if successful, its result may be
 reused on next reconnect attempt.

 - We don't want to wait for reconnect on shutdown, so there is
 CONNECT_THREAD_RUNNING_DETACHED thread state, which means that the block
 layer is no longer interested in a result, and thread should close new
 connected socket on finish and free the state.

How to reproduce the bug, fixed with this commit:

1. Create an image on node1:
   qemu-img create -f qcow2 xx 100M

2. Start NBD server on node1:
   qemu-nbd xx

3. Start vm with second nbd disk on node2, like this:

  ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -drive \
    file=/work/images/cent7.qcow2 -drive file=nbd+tcp://192.168.100.2 \
    -vnc :0 -qmp stdio -m 2G -enable-kvm -vga std

4. Access the vm through vnc (or some other way?), and check that NBD
   drive works:

   dd if=/dev/sdb of=/dev/null bs=1M count=10

   - the command should succeed.

5. Now, let's trigger nbd-reconnect loop in Qemu process. For this:

5.1 Kill NBD server on node1

5.2 run "dd if=/dev/sdb of=/dev/null bs=1M count=10" in the guest
    again. The command should fail and a lot of error messages about
    failing disk may appear as well.

    Now NBD client driver in Qemu tries to reconnect.
    Still, VM works well.

6. Make node1 unavailable on NBD port, so connect() from node2 will
   last for a long time:

   On node1 (Note, that 10809 is just a default NBD port):

   sudo iptables -A INPUT -p tcp --dport 10809 -j DROP

   After some time the guest hangs, and you may check in gdb that Qemu
   hangs in connect() call, issued from the main thread. This is the
   BUG.

7. Don't forget to drop iptables rule from your node1:

   sudo iptables -D INPUT -p tcp --dport 10809 -j DROP

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200812145237.4396-1-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: minor wording and formatting tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-09-02 16:47:23 -05:00
Peter Maydell
e4d8b7c1a9 qemu-nvme
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 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/nvme/tags/pull-nvme-20200902' into staging

qemu-nvme

# gpg: Signature made Wed 02 Sep 2020 15:39:10 BST
# gpg:                using RSA key DBC11D2D373B4A3755F502EC625156610A4F6CC0
# gpg: Good signature from "Keith Busch <kbusch@kernel.org>" [unknown]
# gpg:                 aka "Keith Busch <keith.busch@gmail.com>" [unknown]
# gpg:                 aka "Keith Busch <keith.busch@intel.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: DBC1 1D2D 373B 4A37 55F5  02EC 6251 5661 0A4F 6CC0

* remotes/nvme/tags/pull-nvme-20200902: (39 commits)
  hw/block/nvme: remove explicit qsg/iov parameters
  hw/block/nvme: use preallocated qsg/iov in nvme_dma_prp
  hw/block/nvme: consolidate qsg/iov clearing
  hw/block/nvme: add ns/cmd references in NvmeRequest
  hw/block/nvme: be consistent about zeros vs zeroes
  hw/block/nvme: add check for mdts
  hw/block/nvme: refactor request bounds checking
  hw/block/nvme: verify validity of prp lists in the cmb
  hw/block/nvme: add request mapping helper
  hw/block/nvme: add tracing to nvme_map_prp
  hw/block/nvme: refactor dma read/write
  hw/block/nvme: destroy request iov before reuse
  hw/block/nvme: remove redundant has_sg member
  hw/block/nvme: replace dma_acct with blk_acct equivalent
  hw/block/nvme: add mapping helpers
  hw/block/nvme: memset preallocated requests structures
  hw/block/nvme: bump supported version to v1.3
  hw/block/nvme: provide the mandatory subnqn field
  hw/block/nvme: enforce valid queue creation sequence
  hw/block/nvme: reject invalid nsid values in active namespace id list
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-02 21:20:20 +01:00
Klaus Jensen
69265150aa hw/block/nvme: be consistent about zeros vs zeroes
The NVM Express specification generally uses 'zeroes' and not 'zeros',
so let us align with it.

Cc: Fam Zheng <fam@euphon.net>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
2020-09-02 08:48:50 +02:00
Klaus Jensen
c26f217370 hw/block/nvme: bump spec data structures to v1.3
Add missing fields in the Identify Controller and Identify Namespace
data structures to bring them in line with NVMe v1.3.

This also adds data structures and defines for SGL support which
requires a couple of trivial changes to the nvme block driver as well.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Acked-by: Fam Zheng <fam@euphon.net>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Message-Id: <20200706061303.246057-2-its@irrelevant.dk>
2020-09-02 08:48:50 +02:00
Peter Maydell
887adde81d meson fixes:
* bump submodule to 0.55.1
 * SDL, pixman and zlib fixes
 * firmwarepath fix
 * fix firmware builds
 
 meson related:
 * move install to Meson
 * move NSIS to Meson
 * do not make meson use cmake
 * add description to options
 -----BEGIN PGP SIGNATURE-----
 
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 =NGLI
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging

meson fixes:
* bump submodule to 0.55.1
* SDL, pixman and zlib fixes
* firmwarepath fix
* fix firmware builds

meson related:
* move install to Meson
* move NSIS to Meson
* do not make meson use cmake
* add description to options

# gpg: Signature made Tue 01 Sep 2020 17:11:03 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini-gitlab/tags/for-upstream: (26 commits)
  Makefile: Fix in-tree clean/distclean
  Makefile: Add back TAGS/ctags/cscope rules
  meson: add description to options
  build: fix recurse-all target
  meson: use pkg-config method to find dependencies
  configure: do not include ${prefix} in firmwarepath
  meson: add pixman dependency to UI modules
  meson: add pixman dependency to chardev/baum module
  meson: add NSIS building
  meson: use meson mandir instead of qemu_mandir
  meson: pass docdir option
  meson: use meson datadir instead of qemu_datadir
  meson: pass qemu_suffix option
  configure: build docdir like other suffixed directories
  configure: always /-seperate directory from qemu_suffix
  configure: rename confsuffix option
  meson: move zlib detection to meson
  build-sys: remove install target from Makefile
  meson: install $localstatedir/run for qga
  meson: install desktop file
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-01 22:50:23 +01:00
Liao Pingfang
f181ab4ba5 block/vmdk: Remove superfluous breaks
Remove superfluous breaks, as there is a "return" before them.

Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1594631107-36574-1-git-send-email-wang.yi59@zte.com.cn>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-09-01 08:37:28 +02:00
Paolo Bonzini
a10c8516ed block: always link with zlib
The qcow2 driver needs the zlib dependency.  While emulators
provided it through the migration code, this is not true of
the tools.  Move the dependency from the qcow1 rule directly
into block_ss so that it is included unconditionally.

Fixes build with --disable-qcow1.

Reported-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-01 01:51:51 -04:00
Eduardo Habkost
7c9dcd6cab throttle-groups: Move ThrottleGroup typedef to header
Move typedef closer to the type check macros, to make it easier
to convert the code to OBJECT_DEFINE_TYPE() in the future.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-By: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200825192110.3528606-17-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-08-27 14:04:54 -04:00
Alberto Garcia
7bbb59202a qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters
This function is only used by qcow2_expand_zero_clusters() to
downgrade a qcow2 image to a previous version. This would require
transforming all extended L2 entries into normal L2 entries but this
is not a simple task and there are no plans to implement this at the
moment.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <15e65112b4144381b4d8c0bdf8fb76b0d813e3d1.1594396418.git.berto@igalia.com>
[mreitz: Fixed comment style]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 10:20:15 +02:00
Alberto Garcia
2118771ddf qcow2: Allow preallocation and backing files if extended_l2 is set
Traditional qcow2 images don't allow preallocation if a backing file
is set. This is because once a cluster is allocated there is no way to
tell that its data should be read from the backing file.

