Arch Linux

damjan

Member

Registered: 2006-05-30

Posts: 462

libvirt: guest CPU doesn't match specification: missing features: ibpb

I can't start my Arch VM on an Arch host with libvirt. At the same time a debian 9 guest works fine:

$ sudo virsh start arch-uefi-test
[sudo] password for damjan: 
error: Failed to start domain arch-uefi-test
error: operation failed: guest CPU doesn't match specification: missing features: ibpb

Versions are:

libvirt 4.3.0-1
qemu 2.12.0-1
linux 4.16.12-1

Both VMs have very similar configs, some of it:

  <os><type arch='x86_64' machine='pc-i440fx-2.7'>hvm</type></os>
  …
  <cpu mode='host-model' check='partial'>

Couldn't find what missing features: ibpb means.
The CPU is a Haswell based Intel Pentium G3220

loqs

Member

Registered: 2014-03-06

Posts: 19,113

Re: libvirt: guest CPU doesn't match specification: missing features: ibpb

Indirect Branch Prediction Barrier

damjan

Member

Registered: 2006-05-30

Posts: 462

Re: libvirt: guest CPU doesn't match specification: missing features: ibpb

And I just found that there was a /var/lib/libvirt/qemu/save/arch-uefi-test.save file, which I removed now, and the VM started