Commit Graph

108500 Commits

Author SHA1 Message Date
Fiona Ebner
c45d0e1af0 block/mirror: set actively_synced even after the job is ready
In preparation to allow switching from background to active mode. This
ensures that setting actively_synced will not be missed when the
switch happens after the job is ready.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-3-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 18:20:29 +01:00
Fiona Ebner
61a3a5a76a blockjob: introduce block-job-change QMP command
which will allow changing job-type-specific options after job
creation.

In the JobVerbTable, the same allow bits as for set-speed are used,
because set-speed can be considered an existing change command.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20231031135431.393137-2-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 18:20:25 +01:00
Stefan Hajnoczi
073458da56 virtio-blk: remove batch notification BH
There is a batching mechanism for virtio-blk Used Buffer Notifications
that is no longer needed because the previous commit added batching to
virtio_notify_irqfd().

Note that this mechanism was rarely used in practice because it is only
enabled when EVENT_IDX is not negotiated by the driver. Modern drivers
enable EVENT_IDX.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-5-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 15:42:17 +01:00
Stefan Hajnoczi
84d61e5f36 virtio: use defer_call() in virtio_irqfd_notify()
virtio-blk and virtio-scsi invoke virtio_irqfd_notify() to send Used
Buffer Notifications from an IOThread. This involves an eventfd
write(2) syscall. Calling this repeatedly when completing multiple I/O
requests in a row is wasteful.

Use the defer_call() API to batch together virtio_irqfd_notify() calls
made during thread pool (aio=threads), Linux AIO (aio=native), and
io_uring (aio=io_uring) completion processing.

Behavior is unchanged for emulated devices that do not use
defer_call_begin()/defer_call_end() since defer_call() immediately
invokes the callback when called outside a
defer_call_begin()/defer_call_end() region.

fio rw=randread bs=4k iodepth=64 numjobs=8 IOPS increases by ~9% with a
single IOThread and 8 vCPUs. iodepth=1 decreases by ~1% but this could
be noise. Detailed performance data and configuration specifics are
available here:
https://gitlab.com/stefanha/virt-playbooks/-/tree/blk_io_plug-irqfd

This duplicates the BH that virtio-blk uses for batching. The next
commit will remove it.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-4-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 15:42:14 +01:00
Stefan Hajnoczi
433fcea40c util/defer-call: move defer_call() to util/
The networking subsystem may wish to use defer_call(), so move the code
to util/ where it can be reused.

As a reminder of what defer_call() does:

This API defers a function call within a defer_call_begin()/defer_call_end()
section, allowing multiple calls to batch up. This is a performance
optimization that is used in the block layer to submit several I/O requests
at once instead of individually:

  defer_call_begin(); <-- start of section
  ...
  defer_call(my_func, my_obj); <-- deferred my_func(my_obj) call
  defer_call(my_func, my_obj); <-- another
  defer_call(my_func, my_obj); <-- another
  ...
  defer_call_end(); <-- end of section, my_func(my_obj) is called once

Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-3-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 15:41:42 +01:00
Stefan Hajnoczi
ccee48aa73 block: rename blk_io_plug_call() API to defer_call()
Prepare to move the blk_io_plug_call() API out of the block layer so
that other subsystems call use this deferred call mechanism. Rename it
to defer_call() but leave the code in block/plug.c.

The next commit will move the code out of the block layer.

Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230913200045.1024233-2-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 15:41:24 +01:00
Cong Liu
7f45276269 contrib/plugins: Close file descriptor on error return
This patch closes the file descriptor fd on error return to avoid
resource leak.

