Re: [PATCH v3] virtio-net: Add check for mac address while peer is vdpa

[Cindy Lu]

On Fri, Oct 30, 2020 at 4:55 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Mon, Oct 26, 2020 at 02:21:26PM +0800, 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>
>
> I wonder whether we can retrieve the mac earlier and fail init.
> That would be better than second-guessing bad configs ...
>
Sure, Thanks Michael and Jason, I will check this with NIC vendor
Thanks
Cindy

> > ---
> >  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..65a3a84573 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 {
> > +                info_report("Get an all zero mac address from hardware");
> > +            }
> >          }
> >      }
> >  }
> > --
> > 2.21.3
>