This fixes a balloon bug with a nasty consequence - potentially
corrupting guest memory - but which is extremely unlikely to be
triggered in practice.
The balloon always works in 4kiB units, but the host could have a
larger page size on certain platforms. Since ed48c59 "virtio-balloon:
Safely handle BALLOON_PAGE_SIZE < host page size" we've handled this
by accumulating requests to balloon 4kiB subpages until they formed a
full host page. Since f6deb6d "virtio-balloon: Remove unnecessary
MADV_WILLNEED on deflate" we essentially ignore deflate requests.
Suppose we have a host with 8kiB pages, and one host page has subpages
A & B. If we get this sequence of events -
inflate A
deflate A
inflate B
- the current logic will discard the whole host page. That's
incorrect because the guest has deflated subpage A, and could have
written important data to it.
This patch fixes the problem by adjusting our state information about
partially ballooned host pages when deflate requests are received.
Fixes: ed48c59 "virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host page size"
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190306030601.21986-3-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
ed48c59875 "virtio-balloon: Safely handle BALLOON_PAGE_SIZE < host
page size" introduced a new temporary data structure which tracks 4kiB
chunks which have been inserted into the balloon by the guest but
don't yet form a full host page which we can discard.
Unfortunately, I had a thinko and allocated that structure with
g_malloc0() but freed it with a plain free() rather than g_free().
This corrects the problem.
Fixes: ed48c59875
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190306030601.21986-2-david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
The elem could theorically contain both outbuf and inbufs. We move the
free operation to the end of this function to avoid using elem->in_sg
while elem has been freed.
Fixes: c13c4153f7
("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT")
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Peter Xu <peterx@redhat.com>
Message-Id: <1552383280-4122-1-git-send-email-wei.w.wang@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Currently this just includes Marcel who is a fairly prolific
contributor.
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Based on Tom's LinkedIn profile his QEMU work was while in IBM's
virtualisation group.
Reviewed-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
I know Richard's is right because I asked him in the pub. I'm guessing
Fredrik's based on the fact I vaguely remember an Atari demo. The
others I attributed to academic institutions last time I posted so
have moved them to individuals as requested.
Cc: Fredrik Noring <noring@nocrew.org>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Richard Henderson <rth@twiddle.net>
Add all missing MIPS/Imgtec/Wave contributors (from the inception of
QEMU).
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Add Citrix, Huawei, Intel, and Microsoft to domain-map.
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
[AJB: sorted, added Fujitsu]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This patch adds several tests for the x-blockdev-reopen QMP command.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This command allows reopening an arbitrary BlockDriverState with a
new set of options. Some options (e.g node-name) cannot be changed
and some block drivers don't allow reopening, but otherwise this
command is modelled after 'blockdev-add' and the state of the reopened
BlockDriverState should generally be the same as if it had just been
added by 'blockdev-add' with the same set of options.
One notable exception is the 'backing' option: 'x-blockdev-reopen'
requires that it is always present unless the BlockDriverState in
question doesn't have a current or default backing file.
This command allows reconfiguring the graph by using the appropriate
options to change the children of a node. At the moment it's possible
to change a backing file by setting the 'backing' option to the name
of the new node, but it should also be possible to add a similar
functionality to other block drivers (e.g. Quorum, blkverify).
Although the API is unlikely to change, this command is marked
experimental for the time being so there's room to see if the
semantics need changes.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_reopen_prepare() receives a BDRVReopenState with (among other
things) a new set of options to be applied to that BlockDriverState.
If an option is missing then it means that we want to reset it to its
default value rather than keep the previous one. This way the state
of the block device after being reopened is comparable to that of a
device added with "blockdev-add" using the same set of options.
Not all options from all drivers can be changed this way, however.
If the user attempts to reset an immutable option to its default value
using this method then we must forbid it.
This new function takes a BlockDriverState and a new set of options
and checks if there's any option that was previously set but is
missing from the new set of options.
