diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2024-01-18 09:48:23 -0500 |
|---|---|---|
| committer | Michael Tokarev <mjt@tls.msk.ru> | 2024-01-26 19:31:37 +0300 |
| commit | 4b02c718b59104a3c69f1e5f5d6932961474442d (patch) | |
| tree | 320a67e145f19dc9e5c38a946786edaf8f5a115e /tests/qemu-iotests/127.out | |
| parent | 2f5e27eefa0d99ed9d0b8c9621e8c9f877b1d3cd (diff) | |
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>
Diffstat (limited to 'tests/qemu-iotests/127.out')
| -rw-r--r-- | tests/qemu-iotests/127.out | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tests/qemu-iotests/127.out b/tests/qemu-iotests/127.out index 1685c4850a..dd8c4a8aa9 100644 --- a/tests/qemu-iotests/127.out +++ b/tests/qemu-iotests/127.out @@ -28,6 +28,6 @@ wrote 42/42 bytes at offset 0 { 'execute': 'quit' } {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "concluded", "id": "mirror"}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "null", "id": "mirror"}} -{"return": {}} {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}} +{"return": {}} *** done |