I've posted v2 of these patches back in november http://article.gmane.org/gmane.comp.emulators.qemu/84252
Changes since v2: insertion: * moved insertion later in the process, to handle tso * use qemu_sendv_packet() to insert the tag for us * added dot1q_buf parameter to rtl8139_do_receive() to avoid some memcpy() in loopback mode. Note that the code path through that function is unchanged when dot1q_buf is NULL. extraction: * reduced the amount of copying by moving the "frame too short" logic after the removal of the vlan tag (as is done in e1000.c for example). Unfortunately, that logic can no longer be shared betwen C+ and C mode. I've tested on the following combinations of guest and hosts: host: x86_64, guest: x86_64 host: x86_64, guest: ppc32 host: ppc32, guest: ppc32 Testing on the x86_64 host used '-net tap' and consisted of: * making an http transfert on the untagged interface. * ping -s 0-1472 to another host on a vlan. * making an scp upload to another host on a vlan. Testing on the ppc32 host used '-net socket' connected to an x86_64 qemu-kvm running the virtio nic and consisted of: * establishing an ssh connection between the two using an untagged interface. * ping -s 0-1472 to the ppc32 using a vlan. * making an scp transfer in both directions using a vlan. All that was successful. Nevertheless, it doesn't exercise all code paths so care is in order. Please note that the lack of vlan support in rtl8139 has taken a few people aback: https://bugzilla.redhat.com/show_bug.cgi?id=516587 http://article.gmane.org/gmane.linux.network.general/14266 Thanks, -Ben