Re: [Xen-users] Identifying graphics cards for passthrough

[Peter Maloney <peter.maloney@xxxxxxxxxxxxxxxxxxxx>]

On 04/09/2013 08:49 PM, Paul Stimpson wrote:
> Hi,
>
> I have an HP workstation here with two identical AMD V5900 graphics
> cards in it. I'm finding it really challenging following the
> instructions to get VGA passthrough working. Thanks for the help
> you've given me so far. The host OS is Ubuntu 12.04 LTS 64-bit with
> the XFCE desktop.
>
Is that a firepro?
This page mentions the FirePro V5700, which I guess means it works with
secondary passthrough.
http://wiki.xen.org/wiki/Xen_VGA_Passthrough_Tested_Adapters#ATI.2FAMD_display_adapters

> The Xen install has a Windows guest and I want to pass one of the
> cards through to it. The cards each appear as two devices (a graphics
> card and an associated sound card that provides the HDMI audio out).
> So I have:
>
>     * 00:04:00.0 - Graphics card
>     * 00:04:00.1 - Audio device
>     * 00:05:00.0 - Graphics card
>     * 00:05:00.1 - Audio device
>
> I swapped which device was primary in the BIOS as it made the layout
> of the wiring on the back panel more logical.
>
> My first stupid question is: How do I work out which card is the
> primary and secondary to know which one to pass into the guest please?
>
Not sure... there's probably some X command that should tell you which
one is the one used by X. Otherwise, you can just try unbinding the
driver for one and see :) (if the screen goes black, you picked the one
dom0 is using)
> I think I need to use gfx_passthru=1
>
> I am already passing other PCI devices through to the guest
> successfully. Say for example 00:06:00.0.
>
> How do I write this for the conf file please. I tried things like:
>
>     gfx_passthru=1
>     pci=['0000:04:00.0','0000:04:00.1','0000:06:00.0']
# 0 is secondary passthrough; 1 is primary passthrough
gfx_passthru=0
# without the 0000: (not sure if it is a problem though)
pci=['04:00.0','04:00.1','06:00.0']
>
> and
>
>     gfx_passthru=1
>     pci=['0000:04:00.0']
>
>     pci=['0000:04:00.1','0000:06:00.0']
>
> I've had no success. Are these ways of writing it equivalent or do the
> PCI IDs need to be grouped in a specific way please?
>
> I've seen some guides saying that I need to extract the contents of
> the EEPROM and bring it into the guest and some not mention it. Do I
> need to do this with an AMD card please?
You may need this for primary passthrough, but not AMD secondary passthrough
>
> I've also see reference to needing a copy of Xen after changeset 25070
> for graphics passthrough. I know I'm running Xen 4.2.0 as downloaded
> from the website but I don't still have the source code we compiled it
> from so I don't know if it's the right patch level. How can I work out
> if the copy I have is OK from an installed machine please?
AMD HD cards with secondary passthrough shouldn't need any special
patches, just the ordinary 4.1.4 or 4.2.1 should work fine.
>
> Thanks,
> Paul.
Also, remember to install the drivers in the guest before you expect the
secondary passthrough to work.


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users