Extended L2 entries have individual allocation bits for each
subcluster, and therefore it is perfectly possible to have an
allocated cluster with all its subclusters unallocated.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6d5b0f38e7dc5f2f31d8cab1cb92044e9909aece.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 09:20:04 +02:00
Alberto Garcia
7be2025258 qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit
Now that the implementation of subclusters is complete we can finally
add the necessary options to create and read images with this feature,
which we call "extended L2 entries".

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6476caaa73216bd05b7bb2d504a20415e1665176.1594396418.git.berto@igalia.com>
[mreitz: %s/5\.1/5.2/; fixed 302's and 303's reference output]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 09:19:55 +02:00
Alberto Garcia
40dee94320 qcow2: Add prealloc field to QCowL2Meta
This field allows us to indicate that the L2 metadata update does not
come from a write request with actual data but from a preallocation
request.

For traditional images this does not make any difference, but for
images with extended L2 entries this means that the clusters are
allocated normally in the L2 table but individual subclusters are
marked as unallocated.

This will allow preallocating images that have a backing file.

There is one special case: when we resize an existing image we can
also request that the new clusters are preallocated. If the image
already had a backing file then we have to hide any possible stale
data and zero out the new clusters (see commit 955c7d6687 for more
details).

In this case the subclusters cannot be left as unallocated so the L2
bitmap must be updated.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <960d4c444a4f5a870e2b47e5da322a73cd9a2f5a.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
0dd07b298f qcow2: Add subcluster support to qcow2_measure()
Extended L2 entries are bigger than normal L2 entries so this has an
impact on the amount of metadata needed for a qcow2 file.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <7efae2efd5e36b42d2570743a12576d68ce53685.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
a6841a2de6 qcow2: Add subcluster support to qcow2_co_pwrite_zeroes()
This works now at the subcluster level and pwrite_zeroes_alignment is
updated accordingly.

qcow2_cluster_zeroize() is turned into qcow2_subcluster_zeroize() with
the following changes:

   - The request can now be subcluster-aligned.

   - The cluster-aligned body of the request is still zeroized using
     zero_in_l2_slice() as before.

   - The subcluster-aligned head and tail of the request are zeroized
     with the new zero_l2_subclusters() function.

There is just one thing to take into account for a possible future
improvement: compressed clusters cannot be partially zeroized so
zero_l2_subclusters() on the head or the tail can return -ENOTSUP.
This makes the caller repeat the *complete* request and write actual
zeroes to disk. This is sub-optimal because

   1) if the head area was compressed we would still be able to use
      the fast path for the body and possibly the tail.

   2) if the tail area was compressed we are writing zeroes to the
      head and the body areas, which are already zeroized.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <17e05e2ee7e12f10dcf012da81e83ebe27eb3bef.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
bf4a66eed4 qcow2: Add subcluster support to handle_alloc_space()
The bdrv_co_pwrite_zeroes() call here fills complete clusters with
zeroes, but it can happen that some subclusters are not part of the
write request or the copy-on-write. This patch makes sure that only
the affected subclusters are overwritten.

A potential improvement would be to also fill with zeroes the other
subclusters if we can guarantee that we are not overwriting existing
data. However this would waste more disk space, so we should first
evaluate if it's really worth doing.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <b3dc97e8e2240ddb5191a4f930e8fc9653f94621.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
ff4cdec7f6 qcow2: Clear the L2 bitmap when allocating a compressed cluster
Compressed clusters always have the bitmap part of the extended L2
entry set to 0.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <04455b3de5dfeb9d1cfe1fc7b02d7060a6e09710.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
aca00cd971 qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2()
The L2 bitmap needs to be updated after each write to indicate what
new subclusters are now allocated. This needs to happen even if the
cluster was already allocated and the L2 entry was otherwise valid.

In some cases however a write operation doesn't need change the L2
bitmap (because all affected subclusters were already allocated). This
is detected in calculate_l2_meta(), and qcow2_alloc_cluster_link_l2()
is never called in those cases.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <0875620d49f44320334b6a91c73b3f301f975f38.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
fc2e6528d5 qcow2: Add subcluster support to check_refcounts_l2()
The offset field of an uncompressed cluster's L2 entry must be aligned
to the cluster size, otherwise it is invalid. If the cluster has no
data then it means that the offset points to a preallocation, so we
can clear the offset field without affecting the guest-visible data.
This is what 'qemu-img check' does when run in repair mode.

On traditional qcow2 images this can only happen when QCOW_OFLAG_ZERO
is set, and repairing such entries turns the clusters from ZERO_ALLOC
into ZERO_PLAIN.

Extended L2 entries have no ZERO_ALLOC clusters and no QCOW_OFLAG_ZERO
but the idea is the same: if none of the subclusters are allocated
then we can clear the offset field and leave the bitmap untouched.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <9f4ed1d0a34b0a545b032c31ecd8c14734065342.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
a68cd70326 qcow2: Add subcluster support to discard_in_l2_slice()
Two things need to be taken into account here:

1) With full_discard == true the L2 entry must be cleared completely.
   This also includes the L2 bitmap if the image has extended L2
   entries.

2) With full_discard == false we have to make the discarded cluster
   read back as zeroes. With normal L2 entries this is done with the
   QCOW_OFLAG_ZERO bit, whereas with extended L2 entries this is done
   with the individual 'all zeroes' bits for each subcluster.

   Note however that QCOW_OFLAG_ZERO is not supported in v2 qcow2
   images so, if there is a backing file, discard cannot guarantee
   that the image will read back as zeroes. If this is important for
   the caller it should forbid it as qcow2_co_pdiscard() does (see
   80f5c01183 for more details).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <5ef8274e628aa3ab559bfac467abf488534f2b76.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
205fa50750 qcow2: Add subcluster support to zero_in_l2_slice()
The QCOW_OFLAG_ZERO bit that indicates that a cluster reads as
zeroes is only used in standard L2 entries. Extended L2 entries use
individual 'all zeroes' bits for each subcluster.

This must be taken into account when updating the L2 entry and also
when deciding that an existing entry does not need to be updated.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <b61d61606d8c9b367bd641ab37351ddb9172799a.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
3f9c6b3b1f qcow2: Add subcluster support to qcow2_get_host_offset()
The logic of this function remains pretty much the same, except that
it uses count_contiguous_subclusters(), which combines the logic of
count_contiguous_clusters() / count_contiguous_clusters_unallocated()
and checks individual subclusters.

qcow2_cluster_to_subcluster_type() is not necessary as a separate
function anymore so it's inlined into its caller.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <d2193fd48653a350d80f0eca1c67b1d9053fb2f3.1594396418.git.berto@igalia.com>
[mreitz: Initialize expected_type to anything]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
d53ec3d8d8 qcow2: Add subcluster support to calculate_l2_meta()
If an image has subclusters then there are more copy-on-write
scenarios that we need to consider. Let's say we have a write request
from the middle of subcluster #3 until the end of the cluster:

1) If we are writing to a newly allocated cluster then we need
   copy-on-write. The previous contents of subclusters #0 to #3 must
   be copied to the new cluster. We can optimize this process by
   skipping all leading unallocated or zero subclusters (the status of
   those skipped subclusters will be reflected in the new L2 bitmap).

2) If we are overwriting an existing cluster:

   2.1) If subcluster #3 is unallocated or has the all-zeroes bit set
        then we need copy-on-write (on subcluster #3 only).

   2.2) If subcluster #3 was already allocated then there is no need
        for any copy-on-write. However we still need to update the L2
        bitmap to reflect possible changes in the allocation status of
        subclusters #4 to #31. Because of this, this function checks
        if all the overwritten subclusters are already allocated and
        in this case it returns without creating a new QCowL2Meta
        structure.

