[SCSI] virtio-scsi: unlock during kick
Separate virtqueue_kick_prepare from virtqueue_notify, so that the
expensive vmexit is done without holding the lock.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 1b38431..b0ad5aa 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -264,9 +264,11 @@
ret = virtqueue_add_buf(vq, vscsi->sg, out_num, in_num, cmd, gfp);
if (ret >= 0)
- virtqueue_kick(vq);
+ ret = virtqueue_kick_prepare(vq);
spin_unlock_irqrestore(&vscsi->vq_lock, flags);
+ if (ret > 0)
+ virtqueue_notify(vq);
return ret;
}