Re: [RFC] Revert "kvm: nVMX: Restrict VMX capability MSR changes"

[Paolo Bonzini]

On 20/01/20 16:11, Vitaly Kuznetsov wrote:
> 
> RFC. I think the check for vmx->nested.vmxon is legitimate for everything
> but restore so removing it (what I do with the revert) is likely a no-go.
> I'd like to gather opinions on the proper fix: should we somehow check
> that the vCPU is in 'restore' start (has never being run) and make
> KVM_SET_MSRS pass or should we actually mandate that KVM_SET_NESTED_STATE
> is run after KVM_SET_MSRS by userspace?
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

I think this should be fixed in QEMU, by doing KVM_SET_MSRS for feature
MSRs way earlier.  I'll do it since I'm currently working on a patch to
add a KVM_SET_MSR for the microcode revision.

Thanks,

Paolo