Re: Shared IRQ with PCI Passthrough?

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-08-23 14:52, Michael Sturm wrote:
> On 19-08-11 0:02, Gardziejczyk, Kamil wrote:
>> Hi,
>>
>> Have you resolve your problem with shared IRQ lines? I have checked
>> out qemu-kvm 0.15.0 and found that Jan Kiszka patch was applied to
>> latest version of kvm.
>>
>> [PATCH 0/5] pci-assign: Host IRQ sharing suppport + some fixes and
>> cleanups
>> http://thread.gmane.org/gmane.comp.emulators.kvm.devel/64601
>>
>> Which version of linux kernel do you use? I have tried with 3.0.0. It
>> looks that Jan Kiszka`s patches were not added to that kernel version.
>> Maybe it is in 2.6.xxx?
>> Any ideas how to fix it? :)
>>
>>
> 
> Hi Kamil,
> 
> Thanks for your reply.
> 
> For testing purposes, I've installed Ubuntu 11.04 Server (64-bit) on a
> separate physical disk. The default kernel of this setup is
> 2.6.38-8-server (slightly newer than the Proxmox kernel 2.6.35-1-pve I
> was using previously).
> 
> As you suggested, I too have now tested qemu-kvm 0.15.0. (git clone
> git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git and compiling the
> stable-0.15 branch).
> 
> As before, using the nousb kernel option (with intel_iommu=on) my WinXP
> guest with pci-passthrough works fine, but without the nousb option, the
> guest cannot be started.
> 
> My next attempt will be to try the KVM external module kit, compiling
> the latest code from the git clone
> git://git.kernel.org/pub/scm/virt/kvm/kvm-kmod.git. I think using the
> module kit rather than patching and compiling a custom kernel should
> work better in my case (if I'm moving back to Proxmox later), yet still
> update KVM to the latest code.
> 
> Hopefully this will resolve the IRQ conflict.

Nope, there is no IRQ sharing support for assigned devices in any public
version so far. I'm on it, but some issues remain to be solved.

Jan

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