On Wed, Nov 23, 2022 at 18:34:38 +0530, manish.mishra wrote:
> oh i see you meant something like this,
>
> <cpu mode='custom' match='exact' check='none'>
> <numa>
> <cell id='0' cpus='0-239' memory='8388608' unit='KiB' memAccess='shared'/>
> </numa>
> </cpu>
>
> <qemu:commandline>
> <qemu:arg value='-cpu'/>
> <qemu:arg value='enforce,Icelake-v4,x2apic=on,hv-time,kvm-pv-eoi=on'/>
> </qemu:commandline>
This won't work as libvirt should add a default CPU model there and
replace check='none' with check='full' once the domain starts.
But we actually have a way to do what you need even without any change
in libvirt:
<cpu mode='host-passthrough' check='none'>
<topology .../>
<numa>
...
</numa>
...
</cpu>
<qemu:commandline>
<qemu:arg value='-cpu'/>
<qemu:arg value='Icelake-Server-v4,enforce,x2apic=on,hv-time,kvm-pv-eoi=on'/>
</qemu:commandline>
This will result in
-cpu host,migratable=on
...
-cpu Icelake-Server-v4,enforce,x2apic=on,hv-time,kvm-pv-eoi=on
and libvirt will not touch the check='none' attribute once the domain
starts and it would not complain about any unknown CPU features or
models as there's nothing to check in <cpu/>.
That is, there's no need to come up with anything special to support
passing arbitrary options to -cpu.
Jirka
