Commit Graph

44820 Commits

Author SHA1 Message Date
Markus Armbruster
ddc8528443 ivshmem: Clean up after the previous commit
Move code to more sensible places.  Use the opportunity to reorder and
document IVShmemState members.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-38-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster
5400c02b90 ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem
ivshmem can be configured with and without interrupt capability
(a.k.a. "doorbell").  The two configurations have largely disjoint
options, which makes for a confusing (and badly checked) user
interface.  Moreover, the device can't tell the guest whether its
doorbell is enabled.

Create two new device models ivshmem-plain and ivshmem-doorbell, and
deprecate the old one.

Changes from ivshmem:

* PCI revision is 1 instead of 0.  The new revision is fully backwards
  compatible for guests.  Guests may elect to require at least
  revision 1 to make sure they're not exposed to the funny "no shared
  memory, yet" state.

* Property "role" replaced by "master".  role=master becomes
  master=on, role=peer becomes master=off.  Default is off instead of
  auto.

* Property "use64" is gone.  The new devices always have 64 bit BARs.

Changes from ivshmem to ivshmem-plain:

* The Interrupt Pin register in PCI config space is zero (does not use
  an interrupt pin) instead of one (uses INTA).

* Property "x-memdev" is renamed to "memdev".

* Properties "shm" and "size" are gone.  Use property "memdev"
  instead.

* Property "msi" is gone.  The new device can't have MSI-X capability.
  It can't interrupt anyway.

* Properties "ioeventfd" and "vectors" are gone.  They're meaningless
  without interrupts anyway.

Changes from ivshmem to ivshmem-doorbell:

* Property "msi" is gone.  The new device always has MSI-X capability.

* Property "ioeventfd" defaults to on instead of off.

* Property "size" is gone.  The new device can only map all the shared
  memory received from the server.

Guests can easily find out whether the device is configured for
interrupts by checking for MSI-X capability.

Note: some code added in sub-optimal places to make the diff easier to
review.  The next commit will move it to more sensible places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-37-git-send-email-armbru@redhat.com>
2016-03-21 21:29:03 +01:00
Markus Armbruster
2a845da736 ivshmem: Replace int role_val by OnOffAuto master
In preparation of making it a qdev property.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-36-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
55e8a15435 qdev: New DEFINE_PROP_ON_OFF_AUTO
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-35-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
8baeb22bfc ivshmem: Inline check_shm_size() into its only caller
Improve the error messages while there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-34-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
c2d8019cd7 ivshmem: Simplify memory regions for BAR 2 (shared memory)
ivshmem_realize() puts the shared memory region in a container region.
Used to be necessary to permit delayed mapping of the shared memory.
However, we recently moved to synchronous mapping, in "ivshmem:
Receive shared memory synchronously in realize()" and the commit
following it.  The container is redundant since then.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-33-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
5503e28504 ivshmem: Implement shm=... with a memory backend
ivshmem has its very own code to create and map shared memory.
Replace that with an implicitly created memory backend.  Reduces the
number of ways we create BAR 2 from three to two.

The memory-backend-file is currently available only with CONFIG_LINUX,
so this adds a second Linuxism to ivshmem (the other one is eventfd).
Should we ever need to make it portable to systems where
memory-backend-file can't be made to serve, we could create a
memory-backend-shmem that allocates memory with shm_open().

Bonus fix: shared memory files are now created with permissions 0655
instead of 0777.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-32-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
08183c20b8 ivshmem: Tighten check of property "size"
If size_t is narrower than 64 bits, passing uint64_t ivshmem_size to
mmap() truncates.  Reject such sizes.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-31-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +01:00
Markus Armbruster
ee276391a3 ivshmem: Simplify how we cope with short reads from server
Short reads from a UNIX domain sockets are exceedingly unlikely when
the other side always sends eight bytes and we always read eight
bytes.  We cope with them anyway.  However, the code doing that is
rather convoluted.  Dumb it down radically.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-30-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
ba5970a178 ivshmem: Drop the hackish test for UNIX domain chardev
The chardev must be capable of transmitting SCM_RIGHTS ancillary
messages.  We check it by comparing CharDriverState member filename to
"unix:".  That's almost as brittle as it is disgusting.

