I finally got this work after I realised that the AHCI driver was not being loaded in my disk image and that ACHI was not being enabled in the Seabios .config file. This is really good work Yamahata, thanks.
As far as I can tell, everything works like the stock Qemu 0.14 except networking. The guest OS sees the network device and initialises it but I think the Qemu DHCP server/firewall never gets back, since the network device doesn't even get a 10.0.2.15 ip address during bootup and the guest dhcp client never gets an ip address, eth0 device: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 03) eth0 Starting DHCP4 client. . . . . . . . eth0 DHCP4 continues in background eth0 device: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 03) eth0 DHCP4 client (dhcpcd) is running eth0 . . . but is still waiting for data eth0 interface could not be set up until now So doing an ifconfig later on just shows eth0 Link encap:Ethernet HWaddr 52:54:00:12:34:56 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) lo Link encap:Local loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNING MTU:16436 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) I'm going to start a separate thread to see what the possible cause might be and what might be the best way to debug this. Do you have any idea if this q35 chipset going to be committed to Qemu upstream? Thanks AK