While the hardware MAC address is 0 and the MAC address in
the QEMU command line is also 0, this configuration is
acceptable.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 hw/net/virtio-net.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 5c610d8078..668fbed9f2 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3620,6 +3620,17 @@ static bool virtio_net_check_vdpa_mac(NetClientState *nc, VirtIONet *n,
             return true;
         }
     }
+    /*
+     * 3.The hardware MAC address is 0,
+     *  and the MAC address in the QEMU command line is also 0.
+     *  In this situation, qemu will use random mac address
+     */
+    if ((memcmp(&hwcfg.mac, &zero, sizeof(MACAddr)) == 0) &&
+        (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0)) {
+        memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
+
+        return true;
+    }
 
     error_setg(errp,
                "vDPA device's mac %02x:%02x:%02x:%02x:%02x:%02x"
-- 
2.45.0

On Mon, Sep 30, 2024 at 12:01 AM Cindy Lu <lulu@redhat.com> wrote:
>
> While the hardware MAC address is 0 and the MAC address in
> the QEMU command line is also 0, this configuration is
> acceptable.
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>  hw/net/virtio-net.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 5c610d8078..668fbed9f2 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -3620,6 +3620,17 @@ static bool virtio_net_check_vdpa_mac(NetClientState *nc, VirtIONet *n,
>              return true;
>          }
>      }
> +    /*
> +     * 3.The hardware MAC address is 0,
> +     *  and the MAC address in the QEMU command line is also 0.
> +     *  In this situation, qemu will use random mac address

And explain how the device knows such a random mac address or it's
just for a best effort try.

Thanks

> +     */
> +    if ((memcmp(&hwcfg.mac, &zero, sizeof(MACAddr)) == 0) &&
> +        (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0)) {
> +        memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
> +
> +        return true;
> +    }
>
>      error_setg(errp,
>                 "vDPA device's mac %02x:%02x:%02x:%02x:%02x:%02x"
> --
> 2.45.0
>

On Wed, 9 Oct 2024 at 16:30, Jason Wang <jasowang@redhat.com> wrote:
>
> On Mon, Sep 30, 2024 at 12:01 AM Cindy Lu <lulu@redhat.com> wrote:
> >
> > While the hardware MAC address is 0 and the MAC address in
> > the QEMU command line is also 0, this configuration is
> > acceptable.
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >  hw/net/virtio-net.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 5c610d8078..668fbed9f2 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -3620,6 +3620,17 @@ static bool virtio_net_check_vdpa_mac(NetClientState *nc, VirtIONet *n,
> >              return true;
> >          }
> >      }
> > +    /*
> > +     * 3.The hardware MAC address is 0,
> > +     *  and the MAC address in the QEMU command line is also 0.
> > +     *  In this situation, qemu will use random mac address
>
> And explain how the device knows such a random mac address or it's
> just for a best effort try.
>
> Thanks
>
sure, will add these
Thanks
cindy
> > +     */
> > +    if ((memcmp(&hwcfg.mac, &zero, sizeof(MACAddr)) == 0) &&
> > +        (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0)) {
> > +        memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
> > +
> > +        return true;
> > +    }
> >
> >      error_setg(errp,
> >                 "vDPA device's mac %02x:%02x:%02x:%02x:%02x:%02x"
> > --
> > 2.45.0
> >
>