Single Graphic Card only for KVM-Guest, not Linux?

Single Graphic Card only for KVM-Guest, not Linux?

[Oliver Rath]

Hi,

what must I do assigning a graphic card pci-device to (i.e.
winXP-client) guest? In my case, the vga-adapter uses irq 16, so that I
think, it could be possible to mask out this irq, so that it is free for
using in the guest. Im deactivating _lots_ of linux-options so linux ist
not using the graphics adapter anymore, but no access. Is it usefull to
disable msi-reassigning?

Always i get the failure:

pci 0000:00:02.0: power state changed by ACPI to D0
pci 0000:00:02.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
kvm: failed to enable MSI device!
kvm: failed to enable INTx device!
pci 0000:00:02.0: PCI INT A disabled
kvm: emulating exchange as write

What can i do? If some additional information is needet -> email!

here my actual kernel-line (using actual kvm-git):

vmlinuz-2.6.29-rc6-x64-core2-kvmgit-00637-g9af6015 root=/dev/sda6 
panic=10 pci=nomsi irq_masq=0x0010

My kvm-call:

#!/bin/bash
modprobe pci_stub
modprobe kvm-intel
modprobe tun
kvm \
        -m 1G \
        -hda /home/oliver/KVM/meineXP-Partition.image \
        -hdb /home/oliver/KVM/NETKVM-20081229.iso \
        -net nic,macaddr=00:01:02:03:04:05,model=virtio \
        -net tap,ifname=win0,script=no,downscript=no \
        -boot c \
        -nographic \
        -pcidevice host=00:02.0 \
        -pcidevice host=00:02.1


Any ideas?

TfH,

Oliver

Re: Single Graphic Card only for KVM-Guest, not Linux?

[Thomas Mueller]

On Mon, 16 Mar 2009 17:34:25 +0100, Oliver Rath wrote:

> Hi,
> 
> what must I do assigning a graphic card pci-device to (i.e.
> winXP-client) guest? In my case, the vga-adapter uses irq 16, so that I
> think, it could be possible to mask out this irq, so that it is free for
> using in the guest. Im deactivating _lots_ of linux-options so linux ist
> not using the graphics adapter anymore, but no access. Is it usefull to
> disable msi-reassigning?
> 
> Always i get the failure:
> 
> pci 0000:00:02.0: power state changed by ACPI to D0 pci 0000:00:02.0:
> PCI INT A -> GSI 16 (level, low) -> IRQ 16 kvm: failed to enable MSI
> device!
> kvm: failed to enable INTx device!
> pci 0000:00:02.0: PCI INT A disabled
> kvm: emulating exchange as write
> 
> What can i do? If some additional information is needet -> email!
> 
> here my actual kernel-line (using actual kvm-git):
> 
> vmlinuz-2.6.29-rc6-x64-core2-kvmgit-00637-g9af6015 root=/dev/sda6
> panic=10 pci=nomsi irq_masq=0x0010

maybe you have to redirect the console of the host to a serial device to 
not take the graphics card? 

console=ttyS1,38400

- Thomas

Re: Single Graphic Card only for KVM-Guest, not Linux?

[Charles Duffy]

PCI passthrough for video cards isn't expected to work, even if the host 
isn't using them at all. See prior on-list discussion for details; my 
understanding is that the guest won't run the card's video BIOS at 
boot-time.

Re: Single Graphic Card only for KVM-Guest, not Linux?

[Christian Mueller]

Hi,

I'm also interested in this possibilty of graphic card passthrough to a 
client. As it seems impossible to share the graphic card between 
multiple systems, does it work with high performance if using a second 
graphic card for the host system? I've read that Xen can handle the 
passthrough in that case, but I didn' find any confirmation that it will 
work using KVM.

Thanks.

Regards
Chris