After all these changes l2meta_cow_start() and l2meta_cow_end()
are not necessarily cluster-aligned anymore. We need to update the
calculation of old_start and old_end in handle_dependencies() to
guarantee that no two requests try to write on the same cluster.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <4292dd56e4446d386a2fe307311737a711c00708.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
97490a143e qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC
When dealing with subcluster types there is a new value called
QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC that has no equivalent in
QCow2ClusterType.

This patch handles that value in all places where subcluster types
are processed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <bf09e2e2439a468a901bb96ace411eed9ee50295.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
10dabdc596 qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_*
In order to support extended L2 entries some functions of the qcow2
driver need to start dealing with subclusters instead of clusters.

qcow2_get_host_offset() is modified to return the subcluster type
instead of the cluster type, and all callers are updated to replace
all values of QCow2ClusterType with their QCow2SubclusterType
equivalents.

This patch only changes the data types, there are no semantic changes.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <f6c29737c295f32cbee74c903c30b01820363b34.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
ca4a0bb81b qcow2: Add cluster type parameter to qcow2_get_host_offset()
This function returns an integer that can be either an error code or a
cluster type (a value from the QCow2ClusterType enum).

We are going to start using subcluster types instead of cluster types
in some functions so it's better to use the exact data types instead
of integers for clarity and in order to detect errors more easily.

This patch makes qcow2_get_host_offset() return 0 on success and
puts the returned cluster type in a separate parameter. There are no
semantic changes.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <396b6eab1859a271551dcd7dcba77f8934aa3c3f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
c94d037825 qcow2: Add qcow2_cluster_is_allocated()
This helper function tells us if a cluster is allocated (that is,
there is an associated host offset for it).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6d8771c5c79cbdc6c519875a5078e1cc85856d63.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
70d1cbae03 qcow2: Add qcow2_get_subcluster_range_type()
There are situations in which we want to know how many contiguous
subclusters of the same type there are in a given cluster. This can be
done by simply iterating over the subclusters and repeatedly calling
qcow2_get_subcluster_type() for each one of them.

However once we determined the type of a subcluster we can check the
rest efficiently by counting the number of adjacent ones (or zeroes)
in the bitmap. This is what this function does.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <db917263d568ec6ffb4a41cac3c9100f96bf6c18.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
34905d8eb1 qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type()
This patch adds QCow2SubclusterType, which is the subcluster-level
version of QCow2ClusterType. All QCOW2_SUBCLUSTER_* values have the
the same meaning as their QCOW2_CLUSTER_* equivalents (when they
exist). See below for details and caveats.

In images without extended L2 entries clusters are treated as having
exactly one subcluster so it is possible to replace one data type with
the other while keeping the exact same semantics.

With extended L2 entries there are new possible values, and every
subcluster in the same cluster can obviously have a different
QCow2SubclusterType so functions need to be adapted to work on the
subcluster level.

There are several things that have to be taken into account:

  a) QCOW2_SUBCLUSTER_COMPRESSED means that the whole cluster is
     compressed. We do not support compression at the subcluster
     level.

  b) There are two different values for unallocated subclusters:
     QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN which means that the whole
     cluster is unallocated, and QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC
     which means that the cluster is allocated but the subcluster is
     not. The latter can only happen in images with extended L2
     entries.

  c) QCOW2_SUBCLUSTER_INVALID is used to detect the cases where an L2
     entry has a value that violates the specification. The caller is
     responsible for handling these situations.

     To prevent compatibility problems with images that have invalid
     values but are currently being read by QEMU without causing side
     effects, QCOW2_SUBCLUSTER_INVALID is only returned for images
     with extended L2 entries.

qcow2_cluster_to_subcluster_type() is added as a separate function
from qcow2_get_subcluster_type(), but this is only temporary and both
will be merged in a subsequent patch.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <26ef38e270f25851c98b51278852b4c4a7f97e69.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
39a9f0a50e qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap()
Extended L2 entries are 128-bit wide: 64 bits for the entry itself and
64 bits for the subcluster allocation bitmap.

In order to support them correctly get/set_l2_entry() need to be
updated so they take the entry width into account in order to
calculate the correct offset.

This patch also adds the get/set_l2_bitmap() functions that are
used to access the bitmaps. For convenience we allow calling
get_l2_bitmap() on images without subclusters. In this case the
returned value is always 0 and has no meaning.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6ee0f81ae3329c991de125618b3675e1e46acdbb.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
c8fd8554d9 qcow2: Add l2_entry_size()
qcow2 images with subclusters have 128-bit L2 entries. The first 64
bits contain the same information as traditional images and the last
64 bits form a bitmap with the status of each individual subcluster.

Because of that we cannot assume that L2 entries are sizeof(uint64_t)
anymore. This function returns the proper value for the image.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <d34d578bd0380e739e2dde3e8dd6187d3d249fa9.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
3e71981592 qcow2: Add offset_into_subcluster() and size_to_subclusters()
Like offset_into_cluster() and size_to_clusters(), but for
subclusters.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <3cc2390dcdef3d234d47c741b708bd8734490862.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
a53e8b7202 qcow2: Add offset_to_sc_index()
For a given offset, return the subcluster number within its cluster
(i.e. with 32 subclusters per cluster it returns a number between 0
and 31).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <56e3e4ac0d827c6a2f5f259106c5ddb7c4ca2653.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
d0346b5591 qcow2: Add subcluster-related fields to BDRVQcow2State
This patch adds the following new fields to BDRVQcow2State:

- subclusters_per_cluster: Number of subclusters in a cluster
- subcluster_size: The size of each subcluster, in bytes
- subcluster_bits: No. of bits so 1 << subcluster_bits = subcluster_size

Images without subclusters are treated as if they had exactly one
subcluster per cluster (i.e. subcluster_size = cluster_size).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <55bfeac86b092fa2c9d182a95cbeb479ff7eca4f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
a3c7d91625 qcow2: Add dummy has_subclusters() function
This function will be used by the qcow2 code to check if an image has
subclusters or not.

At the moment this simply returns false. Once all patches needed for
subcluster support are ready then QEMU will be able to create and
read images with subclusters and this function will return the actual
value.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <905526221083581a1b7057bca1585487661c5c13.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
12c6aebedf qcow2: Add get_l2_entry() and set_l2_entry()
The size of an L2 entry is 64 bits, but if we want to have subclusters
we need extended L2 entries. This means that we have to access L2
tables and slices differently depending on whether an image has
extended L2 entries or not.

This patch replaces all l2_slice[] accesses with calls to
get_l2_entry() and set_l2_entry().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <9586363531fec125ba1386e561762d3e4224e9fc.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
57538c864f qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied()
When writing to a qcow2 file there are two functions that take a
virtual offset and return a host offset, possibly allocating new
clusters if necessary:

   - handle_copied() looks for normal data clusters that are already
     allocated and have a reference count of 1. In those clusters we
     can simply write the data and there is no need to perform any
     copy-on-write.

   - handle_alloc() looks for clusters that do need copy-on-write,
     either because they haven't been allocated yet, because their
     reference count is != 1 or because they are ZERO_ALLOC clusters.

The ZERO_ALLOC case is a bit special because those are clusters that
are already allocated and they could perfectly be dealt with in
handle_copied() (as long as copy-on-write is performed when required).

In fact, there is extra code specifically for them in handle_alloc()
that tries to reuse the existing allocation if possible and frees them
otherwise.

This patch changes the handling of ZERO_ALLOC clusters so the
semantics of these two functions are now like this:

   - handle_copied() looks for clusters that are already allocated and
     which we can overwrite (NORMAL and ZERO_ALLOC clusters with a
     reference count of 1).

