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Re: [Qemu-devel] [PATCH RFC] dataplane: Fix startup race.
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH RFC] dataplane: Fix startup race. |
Date: |
Thu, 5 Sep 2013 15:58:54 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Wed, Sep 04, 2013 at 02:16:15PM +0200, Cornelia Huck wrote:
> Avoid trying to setup dataplane again if dataplane setup is already in
> progress. This may happen if an eventfd is triggered during setup.
>
> I saw this occasionally with an experimental s390 irqfd implementation:
>
> virtio_blk_handle_output
> -> virtio_blk_data_plane_start
> -> virtio_ccw_set_host_notifier
> ...
> -> virtio_queue_set_host_notifier_fd_handler
> -> virtio_queue_host_notifier_read
> -> virtio_queue_notify_vq
> -> virtio_blk_handle_output
> -> virtio_blk_data_plane_start
> -> vring_setup
> -> hostmem_init
> -> memory_listener_register
> -> BOOM
>
> As virtio-ccw tries to follow what virtio-pci does, it might be triggerable
> for other platforms as well.
>
> Signed-off-by: Cornelia Huck <address@hidden>
> ---
> hw/block/dataplane/virtio-blk.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block
Stefan