Arch Linux

jakogut

Member

Registered: 2014-11-27

Posts: 9

[Request] Qemu KVMGT

Intel just recently released the 2015Q3 version of their iGVT-g project, which allows for mediated passthrough of Intel GPUs using KVM or Xen.

I tried making a PKGBUILD for the Qemu component based on qemu-git from the AUR using these setup guides:
https://github.com/01org/Igvtg-kernel/b … _Guide.txt
https://github.com/01org/Igvtg-qemu/blo … ADME.kvmgt

However, when I try to connect to the KVM driver using Virt-manager, it says "cannot find suitable emulator for x86_64" When I try to start an otherwise working domain with my build of Qemu using virsh, it says:

error: Failed to start domain $domain
error: Invalid argument: could not find capabilities for arch=x86_64

Here is my PKGBUILD:

https://github.com/jakogut/qemu-kvmgt

I do already have their kernel built and installed, and `dmesg | grep kvm` reports:

[    6.917877] kvm: Nested Virtualization enabled
[    6.917885] kvm: Nested Paging enabled

Unfortunately, I'm not well enough versed with Qemu to diagnose what's gone wrong.

Last edited by jakogut (2015-10-31 18:44:20)

jakogut

Member

Registered: 2014-11-27

Posts: 9

Re: [Request] Qemu KVMGT

It seems that when I try to launch qemu directly, it's reporting an incompatibility with KVM:

(process:1537): GLib-WARNING **: gmem.c:482: custom memory allocation vtable not supported
kvm version too old
failed to initialize KVM: Invalid argument

I'm going to try messing with my config, recompiling my kernel, and seeing if I can get it to work.

gmk

Member

Registered: 2015-03-08

Posts: 8

Re: [Request] Qemu KVMGT

Thanks for the thread, been waiting for an update on kvm-gt for a while now, there's nothing on their blog yet

I tried kvm-gt a couple of months ago but couldn't get it up/running.

The xen branch worked, guests were windows 7 and ubuntu 14.10, but due to some other issues with xen I use kvm in my setup.

I stopped tinkering with it back then (a couple of months ago), but will try again with this update in the next couple of days and post my findings here.

jakogut

Member

Registered: 2014-11-27

Posts: 9

Re: [Request] Qemu KVMGT

After some more research and discussion with the developers, it seems that some code was missing from the kernel repository, and the KVM_API_VERSION constant was not the same between the kernel and Qemu.

I'm building the packages right now, and if they work, I'll neaten them up and upload them to the AUR.

gmk

Member

Registered: 2015-03-08

Posts: 8

Re: [Request] Qemu KVMGT

whelp, it (vgt on kvm) works! I used your PKGBUILD file/repo, thanks for putting it together!

(process:1537): GLib-WARNING **: gmem.c:482: custom memory allocation vtable not supported
kvm version too old

the "vtable not supported" I also get, after updating qemu from 2.2.1 to 2.4.0.1 (on a non-vgt-qemu with a non-vgt-kernel), but also on vgt-qemu+kernel now.

The "kvm version too old" I encountered as well, but not anymore after using your PKGBUILD/git repo

Intel I7-4790k on Asrock Z97 Pro 4
Guest OS is Windows 7 64bit
PCIe passthrough also works (one VM gets a Radeon R9 280 passed through, the other one runs on kvmgt/igvt-g)

Add:
since this relies on a modified kernel, are there intentions to provide a package for a kernel as well?

Last edited by gmk (2015-11-06 01:18:04)

jakogut

Member

Registered: 2014-11-27

Posts: 9

Re: [Request] Qemu KVMGT

I'm happy to hear that! I never did get KVMGT working on my Broadwell machine, but I've got another Haswell machine that I just finished getting XenGT working on today. I'll clean up the packages and upload them to the AUR.

And yes, I do have a kernel package to go along with it.

Last edited by jakogut (2015-11-20 22:21:44)

jakogut

Member

Registered: 2014-11-27

Posts: 9

Re: [Request] Qemu KVMGT

I've finished packaging the kernel and Xen parts of the iGVT-g project as linux-igvtg and xen-igvtg respectively. They can be found on the AUR.

timofonic

Member

Registered: 2007-05-15

Posts: 47

Re: [Request] Qemu KVMGT

• linux-igvtg is irrelevant these days. Am I right?

• xen-igvtg AUR package is outdated. It doesn't build. There are a interesting commit for an old Igvtg-xen branch too.

• qemu-kvmgt] isn't in AUR but on GitHub only. Unmaintained since 2015. The correct name should be igvtg-qemu as the original project. I believe it works for both KVM and Xen virtualization technologies. There's a fork with one change. There's a significant commit in the outdated 2.7 branch  named GVT-g compositor display using GVT-g's dmabuf and the comment is "This is an example implementation on how to use the GVT-g's dmabuf to show the desktop of a vm which use the intel vgpu."

I'll ask in the igvtg intel mailing list to see what's happening. Two years and no merge to both Xen and Qemu. And relevant features implemented as experimental in an outdated version (2.7)

Last edited by timofonic (2017-08-08 04:37:38)

Uriel_Bernhard48

Member

Registered: 2017-08-08

Posts: 29

Re: [Request] Qemu KVMGT

KVMGT is part of linux kernel since 4.10 all the rest you linked are legacy dead stuff

https://www.kraxel.org/blog/2017/01/vir … -upstream/

gmk

Member

Registered: 2015-03-08

Posts: 8

Re: [Request] Qemu KVMGT

hope they don't ditch too much of the good stuff with the upstreaming. I'm currently running a kernel from the latest pre-upstream repo, on a devils canyon cpu.. but they are keen on throwing haswell out. Wouldn't be surprised if that's just intel policy.

Offtopic:
timofonic, where have you heard of kvmgt?
Someone just posted a lengthy text on the mailing list, thought it was you. Or is it just getting some publicity