   - handle_alloc() looks for clusters for which we need a new
     allocation (all other cases).

One important difference after this change is that clusters found
in handle_copied() may now require copy-on-write, but this will be
necessary anyway once we add support for subclusters.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <eb17fc938f6be7be2e8d8ff42763d2c19241f866.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
c1587d877e qcow2: Split cluster_needs_cow() out of count_cow_clusters()
We are going to need it in other places.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <65e5d9627ca2ebe7e62deaeddf60949c33067d9d.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
8f91d6906c qcow2: Add calculate_l2_meta()
handle_alloc() creates a QCowL2Meta structure in order to update the
image metadata and perform the necessary copy-on-write operations.

This patch moves that code to a separate function so it can be used
from other places.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <e5bc4a648dac31972bfa7a0e554be8064be78799.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
388e581615 qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset()
qcow2_get_cluster_offset() takes an (unaligned) guest offset and
returns the (aligned) offset of the corresponding cluster in the qcow2
image.

In practice none of the callers need to know where the cluster starts
so this patch makes the function calculate and return the final host
offset directly. The function is also renamed accordingly.

There is a pre-existing exception with compressed clusters: in this
case the function returns the complete cluster descriptor (containing
the offset and size of the compressed data). This does not change with
this patch but it is now documented.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <ffae6cdc5ca8950e8280ac0f696dcc376cb07095.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Alberto Garcia
9c4269d54b qcow2: Make Qcow2AioTask store the full host offset
The file_cluster_offset field of Qcow2AioTask stores a cluster-aligned
host offset. In practice this is not very useful because all users(*)
of this structure need the final host offset into the cluster, which
they calculate using

   host_offset = file_cluster_offset + offset_into_cluster(s, offset)

There is no reason why Qcow2AioTask cannot store host_offset directly
and that is what this patch does.

(*) compressed clusters are the exception: in this case what
    file_cluster_offset was storing was the full compressed cluster
    descriptor (offset + size). This does not change with this patch
    but it is documented now.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <07c4b15c644dcf06c9459f98846ac1c4ea96e26f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Marc-André Lureau
5e5733e599 meson: convert block
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:18 -04:00
Paolo Bonzini
243af0225a trace: switch position of headers to what Meson requires
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path.  In particular the tracing headers are using
$(build_root)/$(<D).

In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".

This patch is too ugly to be applied to the Makefiles now.  It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:18:24 -04:00
Stefan Reiter
7661a886a1 block/block-copy: always align copied region to cluster size
Since commit 42ac214406 (block/block-copy: refactor task creation)
block_copy_task_create calculates the area to be copied via
bdrv_dirty_bitmap_next_dirty_area, but that can return an unaligned byte
count if the image's last cluster end is not aligned to the bitmap's
granularity.

Always ALIGN_UP the resulting bytes value to satisfy block_copy_do_copy,
which requires the 'bytes' parameter to be aligned to cluster size.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Message-Id: <20200810095523.15071-1-s.reiter@proxmox.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-10 17:12:46 +02:00
Tuguoyi
348fcc4f7a qcow2-cluster: Fix integer left shift error in qcow2_alloc_cluster_link_l2()
When calculating the offset, the result of left shift operation will be promoted
to type int64 automatically because the left operand of + operator is uint64_t.
but the result after integer promotion may be produce an error value for us and
trigger the following asserting error.

For example, consider i=0x2000, cluster_bits=18, the result of left shift
operation will be 0x80000000. Cause argument i is of signed integer type,
the result is automatically promoted to 0xffffffff80000000 which is not
we expected

The way to trigger the assertion error:
  qemu-img create -f qcow2 -o preallocation=full,cluster_size=256k tmpdisk 10G

This patch fix it by casting @i to uint64_t before doing left shift operation

Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 81ba90fe0c014f269621c283269b42ad@h3c.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-08-05 14:56:11 +01:00
Max Reitz
fe16c7ddf8 qcow2: Release read-only bitmaps when inactivated
During migration, we release all bitmaps after storing them on disk, as
long as they are (1) stored on disk, (2) not read-only, and (3)
consistent.

(2) seems arbitrary, though.  The reason we do not release them is
because we do not write them, as there is no need to; and then we just
forget about all bitmaps that we have not written to the file.  However,
read-only persistent bitmaps are still in the file and in sync with
their in-memory representation, so we may as well release them just like
any R/W bitmap that we have updated.

It leads to actual problems, too: After migration, letting the source
continue may result in an error if there were any bitmaps on read-only
nodes (such as backing images), because those have not been released by
bdrv_inactive_all(), but bdrv_invalidate_cache_all() attempts to reload
them (which fails, because they are still present in memory).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200730120234.49288-2-mreitz@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-08-03 08:59:37 -05:00
Peter Maydell
5045be872d nbd patches for 2020-07-28
- fix NBD handling of trim/zero requests larger than 2G
 - allow no-op resizes on NBD (in turn fixing qemu-img convert -c into NBD)
 - several deadlock fixes when using NBD reconnect
 -----BEGIN PGP SIGNATURE-----
 
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 A4s5c0FovLBuMDd9oLr0kJbkJQeVZA==
 =DD6l
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2020-07-28' into staging

nbd patches for 2020-07-28

- fix NBD handling of trim/zero requests larger than 2G
- allow no-op resizes on NBD (in turn fixing qemu-img convert -c into NBD)
- several deadlock fixes when using NBD reconnect

# gpg: Signature made Tue 28 Jul 2020 15:59:42 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2020-07-28:
  block/nbd: nbd_co_reconnect_loop(): don't sleep if drained
  block/nbd: on shutdown terminate connection attempt
  block/nbd: allow drain during reconnect attempt
  block/nbd: split nbd_establish_connection out of nbd_client_connect
  iotests: Test convert to qcow2 compressed to NBD
  iotests: Add more qemu_img helpers
  iotests: Make qemu_nbd_popen() a contextmanager
  block: nbd: Fix convert qcow2 compressed to nbd
  nbd: Fix large trim/zero requests

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-28 20:43:03 +01:00
Peter Maydell
0c4fa5bc1a Block patches for 5.1.0:
- Fix block I/O for split transfers
 - Fix iotest 197 for non-qcow2 formats
 -----BEGIN PGP SIGNATURE-----
 
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 k0axygEBAr9JbeCwbIK3a4hjQ7eaFQ6j9JR+lPZBRaDbLHv/xGNNuvw=
 =C4Lq
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-07-28' into staging

Block patches for 5.1.0:
- Fix block I/O for split transfers
- Fix iotest 197 for non-qcow2 formats

# gpg: Signature made Tue 28 Jul 2020 14:45:28 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-07-28:
  iotests/197: Fix for non-qcow2 formats
  iotests/028: Add test for cross-base-EOF reads
  block: Fix bdrv_aligned_p*v() for qiov_offset != 0

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-28 18:00:21 +01:00
Vladimir Sementsov-Ogievskiy
12c75e20a2 block/nbd: nbd_co_reconnect_loop(): don't sleep if drained
We try to go to wakeable sleep, so that, if drain begins it will break
the sleep. But what if nbd_client_co_drain_begin() already called and
s->drained is already true? We'll go to sleep, and drain will have to
wait for the whole timeout. Let's improve it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200727184751.15704-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-28 09:54:43 -05:00
Vladimir Sementsov-Ogievskiy
fbeb3e63b3 block/nbd: on shutdown terminate connection attempt
On shutdown nbd driver may be in a connecting state. We should shutdown
it as well, otherwise we may hang in
nbd_teardown_connection, waiting for conneciton_co to finish in
BDRV_POLL_WHILE(bs, s->connection_co) loop if remote server is down.