When the actual transmission all happened asynchronously, this check
was all we could do in realize(), and thus better than nothing.  But
now we receive at least one SCM_RIGHTS synchronously in realize(),
it's not worth its keep anymore.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-29-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
a3feb08639 ivshmem: Rely on server sending the ID right after the version
The protocol specification (ivshmem-spec.txt, formerly
ivshmem_device_spec.txt) has always required the ID message to be sent
right at the beginning, and ivshmem-server has always complied.  The
device, however, accepts it out of order.  If an interrupt setup
arrived before it, though, it would be misinterpreted as connect
notification.  Fix the latent bug by relying on the spec and
ivshmem-server's actual behavior.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-28-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
1309cf448a ivshmem: Propagate errors through ivshmem_recv_setup()
This kills off the funny state described in the previous commit.

Simplify ivshmem_io_read() accordingly, and update documentation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-27-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
3a55fc0f24 ivshmem: Receive shared memory synchronously in realize()
When configured for interrupts (property "chardev" given), we receive
the shared memory from an ivshmem server.  We do so asynchronously
after realize() completes, by setting up callbacks with
qemu_chr_add_handlers().

Keeping server I/O out of realize() that way avoids delays due to a
slow server.  This is probably relevant only for hot plug.

However, this funny "no shared memory, yet" state of the device also
causes a raft of issues that are hard or impossible to work around:

* The guest is exposed to this state: when we enter and leave it its
  shared memory contents is apruptly replaced, and device register
  IVPosition changes.

  This is a known issue.  We document that guests should not access
  the shared memory after device initialization until the IVPosition
  register becomes non-negative.

  For cold plug, the funny state is unlikely to be visible in
  practice, because we normally receive the shared memory long before
  the guest gets around to mess with the device.

  For hot plug, the timing is tighter, but the relative slowness of
  PCI device configuration has a good chance to hide the funny state.

  In either case, guests complying with the documented procedure are
  safe.

* Migration becomes racy.

  If migration completes before the shared memory setup completes on
  the source, shared memory contents is silently lost.  Fortunately,
  migration is rather unlikely to win this race.

  If the shared memory's ramblock arrives at the destination before
  shared memory setup completes, migration fails.

  There is no known way for a management application to wait for
  shared memory setup to complete.

  All you can do is retry failed migration.  You can improve your
  chances by leaving more time between running the destination QEMU
  and the migrate command.

  To mitigate silent memory loss, you need to ensure the server
  initializes shared memory exactly the same on source and
  destination.

  These issues are entirely undocumented so far.

I'd expect the server to be almost always fast enough to hide these
issues.  But then rare catastrophic races are in a way the worst kind.

This is way more trouble than I'm willing to take from any device.
Kill the funny state by receiving shared memory synchronously in
realize().  If your hot plug hangs, go kill your ivshmem server.

For easier review, this commit only makes the receive synchronous, it
doesn't add the necessary error propagation.  Without that, the funny
state persists.  The next commit will do that, and kill it off for
real.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-26-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
9db51b4d64 ivshmem: Plug leaks on unplug, fix peer disconnect
close_peer_eventfds() cleans up three things: ioeventfd triggers if
they exist, eventfds, and the array to store them.

Commit 98609cd (v1.2.0) fixed it not to clean up ioeventfd triggers
when they don't exist (property ioeventfd=off, which is the default).
Unfortunately, the fix also made it skip cleanup of the eventfds and
the array then.  This is a memory and file descriptor leak on unplug.

Additionally, the reset of nb_eventfds is skipped.  Doesn't matter on
unplug.  On peer disconnect, however, this permanently wedges the
interrupt vectors used for that peer's ID.  The eventfds stay behind,
but aren't connected to a peer anymore.  When the ID gets recycled for
a new peer, the new peer's eventfds get assigned to vectors after the
old ones.  Commonly, the device's number of vectors matches the
server's, so the new ones get dropped with a "Too many eventfd
received" message.  Interrupts either don't work (common case) or go
to the wrong vector.

Fix by narrowing the conditional to just the ioeventfd trigger
cleanup.

While there, move the "invalid" peer check to the only caller where it
can actually happen, and tighten it to reject own ID.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-25-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
ca0b7566cc ivshmem: Disentangle ivshmem_read()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-24-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
cd9953f720 ivshmem: Simplify rejection of invalid peer ID from server
ivshmem_read() processes server messages.  These are 64 bit signed
integers.  -1 is shared memory setup, 16 bit unsigned is a peer ID,
anything else is invalid.

ivshmem_read() rejects invalid negative messages right away, silently.

