Re: Device pass-through

[Gordon Messmer <yinyang@eburg.com>]

On 01/03/2012 07:44 PM, Alex Williamson wrote:
> Yep, that's what I would have guessed, there's a 256MB resource.  I'm
> not sure if the seabios you're using is mapping the MMIO hole
> efficiently enough to handle that.  Can you test on new upstream
> qemu-kvm?  Thanks,

I'm not done poking the system, but I thought I'd send an update.

I started with an update to seabios, from the bundled version 
0.6.1.2-8.el6 to a rebuilt package from F16, 0.6.2-3.el6.  That's enough 
to get the guest to boot with the pass-through video card.  It doesn't 
work, currently, and I'm pretty sure that's because I can't read the ROM 
from the card.  I'm going to look around for a solution to that and will 
update again.

lspci in the guest shows the device:

00:07.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon
		HD 3470 (prog-if 00 [VGA controller])
	Subsystem: Dell Device 3243
	Physical Slot: 7
	Flags: fast devsel, IRQ 11
	Memory at e0000000 (32-bit, prefetchable) [size=256M]
	Memory at f2050000 (32-bit, non-prefetchable) [size=64K]
	I/O ports at c100 [size=256]
	Expansion ROM at <unassigned> [disabled]
	Capabilities: [58] Express Legacy Endpoint, MSI 00
	Capabilities: [50] Power Management version 3
	Capabilities: [a0] MSI: Enable- Count=1/1 Maskable- 64bit-
	Kernel modules: radeon


dmesg reports some errors:

[    1.048791] [drm] Initialized drm 1.1.0 20060810
[    1.066131] [drm] radeon defaulting to kernel modesetting.
[    1.066133] [drm] radeon kernel modesetting enabled.
[    1.066220] radeon 0000:00:07.0: PCI INT A -> Link[LNKC] ->
		GSI 11 (level, high) -> IRQ 11
[    1.066267] radeon 0000:00:07.0: setting latency timer to 64
[    1.066611] [drm] initializing kernel modesetting
		(RV620 0x1002:0x95C0 0x1028:0x3243).
[    1.066774] [drm] register mmio base: 0xF2050000
[    1.066776] [drm] register mmio size: 65536
[    1.066884] radeon 0000:00:07.0: Expecting atombios for R600 GPU
[    1.066886] radeon 0000:00:07.0: Fatal error during GPU init
[    1.066888] [drm] radeon: finishing device.
[    1.066890] [TTM] Memory type 2 has not been initialized.
[    1.067924] vga_switcheroo: disabled
[    1.068070] radeon 0000:00:07.0: PCI INT A disabled
[    1.068075] radeon: probe of 0000:00:07.0 failed with error -22