How to reproduce the dead lock:

1. Create nbd-fault-injector.conf with the following contents:

[inject-error "mega1"]
event=data
io=readwrite
when=before

2. In one terminal run nbd-fault-injector in a loop, like this:

n=1; while true; do
    echo $n; ((n++));
    ./nbd-fault-injector.py 127.0.0.1:10000 nbd-fault-injector.conf;
done

3. In another terminal run qemu-io in a loop, like this:

n=1; while true; do
    echo $n; ((n++));
    ./qemu-io -c 'read 0 512' nbd://127.0.0.1:10000;
done

After some time, qemu-io will hang. Note, that this hang may be
triggered by another bug, so the whole case is fixed only together with
commit "block/nbd: allow drain during reconnect attempt".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200727184751.15704-4-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-28 09:54:43 -05:00
Vladimir Sementsov-Ogievskiy
dd1ec1a4af block/nbd: allow drain during reconnect attempt
It should be safe to reenter qio_channel_yield() on io/channel read/write
path, so it's safe to reduce in_flight and allow attaching new aio
context. And no problem to allow drain itself: connection attempt is
not a guest request. Moreover, if remote server is down, we can hang
in negotiation, blocking drain section and provoking a dead lock.

How to reproduce the dead lock:

1. Create nbd-fault-injector.conf with the following contents:

[inject-error "mega1"]
event=data
io=readwrite
when=before

2. In one terminal run nbd-fault-injector in a loop, like this:

n=1; while true; do
    echo $n; ((n++));
    ./nbd-fault-injector.py 127.0.0.1:10000 nbd-fault-injector.conf;
done

3. In another terminal run qemu-io in a loop, like this:

n=1; while true; do
    echo $n; ((n++));
    ./qemu-io -c 'read 0 512' nbd://127.0.0.1:10000;
done

After some time, qemu-io will hang trying to drain, for example, like
this:

 #3 aio_poll (ctx=0x55f006bdd890, blocking=true) at
    util/aio-posix.c:600
 #4 bdrv_do_drained_begin (bs=0x55f006bea710, recursive=false,
    parent=0x0, ignore_bds_parents=false, poll=true) at block/io.c:427
 #5 bdrv_drained_begin (bs=0x55f006bea710) at block/io.c:433
 #6 blk_drain (blk=0x55f006befc80) at block/block-backend.c:1710
 #7 blk_unref (blk=0x55f006befc80) at block/block-backend.c:498
 #8 bdrv_open_inherit (filename=0x7fffba1563bc
    "nbd+tcp://127.0.0.1:10000", reference=0x0, options=0x55f006be86d0,
    flags=24578, parent=0x0, child_class=0x0, child_role=0,
    errp=0x7fffba154620) at block.c:3491
 #9 bdrv_open (filename=0x7fffba1563bc "nbd+tcp://127.0.0.1:10000",
    reference=0x0, options=0x0, flags=16386, errp=0x7fffba154620) at
    block.c:3513
 #10 blk_new_open (filename=0x7fffba1563bc "nbd+tcp://127.0.0.1:10000",
    reference=0x0, options=0x0, flags=16386, errp=0x7fffba154620) at
    block/block-backend.c:421

And connection_co stack like this:

 #0 qemu_coroutine_switch (from_=0x55f006bf2650, to_=0x7fe96e07d918,
    action=COROUTINE_YIELD) at util/coroutine-ucontext.c:302
 #1 qemu_coroutine_yield () at util/qemu-coroutine.c:193
 #2 qio_channel_yield (ioc=0x55f006bb3c20, condition=G_IO_IN) at
    io/channel.c:472
 #3 qio_channel_readv_all_eof (ioc=0x55f006bb3c20, iov=0x7fe96d729bf0,
    niov=1, errp=0x7fe96d729eb0) at io/channel.c:110
 #4 qio_channel_readv_all (ioc=0x55f006bb3c20, iov=0x7fe96d729bf0,
    niov=1, errp=0x7fe96d729eb0) at io/channel.c:143
 #5 qio_channel_read_all (ioc=0x55f006bb3c20, buf=0x7fe96d729d28
    "\300.\366\004\360U", buflen=8, errp=0x7fe96d729eb0) at
    io/channel.c:247
 #6 nbd_read (ioc=0x55f006bb3c20, buffer=0x7fe96d729d28, size=8,
    desc=0x55f004f69644 "initial magic", errp=0x7fe96d729eb0) at
    /work/src/qemu/master/include/block/nbd.h:365
 #7 nbd_read64 (ioc=0x55f006bb3c20, val=0x7fe96d729d28,
    desc=0x55f004f69644 "initial magic", errp=0x7fe96d729eb0) at
    /work/src/qemu/master/include/block/nbd.h:391
 #8 nbd_start_negotiate (aio_context=0x55f006bdd890,
    ioc=0x55f006bb3c20, tlscreds=0x0, hostname=0x0,
    outioc=0x55f006bf19f8, structured_reply=true,
    zeroes=0x7fe96d729dca, errp=0x7fe96d729eb0) at nbd/client.c:904
 #9 nbd_receive_negotiate (aio_context=0x55f006bdd890,
    ioc=0x55f006bb3c20, tlscreds=0x0, hostname=0x0,
    outioc=0x55f006bf19f8, info=0x55f006bf1a00, errp=0x7fe96d729eb0) at
    nbd/client.c:1032
 #10 nbd_client_connect (bs=0x55f006bea710, errp=0x7fe96d729eb0) at
    block/nbd.c:1460
 #11 nbd_reconnect_attempt (s=0x55f006bf19f0) at block/nbd.c:287
 #12 nbd_co_reconnect_loop (s=0x55f006bf19f0) at block/nbd.c:309
 #13 nbd_connection_entry (opaque=0x55f006bf19f0) at block/nbd.c:360
 #14 coroutine_trampoline (i0=113190480, i1=22000) at
    util/coroutine-ucontext.c:173

Note, that the hang may be
triggered by another bug, so the whole case is fixed only together with
commit "block/nbd: on shutdown terminate connection attempt".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200727184751.15704-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-28 09:54:43 -05:00
Vladimir Sementsov-Ogievskiy
fa35591b9c block/nbd: split nbd_establish_connection out of nbd_client_connect
We are going to implement non-blocking version of
nbd_establish_connection, which for a while will be used only for
nbd_reconnect_attempt, not for nbd_open, so we need to call it
separately.

Refactor nbd_reconnect_attempt in a way which makes next commit
simpler.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200727184751.15704-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-28 09:54:43 -05:00
Nir Soffer
a2b333c018 block: nbd: Fix convert qcow2 compressed to nbd
When converting to qcow2 compressed format, the last step is a special
zero length compressed write, ending in a call to bdrv_co_truncate(). This
call always fails for the nbd driver since it does not implement
bdrv_co_truncate().

For block devices, which have the same limits, the call succeeds since
the file driver implements bdrv_co_truncate(). If the caller asked to
truncate to the same or smaller size with exact=false, the truncate
succeeds. Implement the same logic for nbd.

Example failing without this change:

In one shell start qemu-nbd:

$ truncate -s 1g test.tar
$ qemu-nbd --socket=/tmp/nbd.sock --persistent --format=raw --offset 1536 test.tar

In another shell convert an image to qcow2 compressed via NBD:

$ echo "disk data" > disk.raw
$ truncate -s 1g disk.raw
$ qemu-img convert -f raw -O qcow2 -c disk1.raw nbd+unix:///?socket=/tmp/nbd.sock; echo $?
1

qemu-img failed, but the conversion was successful:

$ qemu-img info nbd+unix:///?socket=/tmp/nbd.sock
image: nbd+unix://?socket=/tmp/nbd.sock
file format: qcow2
virtual size: 1 GiB (1073741824 bytes)
...