Invalid positive messages get rejected only in resize_peers(), and
ivshmem_read() then prints the rather cryptic message "failed to
resize peers array".

Extend the first check to cover all invalid messages, make it report
"server sent invalid message", and drop the second check.

Now resize_peers() can't fail anymore; simplify.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-23-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
3c27969b3e ivshmem: Assert interrupts are set up once
An interrupt is set up when the interrupt's file descriptor is
received.  Each message applies to the next interrupt vector.
Therefore, each vector cannot be set up more than once.

ivshmem_add_kvm_msi_virq() half-heartedly tries not to rely on this by
doing nothing then, but that's not going to recover from this error
should it become possible in the future.  watch_vector_notifier()
doesn't even try.

Simply assert what is the case, so we get alerted if we ever screw it
up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-22-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
2d1d422d11 ivshmem: Leave INTx alone when using MSI-X
The ivshmem device can either use MSI-X or legacy INTx for interrupts.

With MSI-X enabled, peer interrupt events trigger an MSI as they
should.  But software can still raise INTx via interrupt status and
mask register in BAR 0.  This is explicitly prohibited by PCI Local
Bus Specification Revision 3.0, section 6.8.3.3:

    While enabled for MSI or MSI-X operation, a function is prohibited
    from using its INTx# pin (if implemented) to request service (MSI,
    MSI-X, and INTx# are mutually exclusive).

Fix the device model to leave INTx alone when using MSI-X.

Document that we claim to use INTx in config space even when we don't.
Unlike other devices, ivshmem does *not* use INTx when configured for
MSI-X and MSI-X isn't enabled by software.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-21-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00
Markus Armbruster
082751e82b ivshmem: Clean up MSI-X conditions
There are three predicates related to MSI-X:

* ivshmem_has_feature(s, IVSHMEM_MSI) is true unless the non-MSI-X
  variant of the device is selected with msi=off.

* msix_present() is true when the device has the PCI capability MSI-X.
  It's initially false, and becomes true during successful realize of
  the MSI-X variant of the device.  Thus, it's the same as
  ivshmem_has_feature(s, IVSHMEM_MSI) for realized devices.

* msix_enabled() is true when msix_present() is true and guest software
  has enabled MSI-X.

Code that differs between the non-MSI-X and the MSI-X variant of the
device needs to be guarded by ivshmem_has_feature(s, IVSHMEM_MSI) or
by msix_present(), except the latter works only for realized devices.

Code that depends on whether MSI-X is in use needs to be guarded with
msix_enabled().

Code review led me to two minor messes:

* ivshmem_vector_notify() calls msix_notify() even when
  !msix_enabled(), unlike most other MSI-X-capable devices.  As far as
  I can tell, msix_notify() does nothing when !msix_enabled().  Add
  the guard anyway.

* Most callers of ivshmem_use_msix() guard it with
  ivshmem_has_feature(s, IVSHMEM_MSI).  Not necessary, because
  ivshmem_use_msix() does nothing when !msix_present().  That's
  ivshmem's only use of msix_present(), though.  Guard it
  consistently, and drop the now redundant msix_present() check.
  While there, rename ivshmem_use_msix() to ivshmem_msix_vector_use().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-20-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
434ad76db5 ivshmem: Clean up register callbacks
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-19-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
d855e27565 ivshmem: Failed realize() can leave migration blocker behind
If pci_ivshmem_realize() fails after it created its migration blocker,
the blocker is left in place.  Fix that by creating it last.

Likewise, if it fails after it called fifo8_create(), it leaks fifo
memory.  Fix that the same way.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-18-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
9cf70c5225 ivshmem: Fix harmless misuse of Error
We reuse errp after passing it host_memory_backend_get_memory().  If
both host_memory_backend_get_memory() and the reuse set an error, the
reuse will fail the assertion in error_setv().  Fortunately,
host_memory_backend_get_memory() can't fail.

Pass it &error_abort to make our assumption explicit, and to get the
assertion failure in the right place should it become invalid.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-17-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
71c265816d ivshmem: Don't destroy the chardev on version mismatch
Yes, the chardev is commonly useless after we read a bad version from
it, but destroying it is inappropriate anyway: the user created it, so
the user should be able to hold on to it as long as he likes.  We
don't destroy it on other errors.  Screwed up in commit 5105b1d.

