Comment 5 for bug 2048517

Hello Sergio,

thanks for providing the patch.

I have installed qemu on my test machine. The new epyc-rome-v4 is now listed by qemu

```
# qemu-system-x86_64 -enable-kvm -cpu help| grep -i epyc-rome-v
x86 EPYC-Rome-v1 AMD EPYC-Rome Processor
x86 EPYC-Rome-v2 AMD EPYC-Rome Processor
x86 EPYC-Rome-v3 AMD EPYC-Rome-v3 Processor
x86 EPYC-Rome-v4 AMD EPYC-Rome-v4 Processor (no XSAVES)
```

But I am not able to have the VM dropping xsaves.

I have stopped/started the VM running on my host but it is still requiring the xsaves feature. Same for newly created VMs on the host, they still require the xsaves feature, that means can't be migrated to hosts which have already dropped the xsaves cpu flag. I have also tried to restart nova-compute and libvirtd but still the same:

```
# virsh dumpxml instance-005ac280 | grep xsaves
    <feature policy='require' name='xsaves'/>
```

I believe this patch is not enough to allow migrations between hosts with xsaves and w/o xsaves or I am missing some steps.