$ qemu-img check nbd+unix:///?socket=/tmp/nbd.sock
No errors were found on the image.
1/16384 = 0.01% allocated, 100.00% fragmented, 100.00% compressed clusters
Image end offset: 393216

$ qemu-img compare disk.raw nbd+unix:///?socket=/tmp/nbd.sock
Images are identical.

Fixes: https://bugzilla.redhat.com/1860627
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-Id: <20200727215846.395443-2-nsoffer@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: typo fixes]
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-28 09:54:19 -05:00
Peter Maydell
2649915121 bitmaps patches for 2020-07-27
- Improve handling of various post-copy bitmap migration scenarios. A lost
 bitmap should merely mean that the next backup must be full rather than
 incremental, rather than abruptly breaking the entire guest migration.
 - Associated iotest improvements
 -----BEGIN PGP SIGNATURE-----
 
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 =1dmz
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-07-27' into staging

bitmaps patches for 2020-07-27

- Improve handling of various post-copy bitmap migration scenarios. A lost
bitmap should merely mean that the next backup must be full rather than
incremental, rather than abruptly breaking the entire guest migration.
- Associated iotest improvements

# gpg: Signature made Mon 27 Jul 2020 21:46:17 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2020-07-27: (24 commits)
  migration: Fix typos in bitmap migration comments
  iotests: Adjust which migration tests are quick
  qemu-iotests/199: add source-killed case to bitmaps postcopy
  qemu-iotests/199: add early shutdown case to bitmaps postcopy
  qemu-iotests/199: check persistent bitmaps
  qemu-iotests/199: prepare for new test-cases addition
  migration/savevm: don't worry if bitmap migration postcopy failed
  migration/block-dirty-bitmap: cancel migration on shutdown
  migration/block-dirty-bitmap: relax error handling in incoming part
  migration/block-dirty-bitmap: keep bitmap state for all bitmaps
  migration/block-dirty-bitmap: simplify dirty_bitmap_load_complete
  migration/block-dirty-bitmap: rename finish_lock to just lock
  migration/block-dirty-bitmap: refactor state global variables
  migration/block-dirty-bitmap: move mutex init to dirty_bitmap_mig_init
  migration/block-dirty-bitmap: rename dirty_bitmap_mig_cleanup
  migration/block-dirty-bitmap: rename state structure types
  migration/block-dirty-bitmap: fix dirty_bitmap_mig_before_vm_start
  qemu-iotests/199: increase postcopy period
  qemu-iotests/199: change discard patterns
  qemu-iotests/199: improve performance: set bitmap by discard
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-28 14:38:17 +01:00
Max Reitz
134b7dec6e block: Fix bdrv_aligned_p*v() for qiov_offset != 0
Since these functions take a @qiov_offset, they must always take it into
account when working with @qiov.  There are a couple of places where
they do not, but they should.

Fixes: 65cd4424b9
       ("block/io: bdrv_aligned_preadv: use and support qiov_offset")
Fixes: 28c4da2869
       ("block/io: bdrv_aligned_pwritev: use and support qiov_offset")
Reported-by: Claudio Fontana <cfontana@suse.de>
Reported-by: Bruce Rogers <brogers@suse.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200728120806.265916-2-mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Claudio Fontana <cfontana@suse.de>
Tested-by: Bruce Rogers <brogers@suse.com>
2020-07-28 15:28:47 +02:00
Andrey Shinkevich
8098969cf2 qcow2: Fix capitalization of header extension constant.
Make the capitalization of the hexadecimal numbers consistent for the
QCOW2 header extension constants in docs/interop/qcow2.txt.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1594973699-781898-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2020-07-27 15:39:58 -05:00
Max Reitz
984c367814 block/amend: Check whether the node exists
We should check whether the user-specified node-name actually refers to
a node.  The simplest way to do that is to use bdrv_lookup_bs() instead
of bdrv_find_node() (the former wraps the latter, and produces an error
message if necessary).

Reported-by: Coverity (CID 1430268)
Fixes: ced914d0ab
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200710095037.10885-1-mreitz@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
2020-07-27 12:37:25 +02:00
Peter Maydell
0c1fd2f41f Block layer patches:
- file-posix: Handle `EINVAL` fallocate return value
 - qemu-img convert -n: Keep qcow2 v2 target sparse
 -----BEGIN PGP SIGNATURE-----
 
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 Y/fVHHshlRU=
 =QhOf
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- file-posix: Handle `EINVAL` fallocate return value
- qemu-img convert -n: Keep qcow2 v2 target sparse

# gpg: Signature made Tue 21 Jul 2020 16:45:28 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests: Test sparseness for qemu-img convert -n
  qcow2: Implement v2 zero writes with discard if possible
  file-posix: Handle `EINVAL` fallocate return value

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-21 19:25:48 +01:00
Peter Maydell
b50dab9eca QOM patches for 2020-07-21
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Merge remote-tracking branch 'remotes/armbru/tags/pull-qom-2020-07-21' into staging

QOM patches for 2020-07-21

# gpg: Signature made Tue 21 Jul 2020 16:40:27 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qom-2020-07-21:
  qom: Make info qom-tree sort children more efficiently
  qom: Document object_get_canonical_path() returns malloced string
  qom: Change object_get_canonical_path_component() not to malloc

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-21 18:31:52 +01:00
Kevin Wolf
61b3043965 qcow2: Implement v2 zero writes with discard if possible
qcow2 version 2 images don't support the zero flag for clusters, so for
write_zeroes requests, we return -ENOTSUP and get explicit zero buffer
writes. If the image doesn't have a backing file, we can do better: Just
discard the respective clusters.

This is relevant for 'qemu-img convert -O qcow2 -n', where qemu-img has
to assume that the existing target image may contain any data, so it has
to write zeroes. Without this patch, this results in a fully allocated
target image, even if the source image was empty.

Reported-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200721135520.72355-2-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-21 16:28:57 +02:00
Antoine Damhet
bae127d4dc file-posix: Handle EINVAL fallocate return value
The `detect-zeroes=unmap` option may issue unaligned
`FALLOC_FL_PUNCH_HOLE` requests, raw block devices can (and will) return
`EINVAL`, qemu should then write the zeroes to the blockdev instead of
issuing an `IO_ERROR`.

The problem can be reprodced like this:

$ qemu-io -c 'write -P 0 42 1234' --image-opts driver=host_device,filename=/dev/loop0,detect-zeroes=unmap
write failed: Invalid argument

Signed-off-by: Antoine Damhet <antoine.damhet@blade-group.com>
Message-Id: <20200717135603.51180-1-antoine.damhet@blade-group.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-21 16:28:57 +02:00
Markus Armbruster
7a309cc95b qom: Change object_get_canonical_path_component() not to malloc
object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.

19 of its 25 callers immediately free the returned copy.

Change object_get_canonical_path_component() to return the property
name directly.  Since modifying the name would be wrong, adjust the
return type to const char *.

Drop the free from the 19 callers become simpler, add the g_strdup()
to the other six.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
2020-07-21 16:23:43 +02:00
Stefan Hajnoczi
1d719ddc35 block: fix bdrv_aio_cancel() for ENOMEDIUM requests
bdrv_aio_cancel() calls aio_poll() on the AioContext for the given I/O
request until it has completed. ENOMEDIUM requests are special because
there is no BlockDriverState when the drive has no medium!

