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

[Jason Wang <jasowang@redhat.com>]

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