support tap mac addr

nixos/vm/config.nix

@@ -18,6 +18,7 @@ let
       {
         name = lanName;
         iface = tapInterfaceName;
+        mac = tapCfg.mac;
         create = ''
           ip tuntap add dev ${tapInterfaceName} mode tap
           ip link set dev ${tapInterfaceName} up
@@ -36,6 +37,7 @@ let
       {
         name = macvtapName;
         iface = macvtapInterfaceName;
+        mac = macvtapCfg.mac;
         create = ''
           ip link add link ${macvtapNetworkCfg.uplink.iface} name ${macvtapInterfaceName} type macvtap mode bridge
           ip link set ${macvtapInterfaceName} netns ${netName}.vmix
@@ -86,7 +88,7 @@ let
             -virtfs local,path=${toString shareCfg.source},security_model=passthrough,mount_tag=${shareCfg.target} \
           '') (attrValues vmCfg.shares)} \
           ${concatMapStrings (tapCfg: ''
-            -device virtio-net-pci,netdev=lan-${tapCfg.name} \
+            -device virtio-net-pci,netdev=lan-${tapCfg.name},mac=${tapCfg.mac} \
             -netdev tap,id=lan-${tapCfg.name},ifname=${tapCfg.iface},script=no,downscript=no \
           '') allTaps} \
           ${optionalString cfg.network.user.enable "