Commit Graph

157 Commits

Author SHA1 Message Date
Thomas Lamprecht
20209d8d73 implement support for backup fleecing
Excerpt from Fiona's v3 cover-letter [0]:

When a backup for a VM is started, QEMU will install a
"copy-before-write" filter in its block layer. This filter ensures
that upon new guest writes, old data still needed for the backup is
sent to the backup target first. The guest write blocks until this
operation is finished so guest IO to not-yet-backed-up sectors will be
limited by the speed of the backup target.

With backup fleecing, such old data is cached in a fleecing image
rather than sent directly to the backup target. This can help guest IO
performance and even prevent hangs in certain scenarios, at the cost
of requiring more storage space.

With this series it will be possible to enable backup-fleecing via
e.g. `vzdump 123 --fleecing enabled=1,storage=local-lvm` with fleecing
images created on the storage `local-lvm`. The fleecing storage should
be a fast local storage which supports thin-provisioning and discard.
If the storage supports qcow2, that is used as the fleecing image
format. If the underlying file system does not support discard, with
qcow2 and preallocation=off, at least already allocated parts of the
image can be re-used later.

Fleecing images are created by qemu-server via pve-storage and
attached to QEMU before the backup starts, and cleaned up after the
backup finished or failed. The naming schema for fleecing images is
'vm-ID-fleece-N(.FORMAT)'. The allocated images are recorded in the
guest configuration, so that even after a hard failure, clean-up can
be re-attempted. While not too bad, it's a non-trivial amount of code
and I'm not 100% sure about the cost-benefit, so sending those as RFC.

The fleecing image needs to be the exact same size as the source, but
luckily, an explicit size can be specified when attaching a raw image
to QEMU so there are no size issues when using storages that have
coarser allocation/round up. For qcow2, it seems that virtual size can
be nearly arbitrary (i.e. modulo 512 byte granularity) during
allocation.

[0]: https://lists.proxmox.com/pipermail/pve-devel/2024-April/062815.html

Originally-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2024-04-11 20:05:02 +02:00
Thomas Lamprecht
8dd76cc52d backup: factor out & clean up gathering device info into helper
Squash the two original patches [0][1] from Fiona, which got send
separate to be easier to review, into the big patch that adds the
Proxmox backup integration.

[0]: https://lists.proxmox.com/pipermail/pve-devel/2024-January/061479.html
[1]: https://lists.proxmox.com/pipermail/pve-devel/2024-January/061478.html

Originally-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2024-03-12 13:55:00 +01:00
Fiona Ebner
cd7676f3e6 backup: avoid bubbling up first ECANCELED error
With pvebackup_propagate_error(), the first error wins. When one job
in the transaction fails, it is expected that later jobs get the
ECANCELED error. Those are not interesting and by skipping them a more
interesting error, which is likely the actual root cause, can win.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-03-12 13:20:28 +01:00
Fiona Ebner
862b46e3e0 cleanup: squash backup dump driver change into patch introducing the driver
Makes it simpler and shorter. Still results in the same code after
applying both patches in question.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-03-12 13:19:30 +01:00
Fiona Ebner
061e9ceb36 fix patch for accepting NULL qiov when padding
All callers of the function pass an address, so dereferencing once
before checking for NULL is required. It's also necessary to update
bytes and offset nevertheless, so the request will actually be aligned
later and not trigger an assertion failure.

Seems like this was accidentally broken in 8dca018 ("udpate and rebase
to QEMU v6.0.0") and this is effectively a revert to the original
version of the patch. The qiov functions changed back then, which
might've been the reason Stefan tried to simplify the patch.

Should fix live-import for certain kinds of VMDK images.

Reported-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-03-12 13:11:21 +01:00
Fiona Ebner
86460aef76 fix #4507: add patch to automatically increase NOFILE soft limit
In many configurations, e.g. multiple vNICs with multiple queues or
with many Ceph OSDs, the default soft limit of 1024 is not enough.
QEMU is supposed to work fine with file descriptors >= 1024 and does
not use select() on POSIX. Bump the soft limit to the allowed hard
limit to avoid issues with the aforementioned configurations.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-02-06 10:33:12 +01:00
Fiona Ebner
4b7975e75d update submodule and patches to QEMU 8.1.5
Most notable fixes from a Proxmox VE perspective are:

* "virtio-net: correctly copy vnet header when flushing TX"
  To prevent a stack overflow that could lead to leaking parts of the
  QEMU process's memory.
* "hw/pflash: implement update buffer for block writes"
  To prevent an edge case for half-completed writes. This potentially
  affected EFI disks.
* Fixes to i386 emulation and ARM emulation.

