Re: [Qemu-devel] [PATCH] virtio-scsi: fix object check failure

[Paolo Bonzini]

Il 18/06/2014 17:02, Paolo Bonzini ha scritto:
> Il 18/06/2014 16:18, Ming Lei ha scritto:
> > > > This should never be triggered by vhost-scsi.  Perhaps a bug in the
> > > kernel?
> > It can be triggered with rmmod, system suspend, reboot...
>
> Yes, but it should not.
>
> What happens if you change VHOST_SCSI_VQ_NUM_FIXED from 2 to 3?

Sorry, brain fart here.  The number of interrupts in virtio-scsi is 
queues+3 because of the configuration interrupt.  This does not apply here.

Anyway, vhost-scsi passes the number of virtqueues correctly to the kernel.

QEMU might be triggering this because, when vhost is stopped, the queue 
is still not empty (as expected, since it's a receive queue).

Can you check that this is the case?

If so, patching QEMU is correct, but you need to change 
VIRTIO_SCSI(vdev) to VIRTIO_SCSI_COMMON(vdev), and move events_dropped 
from VirtIOSCSI to VirtIOSCSICommon.

Paolo