Re: [PATCH v2 4/4] KVM: x86: Expose Architectural LBR CPUID and its XSAVES bit

[Paolo Bonzini]

On 05/02/21 09:16, Xu, Like wrote:
> Hi Paolo,
>
> I am wondering if it is acceptable for you to
> review the minor Architecture LBR patch set without XSAVES for v5.12 ?
>
> As far as I know, the guest Arch LBR  can still work without XSAVES 
> support.

I dopn't think it can work.  You could have two guests on the same 
physical CPU and the MSRs would be corrupted if the guests write to the 
MSR but they do not enable the LBRs.

Paolo