No changes for patches were necessary (all are just automatic context
changes).

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-02-02 19:06:29 +01:00
Fiona Ebner
2a49e667ba Revert "add patch to work around stuck guest IO with iothread and VirtIO block/SCSI"
This reverts commit 6b7c1815e1.

The attempted fix has been reported to cause high CPU usage after
backup [0]. Not difficult to reproduce and it's iothreads getting
stuck in a loop. Downgrading to pve-qemu-kvm=8.1.2-4 helps which was
also verified by Christian, thanks! The issue this was supposed to fix
is much rarer, so revert for now, while upstream is still working on a
proper fix.

[0]: https://forum.proxmox.com/threads/138140/

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-12-15 14:16:26 +01:00
Fiona Ebner
dfac4f3593 pick fix for potential deadlock with QMP resize and iothread
While the patch gives bdrv_graph_wrlock() as an example where the
issue can manifest, something similar can happen even when that is
disabled. Was able to reproduce the issue with
while true; do qm resize 115 scsi0 +4M; sleep 1; done
while running
fio --name=make-mirror-work --size=100M --direct=1 --rw=randwrite \
 --bs=4k --ioengine=psync --numjobs=5 --runtime=1200 --time_based
in the VM.

Fix picked up from:
https://lists.nongnu.org/archive/html/qemu-devel/2023-12/msg01102.html

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-12-11 16:56:50 +01:00
Fiona Ebner
6b7c1815e1 add patch to work around stuck guest IO with iothread and VirtIO block/SCSI
When using iothread, after commits
1665d9326f ("virtio-blk: implement BlockDevOps->drained_begin()")
766aa2de0f ("virtio-scsi: implement BlockDevOps->drained_begin()")
it can happen that polling gets stuck when draining. This would cause
IO in the guest to get completely stuck.

A workaround for users is stopping and resuming the vCPUs because that
would also stop and resume the dataplanes which would kick the host
notifiers.

This can happen with block jobs like backup and drive mirror as well
as with hotplug [2].

Reports in the community forum that might be about this issue[0][1]
and there is also one in the enterprise support channel.

As a workaround in the code, just re-enable notifications and kick the
virt queue after draining. Draining is already costly and rare, so no
need to worry about a performance penalty here. This was taken from
the following comment of a QEMU developer [3] (in my debugging,
I had already found re-enabling notification to work around the issue,
but also kicking the queue is more complete).

[0]: https://forum.proxmox.com/threads/137286/
[1]: https://forum.proxmox.com/threads/137536/
[2]: https://issues.redhat.com/browse/RHEL-3934
[3]: https://issues.redhat.com/browse/RHEL-3934?focusedId=23562096&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-23562096

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-12-11 16:56:50 +01:00
Fiona Ebner
763949965f fix #4710: vma create: don't use O_DIRECT for tmpfs
The implementation of the helper is_path_tmpfs() is similar to the
existing qemu_fd_getfs() function in util/mmap-alloc.c, which
unfortunately only takes an existing fd.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-11-07 16:37:34 +01:00
Fiona Ebner
10e1093325 update submodule and patches to QEMU 8.1.2
Bigger notable changes:

* Commit 1a30b0f5d7 ("block: .bdrv_open is non-coroutine and
  unlocked") broke the PVE backup patches, in particular setting up
  the backup dump block driver, because bdrv_new_open_driver() cannot
  be called from a coroutine. To fix it, bdrv_co_open() is used
  instead, and while it's a much more involved function, the result
  should be essentially the same. The only difference I noticed is
  that the BDRV_O_ALLOW_RDWR flag is also set in the resulting bds
  (block driver state), but that shouldn't hurt.

