On 2013-12-20 12:06 AM, Alex Williamson wrote:
On Thu, 2013-12-19 at 12:41 -0500, Stewart Adam wrote:
On 2013-12-19 10:19 AM, Alex Williamson wrote:
On Thu, 2013-12-19 at 01:48 -0500, Stewart Adam wrote:
Hi,
I am trying to get VGA passthrough working using KVM and VFIO like
described on this [1] thread and ran into some issues I was hoping
someone could shed some light on. I have tried various configurations,
but can't seem to get it working correctly. Either I get "Code 10"
device error in Windows, or I get a BSOD 0x00000116 (VIDEO_TDR_ ERROR:
attempt to reset the display driver and recover from a timeout failed)
when booting the machine after installing the Catalyst 3D drivers.
Other users on the Arch Linux forum have also reported similar issues.
<cut>
Hi Stewart,
The "x" in the x-vga option is for eXperimental. It works in some
cases, not others. The archlinux forum thread is the best place to
either get help or commiserate with others having the same problem. The
advice there is largely not distribution specific. The 0x116 BSOD is a
common problem with assigned Radeon graphics, we don't have a solution
yet. Also note that this work is still under development, for the
current "state of the art" you need a 3.13-rc kernel and qemu.git, and
you may need to patch in some Intel graphics fixes for VGA arbitration.
Even then, I have no reason to suspect the 0x116 BSOD is fixed. More
users seem to be having success with Nvidia cards, so if that's an
option for you, it may be the quickest path to results. Thanks,
Alex
Hi Alex,
Thanks for replying so quickly. Ironically, I normally buy nVidia and
purchased this Radeon card because I had read online they tend to do
passthrough better (with Xen at least)... I didn't have much luck when I
tried a Xen VM either though. I do have an nVidia card handy and will try
that later tonight.
Would the VGA arbitration patches relate to the Code 10 errors? Also, I will
try again with 3.13-rc later this week but should I use qemu-vfio.git or
qemu.git?
Probably not related to the Code 10, but I'm no expert in Windows error
codes.
I realize this is all bleeding edge and thank you for all of your work on
it. Is there anything I can do to help you debug the 0x116 problem?
vfio has plenty of debug support for tracing accesses to the card, it
simply needs to be turned on in the source file. The issue is
identifying the problem among all the output. With a closed source
guest and driver, and lack of hardware documentation, it's quite a lot
of guesswork.
Lastly, out of curiosity - is the 0x116 error dependent on particular piece
of hardware or it's a problem with the emulation layer + certain GPUs?
No idea. Thanks,
Alex
Hi Alex,
Yesterday I did a bit more reading and based on your suggestions above,
recompiled rawhide kernel 3.13.0-0.rc4.git4.1.fc21 from Fedora's build
system with a few additional patches applied to fix the problematic
PCIE-to-PCI bridge mentioned in my original post as well as your patches for
the i915 VGA arbitration with Haswell.
I then compiled QEMU from latest git with the NoSnoop patch applied, as I
checked 'lspci -vv' and my card was showing NoSnoop+.
The combination worked perfectly, and I had my monitor displaying at 1080p
with Catalyst Control Center fully functional!
When I have more time I'm going to apply the patches one at a time and also
try using QEMU 1.7.0 to see which changes, exactly, made the difference.
I'll post back once I have more info.
Thanks,
Stewart
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