Stop reading instead.

Also note QEMU's behavior in ivshmem-spec.txt.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-16-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
c20fc0c3ee ivshmem: Drop ivshmem_event() stub
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-15-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
e64befe929 ivshmem: Clean up after commit 9940c32
IVShmemState member eventfd_chr is useless since commit 9940c32.  Drop
it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-14-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
a4fa93bf20 ivshmem: Compile debug prints unconditionally to prevent bit-rot
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-13-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
97553976dd ivshmem: Add missing newlines to debug printfs
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-12-git-send-email-armbru@redhat.com>
2016-03-21 21:29:00 +01:00
Markus Armbruster
fdee2025dd ivshmem: Rewrite specification document
This started as an attempt to update ivshmem_device_spec.txt for
clarity, accuracy and completeness while working on its code, and
quickly became a full rewrite.  Since the diff would be useless
anyway, I'm using the opportunity to rename the file to
ivshmem-spec.txt.

I tried hard to ensure the new text contradicts neither the old text
nor the code.  If the new text contradicts the old text but not the
code, it's probably a bug in the old text.  If the new text
contradicts both, its probably a bug in the new text.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-11-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
41b65e5eda ivshmem-test: Improve test cases /ivshmem/server-*
Document missing test: behavior with MSI-X present but not enabled.

For MSI-X, we test and clear the interrupt pending bit before testing
the interrupt.  For INTx, we only clear.  Change to test and clear for
consistency.

Test MSI-X vector 1 in addition to vector 0.

Improve comments.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-10-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
14c5d49ab3 ivshmem-test: Clean up wait for devices to become operational
test_ivshmem_server() waits until the first byte in BAR 2 contains the
0x42 we put into shared memory.  Works because the byte reads zero
until the device maps the shared memory gotten from the server.

Check the IVPosition register instead: it's initially -1, and becomes
non-negative right when the device maps the share memory, so no
change, just cleaner, because it's what guest software is supposed to
do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-9-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
4958fe5d3c ivshmem-test: Improve test case /ivshmem/single
Test state of registers after reset.

Test reading Interrupt Status clears it.

Test (invalid) read of Doorbell.

Add more comments.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-8-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
998261726a tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned
qpci_pc_iomap() maps BARs one after the other, without padding.  This
is wrong.  PCI Local Bus Specification Revision 3.0, 6.2.5.1. Address
Maps: "all address spaces used are a power of two in size and are
naturally aligned".  That's because the size of a BAR is given by the
number of address bits the device decodes, and the BAR needs to be
mapped at a multiple of that size to ensure the address decoding
works.

Fix qpci_pc_iomap() accordingly.  This takes care of a FIXME in
ivshmem-test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-7-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
330b58368c event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD
Event notifiers are designed for eventfd(2).  They can fall back to
pipes, but according to Paolo, event_notifier_init_fd() really
requires the real thing, and should therefore be under #ifdef
CONFIG_EVENTFD.  Do that.

Its only user is ivshmem, which is currently CONFIG_POSIX.  Narrow it
to CONFIG_EVENTFD.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-6-git-send-email-armbru@redhat.com>
2016-03-21 21:28:59 +01:00
Markus Armbruster
ad4929384b qemu-doc: Fix ivshmem huge page example
Option parameter "share" is missing.  Without it, you get a *private*
mmap(), which defeats ivshmem's purpose pretty thoroughly ;)

While there, switch to the conventional mountpoint of hugetlbfs
/dev/hugepages.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-5-git-send-email-armbru@redhat.com>
2016-03-18 17:34:55 +01:00
Markus Armbruster
3625c739ea ivshmem-server: Don't overload POSIX shmem and file name
Option -m NAME is interpreted as directory name if we can statfs() it
and its on hugetlbfs.  Else it's interpreted as POSIX shared memory
object name.  This is nuts.

Always interpret -m as directory.  Create new -M for POSIX shared
memory.  Last of -m or -M wins.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-4-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-18 17:34:40 +01:00
Markus Armbruster
e3ad72965a ivshmem-server: Fix and clean up command line help
Burying error messages in ~20 lines of usage help is bad form.  Print
a single line pointing to -h instead.