Smaller notable changes:

* aio_set_fd_handler() dropped its 'is_external' parameter stating
  that all callers now pass false in 60f782b6b7 ("aio: remove
  aio_disable_external() API"). The calls in the PVE patches also
  passed false, so just drop the parameter too.

* global_state_store() does not have a return value anymore, so the
  user in the PVE savevm-async patch was adapted. For context, see
  c33f1829f8 ("migration: never fail in global_state_store()").

* Renames affecting the PVE savevm-async patch:
  migrate_use_block() -> migrate_block() and ram_counters -> mig_stats
  9d4b1e5f22 ("migration: Move migrate_use_block() to options.c")
  aff3f6606d ("migration: Rename ram_counters to mig_stats")

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2023-10-24 15:01:23 +02:00
Fiona Ebner
ef3308db71 vma: avoid compiler warning about incompatible pointer type
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-09-08 11:18:30 +02:00
Filip Schauer
0ff45eb23e backup: Fix spelling error in function name
Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
[FE: fixup patch context]
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-09-08 11:13:04 +02:00
Fiona Ebner
9e0186f289 backup: drop broken BACKUP_FORMAT_DIR
Since upstream QEMU 8.0, it's no longer possible to call
bdrv_img_create() from a coroutine anymore, meaning a backup with the
directory format would crash the QEMU instance.

The feature is only exposed via the monitor and was intended to be
experimental. There were no user reports about the breakage and it
only was noticed during the rebase for QEMU 8.1, because other parts
of the backup code needed adaptation and I decided to check the
BACKUP_FORMAT_DIR case too.

It should not stay in a broken state of course, but avoid the
maintenance cost and just make it a removed feature for Proxmox VE 8
retroactively.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-09-06 16:59:12 +02:00
Fiona Ebner
0cffb504e7 backup: create jobs in a drained section
With the drive-backup QMP command, upstream QEMU uses a drained
section for the source drive when creating the backup job. Do the same
here to avoid subtle bugs.

There, the drained section extends until after the job is started, but
this cannot be done here for multi-disk backups (could at most start
the first job). The important thing is that the cbw
(copy-before-write) node is in place and the bcs (block-copy-state)
bitmap is initialized, which both happen during job creation (ensured
by the "block/backup: move bcs bitmap initialization to job creation"
PVE patch).

One such bug is one reported in the community forum [0], where using a
drive with iothread can lead to an overlapping block-copy request and
consequently an assertion failure. The block-copy code relies on the
bcs bitmap to determine if a request for a certain range can be
created. Each time a request is created, it resets the bcs bitmap at
that range to indicate that it's being handled.

The duplicate request can happen as follows:
Thread A attaches the cbw node
Thread B creates a request and resets the bitmap at that range
Thread A clears the bitmap and merges it with the PBS bitmap
The merging can lead to the bitmap being set again at the range of
the previous request, so the block-copy code thinks it's fine to
create a request there.
Thread B creates another requests at an overlapping range before the
other request is finished.

The drained section ensures that nothing else can interfere with the
bcs bitmap between attaching the copy-before-write block node and
initialization of the bitmap.

[0]: https://forum.proxmox.com/threads/133149/

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-09-06 16:59:12 +02:00
Fiona Ebner
f7eed6caa1 regenerate patch stats
Apparently wasn't correct in 0cff91a ("fix #1534: vma: Add extract
filter for disk images").

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-09-06 16:59:12 +02:00
Filip Schauer
0cff91a000 fix #1534: vma: Add extract filter for disk images
Add a filter to the "vma extract" command. A comma seperated list of
disk images that should be extracted can be passed with the "-d" option.

Example to extract an IDE drive and an SCSI drive from vzdump.vma:

vma extract vzdump.vma -d "drive-ide0,drive-scsi0" extractdir

Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
2023-08-30 10:40:51 +02:00
Fiona Ebner
5f9cb29c3a backup: trim heap after finishing
Reported in the community forum [0]. By default, there can be large
amounts of memory left assigned to the QEMU process after backup.
Likely because of fragmentation, it's necessary to explicitly call
malloc_trim() to tell glibc that it shouldn't keep all that memory
resident for the process.

QEMU itself already does a malloc_trim() in the RCU thread, but that
code path might not be reached (or not for a long time) under usual
operation. The value of 4 MiB for the argument was also copied from
there.

