I did some tests with Ubuntu 14.04 / Xen 4.4 regarding VGA passthrough. Here the hardware:
CPU: Intel i7 3930K (supporting VT-d)
M/B: Asus Sabertooth X79 with latest BIOS
dom0 graphics: AMD / ATI 7770
domU graphics: AMD / ATI 6450
dom0 OS: Ubuntu-Gnome 14.04 Beta2 64bit
domU OS: Windows 7 Professional 64bit
dom0 memory: 8GB
domU memory: 8GB
Toolstack: xl
Device model: device_model_version = 'qemu-xen-traditional'
Results:
Aside from some minor glitches like xtightvncviewer not accepting an empty password ](*,) and xvnc4viewer crashing more often than not, the new Xen 4.4 with the 3.13 kernel greatly improved the ability to pass through an AMD graphics card. Now xl can start and restart the domU without causing performance issues, or crashing dom0. It is no more necessary to use the xm toolstack for VGA passthrough.
Below is my /etc/xen/guest.cfg file:
In the past I had serious issues getting this AMD 6450 card passed through. I tried various releases of Linux Mint/Ubuntu 12.04/12.10/13.10 with Xen 4.1.2/4.1.3/4.2/4.3 and only Ubuntu 12.04 with an old kernel and Xen 4.1.2 (the original version) worked with the xm toolstack.
More on the experiments and results can be found here (Linux Mint 13/Ubuntu 12.04 with Xen 4.1.2) and here (Ubuntu 14.04 with Xen 4.4).
CPU: Intel i7 3930K (supporting VT-d)
M/B: Asus Sabertooth X79 with latest BIOS
dom0 graphics: AMD / ATI 7770
domU graphics: AMD / ATI 6450
dom0 OS: Ubuntu-Gnome 14.04 Beta2 64bit
domU OS: Windows 7 Professional 64bit
dom0 memory: 8GB
domU memory: 8GB
Toolstack: xl
Device model: device_model_version = 'qemu-xen-traditional'
Results:
Aside from some minor glitches like xtightvncviewer not accepting an empty password ](*,) and xvnc4viewer crashing more often than not, the new Xen 4.4 with the 3.13 kernel greatly improved the ability to pass through an AMD graphics card. Now xl can start and restart the domU without causing performance issues, or crashing dom0. It is no more necessary to use the xm toolstack for VGA passthrough.
Below is my /etc/xen/guest.cfg file:
Code:
builder='hvm'
memory = 8192
name = 'win7'
vcpus=6
pae=1
acpi=1
apic=1
on_xend_stop='shutdown'
vif = [ 'mac=00:16:3e:68:e1:01,bridge=xenbr0' ]
disk = [ '/dev/mapper/guests-win7,raw,hda,rw' , '/home/user/ISOs/Win7.iso,raw,hdc,devtype=cdrom' ]
device_model_version = 'qemu-xen-traditional'
boot='cd'
sdl=0
vnc=1
vncpasswd='password'
stdvga=0
serial='pty'
tsc_mode='default'
viridian=1
usb=1
usbdevice='tablet'
gfx_passthru=0
pci=[ '02:00.0', '02:00.1' ]
localtime=1
pci_power_mgmt=1More on the experiments and results can be found here (Linux Mint 13/Ubuntu 12.04 with Xen 4.1.2) and here (Ubuntu 14.04 with Xen 4.4).