Re: [PATCH 15/19] kvm: x86: Save and restore guest XFD_ERR properly

[Paolo Bonzini]

On 12/11/21 01:10, Thomas Gleixner wrote:
>      2) When the guest triggers #NM is takes an VMEXIT and the host
>         does:
>
>                  rdmsrl(MSR_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
>
>         injects the #NM and goes on.
>
>      3) When the guest writes to MSR_XFD_ERR it takes an VMEXIT and
>         the host does:
>
>             vcpu->arch.guest_fpu.xfd_err = msrval;
>             wrmsrl(MSR_XFD_ERR, msrval);

No wrmsrl here I think, the host value is 0 and should stay so.  Instead 
the wrmsrl will happen the next time the VCPU loop is entred.

Paolo