On Thu, Apr 17, 2025 at 6:26 PM Cindy Lu <l...@redhat.com> wrote:
>
> For VDPA devices, Allow configurations where both the hardware MAC address
> and QEMU command line MAC address are zero.
> In this case, QEMU will automatically generate a random MAC address and
> assign it to the hardware, and the VM will use this random MAC address as
> its MAC address.
>
> Signed-off-by: Cindy Lu <l...@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 808a2fe4d4..2d4ac20ee0 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -3772,7 +3772,18 @@ static bool virtio_net_check_vdpa_mac(VirtIONet *n,
> uint8_t *hwmac,
> return true;
> }
> }
> + /*
> + * 3. The hardware MAC address is 0,
> + * and the MAC address in the QEMU command line is also 0.
Can this happen? I'd expect qemu should check for invalid mac addresses.
> + * In this situation, QEMU generates a random MAC address and
> + * uses CVQ/set_config to assign it to the device.
> + */
> + if ((memcmp(hwmac, &zero, sizeof(MACAddr)) == 0) &&
> + (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0)) {
> + memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
>
> + return true;
> + }
> return false;
> }
> static void virtio_net_device_realize(DeviceState *dev, Error **errp)
> --
> 2.45.0
>
Thanks