Fixes: ec7ee95db9 ("contrib/plugins: fix coverity warning in lockstep")
Signed-off-by: Cong Liu <liucong2@kylinos.cn>
Message-Id: <20231018025225.1640122-1-liucong2@kylinos.cn>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-20-alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Akihiko Odaki
946bf79e40 plugins: Remove an extra parameter
copy_call() has an unused parameter so remove it.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231019101030.128431-7-akihiko.odaki@daynix.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231029145033.592566-19-alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Matheus Tavares Bernardino
2eb71a0c20 semihosting: fix memleak at semihosting_arg_fallback
We duplicate "cmd" as strtok may modify its argument, but we forgot
to free it later. Furthermore, add_semihosting_arg doesn't take
responsibility for this memory either (it strdup's the argument).

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <03d81c56bfc3d08224e4106efca5949d8894cfa5.1697801632.git.quic_mathbern@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-18-alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Akihiko Odaki
dbd6623ce7 gdbstub: Check if gdb_regs is NULL
cpu->gdb_regs may be NULL if no coprocessor is registered.

Fixes: 73c392c26b ("gdbstub: Replace gdb_regs with an array")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20231029145033.592566-17-alex.bennee@linaro.org>
Message-Id: <20231019101030.128431-2-akihiko.odaki@daynix.com>
Tested-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Alex Bennée
aba77ac5db tests/docker: upgrade debian-all-test-cross to bookworm
This requires a few more tweaks than usual as:

  - the default sources format has changed
  - bring in python3-tomli from the repos
  - split base install from cross compilers
  - also include libclang-rt-dev for sanitiser builds

Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-16-alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Alex Bennée
7ccb4153fe tests/docker: use debian-all-test-cross for sparc64
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-15-alex.bennee@linaro.org>
2023-10-31 14:10:21 +00:00
Alex Bennée
26025d8e36 tests/docker: use debian-all-test-cross for riscv64
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-14-alex.bennee@linaro.org>
2023-10-31 14:10:14 +00:00
Alex Bennée
b09bb6d1b8 tests/docker: use debian-all-test-cross for mips
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-13-alex.bennee@linaro.org>
2023-10-31 14:10:14 +00:00
Alex Bennée
92a3165e1a tests/docker: use debian-all-test-cross for mips64
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-12-alex.bennee@linaro.org>
2023-10-31 14:10:14 +00:00
Alex Bennée
9d9a573612 tests/docker: use debian-all-test-cross for m68k
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-11-alex.bennee@linaro.org>
2023-10-31 14:10:14 +00:00
Alex Bennée
95f5bf9521 tests/docker: use debian-all-test-cross for hppa
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-10-alex.bennee@linaro.org>
2023-10-31 14:10:14 +00:00
Alex Bennée
eb4cb4ed1f tests/docker: use debian-all-test-cross for power
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-9-alex.bennee@linaro.org>
2023-10-31 14:10:06 +00:00
Alex Bennée
4e76d98ae9 tests/docker: move sh4 to use debian-legacy-test-cross
sh4 is another target which doesn't work with bookworm compilers. To
keep on buster move across to the debian-legacy-test-cross image and
update accordingly.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231030135715.800164-1-alex.bennee@linaro.org>
2023-10-31 13:28:34 +00:00
Alex Bennée
d004e27b4e tests/docker: use debian-legacy-test-cross for alpha
Maintaining two sets of containers for test building is silly. While
it makes sense for the QEMU cross-compile targets to have their own
fat containers built by lcitool we might as well merge the other
random debian based compilers into the same one used on gitlab.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-7-alex.bennee@linaro.org>
2023-10-31 13:28:30 +00:00
Alex Bennée
cb8715bf0c gitlab: add build-loongarch to matrix
We have the compiler and with a few updates a container that can build
QEMU so we should at least run the check-tcg smoke tests.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-6-alex.bennee@linaro.org>
2023-10-31 13:28:30 +00:00
Alex Bennée
6f6c399976 gitlab: clean-up build-soft-softmmu job
Having dropped alpha we also now drop xtensa as we don't have the
compiler in this image. It's not all doom and gloom though as a number
of other targets have gained softmmu TCG tests so we can add them. We
will take care of the other targets with their own containers in
future commits.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-5-alex.bennee@linaro.org>
2023-10-31 13:28:30 +00:00
Alex Bennée
aa39c4c098 gitlab: split alpha testing into a legacy container
The current bookworm compiler doesn't build the static binaries due to
bug #1054412 and it might be awhile before it gets fixed. The problem
of keeping older architecture compilers running isn't going to go away
so lets prepare the ground. Create a legacy container and move some
tests around so the others can get upgraded.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-4-alex.bennee@linaro.org>
2023-10-31 13:28:25 +00:00
Akihiko Odaki
580731dcc8 tests/tcg: Add -fno-stack-protector
A build of GCC 13.2 will have stack protector enabled by default if it
was configured with --enable-default-ssp option. For such a compiler,
it is necessary to explicitly disable stack protector when linking
without standard libraries.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230731091042.139159-3-akihiko.odaki@daynix.com>
[AJB: fix comment string typo]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-3-alex.bennee@linaro.org>
2023-10-31 13:28:19 +00:00
Thomas Huth
05c223cef7 tests/vm/openbsd: Use the system dtc package
We can use the pre-packaged libfdt from the dtc package to avoid
that we have to compile this code each time again and again.