Define a .get_aio_context() function for BlkAioEmAIOCB requests so that
bdrv_aio_cancel() can find the AioContext where the completion BH is
pending. Without this function bdrv_aio_cancel() aborts on ENOMEDIUM
requests!

libFuzzer triggered the following assertion:

  cat << EOF | qemu-system-i386 -M pc-q35-5.0 \
    -nographic -monitor none -serial none \
    -qtest stdio -trace ide\*
  outl 0xcf8 0x8000fa24
  outl 0xcfc 0xe106c000
  outl 0xcf8 0x8000fa04
  outw 0xcfc 0x7
  outl 0xcf8 0x8000fb20
  write 0x0 0x3 0x2780e7
  write 0xe106c22c 0xd 0x1130c218021130c218021130c2
  write 0xe106c218 0x15 0x110010110010110010110010110010110010110010
  EOF
  ide_exec_cmd IDE exec cmd: bus 0x56170a77a2b8; state 0x56170a77a340; cmd 0xe7
  ide_reset IDEstate 0x56170a77a340
  Aborted (core dumped)

  (gdb) bt
  #1  0x00007ffff4f93895 in abort () at /lib64/libc.so.6
  #2  0x0000555555dc6c00 in bdrv_aio_cancel (acb=0x555556765550) at block/io.c:2745
  #3  0x0000555555dac202 in blk_aio_cancel (acb=0x555556765550) at block/block-backend.c:1546
  #4  0x0000555555b1bd74 in ide_reset (s=0x555557213340) at hw/ide/core.c:1318
  #5  0x0000555555b1e3a1 in ide_bus_reset (bus=0x5555572132b8) at hw/ide/core.c:2422
  #6  0x0000555555b2aa27 in ahci_reset_port (s=0x55555720eb50, port=2) at hw/ide/ahci.c:650
  #7  0x0000555555b29fd7 in ahci_port_write (s=0x55555720eb50, port=2, offset=44, val=16) at hw/ide/ahci.c:360
  #8  0x0000555555b2a564 in ahci_mem_write (opaque=0x55555720eb50, addr=556, val=16, size=1) at hw/ide/ahci.c:513
  #9  0x000055555598415b in memory_region_write_accessor (mr=0x55555720eb80, addr=556, value=0x7fffffffb838, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:483

Looking at bdrv_aio_cancel:

2728 /* async I/Os */
2729
2730 void bdrv_aio_cancel(BlockAIOCB *acb)
2731 {
2732     qemu_aio_ref(acb);
2733     bdrv_aio_cancel_async(acb);
2734     while (acb->refcnt > 1) {
2735         if (acb->aiocb_info->get_aio_context) {
2736             aio_poll(acb->aiocb_info->get_aio_context(acb), true);
2737         } else if (acb->bs) {
2738             /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so
2739              * assert that we're not using an I/O thread.  Thread-safe
2740              * code should use bdrv_aio_cancel_async exclusively.
2741              */
2742             assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context());
2743             aio_poll(bdrv_get_aio_context(acb->bs), true);
2744         } else {
2745             abort();     <===============
2746         }
2747     }
2748     qemu_aio_unref(acb);
2749 }

Fixes: 02c50efe08 ("block: Add bdrv_aio_cancel_async")
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Buglink: https://bugs.launchpad.net/qemu/+bug/1878255
Originally-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200720100141.129739-1-stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-21 12:00:38 +02:00
Maxim Levitsky
662d0c5392 block/crypto: disallow write sharing by default
My commit 'block/crypto: implement the encryption key management'
accidently allowed raw luks images to be shared between different
qemu processes without share-rw=on explicit override.
Fix that.

Fixes: bbfdae91fb ("block/crypto: implement the encryption key management")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1857490

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200719122059.59843-2-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-21 10:49:02 +02:00
Kevin Wolf
a8c5cf27c9 file-posix: Fix leaked fd in raw_open_common() error path
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-4-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
bca5283bd4 file-posix: Fix check_hdev_writable() with auto-read-only
For Linux block devices, being able to open the device read-write
doesn't necessarily mean that the device is actually writable (one
example is a read-only LV, as you get with lvchange -pr <device>). We
have check_hdev_writable() to check this condition and fail opening the
image read-write if it's not actually writable.

However, this check doesn't take auto-read-only into account, but
results in a hard failure instead of downgrading to read-only where
possible.

Fix this and do the writable check not based on BDRV_O_RDWR, but only
when this actually results in opening the file read-write. A second
check is inserted in raw_reconfigure_getfd() to have the same check when
dynamic auto-read-only upgrades an image file from read-only to
read-write.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-3-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
20eaf1bf6e file-posix: Move check_hdev_writable() up
We'll need to call it in raw_open_common(), so move the function to
avoid a forward declaration.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-2-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
5edc85571e file-posix: Allow byte-aligned O_DIRECT with NFS
Since commit a6b257a08e ('file-posix: Handle undetectable alignment'),
we assume that if we open a file with O_DIRECT and alignment probing
returns 1, we just couldn't find out the real alignment requirement
because some filesystems make the requirement only for allocated blocks.
In this case, a safe default of 4k is used.

This is too strict for NFS, which does actually allow byte-aligned
requests even with O_DIRECT. Because we can't distinguish both cases
with generic code, let's just look at the file system magic and disable
s->needs_alignment for NFS. This way, O_DIRECT can still be used on NFS
for images that are not aligned to 4k.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200716142601.111237-3-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Marc-André Lureau
a08464521c Remove VXHS block device
The vxhs code doesn't compile since v2.12.0. There's no point in fixing
and then adding CI for a config that our users have demonstrated that
they do not use; better to just remove it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200711065926.2204721-1-marcandre.lureau@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Peter Maydell
d2628b1eb7 Block layer patches:
- file-posix: Mitigate file fragmentation with extent size hints
 - Tighten qemu-img rules on missing backing format
 - qemu-img map: Don't limit block status request size
 - Fix crash with virtio-scsi and iothreads
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- file-posix: Mitigate file fragmentation with extent size hints
- Tighten qemu-img rules on missing backing format
- qemu-img map: Don't limit block status request size
- Fix crash with virtio-scsi and iothreads

# gpg: Signature made Tue 14 Jul 2020 14:24:19 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: Avoid stale pointer dereference in blk_get_aio_context()
  qemu-img: Deprecate use of -b without -F
  block: Add support to warn on backing file change without format
  iotests: Specify explicit backing format where sensible
  qcow2: Deprecate use of qemu-img amend to change backing file
  block: Error if backing file fails during creation without -u
  qcow: Tolerate backing_fmt=
  vmdk: Add trivial backing_fmt support
  sheepdog: Add trivial backing_fmt support
  block: Finish deprecation of 'qemu-img convert -n -o'
  qemu-img: Flush stdout before before potential stderr messages
  file-posix: Mitigate file fragmentation with extent size hints
  iotests/059: Filter out disk size with more standard filter
  qemu-img map: Don't limit block status request size
  iotests: Simplify _filter_img_create() a bit

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-14 19:39:52 +01:00
Greg Kurz
e6cada9231 block: Avoid stale pointer dereference in blk_get_aio_context()
It is possible for blk_remove_bs() to race with blk_drain_all(), causing
the latter to dereference a stale blk->root pointer:

  blk_remove_bs(blk)
   bdrv_root_unref_child(blk->root)
    child_bs = blk->root->bs
    bdrv_detach_child(blk->root)
     ...
     g_free(blk->root) <============== blk->root becomes stale
    bdrv_unref(child_bs) <============ yield at some point

A blk_drain_all() can be triggered by some guest action in the
meantime, eg. on POWER, SLOF might disable bus mastering on
a virtio-scsi-pci device:

  virtio_write_config()
   virtio_pci_stop_ioeventfd()
    virtio_bus_stop_ioeventfd()
     virtio_scsi_dataplane_stop()
      blk_drain_all()
       blk_get_aio_context()
       bs = blk->root ? blk->root->bs : NULL
            ^^^^^^^^^
              stale

Then, depending on one's luck, QEMU either crashes with SEGV or
hits the assertion in blk_get_aio_context().

blk->root is set by blk_insert_bs() which calls bdrv_root_attach_child()
first. The blk_remove_bs() function should rollback the changes made
by blk_insert_bs() in the opposite order (or it should be documented
somewhere why this isn't the case). Clear blk->root before calling
bdrv_root_unref_child() in blk_remove_bs().

