Re: Graphics card pass-through working with two pass pci-initialization

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Hi,

On 28.05.2011 10:18, Jan Kiszka wrote:
On 2011-05-26 23:19, Andrà Weidemann wrote:
On 27.05.2011 21:50, Andrà Weidemann wrote:
On 27.05.2011 21:40, Andrà Weidemann wrote:

If I am not mistaken then the graphics card needs 2 bars, one with 256MB
and one with 128K. The sound card then needs 1 bar with 16K of PCI
memory.
How big is the PCI memory with seabios?
Is there really not enough space to "squeeze" in those extra 16K?

I obviously forgot to add up the other memory that is used...
32MB go to the standard VGA card. Running qemu-kvm with "-vga none" did
not work, so I left it in. And the e1000 NIC needs another 128K.

I'll see if I can get rid of the standard VGA card. I guess that should
free enough memory for the sound card.

I did some more testing by starting the VM with the paramter "-vga none"
and passed both the VGA card and the sound card to it. With this option
the VM did not boot,

Where did it hang, ie. what IP was reported by info cpus?

I added some debug options and found out, that the VM hangs when trying to initialize the graphics card ROM.
See here:
http://pastebin.com/S9a8uQfU

And some additional info here:

http://pastebin.com/AC4rw8Ek (info cpus/registers)
http://pastebin.com/yYkn8jL2 (info pci)

but I could use the monitor to take a look at the
PCI bar assignment. Even though the memory for the standard VGA card is
freed, the soundcard does not seem to get the 16K bar it needs. "info
pci" for the sound card still looks like this:
  Bus  0, device   5, function 0:
     Audio controller: PCI device 8086:3a3e
       IRQ 10.
       BAR0: 32 bit memory at 0xffffffffffffffff [0x00003ffe].

Does anyone have an idea why there was no bar assigned?

Maybe Gerd's patches aren't sufficient and you still need to change
BUILD_MAX_HIGHMEM. See the hacks in
http://git.kiszka.org/?p=seabios.git;a=shortlog;h=refs/heads/vga-assign,
either replacing Gerd's patches or combined with them (I haven't checked
if the latter makes sense).

I do not have access to the machine until tomorrow. I'm curious to see if extending the PCI memory window will cure the problem.

Can the kernel be too old? (2.6.35.7.)

It would be good to check the latest kvm kernel to see if that oops is
still present. In that case, please try to collect the backtrace via
serial console, hopefully complete then. We may have an resource cleanup
issue there.

I will see if I can upgrade to the latest kernel tomorrow.


Just to test whether or not two devices can be assigned, I passed
through 2 sound cards. (There is an onbard sound card and the Radeon has
one too).

Each sound card gets its bar assigned as you can see:
   Bus  0, device   4, function 0:
     Audio controller: PCI device 1002:aa80
       IRQ 10.
       BAR0: 32 bit memory at 0xfebf0000 [0xfebf3fff].
       id ""
   Bus  0, device   5, function 0:
     Audio controller: PCI device 8086:3a3e
       IRQ 10.
       BAR0: 32 bit memory at 0xfebf4000 [0xfebf7fff].

but the sound cards do not show inside the Windows VM.

With both sound cards still passed to the VM I then booted an Ubuntu
10.10 image instead of Windows7. It got as far as starting gdm, but then
the entire host and VM became very slow.
The last message I saw on the terminal before gdm started was this:
[   23.030016 ] hda_intel: azx_get_response timeout, switching to
single_cmd mode: last cmd=0x000f0000
[   29.290017 ] hda_intel: azx_get_response timeout, switching to
single_cmd mode: last cmd=0x200f0000

Likely some IRQ issue. Please check if latest qemu-kvm.git +
http://thread.gmane.org/gmane.comp.emulators.qemu/102540 makes any
difference.

See above comments. I will try this tomorrow.

Regards
 AndrÃ
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