While we're at it, the "--python=python3" does not seemt to be
necessary anymore, so we can drop it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20231016154049.37147-1-thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231029145033.592566-2-alex.bennee@linaro.org>
2023-10-31 13:28:13 +00:00
Fiona Ebner
302823854b blockdev: mirror: avoid potential deadlock when using iothread
The bdrv_getlength() function is a generated co-wrapper and uses
AIO_WAIT_WHILE() to wait for the spawned coroutine. AIO_WAIT_WHILE()
expects the lock to be acquired exactly once.

Fix a case where it may be acquired twice. This can happen when the
source node is explicitly specified as the @replaces parameter or if the
source node is a filter node.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231019131936.414246-4-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:36 +01:00
Fiona Ebner
e462c6d27d block: avoid potential deadlock during bdrv_graph_wrlock() in bdrv_close()
by passing the BlockDriverState along, so the held AioContext can be
dropped before polling. See commit 31b2ddfea3 ("graph-lock: Unlock the
AioContext while polling") which introduced this functionality for
more information.

The only way to reach bdrv_close() is via bdrv_unref() and for calling
that the BlockDriverState's AioContext lock is supposed to be held.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231019131936.414246-3-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:36 +01:00
Fiona Ebner
67446e605d blockjob: drop AioContext lock before calling bdrv_graph_wrlock()
Same rationale as in 31b2ddfea3 ("graph-lock: Unlock the AioContext
while polling"). Otherwise, a deadlock can happen.

The alternative would be to pass a BlockDriverState along to
bdrv_graph_wrlock(), but there is no BlockDriverState readily
available and it's also better conceptually, because the lock is held
for the job.

The function is always called with the job's AioContext lock held, via
one of the .abort, .clean, .free or .prepare job driver functions.
Thus, it's safe to drop it.

While mirror_exit_common() does hold a second AioContext lock while
calling block_job_remove_all_bdrv(), that is for the main thread's
AioContext and does not need to be dropped (bdrv_graph_wrlock(bs) also
skips dropping the lock if bdrv_get_aio_context(bs) ==
qemu_get_aio_context()).

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20231019131936.414246-2-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:36 +01:00
Kevin Wolf
3be5762294 iotests: Test media change with iothreads
iotests case 118 already tests all relevant operations for media change
with multiple devices, however never with iothreads. This changes the
test so that the virtio-scsi tests run with an iothread.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231013153302.39234-3-kwolf@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:33 +01:00
Kevin Wolf
fed8245015 block: Fix locking in media change monitor commands
blk_insert_bs() requires that the caller holds the AioContext lock for
the node to be inserted. Since commit c066e808e1, neglecting to do so
causes a crash when the child has to be moved to a different AioContext
to attach it to the BlockBackend.

