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

# -----BEGIN PGP SIGNATURE-----
#
# iQJFBAABCAAvFiEE3D3rFZqa+V09dFb+fwmycsiPL9YFAmWzpOwRHGt3b2xmQHJl
# ZGhhdC5jb20ACgkQfwmycsiPL9ZNzg//W1+C7HxLft4Jc4O1BcOoOLlGCg4Esupt
# z0/XLZ9+xVQUtjQ82pFzf9XaWQs8CuNT3FBUKi+ngdwZ0JBThIv0aGiMZBcAeQjD
# qshPFgDM1lGL4ICIaT73/qfUzQgO3oruZj9F+ShBBzoasNWVoRzqqVDR3pinLwTp
# D4TU+3A6LkdhlYGT60SYfRq/UKNmCA1s2wysdjqXxS6KOEURNF2VBnz0Nu76qrVb
# 3P/a55GPiJIn+VVsdQ0J4vyyzn23m7I7WZOJ7Sjm1EfSJ6SvcDbhWsZTUonaV2rU
# qZ3WI/jggqxXRV8F2AaA4suS/Cc8RkX2KfcN8fB6wDC2eI5USSatjh6xfw5xH9Ll
# NRKUO4vFFR3Lf8wN9apg0Bwxqi0GOm9kvBJT5QqjQ16R1dvqBLqbZqcx6ZXqWFXe
# /Iy243Tz19mWTFVUj0EgCKQpNz9F4SyXxV83HtSR1lJ5mhthnLxkvUOe7jsFPE4d
# 1Z3uBNWnx2mKFkhlwocMTKayYqxPuKQ+YjqrRoplLW1GZoBeoalKRGf8/RHa6kQx
# gh4cguihlb71AH1AO1QuYpiZt9G4RJR2RZlIoCPJY5TaKJedcxMVn8H+8/F0PnQd
# gPysZf7hTU1xCUV6TClDd+f2fuvqZYwXdwHJ9iiohNkbFq4HFQUp4nk4/eEPGSe/
# uv8oE813E30=
# =KQJl
# -----END PGP SIGNATURE-----
# 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 remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-12-18' into staging

Block patches:
- New block filter: preallocate (which, on writes beyond an image file's
end, allocates big c

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-12-18' into staging

Block patches:
- New block filter: preallocate (which, on writes beyond an image file's
end, allocates big chunks of data so that such post-EOF writes will
occur less frequently)
- write-zeroes and block-status support for Quorum
- Implementation of truncate for the nvme block driver similarly to the
existing implementations for host block devices and iscsi devices
- Block layer refactoring: Drop the tighten_restrictions concept in the
block permission functions
- iotest fixes

# gpg: Signature made Fri 18 Dec 2020 14:45:30 GMT
# gpg: using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg: issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1 1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-12-18: (30 commits)
iotests: Fix _send_qemu_cmd with bash 5.1
iotests/102: Pass $QEMU_HANDLE to _send_qemu_cmd
block/nvme: Implement fake truncate() coroutine
quorum: Implement bdrv_co_pwrite_zeroes()
quorum: Implement bdrv_co_block_status()
scripts/simplebench: add bench_prealloc.py
simplebench/results_to_text: make executable
simplebench/results_to_text: add difference line to the table
simplebench/results_to_text: improve view of the table
simplebench: move results_to_text() into separate file
simplebench: rename ascii() to results_to_text()
scripts/simplebench: use standard deviation for +- error
scripts/simplebench: support iops
scripts/simplebench: fix grammar: s/successed/succeeded/
iotests: add 298 to test new preallocate filter driver
iotests.py: execute_setup_common(): add required_fmts argument
iotests: qemu_io_silent: support --image-opts
qemu-io: add preallocate mode parameter for truncate command
block: introduce preallocate filter
block: bdrv_check_perm(): process children anyway
...

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

show more ...

iotests: Fix _send_qemu_cmd with bash 5.1

With bash 5.1, the output of the following script changes:

a=("double space")
a=${a[@]:0:1}
echo "$a"

from "double space" to "double space", i.e.

iotests: Fix _send_qemu_cmd with bash 5.1

With bash 5.1, the output of the following script changes:

a=("double space")
a=${a[@]:0:1}
echo "$a"

from "double space" to "double space", i.e. all white space is
preserved as-is. This is probably what we actually want here (judging
from the "...to accommodate pathnames with spaces" comment), but before
5.1, we would have to quote the ${} slice to get the same behavior.

In any case, without quoting, the reference output of many iotests is
different between bash 5.1 and pre-5.1, which is not very good. The
output of 5.1 is what we want, so whatever we do to get pre-5.1 to the
same result, it means we have to fix the reference output of basically
all tests that invoke _send_qemu_cmd (except the ones that only use
single spaces in the commands they invoke).

