diff options
author | Stefan Hajnoczi <stefanha@redhat.com> | 2024-01-18 09:48:23 -0500 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2024-01-26 11:16:58 +0100 |
commit | effd60c878176bcaf97fa7ce2b12d04bb8ead6f7 (patch) | |
tree | 5a3f0891deebbad4b00ba3f759b42cafbc4abb8b /tests/qemu-iotests/191.out | |
parent | 9ee2dd4c22a3639c5462b3fc20df60c005c3de64 (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>
Diffstat (limited to 'tests/qemu-iotests/191.out')
-rw-r--r-- | tests/qemu-iotests/191.out | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/tests/qemu-iotests/191.out b/tests/qemu-iotests/191.out index ea88777374..c3309e4bc6 100644 --- a/tests/qemu-iotests/191.out +++ b/tests/qemu-iotests/191.out @@ -379,10 +379,6 @@ wrote 65536/65536 bytes at offset 1048576 } { 'execute': 'quit' } { - "return": { - } -} -{ "timestamp": { "seconds": TIMESTAMP, "microseconds": TIMESTAMP @@ -393,6 +389,10 @@ wrote 65536/65536 bytes at offset 1048576 "reason": "host-qmp-quit" } } +{ + "return": { + } +} image: TEST_DIR/t.IMGFMT file format: IMGFMT virtual size: 64 MiB (67108864 bytes) @@ -797,10 +797,6 @@ wrote 65536/65536 bytes at offset 1048576 } { 'execute': 'quit' } { - "return": { - } -} -{ "timestamp": { "seconds": TIMESTAMP, "microseconds": TIMESTAMP @@ -811,6 +807,10 @@ wrote 65536/65536 bytes at offset 1048576 "reason": "host-qmp-quit" } } +{ + "return": { + } +} image: TEST_DIR/t.IMGFMT file format: IMGFMT virtual size: 64 MiB (67108864 bytes) |