If the option is present in both sets we don't need to check that they
have the same value. The loop at the end of bdrv_reopen_prepare()
already takes care of that.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If we reopen a BlockDriverState and there is an option that is present
in bs->options but missing from the new set of options then we have to
return an error unless the driver is able to reset it to its default
value.
This patch adds a new 'mutable_opts' field to BlockDriver. This is
a list of runtime options that can be modified during reopen. If an
option in this list is unspecified on reopen then it must be reset (or
return an error).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch allows the user to change the backing file of an image that
is being reopened. Here's what it does:
- In bdrv_reopen_prepare(): check that the value of 'backing' points
to an existing node or is null. If it points to an existing node it
also needs to make sure that replacing the backing file will not
create a cycle in the node graph (i.e. you cannot reach the parent
from the new backing file).
- In bdrv_reopen_commit(): perform the actual node replacement by
calling bdrv_set_backing_hd().
There may be temporary implicit nodes between a BDS and its backing
file (e.g. a commit filter node). In these cases bdrv_reopen_prepare()
looks for the real (non-implicit) backing file and requires that the
'backing' option points to it. Replacing or detaching a backing file
is forbidden if there are implicit nodes in the middle.
Although x-blockdev-reopen is meant to be used like blockdev-add,
there's an important thing that must be taken into account: the only
way to set a new backing file is by using a reference to an existing
node (previously added with e.g. blockdev-add). If 'backing' contains
a dictionary with a new set of options ({"driver": "qcow2", "file": {
... }}) then it is interpreted that the _existing_ backing file must
be reopened with those options.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Of all options of type BlockdevRef used to specify children in
BlockdevOptions, 'backing' is the only one that is optional.
For "x-blockdev-reopen" we want that if an option is omitted then it
must be reset to its default value. The default value of 'backing'
means that QEMU opens the backing file specified in the image
metadata, but this is not something that we want to support for the
reopen operation.
Because of this the 'backing' option has to be specified during
reopen, pointing to the existing backing file if we want to keep it,
or pointing to a different one (or NULL) if we want to replace it (to
be implemented in a subsequent patch).
In order to simplify things a bit and not to require that the user
passes the 'backing' option to every single block device even when
it's clearly not necessary, this patch allows omitting this option if
the block device being reopened doesn't have a backing file attached
_and_ no default backing file is specified in the image metadata.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Children in QMP are specified with BlockdevRef / BlockdevRefOrNull,
which can contain a set of child options, a child reference, or
NULL. In optional attributes like "backing" it can also be missing.
Only the first case (set of child options) is being handled properly
by bdrv_reopen_queue(). This patch deals with all the others.
Here's how these cases should be handled when bdrv_reopen_queue() is
deciding what to do with each child of a BlockDriverState:
1) Set of child options: if the child was implicitly created (i.e
inherits_from points to the parent) then the options are removed
from the parent's options QDict and are passed to the child with
a recursive bdrv_reopen_queue() call. This case was already
working fine.
2) Child reference: there's two possibilites here.
2a) Reference to the current child: if the child was implicitly
created then it is put in the reopen queue, keeping its
current set of options (since this was a child reference
there was no way to specify a different set of options).
If the child is not implicit then it keeps its current set
of options but it is not reopened (and therefore does not
inherit any new option from the parent).
2b) Reference to a different BDS: the current child is not put
in the reopen queue at all. Passing a reference to a
different BDS can be used to replace a child, although at
the moment no driver implements this, so it results in an
error. In any case, the current child is not going to be
reopened (and might in fact disappear if it's replaced)
3) NULL: This is similar to (2b). Although no driver allows this
yet it can be used to detach the current child so it should not
be put in the reopen queue.
