Some time ago it was noticed that Win10 1803 WM's would give high CPU usage on the host e.g. 25%, even though client CPU usage 0%. It was solved by having these settings in your virt XML file:
<hyperv> <relaxed state='on'/> <vapic state='on'/> <spinlocks state='on' retries='8191'/> <synic state='on'/> <stimer state='on'/> </hyperv> <clock offset='localtime'> <timer name='rtc' tickpolicy='catchup'/> <timer name='pit' tickpolicy='delay'/> <timer name='hpet' present='no'/> <timer name='hypervclock' present='yes'/> </clock>
But the problem is new back.
I've moved from Debian stretch (
QEMU 2.8.1 /
Kernel 4.9) to Buster (
QEMU 3.1.0 /
Kernel 4.19) and Windows 10 1809.
The problem might be related to I can no longer use
<synic state='on'/> on Buster which I could on Stretch on the same hardware.
When I try to start the VM i get this error
error: internal error: process exited while connecting to monitor: Hyper-V SynIC (requested by 'hv-synic' cpu flag) requires Hyper-V VP_INDEX ('hv-vpindex') 2019-08-06T13:29:14.114943Z qemu-system-x86_64: kvm_init_vcpu failed: Function not implemented
When I run
lscpu I don't have any
hv* flags at all. But again, it worked on Stretch on the same CPU.