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159430264541.389456.11925072456012783045.stgit@bahia.lan>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:24:15 +02:00
Eric Blake
e54ee1b385 block: Add support to warn on backing file change without format
For now, this is a mechanical addition; all callers pass false. But
the next patch will use it to improve 'qemu-img rebase -u' when
selecting a backing file with no format.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Message-Id: <20200706203954.341758-10-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
bc5ee6da71 qcow2: Deprecate use of qemu-img amend to change backing file
The use of 'qemu-img amend' to change qcow2 backing files is not
tested very well.  In particular, our implementation has a bug where
if a new backing file is provided without a format, then the prior
format is blindly reused, even if this results in data corruption, but
this is not caught by iotests.

There are also situations where amending other options needs access to
the original backing file (for example, on a downgrade to a v2 image,
knowing whether a v3 zero cluster must be allocated or may be left
unallocated depends on knowing whether the backing file already reads
as zero), but the command line does not have a nice way to tell us
both the backing file to use for opening the image as well as the
backing file to install after the operation is complete.

Even if we do allow changing the backing file, it is redundant with
the existing ability to change backing files via 'qemu-img rebase -u'.
It is time to deprecate this support (leaving the existing behavior
intact, even if it is buggy), and at a point in the future, require
the use of only 'qemu-img rebase' for adjusting backing chain
relations, saving 'qemu-img amend' for changes unrelated to the
backing chain.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-8-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
344acbd62f qcow: Tolerate backing_fmt=
qcow has no space in the metadata to store a backing format, and there
are existing qcow images backed both by raw or by other formats
(usually qcow) images, reliant on probing to tell the difference.  On
the bright side, because we probe every time, raw files are marked as
probed and we thus forbid a commit action into the backing file where
guest-controlled contents could change the result of the probe next
time around (the iotest added here proves that).

Still, allowing the user to specify the backing format during
creation, even if we can't record it, is a good thing.  This patch
blindly allows any value that resolves to a known driver, even if the
user's request is a mismatch from what probing finds; then the next
patch will further enhance things to verify that the user's request
matches what we actually probe.  With this and the next patch in
place, we will finally be ready to deprecate the creation of images
where a backing format was not explicitly specified by the user.

Note that this is only for QemuOpts usage; there is no change to the
QAPI to allow a format through -blockdev.

Add a new iotest 301 just for qcow, to demonstrate the latest
behavior, and to make it easier to show the improvements made in the
next patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-6-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
d51a814cf4 vmdk: Add trivial backing_fmt support
vmdk already requires that if backing_file is present, that it be
another vmdk image (see vmdk_co_do_create).  Meanwhile, we want to
move towards always being explicit about the backing format for other
drivers where it matters.  So for convenience, make qemu-img create -F
vmdk work, while rejecting all other explicit formats (note that this
is only for QemuOpts usage; there is no change to the QAPI to allow a
format through -blockdev).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-5-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
80fa43e7df sheepdog: Add trivial backing_fmt support
Sheepdog already requires that if backing_file is present, that it be
another sheepdog image (see sd_co_create).  Meanwhile, we want to move
towards always being explicit about the backing format for other
drivers where it matters.  So for convenience, make qemu-img create -F
sheepdog work, while rejecting all other explicit formats (note that
this is only for QemuOpts usage; there is no change to the QAPI to
allow a format through -blockdev).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-4-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Kevin Wolf
ffa244c84a file-posix: Mitigate file fragmentation with extent size hints
Especially when O_DIRECT is used with image files so that the page cache
indirection can't cause a merge of allocating requests, the file will
fragment on the file system layer, with a potentially very small
fragment size (this depends on the requests the guest sent).

On Linux, fragmentation can be reduced by setting an extent size hint
when creating the file (at least on XFS, it can't be set any more after
the first extent has been allocated), basically giving raw files a
"cluster size" for allocation.

This adds a create option to set the extent size hint, and changes the
default from not setting a hint to setting it to 1 MB. The main reason
why qcow2 defaults to smaller cluster sizes is that COW becomes more
expensive, which is not an issue with raw files, so we can choose a
larger size. The tradeoff here is only potentially wasted disk space.

For qcow2 (or other image formats) over file-posix, the advantage should
even be greater because they grow sequentially without leaving holes, so
there won't be wasted space. Setting even larger extent size hints for
such images may make sense. This can be done with the new option, but
let's keep the default conservative for now.

The effect is very visible with a test that intentionally creates a
badly fragmented file with qemu-img bench (the time difference while
creating the file is already remarkable) and then looks at the number of
extents and the time a simple "qemu-img map" takes.

Without an extent size hint:

    $ ./qemu-img create -f raw -o extent_size_hint=0 ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=0
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 25.848 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 19.616 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 2000000 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m1,279s
    user    0m0,043s
    sys     0m1,226s

With the new default extent size hint of 1 MB:

    $ ./qemu-img create -f raw -o extent_size_hint=1M ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=1048576
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 11.833 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 10.155 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 178 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m0,061s
    user    0m0,040s
    sys     0m0,014s

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200707142329.48303-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
00d69986da nbd: Avoid off-by-one in long export name truncation
When snprintf returns the same value as the buffer size, the final
byte was truncated to ensure a NUL terminator.  Fortunately, such long
export names are unusual enough, with no real impact other than what
is displayed to the user.

Fixes: 5c86bdf120
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200622210355.414941-1-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-07-13 09:01:01 -05:00
Xie Yongji
c58daf76a6 iscsi: return -EIO when sense fields are meaningless
When an I/O request failed, now we only return correct
value on scsi check condition. We should also have a
default errno such as -EIO in other case.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-2-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Xie Yongji
dd3b00202a iscsi: handle check condition status in retry loop
The handling of check condition was incorrect because
we would only do it after retries exceed maximum.

Fixes: 8c460269aa ("iscsi: base all handling of check condition on scsi_sense_to_errno")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-1-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Vladimir Sementsov-Ogievskiy
795d946d07 nbd: Use ERRP_GUARD()
If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix several such cases, e.g. in nbd_read().

This commit is generated by command

    sed -n '/^Network Block Device (NBD)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]
2020-07-10 15:18:09 +02:00
Markus Armbruster
386f6c07d2 error: Avoid error_propagate() after migrate_add_blocker()
When migrate_add_blocker(blocker, &errp) is followed by
error_propagate(errp, err), we can often just as well do
migrate_add_blocker(..., errp).

Do that with this Coccinelle script:

    @@
    expression blocker, err, errp;
    expression ret;
    @@
    -    ret = migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    ret = migrate_add_blocker(blocker, errp);
    +    if (ret < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

    @@
    expression blocker, err, errp;
    @@
    -    migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    if (migrate_add_blocker(blocker, errp) < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

Double-check @err is not used afterwards.  Dereferencing it would be
use after free, but checking whether it's null would be legitimate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-43-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
b11a093c60 qapi: Smooth another visitor error checking pattern
Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
4bc6d7ee0e block/parallels: Simplify parallels_open() after previous commit
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-39-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
a5f9b9df25 error: Reduce unnecessary error propagation
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away, even when we need to keep error_propagate() for other
error paths.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-38-armbru@redhat.com>
2020-07-10 15:18:08 +02:00