Not sure if this is the correct channel for this but…
I have recently built a 1920x Threadripper system and running Ubuntu 19.10 as the host OS. I have installed KVM with a Windows 10 VM but the CPU in the VM is not being reported correctly.
It is being reported as AMD EPYC Processor (with IBPB) I have assigned 8 cpus to the VM but windows task manager is reporting 2 sockets and 2 virtual cpus.
In the details for the VM under CPU there is the drop down menu to select the CPU type but threadripper is not listed.
How can I get the correct CPU detected? I tried VirtualBox and the CPU is detected correctly.
I have a Ryzen 3900x which had a similar problem in my windows 10 VM, showing up as epyc, and not the correct cpu/thread count
First, cpu-mode should be “host-passthrough”… this made my windows vm’s (7 &10) to show as a ryzen 3900x. In fact, windows 7 refuses to update BECAUSE it sees the ryzen processor.
If your using virt-manager you can just type that in the model box under CPU.
second, add this to the cpu tag in your xml <feature policy='disable' name='smep'>
This, you will have to add by manually editing the vm’s xml file, like this
So I made the changes you mentioned in your message but my Win10 VM blue screens immediately with “SYSTEM THREAD EXCEPTION NOT HANDLED” this is when I put “host-passthrough” in leave it on “host-model” boots ok.
Hm, ok well task manager isn’t reporting the correct CPU still however after editing the XML with the correct cpu/thread counts performance is much improved.
Running CPU passmark before the changes got me 1,733 after the changes 14,500 I can live with this…
“options kvm ignore_msrs=1” to “/etc/modprobe.d/kvm.conf”
However in my case the file is “/etc/modprobe.d/qemu-system-x86.conf” and when added I rebooted I changed to host-passthrough and disabled SMEP now task manager is reporting the CPU correctly.