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:
<vcpu placement='static'>4</vcpu> <cputune> <vcpupin vcpu='0' cpuset='4'/> <vcpupin vcpu='1' cpuset='5'/> <vcpupin vcpu='2' cpuset='6'/> <vcpupin vcpu='3' cpuset='7'/> <emulatorpin cpuset='4-7'/> </cputune> … … <cpu mode='host-passthrough'> <topology sockets='1' cores='4' threads='1'/> </cpu>
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:
[email protected]:~$ cat /proc/meminfo | grep Huge AnonHugePages: 512000 kB HugePages_Total: 946 HugePages_Free: 946 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB
and added this to the VM XML:
<memoryBacking> <hugepages/> </memoryBacking>
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?