monitor: only run coroutine commands in qemu_aio_context

monitor_qmp_dispatcher_co() runs in the iohandler AioContext that is not
polled during nested event loops. The coroutine currently reschedule

monitor: only run coroutine commands in qemu_aio_context

monitor_qmp_dispatcher_co() runs in the iohandler AioContext that is not
polled during nested event loops. The coroutine currently reschedules
itself in the main loop's qemu_aio_context AioContext, which is polled
during nested event loops. One known problem is that QMP device-add
calls drain_call_rcu(), which temporarily drops the BQL, leading to all
sorts of havoc like other vCPU threads re-entering device emulation code
while another vCPU thread is waiting in device emulation code with
aio_poll().

Paolo Bonzini suggested running non-coroutine QMP handlers in the
iohandler AioContext. This avoids trouble with nested event loops. His
original idea was to move coroutine rescheduling to
monitor_qmp_dispatch(), but I resorted to moving it to qmp_dispatch()
because we don't know if the QMP handler needs to run in coroutine
context in monitor_qmp_dispatch(). monitor_qmp_dispatch() would have
been nicer since it's associated with the monitor implementation and not
as general as qmp_dispatch(), which is also used by qemu-ga.

A number of qemu-iotests need updated .out files because the order of
QMP events vs QMP responses has changed.

Solves Issue #1933.

Cc: qemu-stable@nongnu.org
Fixes: 7bed89958bfbf40df9ca681cefbdca63abdde39d ("device_core: use drain_call_rcu in in qmp_device_add")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2215192
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2214985
Buglink: https://issues.redhat.com/browse/RHEL-17369
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20240118144823.1497953-4-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit effd60c878176bcaf97fa7ce2b12d04bb8ead6f7)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

show more ...

Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- virtio-blk: Multiqueue fixes and cleanups
- blklogwrites: Fixes for write_zeroes and superblock update r

Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- virtio-blk: Multiqueue fixes and cleanups
- blklogwrites: Fixes for write_zeroes and superblock update races
- commit/stream: Allow users to request only format driver names in
backing file format
- monitor: only run coroutine commands in qemu_aio_context
- Some iotest fixes

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# gpg: Signature made Fri 26 Jan 2024 12:26:20 GMT
# gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg: issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6

* tag 'for-upstream' of https://repo.or.cz/qemu/kevin:
iotests/277: Use iotests.sock_dir for socket creation
iotests/iothreads-stream: Use the right TimeoutError
tests/unit: Bump test-replication timeout to 60 seconds
iotests/264: Use iotests.sock_dir for socket creation
block/blklogwrites: Protect mutable driver state with a mutex.
virtio-blk: always set ioeventfd during startup
virtio-blk: tolerate failure to set BlockBackend AioContext
virtio-blk: restart s->rq reqs in vq AioContexts
virtio-blk: rename dataplane to ioeventfd
virtio-blk: rename dataplane create/destroy functions
virtio-blk: move dataplane code into virtio-blk.c
monitor: only run coroutine commands in qemu_aio_context
iotests: port 141 to Python for reliable QMP testing
iotests: add filter_qmp_generated_node_ids()
stream: Allow users to request only format driver names in backing file format
commit: Allow users to request only format driver names in backing file format
string-output-visitor: Fix (pseudo) struct handling
block/blklogwrites: Fix a bug when logging "write zeroes" operations.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

monitor: only run coroutine commands in qemu_aio_context

monitor_qmp_dispatcher_co() runs in the iohandler AioContext that is not
polled during nested event loops. The coroutine currently reschedule

monitor: only run coroutine commands in qemu_aio_context

monitor_qmp_dispatcher_co() runs in the iohandler AioContext that is not
polled during nested event loops. The coroutine currently reschedules
itself in the main loop's qemu_aio_context AioContext, which is polled
during nested event loops. One known problem is that QMP device-add
calls drain_call_rcu(), which temporarily drops the BQL, leading to all
sorts of havoc like other vCPU threads re-entering device emulation code
while another vCPU thread is waiting in device emulation code with
aio_poll().

Paolo Bonzini suggested running non-coroutine QMP handlers in the
iohandler AioContext. This avoids trouble with nested event loops. His
original idea was to move coroutine rescheduling to
monitor_qmp_dispatch(), but I resorted to moving it to qmp_dispatch()
because we don't know if the QMP handler needs to run in coroutine
context in monitor_qmp_dispatch(). monitor_qmp_dispatch() would have
been nicer since it's associated with the monitor implementation and not
as general as qmp_dispatch(), which is also used by qemu-ga.

A number of qemu-iotests need updated .out files because the order of
QMP events vs QMP responses has changed.

Solves Issue #1933.

Cc: qemu-stable@nongnu.org
Fixes: 7bed89958bfbf40df9ca681cefbdca63abdde39d ("device_core: use drain_call_rcu in in qmp_device_add")
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2215192
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2214985
Buglink: https://issues.redhat.com/browse/RHEL-17369
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20240118144823.1497953-4-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

Merge tag 'pull-block-2022-04-20' of https://gitlab.com/hreitz/qemu into staging

Block patches:
- Some changes for qcow2's refcount repair algorithm to make it work for
qcow2 images stored on bloc

Merge tag 'pull-block-2022-04-20' of https://gitlab.com/hreitz/qemu into staging

Block patches:
- Some changes for qcow2's refcount repair algorithm to make it work for
qcow2 images stored on block devices
- Skip test cases that require zstd when support for it is missing
- Some refactoring in the iotests' meson.build