Print -h help to stdout rather than stderr.  Fix default of -p.  Clean
up the help text a bit.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-3-git-send-email-armbru@redhat.com>
2016-03-18 17:34:40 +01:00
Markus Armbruster
3be5cc2324 target-ppc: Document TOCTTOU in hugepage support
The code to find the minimum page size is is vulnerable to TOCTTOU.
Added in commit 2d103aa "target-ppc: fix hugepage support when using
memory-backend-file" (v2.4.0).  Since I can't fix it myself right now,
add a FIXME comment.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-2-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-18 17:34:21 +01:00
Peter Maydell
6741d38ad0 Block layer patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Thu 17 Mar 2016 15:49:29 GMT using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (29 commits)
  iotests: Test QUORUM_REPORT_BAD in fifo mode
  quorum: Emit QUORUM_REPORT_BAD for reads in fifo mode
  block: Use blk_co_pwritev() in blk_co_write_zeroes()
  block: Use blk_aio_prwv() for aio_read/write/write_zeroes
  block: Use blk_prw() in blk_pread()/blk_pwrite()
  block: Use blk_co_pwritev() in blk_write_zeroes()
  block: Pull up blk_read_unthrottled() implementation
  block: Use blk_co_pwritev() for blk_write()
  block: Use blk_co_preadv() for blk_read()
  block: Use BdrvChild in BlockBackend
  block: Remove bdrv_states list
  block: Use bdrv_next() instead of bdrv_states
  block: Rewrite bdrv_next()
  block: Add blk_next_root_bs()
  block: Add bdrv_next_monitor_owned()
  block: Move some bdrv_*_all() functions to BB
  blockdev: Remove blk_hide_on_behalf_of_hmp_drive_del()
  blockdev: Split monitor reference from BB creation
  blockdev: Separate BB name management
  blockdev: Add list of all BlockBackends
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-03-17 15:59:42 +00:00
Kevin Wolf
361dca7a5a Two quorum patches for the block queue, v2.
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Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-03-17-v2' into queue-block

Two quorum patches for the block queue, v2.

# gpg: Signature made Thu Mar 17 16:44:11 2016 CET using RSA key ID E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"

* mreitz/tags/pull-block-for-kevin-2016-03-17-v2:
  iotests: Test QUORUM_REPORT_BAD in fifo mode
  quorum: Emit QUORUM_REPORT_BAD for reads in fifo mode

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 16:48:49 +01:00
Alberto Garcia
509565f36f iotests: Test QUORUM_REPORT_BAD in fifo mode
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: c0a8dbfdbe939520cda5f661af6f1cd7b6b4df9d.1458034554.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-03-17 16:43:30 +01:00
Alberto Garcia
6049490df4 quorum: Emit QUORUM_REPORT_BAD for reads in fifo mode
If there's an I/O error in one of Quorum children then QEMU
should emit QUORUM_REPORT_BAD. However this is not working with
read-pattern=fifo. This patch fixes this problem.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: d57e39e8d3e8564003a1e2aadbd29c97286eb2d2.1458034554.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-03-17 16:43:30 +01:00
Kevin Wolf
8896e08814 block: Use blk_co_pwritev() in blk_co_write_zeroes()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 16:30:00 +01:00
Kevin Wolf
57d6a42883 block: Use blk_aio_prwv() for aio_read/write/write_zeroes
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 16:30:00 +01:00
Kevin Wolf
a55d3fba99 block: Use blk_prw() in blk_pread()/blk_pwrite()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Kevin Wolf
fc1453cdfc block: Use blk_co_pwritev() in blk_write_zeroes()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Kevin Wolf
5bd5119667 block: Pull up blk_read_unthrottled() implementation
Use blk_read(), so that it goes through blk_co_preadv() like all read
requests from the BB to the BDS.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Kevin Wolf
a8823a3bfd block: Use blk_co_pwritev() for blk_write()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Kevin Wolf
1bf1cbc91f block: Use blk_co_preadv() for blk_read()
This patch introduces blk_co_preadv() as a central function on the
BlockBackend level that is supposed to handle all read requests from the
BB to its root BDS eventually.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Kevin Wolf
f21d96d04b block: Use BdrvChild in BlockBackend
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00
Max Reitz
9aaf28c61d block: Remove bdrv_states list
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:57 +01:00