4) Missing option: at the moment "backing" is the only case where
this can happen. With "blockdev-add", leaving "backing" out
means that the default backing file is opened. We don't want to
open a new image during reopen, so we require that "backing" is
always present. We'll relax this requirement a bit in the next
patch. If keep_old_opts is true and "backing" is missing then
this behaves like 2a (the current child is reopened).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The bdrv_reopen_queue() function is used to create a queue with
the BDSs that are going to be reopened and their new options. Once
the queue is ready bdrv_reopen_multiple() is called to perform the
operation.
The original options from each one of the BDSs are kept, with the new
options passed to bdrv_reopen_queue() applied on top of them.
For "x-blockdev-reopen" we want a function that behaves much like
"blockdev-add". We want to ignore the previous set of options so that
only the ones actually specified by the user are applied, with the
rest having their default values.
One of the things that we need is a way to tell bdrv_reopen_queue()
whether we want to keep the old set of options or not, and that's what
this patch does. All current callers are setting this new parameter to
true and x-blockdev-reopen will set it to false.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Our permission system is useful to define what operations are allowed
on a certain block node and includes things like BLK_PERM_WRITE or
BLK_PERM_RESIZE among others.
One of the permissions is BLK_PERM_GRAPH_MOD which allows "changing
the node that this BdrvChild points to". The exact meaning of this has
never been very clear, but it can be understood as "change any of the
links connected to the node". This can be used to prevent changing a
backing link, but it's too coarse.
This patch adds a new 'frozen' attribute to BdrvChild, which forbids
detaching the link from the node it points to, and new API to freeze
and unfreeze a backing chain.
After this change a few functions can fail, so they need additional
checks.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The implementation used blocks units rather than the expected bytes.
Fixes: c03e7ef12a ("nvme: Implement Write Zeroes")
Reported-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Until now, with auto-read-only=on we tried to open the file read-write
first and if that failed, read-only was tried. This is actually not good
enough for libvirt, which gives QEMU SELinux permissions for read-write
only as soon as it actually intends to write to the image. So we need to
be able to switch between read-only and read-write at runtime.
This patch makes auto-read-only dynamic, i.e. the file is opened
read-only as long as no user of the node has requested write
permissions, but it is automatically reopened read-write as soon as the
first writer is attached. Conversely, if the last writer goes away, the
file is reopened read-only again.
bs->read_only is no longer set for auto-read-only=on files even if the
file descriptor is opened read-only because it will be transparently
upgraded as soon as a writer is attached. This changes the output of
qemu-iotests 232.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to be able to dynamically reopen the file read-only or
read-write, depending on the users that are attached, we need to be able
to switch to a different file descriptor during the permission change.
This interacts with reopen, which also creates a new file descriptor and
performs permission changes internally. In this case, the permission
change code must reuse the reopen file descriptor instead of creating a
third one.
In turn, reopen can drop its code to copy file locks to the new file
descriptor because that is now done when applying the new permissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There is no reason why we can take locks on the new file descriptor only
in raw_reopen_commit() where error handling isn't possible any more.
Instead, we can already do this in raw_reopen_prepare().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We'll want to access the file descriptor in the reopen_state while
processing permission changes in the context of the repoen.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Using a different read-only setting for bs->open_flags than for the
flags to the driver's open function is just inconsistent and a bad idea.
After this patch, the temporary snapshot keeps being opened read-only if
read-only=on,snapshot=on is passed.
If we wanted to change this behaviour to make only the orginal image
file read-only, but the temporary overlay read-write (as the comment in
the removed code suggests), that change would have to be made in
bdrv_temp_snapshot_options() (where the comment suggests otherwise).
Addressing this inconsistency before introducing dynamic auto-read-only
is important because otherwise we would immediately try to reopen the
temporary overlay even though the file is already unlinked.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The way that reopen interacts with permission changes has one big
problem: Both operations are recursive, and the permissions are changes
for each node in the reopen queue.
For a simple graph that consists just of parent and child,
.bdrv_check_perm will be called twice for the child, once recursively
when adjusting the permissions of parent, and once again when the child
itself is reopened.
