[PATCH v6 3/4] virtio_net: Add second acceptable configuration for MAC setup

[Cindy Lu]

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 <l...@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 94ee21d1fc..45b63eb9de 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3769,6 +3769,20 @@ 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 and the MAC address in
+         *  the QEMU command line is 0.
+         *  In this situation, we use the hardware MAC address overwrite
+         *  the QEMU command line address saved in VirtIONet->mac[0].
+         *  In the following process, QEMU will use this MAC address
+         *  in VirtIONet to complete the initialization.
+         */
+        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,
                "vDPA device's MAC address %02x:%02x:%02x:%02x:%02x:%02x "
-- 
2.45.0