Example with the following configuration:
> agent: 1
> boot: order=scsi0
> cores: 4
> cpu: x86-64-v2-AES
> ide2: none,media=cdrom
> memory: 1024
> name: backup-mem
> net0: virtio=DA:58:18:26:59:9F,bridge=vmbr0,firewall=1
> numa: 0
> ostype: l26
> scsi0: rbd:base-107-disk-0/vm-106-disk-1,size=4302M
> scsihw: virtio-scsi-pci
> smbios1: uuid=b2d4511e-8d01-44f1-afd6-9581b30c24a6
> sockets: 2
> startup: order=2
> virtio0: lvmthin:vm-106-disk-1,iothread=1,size=1G
> virtio1: lvmthin:vm-106-disk-2,iothread=1,size=1G
> virtio2: lvmthin:vm-106-disk-3,iothread=1,size=1G
> vmgenid: 0a1d8751-5e02-449d-977e-c0160e900231

Before the change:

> root@pve8a1 ~ # grep VmRSS /proc/$(cat /var/run/qemu-server/106.pid)/status
> VmRSS:	  370948 kB
> root@pve8a1 ~ # vzdump 106 --storage pbs
> (...)
> INFO: Backup job finished successfully
> root@pve8a1 ~ # grep VmRSS /proc/$(cat /var/run/qemu-server/106.pid)/status
> VmRSS:	 2114964 kB

After the change:

> root@pve8a1 ~ # grep VmRSS /proc/$(cat /var/run/qemu-server/106.pid)/status
> VmRSS:	  398788 kB
> root@pve8a1 ~ # vzdump 106 --storage pbs
> (...)
> INFO: Backup job finished successfully
> root@pve8a1 ~ # grep VmRSS /proc/$(cat /var/run/qemu-server/106.pid)/status
> VmRSS:	  424356 kB

[0]: https://forum.proxmox.com/threads/131339/

Co-diagnosed-by: Friedrich Weber <f.weber@proxmox.com>
Co-diagnosed-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Acked-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2023-08-16 11:50:12 +02:00
Fiona Ebner
c36e3f9d17 refresh patch context
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Acked-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2023-08-16 11:50:08 +02:00
Filip Schauer
b8b4ce0480 Add format attributes to function candidates
Add format attributes to functions that take printf-like arguments. This
provides additional compile-time checking that the correct parameters
are passed to the functions.

This fixes compiler warnings generated by the -Wsuggest-attribute=format
flag.

Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
2023-08-08 09:08:48 +02:00
Fiona Ebner
5919ec1446 add patch fixing resume for snapshot and hibernate with drive with iothread and a dirty bitmap
Not difficult to run into, just have a drive with iothread, take a PBS
backup and then take a snapshot or hibernate. Resuming will fail with
> qemu: qemu_mutex_unlock_impl: Operation not permitted
because of not acquiring the correct AioContext first.

Migration is not affected, because it runs in coroutine context.

Reported in the community forum:
https://forum.proxmox.com/threads/129899/

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-07-28 12:00:50 +02:00
Fiona Ebner
ea7662074d fix checks for drive mirror with bitmap
The QAPI change for QEMU 8.0 dropped redundant has_foo parameters, but
in the blockdev_mirror_common() function (which is not part of the
QAPI itself but called from there) the argument pair was has_bitmap
and bitmap_name rather than has_bitmap and bitmap.

Reported-by: Aaron Lauterer <a.lauterer@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-06-15 13:55:22 +02:00
Fiona Ebner
d847446186 regenerate patches
There's still some context changes not covered by earlier series. No
functional change intended.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-06-15 13:55:22 +02:00
Fiona Ebner
99f9ce2cd2 drop deprecated custom drive snapshot QMP commands
They are not required anymore since qemu-server >= 5.0-36.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-06-07 19:35:53 +02:00
Fiona Ebner
a816d2969e drop patch for custom get_link_status QMP command
There doesn't seem to be any Proxmox VE code using this.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-06-07 19:35:40 +02:00
Fiona Ebner
db5d2a4b77 squash related patches
where there is no good reason to keep them separate. It's a pain
during rebase if there are multiple patches changing the same code
over and over again. This was especially bad for the backup-related
patches. If the history of patches really is needed, it can be
extracted via git. Additionally, compilation with partial application
of patches was broken since a long time, because one of the master key
changes became part of an earlier patch during a past rebase.