Even worse, the first .bdrv_check_perm call happens before
.bdrv_reopen_prepare was called for the child and the second one is
called afterwards.
Making sure that .bdrv_check_perm (and the other permission callbacks)
are called only once is hard. We can cope with multiple calls right now,
but as soon as file-posix gets a dynamic auto-read-only that may need to
open a new file descriptor, we get the additional requirement that all
of them are after the .bdrv_reopen_prepare call.
So reorder things in bdrv_reopen_multiple() to first call
.bdrv_reopen_prepare for all involved nodes and only then adjust
permissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
tests/virtio-blk-test uses a temporary image file that it deletes while
QEMU is still running, so it can't be reopened when writers are
attached or detached. Disable auto-read-only to keep it always writable.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Drop x- and x_ prefixes for latency histograms and update version to
4.0
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Test that we can actually resize qcow2 images with persistent bitmaps
correctly. Throw some other goofy stuff at the test while we're at it,
like adding bitmaps of different granularities and at different times.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Eric Blake <eblake@redhat.com>
Message-id: 20190311185147.52309-5-vsementsov@virtuozzo.com
[vsmentsov: drop \n from the end of test output,
test output changed a bit: some bitmaps goes in other order
int the output]
Signed-off-by: John Snow <jsnow@redhat.com>
Since we now load all bitmaps into memory anyway, we can just truncate
them in-memory and then flush them back to disk. Just in case, we will
still check and enforce that this shortcut is valid -- i.e. that any
bitmap described on-disk is indeed in-memory and can be modified.
If there are any inconsistent bitmaps, we refuse to allow the truncate
as we do not actually load these bitmaps into memory, and it isn't safe
or reasonable to attempt to truncate corrupted data.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-4-vsementsov@virtuozzo.com
[vsementsov: drop bitmap flushing, fix block comments style]
Signed-off-by: John Snow <jsnow@redhat.com>
We are going to allow image resize when there are persistent bitmaps.
It may lead to appearing of inconsistent bitmaps (IN_USE=1) with
inconsistent size. But we still want to load them as inconsistent.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
While used by TCG it is not explicitly part of TCG and the tests can
be run standalone in a minimal build.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Pointer authentication isn't guaranteed to always detect a clash
between different keys. Take this into account in the test by running
several times and checking the percentage hit rate of the test.
Cc: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This introduces the build framework for simple i386 system tests. The
first test is the eponymous "Hello World" which simply outputs the
text on the serial port and then exits.
I've included the framework for x86_64 but it is not in this series as
it is a work in progress.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
We will likely want a few common functions to make up for the fact we
don't have a libc and we don't want to feel like we are programming by
banging rocks together.
I've purloined the printf function from:
https://git.virtualopensystems.com/dev/tcg_baremetal_tests
Although I have tweaked the names to avoid confusing GCC about clashing
with builtins.
Cc: Alexander Spyridakis <a.spyridakis@virtualopensystems.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This converts the existing Makefile into a Makefile.target and updates
it so it can be called by the tcg build system. The original Makefile
didn't set -cpu except for the v17 tests however that has broken (I
assume because linux-user is a "max" cpu) so here I force it to be
crisv17.
I've also replicated the GNU simulator targets (run-FOO-on-sim).
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Bare tests are standalone assembly tests that don't require linking to
any libc and hence can be built with kernel only compilers. The libc
tests need a compiler capable of building properly linked userspace
binaries. As we don't have such a cross compiler at the moment we
won't be building those tests.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
This is a mini library which provides helper functions to the tests
which are all currently written in assembly. A bunch of minor changes:
- removed libc related headers (fedora-cris-cross is a system compiler)
- re-organised the functions to avoid forward declarations
- cleaned up brace usage
- restored exit for _fail case
- removed tabs and fixed indentation
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
