On Thu, Jun 3, 2021 at 2:58 PM Jason Wang <jasow...@redhat.com> wrote:
>
> 在 2021/6/2 上午11:47, Cindy Lu 写道:
> > During the test, We found this function will continue running
> > while the peer is deleted, this will cause the crash. so add
> > check for this. this only exist in machines type microvm
>
>
> Any idea why it only happens on microvm?
>
>
> >
> > reproduce step :
> > load the VM with
> > qemu-system-x86_64 -M microvm
> > ...
> > -netdev tap,id=tap0,vhost=on,script=no,downscript=no \
> > -device virtio-net-device,netdev=tap0 \
> > ..
> > enter the VM's console
> > shutdown the VM
> > (gdb) bt
> >
> > 0 0x000055555595b926 in qemu_net_queue_flush (queue=0x0) at
> ../net/queue.c:275
>
>
> So which piece of code trigger this? When the nc has a NIC peer we don't
> free it until the NIC is freed.
>
>
> > 1 0x0000555555a046ea in qemu_flush_or_purge_queued_packets
> (nc=0x555556ccb920, purge=false)
> > at ../net/net.c:624
> > 2 0x0000555555a04736 in qemu_flush_queued_packets (nc=0x555556ccb920)
> at ../net/net.c:637
> > 3 0x0000555555ccc01a in virtio_net_handle_rx (vdev=0x555557360ed0,
> vq=0x7ffff40d6010)
> > at ../hw/net/virtio-net.c:1401
> > 4 0x0000555555ce907a in virtio_queue_notify_vq (vq=0x7ffff40d6010) at
> ../hw/virtio/virtio.c:2346
> > 5 0x0000555555cec07c in virtio_queue_host_notifier_read
> (n=0x7ffff40d608c)
> > at ../hw/virtio/virtio.c:3606
> > 6 0x00005555560376ac in aio_dispatch_handler (ctx=0x555556a857e0,
> node=0x555556f013d0)
> > at ../util/aio-posix.c:329
> > 7 0x00005555560377a4 in aio_dispatch_ready_handlers (ctx=0x555556a857e0,
> > ready_list=0x7fffffffdfe0) at ../util/aio-posix.c:359
> > 8 0x0000555556038209 in aio_poll (ctx=0x555556a857e0, blocking=false)
> at ../util/aio-posix.c:662
> > 9 0x0000555555e51c6f in monitor_cleanup () at ../monitor/monitor.c:637
> > 10 0x0000555555d2d626 in qemu_cleanup () at ../softmmu/runstate.c:821
> > 11 0x000055555585b19b in main (argc=21, argv=0x7fffffffe1c8,
> envp=0x7fffffffe278)
> >
> > Signed-off-by: Cindy Lu <l...@redhat.com>
> > ---
> > hw/net/virtio-net.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 02033be748..927a808654 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -1397,7 +1397,9 @@ static void virtio_net_handle_rx(VirtIODevice
> *vdev, VirtQueue *vq)
> > {
> > VirtIONet *n = VIRTIO_NET(vdev);
> > int queue_index = vq2q(virtio_get_queue_index(vq));
> > -
> > + if (n->nic->peer_deleted) {
> > + return;
>
>
> This needs to be fixed in the network core instead of virtio-net.
>
> Thanks
>
>
> sure I will fix this problem
> > + }
> > qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
> > }
> >
>
>