If only the same files were changed by a subsequent patch and the
changes felt to belong together (obvious for later bug fixes, but also
done for features e.g. adding master key support for PBS), the patches
were squashed together.

The PBS namespace support patch was split into the individual parts
it changes, i.e. PBS block driver, pbs-restore binary and QMP backup
infrastructure, and squashed into the respective patches.

No code change is intended, git diff in the submodule should not show
any difference between applying all patches before this commit and
applying all patches after this commit.

The query-proxmox-support QMP function has been left as part of the
"PVE-Backup: Proxmox backup patches for QEMU" patch, because it's
currently only used there. If it ever is used elsewhere too, it can
be split out from there.

The recent alloc-track and BQL-related savevm-async changes have been
left separate for now, because it's not 100% clear they are the best
approach yet. This depends on what upstream decides about the BQL
stuff and whether and what kind of issues with the changes pop up.

The qemu-img dd snapshot patch has been re-ordered to after the other
qemu-img dd patches.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00
Fiona Ebner
b64c4dec1c PVE backup: don't call no_co_wrapper function from coroutine
Namely, pvebackup_co_prepare() needs to call bdrv_co_open() rather
than bdrv_open(), because it is a coroutine itself.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00
Fiona Ebner
53b56ca781 add stable patches for 8.0.0
Changes to other patches are all just metadata/context changes except
for pvebackup_co_prepare() needing to call bdrv_co_unref() rather than
bdrv_unref(), because it is a coroutine itself. This is documented in
d6ee2e324e ("block-coroutine-wrapper: Introduce no_co_wrapper"). The
change is necessary, because one of the stable fixes converts
bdrv_unref and blk_unref into no_co_wrappers (in preparation for a
second patch to fix a hang with the block resize QMP command).

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00
Fiona Ebner
bf251437e9 update submodule and patches to QEMU 8.0.0
Many changes were necessary this time around:

* QAPI was changed to avoid redundant has_* variables, see commit
44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C")
for details. This affected many QMP commands added by Proxmox too.

* Pending querying for migration got split into two functions, one to
estimate, one for exact value, see commit c8df4a7aef ("migration:
Split save_live_pending() into state_pending_*") for details. Relevant
for savevm-async and PBS dirty bitmap.

* Some block (driver) functions got converted to coroutines, so the
Proxmox block drivers needed to be adapted.

* Alloc track auto-detaching during PBS live restore got broken by
AioContext-related changes resulting in a deadlock. The current, hacky
method was replaced by a simpler one. Stefan apparently ran into a
problem with that when he wrote the driver, but there were
improvements in the stream job code since then and I didn't manage to
reproduce the issue. It's a separate patch "alloc-track: fix deadlock
during drop" for now, you can find the details there.

* Async snapshot-related changes:
  - The pending querying got adapted to the above-mentioned split and
  a patch is added to optimize it/make it more similar to what
  upstream code does.
  - Added initialization of the compression counters (for
    future-proofing).
  - It's necessary the hold the BQL (big QEMU lock = iothread mutex)
  during the setup phase, because block layer functions are used there
  and not doing so leads to racy, hard-to-debug crashes or hangs. It's
  necessary to change some upstream code too for this, a version of
  the patch "migration: for snapshots, hold the BQL during setup
  callbacks" is intended to be upstreamed.
  - Need to take the bdrv graph read lock before flushing.

* hmp_info_balloon was moved to a different file.

* Needed to include a new headers from time to time to still get the
correct functions.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00
Fiona Ebner
1688b43738 QMP backup: use correct errno when getting blockdrive length fails
di->size would only be set later. The errno is minus the return value
from the function.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-02-21 09:19:16 +01:00
Fiona Ebner
eee064d954 savevm-async: keep more free space when entering final stage
In qemu-server, we already allocate 2 * $mem_size + 500 MiB for driver
state (which was 32 MiB long ago according to git history). It seems
likely that the 30 MiB cutoff in the savevm-async implementation was
chosen based on that.

