Re: [Qemu-devel] [PATCHv3 4/6] virtio-net: stop/start bh when appropriate

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Dec 02, 2010 at 10:19:55PM +0800, Jason Wang wrote:
> Michael S. Tsirkin writes:
>  > On Thu, Dec 02, 2010 at 08:56:30PM +0800, Jason Wang wrote:
>  > > Michael S. Tsirkin writes:
>  > >  > On Wed, Dec 01, 2010 at 01:45:09PM +0800, Jason Wang wrote:
>  > >  > > Michael S. Tsirkin writes:
>  > >  > >  > Avoid sending out packets, and modifying
>  > >  > >  > device state, when VM is stopped.
>  > >  > >  > Add assert statements to verify this does not happen.
>  > >  > >  > 
>  > >  > >  > Avoid scheduling bh when vhost-net is started.
>  > >  > >  > 
>  > >  > >  > Stop bh when driver disabled bus mastering
>  > >  > >  > (we must not access memory after this).
>  > >  > >  > 
>  > >  > >  > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>  > >  > >  > 
>  > >  > > 
>  > >  > > There's no need to disable it bh we call qemu_aio_flush() after
>  > >  > > vm_state_notify() in do_vm_stop(). And for timer, looks like every device should
>  > >  > > stop its timer in vm state change handler, not only for virtio-net?
>  > >  > 
>  > >  > BTW I fixed some typos. Here a fixed version.
>  > >  > Jason, could you review/test please?
>  > >  > 
>  > > 
>  > > Have done the test, it's more stable than before but still get small deltas in
>  > > cpu section.
>  > 
>  > And just to clarify: no more deltas in the memory section?
>  > 
> 
> Yes.
> 
> And the offset for cpu section is 1161-1165 and sometimes I get deltas for ide
> section at offset 295 and 314.


Kevin, could you take a look please?

Jason, does the following do anything?

Subject: ide: cancel bh on vm stop

If bh is running on vm stop, ide state might change
after vm stop is completed. Solve by deleting bh on stop.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/ide/core.c b/hw/ide/core.c
index 484e0ca..8d86114 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -698,8 +698,13 @@ void ide_dma_restart_cb(void *opaque, int running, int reason)
 {
     BMDMAState *bm = opaque;
 
-    if (!running)
+    if (!running) {
+        if (bm->bh) {
+            qemu_bh_delete(bm->bh);
+            bm->bh = NULL;
+        }
         return;
+    }
 
     if (!bm->bh) {
         bm->bh = qemu_bh_new(ide_dma_restart_bh, bm);