Alex Williamson: > On Thu, 2013-04-25 at 11:38 +0000, deniv wrote: >> Sorry for the long delay. >> >> Alex Williamson: >>> On Thu, 2013-04-11 at 13:59 -0400, de...@lavabit.com wrote: >>>>> On Wed, 2013-04-10 at 16:32 -0400, de...@lavabit.com wrote: >>>>>>>> However, turning gfx_passthru off did >>>>>>>> the trick. Win7 started loading with cirrus and switched to HD7750 >>>>>>>> halfway >>>>>>>> through boot proccess. I didn't do any testing just let Windows >>>>>>>> calculate >>>>>>>> its score. The result was 7.4 and Aero was working. >>>>>>> >>>>>>> You should be able to do this with vfio too, use -vga cirrus and don't >>>>>>> use the x-vga option on pci-assign. The x-vga enables legacy VGA >>>>>>> support for boot and primary console, as a secondary head normal PCI >>>>>>> device assignment should be sufficient. >>>>>>> >>>>>> Oh, how I wish it was true! Trying to load with cirrus and vfio-pci >>>>>> results in BSOD: >>>>>> Attemp to reset the display driver and recover from timeout failed. >>>>> >>>>> Is this a fresh windows install? Windows doesn't like change and will >>>>> BSOD pretty easily when attaching graphics to an existing image. >>>>> >>>>>> Trying the old pci-assign with kvm results in non-working GFX. Windows >>>>>> shows code 10 and sometimes code 43 for the card. >>>>> >>>>> What happens if you don't use a q35 machine? Windows is very particular >>>>> about the PCIe type of a device and will often show Code 10 if it >>>>> doesn't have a type compatible with a root complex. Alternatively you >>>>> can use the q35 config in the docs directory with the -readconfig option >>>>> and the bus= option on the pci-assign device to place the graphics >>>>> behind a root port. >>>>> >>>> >>>> After many attempts I have VGA passthrough working. Each test has been >>>> performed in a clean Win7 install with kvm enabled. Installation was done >>>> with i440fx machine and changed to q35 after virtio drivers were >>>> installed. I did that because there's no AHCI driver for q35 yet and win7 >>>> doesn't have drivers for lsi scsi. >>>> >>>> 1. q35/pc, vga=none, vfio-pci, x-vga=on. Nothing on the VM's screen, debug >>>> output can be seen in the previous mails. >>>> 2. q35/pc, vga=cirrus, vfio-pci, x-vga=on. Screen corruption on host >>>> (correction to the previous mails: corruption also happens even in kms >>>> console). Nothing on the VM's screen. >>>> 3. q35/pc, vga=cirrus, vfio-pci, no x-vga. BSOD: Attempt to reset the >>>> display driver and recover from timeout failed. >>>> 4. q35, vga=cirrus, pci-assign. Windows boots, the graphic card doesn't >>>> start: Code 10. >>>> 5. pc, vga=cirrus, pci-assign. IT'S ALIVE! Ironically, this is the oldest >>>> way to assign pci devices in kvm. Why I could make it work previously? >>>> Silly me! >>> >>> What does your /sys/kernel/iommu_groups look like for the group >>> containing your VGA device? I'm curious if it includes the PCIe root >>> port and whether you're attaching those to vfio-pci or leaving them >>> bound to pcieport. If the former, that may contribute to why you're >>> having problems with vfio-pci. >> Yes, the group containing the VGA device includes PCIe root port. No, I >> did not attach it to vfio-pci. I tried this right now, it didn't make >> any difference. > > You were right by not attaching it to vfio-pci. Previous versions of > vfio-pci still required it, but we've since found that causes more > problems than it solves. I wanted to make sure it wasn't attached. > >> For what it's worth, I also noticed errors in dmesg output when Windows >> BSODs (q35, vga=cirrus, vfio-pci, no x-vga). There are about ten >> thousand lines of >> --- >> dmar: DRHD: handling fault status reg 3 >> dmar: DMAR:[DMA Read] Request device [01:00.0] fault addr 1200b6000 >> DMAR:[fault reason 06] PTE Read access is not set >> --- >> Fault addresses start at 11fff6000 (always the same) and go to about >> 1201b3000 (varies on each start). >> >> Those read faults are followed a bunch of >> --- >> dmar: DRHD: handling fault status reg 3 >> dmar: DMAR:[DMA Write] Request device [01:00.0] fault addr 11ffed000 >> DMAR:[fault reason 05] PTE Write access is not set >> --- >> Fault addresses 11fef3000-11fff0000 (the last address varies). > > And only with vfio-pci? Very odd. > > I've since gotten my HD7850 working with vfio-pci,x-vga=on with my Intel > VT-d system. Gleb is working on a patch to fix the emulator bug, but it > can be avoided using the emulate_invalid_guest_state=0 module option to > kvm_intel. Okay. This time I used your next branch. kernel command line included "kvm_intel.emulate_invalid_guest_state=0"
> I see we've already mentioned it in this thread, but I'll re-iterate the > importance of not loading host drivers for graphics cards until we can > reset them better. Another user was having trouble with nvidia cards > that was cleared by not loading the host nvidia kernel driver. As far as I know, nothing touches HD7750 before qemu comes in. My kernel config: http://pastebin.com/sE73CMgH > I believe you're using the stock upstream kernel, 3.9-rc5 last I saw in > this thread. One potential difference between vfio-pci and pci-assign > is that vfio does not allow access to unarchitected PCI config space. > That is, regions not covered by capabilities. This has also been shown > to be a problem, so it's being fixed, but is not yet upstream. I plan > to push this in for 3.10, but it's already in my next branch: I reran some test with your branch. pc/q35, vga=none, vfio-pci, x-vga=on. As previously, without 'if (1 || data == quirk->data)' in hw/misc/vfio.c qemu freezes early. With the patch it goes a bit further, corrupts the main screen, and freezes again. pc, vga=cirrus, vfio-pci, no x-vga. [ 104.469331] vfio-pci 0000:01:00.0: enabling device (0000 -> 0003) [ 104.494873] vfio_ecap_init: 0000:01:00.0 hiding ecap 0x19@0x270 [ 125.895842] vfio-pci 0000:01:00.0: irq 48 for MSI/MSI-X And then BSOD: Attempt to reset the display driver and recover from timeout failed. q35, vga=cirrus, vfio-pci, no x-vga. It's like the previous config, but with many DMAR faults. [ 73.235513] vfio-pci 0000:01:00.0: enabling device (0000 -> 0003) [ 73.260776] vfio_ecap_init: 0000:01:00.0 hiding ecap 0x19@0x270 [ 95.919689] vfio-pci 0000:01:00.0: irq 48 for MSI/MSI-X [ 97.642747] dmar: DRHD: handling fault status reg 3 [ 97.642752] dmar: DMAR:[DMA Read] Request device [01:00.0] fault addr 11fff6000 [ 97.642752] DMAR:[fault reason 06] PTE Read access is not set .. + BSOD. q35, vga=cirrus, pci-assign. Windows boots, the GPU doesn't start (code 10). pc, vga=cirrus, pci-assign. This is the working config.
