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[0/2] virtio-scsi: fix hotplug ->reset() vs event race

Message ID 20180710155037.16834-1-stefanha@redhat.com
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Series virtio-scsi: fix hotplug ->reset() vs event race | expand

Message

Stefan Hajnoczi July 10, 2018, 3:50 p.m. UTC 
The virtio-scsi command virtqueues run during hotplug.  This creates the
possibility of race conditions since the guest can submit commands while the
monitor is performing hotplug.

See Patch 2 for a fix for the ->reset() vs event race condition that Zhengui Li
encountered.

Zhengui Li: Sorry it took me so long to look into this.  Please let me know if
this fixes the issue you are seeing.  Thanks!

Stefan Hajnoczi (2):
  qdev: add HotplugHandler->post_plug() callback
  virtio-scsi: fix hotplug ->reset() vs event race

 include/hw/hotplug.h  | 12 ++++++++++++
 hw/core/hotplug.c     | 11 +++++++++++
 hw/core/qdev.c        |  7 +++++++
 hw/scsi/virtio-scsi.c | 11 ++++++++++-
 4 files changed, 40 insertions(+), 1 deletion(-)

Comments

Fam Zheng July 11, 2018, 1:43 a.m. UTC | #1 
On Tue, 07/10 16:50, Stefan Hajnoczi wrote:
> The virtio-scsi command virtqueues run during hotplug.  This creates the
> possibility of race conditions since the guest can submit commands while the
> monitor is performing hotplug.
> 
> See Patch 2 for a fix for the ->reset() vs event race condition that Zhengui Li
> encountered.
> 
> Zhengui Li: Sorry it took me so long to look into this.  Please let me know if
> this fixes the issue you are seeing.  Thanks!
> 
> Stefan Hajnoczi (2):
>   qdev: add HotplugHandler->post_plug() callback
>   virtio-scsi: fix hotplug ->reset() vs event race
> 
>  include/hw/hotplug.h  | 12 ++++++++++++
>  hw/core/hotplug.c     | 11 +++++++++++
>  hw/core/qdev.c        |  7 +++++++
>  hw/scsi/virtio-scsi.c | 11 ++++++++++-
>  4 files changed, 40 insertions(+), 1 deletion(-)
> 
> -- 
> 2.17.1

Reviewed-by: Fam Zheng <famz@redhat.com>
Zhengui li July 11, 2018, 3:13 a.m. UTC | #2 
Ok, I will test your patch soon.


On 2018/7/10 23:50, Stefan Hajnoczi wrote:
> The virtio-scsi command virtqueues run during hotplug.  This creates the
> possibility of race conditions since the guest can submit commands while the
> monitor is performing hotplug.
>
> See Patch 2 for a fix for the ->reset() vs event race condition that Zhengui Li
> encountered.
>
> Zhengui Li: Sorry it took me so long to look into this.  Please let me know if
> this fixes the issue you are seeing.  Thanks!
>
> Stefan Hajnoczi (2):
>    qdev: add HotplugHandler->post_plug() callback
>    virtio-scsi: fix hotplug ->reset() vs event race
>
>   include/hw/hotplug.h  | 12 ++++++++++++
>   hw/core/hotplug.c     | 11 +++++++++++
>   hw/core/qdev.c        |  7 +++++++
>   hw/scsi/virtio-scsi.c | 11 ++++++++++-
>   4 files changed, 40 insertions(+), 1 deletion(-)
>
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