In bug #4476 [0], another issue caused the iteration to not make any
progress and the state file filled up all the way to the 30 MiB +
pending_size cutoff. Since the guest is not stopped immediately after
the check, it can still dirty some RAM and the current cutoff is not
enough for a reproducer VM (was done while bug #4476 still was not
fixed), dirtying memory with
> stress-ng -B 2 --bigheap-growth 64.0M'
After entering the final stage, savevm actually filled up the state
file completely, leading to an I/O error. It's probably the same
scenario as reported in the bug report, the error message was fixed in
commit a020815 ("savevm-async: fix function name in error message")
after the bug report.

If not for the bug, the cutoff will only be reached by a VM that's
dirtying RAM faster than can be written to the storage, so increase
the cutoff to 100 MiB to have a bigger chance to finish successfully,
while still trying to not increase downtime too much for
non-hibernation snapshots.

[0]: https://bugzilla.proxmox.com/show_bug.cgi?id=4476

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-02-21 08:39:08 +01:00
Fiona Ebner
8051a24b5f fix #4476: savevm-async: avoid looping without progress
when pend_postcopy is large. By definition, pend_postcopy won't
decrease when iterating, so a value larger than the cutoff of 400000
would lead to essentially empty iterations, filling up the state file
until only 30 MiB + pending_size remain and the second half of the
check would trigger.

Avoid this, by not considering pend_postcopy for the cutoff to enter
the final phase.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-02-21 08:39:08 +01:00
Fiona Ebner
a02081501a savevm-async: fix function name in error message
which also makes it distinguishable from the other
"qemu_savevm_state_iterate error" message.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-01-24 17:08:54 +01:00
Fiona Ebner
271ac0a8a7 add QAPI naming exceptions in patches introducing them
Avoids a patch and is required to compile when not all patches are
applied. No functional change is intended.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-01-10 15:42:16 +01:00
Fiona Ebner
d03e1b3ce3 update submodule and patches to 7.2.0
User-facing breaking change:

The slirp submodule for user networking got removed. It would be
necessary to add the --enable-slirp option to the build and/or install
the appropriate library to continue building it. Since PVE is not
explicitly supporting it, it would require additionally installing the
libslirp0 package on all installations and there is *very* little
mention on the community forum when searching for "slirp" or
"netdev user", the plan is to only enable it again if there is some
real demand for it.

Notable changes:

* The big change for this release is the rework of job locking, using
  a job mutex and introducing _locked() variants of job API functions
  moving away from call-side AioContext locking. See (in the qemu
  submodule) commit 6f592e5aca ("job.c: enable job lock/unlock and
  remove Aiocontext locks") and previous commits for context.

  Changes required for the backup patches:
  * Use WITH_JOB_LOCK_GUARD() and call the _locked() variant of job
    API functions where appropriate (many are only availalbe as
    a _locked() variant).
  * Remove acquiring/releasing AioContext around functions taking the
    job mutex lock internally.

  The patch introducing sequential transaction support for jobs needs
  to temporarily unlock the job mutex to call job_start() when
  starting the next job in the transaction.

* The zeroinit block driver now marks its child as primary.

  The documentation in include/block/block-common.h states:
  > Filter node has exactly one FILTERED|PRIMARY child, and may have
  > other children which must not have these bits

  Without this, an assert will trigger when copying to a zeroinit target
  with qemu-img convert, because bdrv_child_cb_attach() expects any
  non-PRIMARY child to be not FILTERED:
  > qemu-img convert -n -p -f raw -O raw input.raw zeroinit:output.raw
  > qemu-img: ../block.c:1476: bdrv_child_cb_attach: Assertion
  > `!(child->role & BDRV_CHILD_FILTERED)' failed.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-12-16 11:47:20 +01:00
Fiona Ebner
0af826b448 savevm async IO channel: channel writev: fix return value in error case
The documentation in include/io/channel.h states that -1 or
QIO_CHANNEL_ERR_BLOCK should be returned upon error. Simply passing
along the return value from the blk-functions has the potential to
confuse the call sides. Non-blocking mode is not implemented
currently, so -1 it is.

