[libvirt-users] LibVirt query CPU Model support and restore operation

[akhilesh rawat]

hi,

yes we are talking about same host here.

You could've just used -cpu host-model-only
>> I dont want to host model ( it is working with host model) .

AS KVM seems to allow support Haswell with native commands . Does this mean
in my case KVM is allowing software emulated cpu model.

Can libvirt allow  software-emulated for non host model ?  if yes how .

thanks





On Tue, Jan 24, 2017 at 1:32 PM, Martin Kletzander <mkletzan at redhat.com>
wrote:

> On Tue, Jan 24, 2017 at 10:08:12AM +0530, akhilesh rawat wrote:
>
>> Hello ,
>>
>> It was working good working with kvm management tools using libvirt .
>> virsh/virt-manager .
>>
>> But then i got annoyed when management tool did not allow me to change the
>> CPU model while creating new virtual machine .
>> error
>>
>>
> Are we talking about the same host?
>
> root at kvm-server qemu]# virt-install --virt-type kvm --name compute-2 --cpu
>> Haswell-noTSX --ram=61440 --vcpus=20 --os-type=linux --os-variant=generic
>> --disk
>> compute2-disk0.qcow2,device=disk,bus=ide,size=300,sparse=tru
>> e,format=qcow2
>> --pxe --network bridge=virbr0,model=e1000 --network
>> bridge=virbr0,model=e1000 --network bridge=virbr0,model=virtio --network
>> bridge=virbr0,model=virtio --graphics vnc,port=5906 --noautoconsole
>>
>> Starting install...
>> ERROR    unsupported configuration: guest and host CPU are not compatible:
>> Host CPU does not provide required features: invpcid, erms, bmi2, smep,
>> avx2, bmi1, fsgsbase, movbe, fma
>> Domain installation does not appear to have been successful.
>>
>> I could not resolve this error .
>>
>>
> You could've just used -cpu host-model-only.
>
> Finally i came across the post which say that libvirt cross verifies  flags
>> under CPU model present in
>> /usr/share/libvirt/cpu_map.xml and cat /proc/cpuinfo .
>>
>> An yes the flag complained were not present in host proc/cpuinfo.
>>
>> Question 1: Is it really needed for Libvirt to do this check .
>>
>>
> It is, otherwise users might not get what they asked for.  Or it might
> be software-emulated.
>
> AS KVM seems to allow support Haswell with native commands . Why libvirt is
>> doing this check then ?
>>
>> As i was not sure where the problem lies and i was using libvirt 2.0.0
>> version i upgraded to 2.5.0 by compiling form source .
>> But then i faces issue using virsh/virt-manager as seem it was not
>> compatilble with upgarded version of libvirt.
>>
>> Now my system is little messed  around libvirt . I did reinstall/reboot
>> Quite many things not working .
>>
>> Question 2 : How can i restore original Libvirt 2.0.0 .
>>
>>
> Depends on your distro.  You can just uninstall and install the older
> version if your package managed doesn't support downgrading.  But try to
> keep on the newer one and fix your workflow.
>
>
>> br aki
>>
>
> _______________________________________________
>> libvirt-users mailing list
>> libvirt-users at redhat.com
>> https://www.redhat.com/mailman/listinfo/libvirt-users
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvirt-users/attachments/20170124/fc99e49c/attachment.htm>