[vfio-users] Hyper-v enlightments on recent NVIDIA drivers?

[Eddie Yen]

2015-12-05 19:02 GMT+08:00 Ruben Torrero Marijnissen <
ruben.torrero at gmail.com>:

> Hi,
>
> I installed last week a Windows 10 guest on my flaming new Skylake
> build, on top of my Arch Linux install. After doing some reading, I
> understood I had to disable any Hyper-V enlightment and make KVM run in
> 'hidden' mode, so my Nvidia drivers wouldn't shut down.
>
> However, just for the curiosity, I googled for a while and found the
> last version that didn't check for KVM presence and tested the
> different performance with and without Hyper-V enlightments: Oddly,
> Unigine benchmark doesn't show almost *any* performance gain, but with
> several games, the difference can be as big as 50% in heavily loaded
> scenarios. My guess on this games that rely more on the GPU won't see
> much improvements, but games that also use I/O and CPU extensively will
> see a big improvement. Any idea what other reasons there could be?
>

IME, if you didn't add any signs in -cpu tag, or if you deleted any Hvper-V
signs in VM XML file, it will disabled Hyper-V functions.

And, there are many games will got unstable performance without Hyper-V,
especially online games and games that use a lot of mappings.
I got huge performance differences on 3DMark tests. With Hyper-V, I can got
about 103xx, BUT i got only 95xx when I disabled Hyper-V.

If Hyper-V checker has removed since newest driver, it's a good news, but
still need to test it.
Also, some graphic cards only can use previous driver, especially using in
old OS.


> I also read in a forum (https://lime-technology.com/forum/index.php?top
> ic=43824.0) that Alex Williamson is working on a QEMU patch to allow
> Windows guests to use Hyper-V enlightments without Nvidia beeing able
> to detect is. Is this true?. Where could I follow the development /
> test it?
>

You can get that patch by downloading QEMU with git version.
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