Re: [PATCH v2] virtio-net: Add check for mac address while peer is vdpa

[Jason Wang]

On 2020/10/26 上午10:43, Jason Wang wrote:
> On 2020/10/23 下午5:15, Cindy Lu wrote:
> > Sometime vdpa get an all 0 mac address from the hardware, this will 
> > cause the traffic down
> > So we add the check for this part.
> > if we get an 0 mac address we will use the default mac address instead
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >   hw/net/virtio-net.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 9179013ac4..f1648fc47d 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -126,6 +126,7 @@ static void virtio_net_get_config(VirtIODevice 
> > *vdev, uint8_t *config)
> >       VirtIONet *n = VIRTIO_NET(vdev);
> >       struct virtio_net_config netcfg;
> >       NetClientState *nc = qemu_get_queue(n->nic);
> > +    static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
> >         int ret = 0;
> >       memset(&netcfg, 0 , sizeof(struct virtio_net_config));
> > @@ -151,7 +152,11 @@ static void virtio_net_get_config(VirtIODevice 
> > *vdev, uint8_t *config)
> >           ret = vhost_net_get_config(get_vhost_net(nc->peer), 
> > (uint8_t *)&netcfg,
> >                                      n->config_size);
> >           if (ret != -1) {
> > -            memcpy(config, &netcfg, n->config_size);
> > +            if (memcmp(&netcfg.mac, &zero, sizeof(zero)) != 0) {
> > +                memcpy(config, &netcfg, n->config_size);
> > +        } else {
> > +                error_report("Get an all zero mac address from 
> > hardware");
> > +            }
> >           }
> >       }
> >   }
>
>
> Applied.
>
> Thanks

Speak too fast. Some questions:

1) Any reason that you do such check or get_config() instead of doing it 
once in device initalization
2) the indentation looks wrong
3) There's no need for an error here since we can workaround it

Thanks