Instead of quoting the ${} slice (cmd="${$@: 1:...}"), we can also just
not use array slicing and replace the whole thing with a simple "cmd=$1;
shift", which works because all callers quote the whole $cmd argument
anyway.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201217153803.101231-3-mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-11-19' into staging

nbd patches for 2019-11-19

- iotests: more tests of NBD reconnect, various test output improvements
- nbd: fix spe

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-11-19' into staging

nbd patches for 2019-11-19

- iotests: more tests of NBD reconnect, various test output improvements
- nbd: fix spec compliance issue with long strings
- slience a Coverity warning on coroutines

# gpg: Signature made Tue 19 Nov 2019 03:06:41 GMT
# gpg: using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg: aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg: aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2 F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-11-19:
tests: More iotest 223 improvements
iotests: Include QMP input in .out files
iotests: Switch nbd tests to use Unix rather than TCP
iotests: Fix 173
MAINTAINERS: add more bitmap-related to Dirty Bitmaps section
nbd: Don't send oversize strings
bitmap: Enforce maximum bitmap name length
nbd/server: Prefer heap over stack for parsing client names
qemu-coroutine-sleep: Silence Coverity warning
iotests: Test NBD client reconnection

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

show more ...

iotests: Include QMP input in .out files

We generally include relevant HMP input in .out files, by virtue of
the fact that HMP echoes its input. But QMP does not, so we have to
explicitly inject it

iotests: Include QMP input in .out files

We generally include relevant HMP input in .out files, by virtue of
the fact that HMP echoes its input. But QMP does not, so we have to
explicitly inject it in the output stream (appropriately filtered to
keep the tests passing), in order to make it easier to read .out files
to see what behavior is being tested (especially true where the output
file is a sequence of {'return': {}}).

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20191114213415.23499-4-eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2018-12-18' into staging

QAPI patches for 2018-12-18

# gpg: Signature made Tue 18 Dec 2018 07:20:11 GMT
# gpg: using RSA k

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2018-12-18' into staging

QAPI patches for 2018-12-18

# gpg: Signature made Tue 18 Dec 2018 07:20:11 GMT
# gpg: using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2018-12-18:
qapi: fix flat union on uncovered branches conditionals
qmp hmp: Make system_wakeup check wake-up support and run state
qga: update guest-suspend-ram and guest-suspend-hybrid descriptions
qmp: query-current-machine with wakeup-suspend-support
qmp: Split ShutdownCause host-qmp into quit and system-reset
qmp: Add reason to SHUTDOWN and RESET events
qapi: Turn ShutdownCause into QAPI enum

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

show more ...

qmp: Split ShutdownCause host-qmp into quit and system-reset

It is interesting to know whether the shutdown cause was 'quit' or
'reset', especially when using "--no-reboot". In that case, a manageme

qmp: Split ShutdownCause host-qmp into quit and system-reset

It is interesting to know whether the shutdown cause was 'quit' or
'reset', especially when using "--no-reboot". In that case, a management
layer can now determine if the guest wanted a reboot or shutdown, and
can act accordingly.

Changes the output of the reason in the iotests from 'host-qmp' to
'host-qmp-quit'. This does not break compatibility because
the field was introduced in the same version.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-4-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qmp: Add reason to SHUTDOWN and RESET events

This makes it possible to determine what the exact reason was for
a RESET or a SHUTDOWN. A management layer might need the specific reason
of those event

qmp: Add reason to SHUTDOWN and RESET events

This makes it possible to determine what the exact reason was for
a RESET or a SHUTDOWN. A management layer might need the specific reason
of those events to determine which cleanups or other actions it needs to do.

This patch also updates the iotests to the new expected output that includes
the reason.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-3-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'armbru/tags/pull-qapi-2017-05-23' into staging

QAPI patches for 2017-05-23

# gpg: Signature made Tue 23 May 2017 12:33:32 PM BST
# gpg: using RSA key 0x

Merge remote-tracking branch 'armbru/tags/pull-qapi-2017-05-23' into staging

QAPI patches for 2017-05-23

# gpg: Signature made Tue 23 May 2017 12:33:32 PM BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* armbru/tags/pull-qapi-2017-05-23:
qapi-schema: Remove obsolete note from ObjectTypeInfo
block: Use QDict helpers for --force-share
shutdown: Expose bool cause in SHUTDOWN and RESET events
shutdown: Add source information to SHUTDOWN and RESET
shutdown: Preserve shutdown cause through replay
shutdown: Prepare for use of an enum in reset/shutdown_request
shutdown: Simplify shutdown_signal
sockets: Plug memory leak in socket_address_flatten()
scripts/qmp/qom-set: fix the value argument passed to srv.command()

