QEMU 2.5 Is Near With 3D GPU Support & More

[mike4]

Just a reminder folks:

You will need... Mesa 11.1, Kernel 4.4, and QEMU 2.5 in order to use Virtual 3D. If you're not on a rolling release distro, it'll probably be a bit before you see the fruits of these labors.

So in a short while we all can play 3D games on Windows with qemu? No need for a special CPU etc.? Cool, I wouldn't need a dual boot (actually a triple with osx86) setup on my next pc anymore.

[bitman]

So in a short while we all can play 3D games on Windows with qemu? No need for a special CPU etc.? Cool, I wouldn't need a dual boot (actually a triple with osx86) setup on my next pc anymore.

It will be a while before windows gets driver that supports 3d acceleration. Yes, here you will have to use special qemu driver, not vendor driver. It will certainly be slower, dont know how much however but i bet it will be enough to make some titles unplayable. No idea about CPU requirements, but i would not call vt-x/vt-d something special nowdays..

[LightBit]

windows guests have no kernel

Really?

[mike4]

It will be a while before windows gets driver that supports 3d acceleration. Yes, here you will have to use special qemu driver, not vendor driver. It will certainly be slower, dont know how much however but i bet it will be enough to make some titles unplayable. No idea about CPU requirements, but i would not call vt-x/vt-d something special nowdays..

Baah, I thought that's qemu 2.5 all about to use the hosts graphics driver. CPUs with vt-d/x passthrough costs extra hence it's special. qemu 2.5 still needs vt-d/x?

[Ericg]

Baah, I thought that's qemu 2.5 all about to use the hosts graphics driver. CPUs with vt-d/x passthrough costs extra hence it's special. qemu 2.5 still needs vt-d/x?

Passing the driver through still.has overhead though, vt-d/vt-x Passthrough will always be faster since its direct access. And yes, the feature is extra, but not by very much. Doing pass-through will require vt-d/vt-x no matter the version of QEMU

[tajjada]

qemu 2.5 enables hyper-v enlightenments when using GPU passthrough with an Nvidia card

requires you to use the hv_vendor_id cpu flag

Very interesting! Do you have any additional details/information/instructions about this?

I have a virtual machine running Windows 10 with NVIDIA GPU passthrough that I use for gaming. Do you mean that with qemu 2.5 I will be able to actually enable the hyper-v virtual machine enhancements without the NVIDIA driver b*itching about it? If yes, this is really exciting! Can't wait to try it out when qemu 2.5 is released! (I am on gentoo, and am willing and able to write/modify ebuilds to install the stuff I want, so no problem with having to wait for distro to catch up for me)

After this, all that's left is to wait for an annoying kernel bug (that breaks VFIO passthrough) to get fixed, so that I can finally upgrade to something newer than 4.1. https://bugzilla.kernel.org/show_bug.cgi?id=107561 arrgh.

[peppercats]

Very interesting! Do you have any additional details/information/instructions about this?

just add hv_vendor_id= to your CPU flag along with the other hyper-v flags, it(hv_vendor_id) can be completely empty. e.g, here's my cpu flag for qemu
-cpu Opteron_G5,check,enforce,-rdtscp,+bmi1,+osvw,+cr8legacy,+cmp_legacy,+fxsr_op t,+mmxext,+vme,hv_time,hv_relaxed,hv_vapic,hv_spin locks=0x1fff,hv_vendor_id=,kvm=off

I have a virtual machine running Windows 10 with NVIDIA GPU passthrough that I use for gaming. Do you mean that with qemu 2.5 I will be able to actually enable the hyper-v virtual machine enhancements without the NVIDIA driver b*itching about it? If yes, this is really exciting! Can't wait to try it out when qemu 2.5 is released! (I am on gentoo, and am willing and able to write/modify ebuilds to install the stuff I want, so no problem with having to wait for distro to catch up for me)

that's specifically what it fixes, I assume nvidia is blacklisting the kvm ID or something because fuck nvidia

After this, all that's left is to wait for an annoying kernel bug (that breaks VFIO passthrough) to get fixed, so that I can finally upgrade to something newer than 4.1. https://bugzilla.kernel.org/show_bug.cgi?id=107561 arrgh.

check /proc/mtrr, it might be registering addresses in use by your video card, it does it for me on 4.2+. Disable them if so(echo "disable=n" > /proc/mtrr where n is the # from /proc/mtrr)

[pal666]

Really?

really no kernel 4.4
surprise

[bitman]

Baah, I thought that's qemu 2.5 all about to use the hosts graphics driver. CPUs with vt-d/x passthrough costs extra hence it's special. qemu 2.5 still needs vt-d/x?

Yes, its all about using host's graphics driver. However VM has to know how to fetch video data from your host therefore custom driver required. Its exactly same thing like with virtio - under the hoold it uses host's drivers but guest still needs virtio drivers so it can talk to host.