Hi Guys, I am suffering from some horrible CPU performance within my VM. It is a windows 10 VM with GPU pass through made primarily for gaming. After experiencing such poor performance I tried my hand at CPU pinning and setting up Hugepages but ended up with the same performance.
My specs and set up are as follows:
AMD 8350 (4 cores assigned to VM)
AMD R9 390(Guest)
Nvidia 610 (Host)
Memory 16GB (8GB assigned to guest)
Current OS: Ubuntu 16.04
Virt Manager 1.4 with latest OVMF & virtio 0.1.126 PV drivers.
*This was setup prmarily following the Guides at VFIO blogspot and Graywolf's tutorial. I initially attempted this with Debian and Fedora 24 but had the same CPU performance issue.
I have 4 cores isolated and assigned to the VM as seen below:
<vcpupin vcpu='0' cpuset='4'/>
<vcpupin vcpu='1' cpuset='5'/>
<vcpupin vcpu='2' cpuset='6'/>
<vcpupin vcpu='3' cpuset='7'/>
<topology sockets='1' cores='4' threads='1'/>
*Info taken from https://forum.level1techs.com/t/gpu-passthrough-with-kvm-have-your-cake-and-eat-it-too/82250/195"
When using system monitor on Ubuntu, these cores are at 0% usage until the VM is started. When the VM is started the core usage starts to go up and once I start running a game it basically maxes out from 80 -100% on all 4 cores giving horrible performance.
I have also tried setting up Huge pages following https://help.ubuntu.com/community/KVM%20-%20Using%20Hugepages and adding it into the VM as well:
marlon@MBLPC:~$ cat /proc/meminfo | grep Huge
AnonHugePages: 512000 kB
Hugepagesize: 2048 kB
and added this to the VM XML:
When the VM is running the total amount of free huge pages is still equal to the total amount so I am assuming that it is not being used?
Any ideas on what I maybe missing and why the CPU cores are maxing out?