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

shutdown: Expose bool cause in SHUTDOWN and RESET events

Libvirt would like to be able to distinguish between a SHUTDOWN
event triggered solely by guest request and one triggered by a
SIGTERM or oth

shutdown: Expose bool cause in SHUTDOWN and RESET events

Libvirt would like to be able to distinguish between a SHUTDOWN
event triggered solely by guest request and one triggered by a
SIGTERM or other action on the host. While qemu_kill_report() was
already able to give different output to stderr based on whether a
shutdown was triggered by a host signal (but NOT by a host UI event,
such as clicking the X on the window), that information was then
lost to management. The previous patches improved things to use an
enum throughout all callsites, so now we have something ready to
expose through QMP.

Note that for now, the decision was to expose ONLY a boolean,
rather than promoting ShutdownCause to a QAPI enum; this is because
libvirt has not expressed an interest in anything finer-grained.
We can still add additional details, in a backwards-compatible
manner, if a need later arises (if the addition happens before 2.10,
we can replace the bool with an enum; otherwise, the enum will have
to be in addition to the bool); this patch merely adds a helper
shutdown_caused_by_guest() to map the internal enum into the
external boolean.

Update expected iotest outputs to match the new data (complete
coverage of the affected tests is obtained by -raw, -qcow2, and -nbd).

Here is output from 'virsh qemu-monitor-event --loop' with the
patch installed:

event SHUTDOWN at 1492639680.731251 for domain fedora_13: {"guest":true}
event STOP at 1492639680.732116 for domain fedora_13: <null>
event SHUTDOWN at 1492639680.732830 for domain fedora_13: {"guest":false}

Note that libvirt runs qemu with -no-shutdown: the first SHUTDOWN event
was triggered by an action I took directly in the guest (shutdown -h),
at which point qemu stops the vcpus and waits for libvirt to do any
final cleanups; the second SHUTDOWN event is the result of libvirt
sending SIGTERM now that it has completed cleanup. Libvirt is already
smart enough to only feed the first qemu SHUTDOWN event to the end user
(remember, virsh qemu-monitor-event is a low-level debugging interface
that is explicitly unsupported by libvirt, so it sees things that normal
end users do not); changing qemu to emit SHUTDOWN only once is outside
the scope of this series.

See also https://bugzilla.redhat.com/1384007

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170515214114.15442-6-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-for-peter-2016-02-02' into staging

Block patches

# gpg: Signature made Tue 02 Feb 2016 17:23:44 GMT using RSA key ID E838ACAD
# gpg: G

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-for-peter-2016-02-02' into staging

Block patches

# gpg: Signature made Tue 02 Feb 2016 17:23:44 GMT using RSA key ID E838ACAD
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"

* remotes/maxreitz/tags/pull-block-for-peter-2016-02-02: (50 commits)
block: qemu-iotests - add test for snapshot, commit, snapshot bug
block: set device_list.tqe_prev to NULL on BDS removal
iotests: Add "qemu-img map" test for VMDK extents
qemu-img: Make MapEntry a QAPI struct
qemu-img: In "map", use the returned "file" from bdrv_get_block_status
block: Use returned *file in bdrv_co_get_block_status
vmdk: Return extent's file in bdrv_get_block_status
vmdk: Fix calculation of block status's offset
vpc: Assign bs->file->bs to file in vpc_co_get_block_status
vdi: Assign bs->file->bs to file in vdi_co_get_block_status
sheepdog: Assign bs to file in sd_co_get_block_status
qed: Assign bs->file->bs to file in bdrv_qed_co_get_block_status
parallels: Assign bs->file->bs to file in parallels_co_get_block_status
iscsi: Assign bs to file in iscsi_co_get_block_status
raw: Assign bs to file in raw_co_get_block_status
qcow2: Assign bs->file->bs to file in qcow2_co_get_block_status
qcow: Assign bs->file->bs to file in qcow_co_get_block_status
block: Add "file" output parameter to block status query functions
block: acquire in bdrv_query_image_info
iotests: Add test for block jobs and BDS ejection
...

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

show more ...

iotests: Add test for multiple BB on BDS tree

This adds a test for having multiple BlockBackends in one BDS tree. In
this case, there is one BB for the protocol BDS and one BB for the
format BDS in

iotests: Add test for multiple BB on BDS tree

This adds a test for having multiple BlockBackends in one BDS tree. In
this case, there is one BB for the protocol BDS and one BB for the
format BDS in a simple two-BDS tree (with the protocol BDS and BB added
first).

When bdrv_close_all() is executed, no cached data from any BDS should be
lost; the protocol BDS may not be closed until the format BDS is closed.
Otherwise, metadata updates may be lost.

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

show more ...