Re: [PATCH v5 3/4] virtio_net: Add second acceptable configuration for MAC setup

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

On Wed, Mar 26, 2025 at 09:19:32PM +0800, Cindy Lu wrote:
> For VDPA devices, Allow configurations where the hardware MAC address
> is non-zero while the MAC address in the QEMU command line is zero.
> 
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>  hw/net/virtio-net.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index a3b431e000..1fd0403d5d 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -3767,6 +3767,20 @@ static bool virtio_net_check_vdpa_mac(NetClientState *nc, VirtIONet *n,
>          if ((memcmp(&hwcfg.mac, cmdline_mac, sizeof(MACAddr)) == 0)) {
>              return true;
>          }
> +        /*
> +         * 2.The hardware MAC address is NOT 0,

space after .

> +         *  and the MAC address in the QEMU command line is 0.
> +         *  In this situation, Here we use the hardware MAC address overwrite
> +         *  the QEMU command line address(is 0) in VirtIONet->mac[0].

drop "here" and add punctiation. period before overwrite maybe?
what is (is 0)?

> +         *  in the follwoing process, QEMU will use this mac in VirtIONet and
> +         *  finish the bring up
> +         */
> +        if (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0) {
> +            /* overwrite the mac address with hardware address*/
> +            memcpy(&n->mac[0], &hwcfg.mac, sizeof(n->mac));
> +            memcpy(&n->nic_conf.macaddr, &hwcfg.mac, sizeof(n->mac));
> +            return true;
> +        }
>      }
>  
>      error_setg(errp,
> -- 
> 2.45.0