From: Sergio Lopez <slp@redhat.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, Sergio Lopez <slp@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Max Reitz <mreitz@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: [PATCH 0/2] virtio-blk: Avoid processing requests on the main context on restart
Date: Wed, 3 Jun 2020 11:32:38 +0200 [thread overview]
Message-ID: <20200603093240.40489-1-slp@redhat.com> (raw)
On restart, we were scheduling a BH to process queued requests, which
would run before starting up the data plane, leading to those requests
being assigned and started on coroutines on the main context.
This could cause requests to be wrongly processed in parallel from
different threads (the main thread and the iothread managing the data
plane), potentially leading to multiple issues.
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1812765
See "virtio-blk: Disable request queuing while switching contexts" for
previous discussion:
- https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00304.html
Sergio Lopez (2):
virtio-blk: Refactor the code that processes queued requests
virtio-blk: On restart, process queued requests in the proper context
include/hw/virtio/virtio-blk.h | 1 +
hw/block/dataplane/virtio-blk.c | 8 ++++++++
hw/block/virtio-blk.c | 30 +++++++++++++++++++++---------
3 files changed, 30 insertions(+), 9 deletions(-)
--
2.26.2
next reply other threads:[~2020-06-03 9:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 9:32 Sergio Lopez [this message]
2020-06-03 9:32 ` [PATCH 1/2] virtio-blk: Refactor the code that processes queued requests Sergio Lopez
2020-06-03 9:32 ` [PATCH 2/2] virtio-blk: On restart, process queued requests in the proper context Sergio Lopez
2020-06-03 14:14 ` [PATCH 0/2] virtio-blk: Avoid processing requests on the main context on restart Kevin Wolf
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