This fixes qmp_blockdev_insert_anon_medium(), which is called for the
QMP commands 'blockdev-insert-medium' and 'blockdev-change-medium', to
correctly take the lock.

Cc: qemu-stable@nongnu.org
Fixes: https://issues.redhat.com/browse/RHEL-3922
Fixes: c066e808e1
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231013153302.39234-2-kwolf@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
87fe52ceca iotests: add tests for "qemu-img rebase" with compression
The test cases considered so far:

314 (new test suite):

1. Check that compression mode isn't compatible with "-f raw" (raw
   format doesn't support compression).
2. Check that rebasing an image onto no backing file preserves the data
   and writes the copied clusters actually compressed.
3. Same as 2, but with a raw backing file (i.e. the clusters copied from the
   backing are originally uncompressed -- we check they end up compressed
   after being merged).
4. Remove a single delta from a backing chain, perform the same checks
   as in 2.
5. Check that even when backing and overlay are initially uncompressed,
   copied clusters end up compressed when rebase with compression is
   performed.

271:

1. Check that when target image has subclusters, rebase with compression
   will make an entire cluster containing the written subcluster
   compressed.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-9-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
26ea27898b qemu-img: add compression option to rebase subcommand
If we rebase an image whose backing file has compressed clusters, we
might end up wasting disk space since the copied clusters are now
uncompressed.  In order to have better control over this, let's add
"--compress" option to the "qemu-img rebase" command.

Note that this option affects only the clusters which are actually being
copied from the original backing file.  The clusters which were
uncompressed in the target image will remain so.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-8-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
f93e65ee51 iotests/{024, 271}: add testcases for qemu-img rebase
As the previous commit changes the logic of "qemu-img rebase" (it's using
write alignment now), let's add a couple more test cases which would
ensure it works correctly.  In particular, the following scenarios:

024: add test case for rebase within one backing chain when the overlay
     cluster size > backings cluster size;
271: add test case for rebase images that contain subclusters.  Check
     that no extra allocations are being made.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-7-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
12df580b3b qemu-img: rebase: avoid unnecessary COW operations
When rebasing an image from one backing file to another, we need to
compare data from old and new backings.  If the diff between that data
happens to be unaligned to the target cluster size, we might end up
doing partial writes, which would lead to copy-on-write and additional IO.

Consider the following simple case (virtual_size == cluster_size == 64K):

base <-- inc1 <-- inc2

qemu-io -c "write -P 0xaa 0 32K" base.qcow2
qemu-io -c "write -P 0xcc 32K 32K" base.qcow2
qemu-io -c "write -P 0xbb 0 32K" inc1.qcow2
qemu-io -c "write -P 0xcc 32K 32K" inc1.qcow2
qemu-img rebase -f qcow2 -b base.qcow2 -F qcow2 inc2.qcow2

While doing rebase, we'll write a half of the cluster to inc2, and block
layer will have to read the 2nd half of the same cluster from the base image
inc1 while doing this write operation, although the whole cluster is already
read earlier to perform data comparison.

In order to avoid these unnecessary IO cycles, let's make sure every
write request is aligned to the overlay subcluster boundaries.  Using
subcluster size is universal as for the images which don't have them
this size equals to the cluster size. so in any case we end up aligning
to the smallest unit of allocation.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Message-ID: <20230919165804.439110-6-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
c20c8ae700 qemu-img: add chunk size parameter to compare_buffers()
Add @chsize param to the function which, if non-zero, would represent
the chunk size to be used for comparison.  If it's zero, then
BDRV_SECTOR_SIZE is used as default chunk size, which is the previous
behaviour.