The "return ret" was mistakenly left over from the previous
QEMUFileOps based implementation. Also, use error_setg_errno(), since
the blk(_co)_p{readv,writev} functions return errno codes.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-18 15:32:13 +02:00
Fiona Ebner
4e1935c2c9 {alloc track, pbs} block driver: bdrv_co_preadv: adapt return values
to be in-line with what other implementations in QEMU do. Commit
1d39c7098bbfa6862cb96066c4f8f6735ea397c5 mentions the EIO bit and
the function is expected to return 0 upon success (see other
implementations).

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 14:52:36 +02:00
Fiona Ebner
a262e9642b savevm async: cleaner initialization of target_close_wait member
Suggested-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 14:52:34 +02:00
Fiona Ebner
5b15e2ecaf update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
  savevm-async, because the previously used QEMUFileOps was dropped.

  Changes to the current implementation:

  * Switch to vector based methods as required for an IO channel. For
    short reads the passed-in IO vector is stuffed with zeroes at the
    end, just to be sure.

  * For reading: The documentation in include/io/channel.h states that
    at least one byte should be read, so also error out when whe are
    at the very end instead of returning 0.

  * For reading: Fix off-by-one error when request goes beyond end.

    The wrong code piece was:
    if ((pos + size) > maxlen) {
        size = maxlen - pos - 1;
    }

    Previously, the last byte would not be read. It's actually
    possible to get a snapshot .raw file that has content all the way
    up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
    trailing zero bytes (I wrote a script to do it).

    Luckily, it didn't cause a real issue, because qemu_loadvm_state()
    is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
    section. The buffer for reading it is simply freed up afterwards
    and the function will assume that it read the whole section, even
    if that's not the case.

  * For writing: Make use of the generated blk_pwritev() wrapper
    instead of manually wrapping the coroutine to simplify and save a
    few lines.

* Adapt to changed interfaces for blk_{pread,pwrite}:
  * a9262f551e ("block: Change blk_{pread,pwrite}() param order")
  * 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
  * bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
  Those changes especially affected the qemu-img dd patches, because
  the context also changed, but also some of our block drivers used
  the functions.

* Drop qemu-common.h include: it got renamed after essentially
  everything was moved to other headers. The only remaining user I
  could find for things dropped from the header between 7.0 and 7.1
  was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
  already includes the header to which the function was moved.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 14:52:29 +02:00
Wolfgang Bumiller
ed01236593 add patch: PVE Backup: allow passing max-workers performance setting
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2022-10-10 11:55:15 +02:00
Fiona Ebner
1976ca4607 savevm-async: set SAVE_STATE_DONE when closing state file was successful
Without this change, it's necessary to send a second savevm-end QMP
command after aborting a snaphsot, before a new savevm-start QMP
command can succeed.

In process_savevm_finalize(), no longer set an error in the abort
scenario. If there already is another error, there's no need to
override it. If canceling was done intentionally, qmp_savevm_end()
is responsible for setting the state now.

Reported-by: Mira Limbeck <m.limbeck@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-08-19 09:44:16 +02:00
Fiona Ebner
563c592898 savevm-async: avoid segfault when aborting snapshot
Reported in the community forum[0].

For 6.1.0, there were a few changes to the coroutine-sleep API, but
the adaptations in f376b2b ("update and rebase to QEMU v6.1.0") made
a mistake.

Currently, target_close_wait is NULL when passed to
qemu_co_sleep_ns_wakeable(), which further passes it to
qemu_co_sleep(), but there, it is dereferenced when trying to access
the 'to_wake' member:

> Thread 1 "kvm" received signal SIGSEGV, Segmentation fault.
> qemu_co_sleep (w=0x0) at ../util/qemu-coroutine-sleep.c:57

To fix it, create a proper struct and pass its address instead. Also
call qemu_co_sleep_wake unconditionally, because the NULL check (for
the 'to_wake' member) is done inside the function itself.