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# gpg: Signature made Wed 20 Apr 2022 05:33:47 AM PDT
# gpg: using RSA key CB62D7A0EE3829E45F004D34A1FA40D098019CDF
# gpg: issuer "hreitz@redhat.com"
# gpg: Good signature from "Hanna Reitz <hreitz@redhat.com>" [undefined]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: CB62 D7A0 EE38 29E4 5F00 4D34 A1FA 40D0 9801 9CDF

* tag 'pull-block-2022-04-20' of https://gitlab.com/hreitz/qemu:
qcow2: Add errp to rebuild_refcount_structure()
iotests/108: Test new refcount rebuild algorithm
qcow2: Improve refcount structure rebuilding
iotests/303: Check for zstd support
iotests/065: Check for zstd support
iotests.py: Add supports_qcow2_zstd_compression()
tests/qemu-iotests: Move the bash and sanitizer checks to meson.build
tests/qemu-iotests/meson.build: Improve the indentation

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

show more ...

iotests/108: Test new refcount rebuild algorithm

One clear problem with how qcow2's refcount structure rebuild algorithm
used to be before "qcow2: Improve refcount structure rebuilding" was
that it

iotests/108: Test new refcount rebuild algorithm

One clear problem with how qcow2's refcount structure rebuild algorithm
used to be before "qcow2: Improve refcount structure rebuilding" was
that it is prone to failure for qcow2 images on block devices: There is
generally unused space after the actual image, and if that exceeds what
one refblock covers, the old algorithm would invariably write the
reftable past the block device's end, which cannot work. The new
algorithm does not have this problem.

Test it with three tests:
(1) Create an image with more empty space at the end than what one
refblock covers, see whether rebuilding the refcount structures
results in a change in the image file length. (It should not.)

(2) Leave precisely enough space somewhere at the beginning of the image
for the new reftable (and the refblock for that place), see whether
the new algorithm puts the reftable there. (It should.)

(3) Test the original problem: Create (something like) a block device
with a fixed size, then create a qcow2 image in there, write some
data, and then have qemu-img check rebuild the refcount structures.
Before HEAD^, the reftable would have been written past the image
file end, i.e. outside of what the block device provides, which
cannot work. HEAD^ should have fixed that.
("Something like a block device" means a loop device if we can use
one ("sudo -n losetup" works), or a FUSE block export with
growable=false otherwise.)

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220405134652.19278-3-hreitz@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Fri 12 Dec 2014 17:09:56 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan H

Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Fri 12 Dec 2014 17:09:56 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/block-pull-request:
linux-aio: simplify removal of completed iocbs from the list
linux-aio: drop return code from laio_io_unplug and ioq_submit
linux-aio: rename LaioQueue idx field to "n"
linux-aio: track whether the queue is blocked
linux-aio: queue requests that cannot be submitted
block: drop unused bdrv_clear_incoming_migration_all() prototype
block: Don't add trailing space in "Formating..." message
qemu-iotests: Remove traling whitespaces in *.out
block: vhdx - set .bdrv_has_zero_init to bdrv_has_zero_init_1
iotests: Fix test 039
iotests: Filter for "Killed" in qemu-io output
qemu-io: Add sigraise command
block: vhdx - change .vhdx_create default block state to ZERO
block: vhdx - update PAYLOAD_BLOCK_UNMAPPED value to match 1.00 spec
block: vhdx - remove redundant comments
block/rbd: fix memory leak
iotests: Add test for vmdk JSON file names
vmdk: Fix error for JSON descriptor file names
block migration: fix return value

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qemu-iotests: Remove traling whitespaces in *.out

This is simply:

$ cd tests/qemu-iotests; sed -i -e 's/ *$//' *.out

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@re

qemu-iotests: Remove traling whitespaces in *.out

This is simply:

$ cd tests/qemu-iotests; sed -i -e 's/ *$//' *.out

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418110684-19528-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

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

Block patches

# gpg: Signature made Thu 23 Oct 2014 18:56:05 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Ke

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

Block patches

# gpg: Signature made Thu 23 Oct 2014 18:56:05 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (32 commits)
qemu-img: Print error if check failed
block: char devices on FreeBSD are not behind a pager
iotests: Add test for qcow2 L1 table update
qcow2: Do not overflow when writing an L1 sector
iotests: Add test for map commands
qemu-io: Respect early image end for map
block: Respect underlying file's EOF
docs/qcow2: Limit refcount_order to [0, 6]
docs/qcow2: Correct refcount_block_entries
qcow2: Drop REFCOUNT_SHIFT
iotests: Add test for potentially damaging repairs
iotests: Fix test outputs
qcow2: Clean up after refcount rebuild
qcow2: Rebuild refcount structure during check
qcow2: Do not perform potentially damaging repairs
qcow2: Fix refcount blocks beyond image end
qcow2: Reuse refcount table in calculate_refcounts()
qcow2: Let inc_refcounts() resize the reftable
qcow2: Let inc_refcounts() return -errno
qcow2: Split fail code in L1 and L2 checks
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

iotests: Add test for potentially damaging repairs

There are certain cases where repairing a qcow2 image might actually
damage it further (or rather, where repairing it has in fact damaged it
furthe

iotests: Add test for potentially damaging repairs

There are certain cases where repairing a qcow2 image might actually
damage it further (or rather, where repairing it has in fact damaged it
further with the old qcow2 check implementation). This should not
happen, so add a test for these cases.

Furthermore, the repair function now repairs refblocks beyond the image
end by resizing the image accordingly. Add several tests for this as
well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...