[Pkg-libvirt-maintainers] Bug#830857: Bug#830857: libvirt-daemon: CPU feature cmt not found

[Guido Günther]

On Tue, Jul 12, 2016 at 12:13:13PM +0200, Ansgar Hegerfeld wrote:
> Package: libvirt-daemon
> Version: 2.0.0-1
> Severity: normal
> 
> Dear Maintainer,
> 
> after upgrading libvirt-daemon from 1.3.5-1 to 2.0.0-1 I am unable to start
> a virtual machine which is configured with these CPU settings:
> 
> <domain type='kvm'>
>   <name>foobar</name>
>   <uuid>05a431db-0927-4ce2-8fb9-2830c962fa2d</uuid>
>   <memory unit='KiB'>1048576</memory>
>   <currentMemory unit='KiB'>1048576</currentMemory>
>   <vcpu placement='static'>4</vcpu>
>   <resource>
>     <partition>/machine</partition>
>   </resource>
>   <os>
>     <type arch='x86_64' machine='pc-i440fx-2.1'>hvm</type>
>     <bootmenu enable='yes'/>
>   </os>
>   <features>
>     <acpi/>
>     <apic/>
>     <pae/>
>   </features>
>   <cpu mode='host-model'>
>     <model fallback='allow'/>
>   </cpu>
> [...]
> 
> Important is the <cpu mode='host-model'>. With libvirt-daemon 1.3.5-1 this
> worked just fine but now you receive an error like this after turning a
> machine (which was live migrated to the updated host) off and on again:
> 
> "qemu-system-x86_64: CPU feature cmt not found"

That's kind of expected, see:

    http://www.spinics.net/linux/fedora/libvir/msg132822.html

I'd recommend to take this upstream though (since it breaks backward
compat), since I won't be able to do this for quiet some time.

Cheers,
 -- Guido