This patch is based on what the QEMU commits introducing the changes
to the coroutine-sleep API did to the callers in QEMU:
eaee072085 ("coroutine-sleep: allow qemu_co_sleep_wake that wakes nothing")
29a6ea24eb ("coroutine-sleep: replace QemuCoSleepState pointer with struct in the API")

[0]: https://forum.proxmox.com/threads/112130/

Tested-by: Mira Limbeck <m.limbeck@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-08-19 09:44:14 +02:00
Fabian Ebner
dc9827a6a4 update submodule and patches to 7.0.0
Only very minor changes needed:
* Most patches in extra (or some version of them) are part of 7.0.0.
* aio_set_fd_handler got an extra parameter, but can just pass NULL
  like we did for the related 'poll' parameter. See QEMU commit
  826cc32423db2a99d184dbf4f507c737d7e7a4ae for more.
* Add include for qemu/memalign.h in vma.c and vma-writer.c.
* Add reverts for fixups of already reverted 0347a8fd4c ("block/rbd:
  implement bdrv_co_block_status") that came in with 7.0.0. Those
  fixups are not enough, see Proxmox bugzilla #4047.
* Two trivial context changes for bitmap-mirror patches.
* block_int.h got split up into multiple headers.
* Some context changes in configure and meson.build.
* Used the oppurtunity to squash fixup of bdrv_backuo_dump_create typo
  in a later patch into the patch introducing the function (had to
  move code to new header during rebase).

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2022-06-29 12:29:21 +02:00
Thomas Lamprecht
39e84ba82d vma/alloc-track improvements
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2022-06-22 15:52:16 +02:00
Thomas Lamprecht
4fd0fa7fb3 re-export patches in normalized form
iow. using:

git format-patch --zero-commit --no-signature --no-numbered --diff-algorithm=myers ...

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2022-06-22 15:49:53 +02:00
Dominik Csapak
539e333eaa add 'namespace' to BlockdevOptionsPbs
so that we can use it for the -blockdev options (used for live-restore)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
2022-06-22 15:10:49 +02:00
Fabian Ebner
7bd4d8645a fix #4101: acquire job's aio context before calling job_unref
Otherwise, we might run into an abort via bdrv_co_yield_to_drain()
(can at least happen when a disk with iothread is used):
> #0  0x00007fef4f5dece1 __GI_raise (libc.so.6 + 0x3bce1)
> #1  0x00007fef4f5c8537 __GI_abort (libc.so.6 + 0x25537)
> #2  0x00005641bce3c71f error_exit (qemu-system-x86_64 + 0x80371f)
> #3  0x00005641bce3d02b qemu_mutex_unlock_impl (qemu-system-x86_64 + 0x80402b)
> #4  0x00005641bcd51655 bdrv_co_yield_to_drain (qemu-system-x86_64 + 0x718655)
> #5  0x00005641bcd52de8 bdrv_do_drained_begin (qemu-system-x86_64 + 0x719de8)
> #6  0x00005641bcd47e07 blk_drain (qemu-system-x86_64 + 0x70ee07)
> #7  0x00005641bcd498cd blk_unref (qemu-system-x86_64 + 0x7108cd)
> #8  0x00005641bcd31e6f block_job_free (qemu-system-x86_64 + 0x6f8e6f)
> #9  0x00005641bcd32d65 job_unref (qemu-system-x86_64 + 0x6f9d65)
> #10 0x00005641bcd93b3d pvebackup_co_complete_stream (qemu-system-x86_64 + 0x75ab3d)
> #11 0x00005641bce4e353 coroutine_trampoline (qemu-system-x86_64 + 0x815353)

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Acked-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2022-06-09 14:57:28 +02:00
Wolfgang Bumiller
7f4326d1dc pbs cleanup fixes
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
2022-06-08 13:10:51 +02:00
Fabian Ebner
dc265df350 add revert to work around performance regression when backing up large RBD disk
resulting in QMP timeouts and very slow backups. The plan is to figure
out (ideally together with upstream) a way to make the implementation
of bdrv_co_block_status for RBD more efficient. But for now, revert
the problematic change as a stop-gap measure.

Upstream bug report:
https://gitlab.com/qemu-project/qemu/-/issues/1026

Forum threads:
https://forum.proxmox.com/threads/109272/
https://forum.proxmox.com/threads/109448/
https://forum.proxmox.com/threads/101334/ (partially)

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
2022-05-19 09:23:38 +02:00