In particular, we're going to use this param in img_rebase() to make the
write requests aligned to a predefined alignment value.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-5-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
ce8b8f9fe7 qemu-img: rebase: use backing files' BlockBackend for buffer alignment
Since commit bb1c05973c ("qemu-img: Use qemu_blockalign"), buffers for
the data read from the old and new backing files are aligned using
BlockDriverState (or BlockBackend later on) referring to the target image.
However, this isn't quite right, because buf_new is only being used for
reading from the new backing, while buf_old is being used for both reading
from the old backing and writing to the target.  Let's take that into account
and use more appropriate values as alignments.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Message-ID: <20230919165804.439110-4-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
827171c318 qemu-iotests: 024: add rebasing test case for overlay_size > backing_size
Before previous commit, rebase was getting infitely stuck in case of
rebasing within the same backing chain and when overlay_size > backing_size.
Let's add this case to the rebasing test 024 to make sure it doesn't
break again.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-3-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:28 +01:00
Andrey Drobyshev
8b097fd6b0 qemu-img: rebase: stop when reaching EOF of old backing file
In case when we're rebasing within one backing chain, and when target image
is larger than old backing file, bdrv_is_allocated_above() ends up setting
*pnum = 0.  As a result, target offset isn't getting incremented, and we
get stuck in an infinite for loop.  Let's detect this case and proceed
further down the loop body, as the offsets beyond the old backing size need
to be explicitly zeroed.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20230919165804.439110-2-andrey.drobyshev@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-31 13:51:27 +01:00
Juan Quintela
be07a0ed22 qemu-file: Make qemu_fflush() return errors
This let us simplify code of this shape.

   qemu_fflush(f);
   int ret = qemu_file_get_error(f);
   if (ret) {
      return ret;
   }

into:

   int ret = qemu_fflush(f);
   if (ret) {
      return ret;
   }

I updated all callers where there is any error check.
qemu_fclose() don't need to check for f->last_error because
qemu_fflush() returns it at the beggining of the function.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Message-ID: <20231025091117.6342-13-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
0f8596180a migration: Remove transferred atomic counter
After last commit, it is a write only variable.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-12-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
897fd8bdce migration: Use migration_transferred_bytes()
There are only two differnces with the old value:

- the amount of QEMUFile that hasn't yet been flushed.  It can be
  discussed what is more exact, the new or the old one.
- the amount of transferred bytes that we forgot to account for (the
  newer is better, i.e. exact).

Notice that this two values are used to:
a - present to the user
b - calculate the rate_limit

So a few KB here and there is not going to make a difference.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-11-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
fc55cf318a qemu-file: Simplify qemu_file_get_error()
If we pass a NULL error is the same that returning directly the value.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-10-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
0743f41fd2 migration: migration_rate_limit_reset() don't need the QEMUFile
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-9-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
f57e5a6ce5 migration: migration_transferred_bytes() don't need the QEMUFile
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-8-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
e9c0eed7c2 qemu-file: Remove _noflush from qemu_file_transferred_noflush()
qemu_file_transferred() don't exist anymore, so we can reuse the name.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Message-ID: <20231025091117.6342-7-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
e833cad7e7 qemu_file: Remove unused qemu_file_transferred()
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-6-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
737840e2c6 migration: Use the number of transferred bytes directly
We only use migration_transferred_bytes() to calculate the rate_limit,
for that we don't need to flush whatever is on the qemu_file buffer.
Remember that the buffer is really small (normal case is 32K if we use
iov's can be 64 * TARGET_PAGE_SIZE), so this is not relevant to
calculations.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-5-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
5e2652185b qemu_file: total_transferred is not used anymore
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-4-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
2d897237e0 qemu_file: Use a stat64 for qemu_file_transferred
This way we can read it from any thread.
I checked that it gives the same value as the current one.  We never
use two qemu_files at the same time.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-3-quintela@redhat.com>
2023-10-31 08:44:33 +01:00
Juan Quintela
cc8bf57d56 qemu-file: Don't increment qemu_file_transferred at qemu_file_fill_buffer
We only call qemu_file_transferred_* on the sending side. Remove the
increment at qemu_file_fill_buffer() and add asserts to
qemu_file_transferred* functions.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231025091117.6342-2-quintela@redhat.com>
2023-10-31 08:44:33 +01:00