Re: [PATCH v2 3/3] KVM: vmx: handle vm-exit for UMWAIT and TPAUSE

[Tao Xu]

On 29/05/2019 09:28, Paolo Bonzini wrote:
> On 24/05/19 09:56, Tao Xu wrote:
> > As the latest Intel 64 and IA-32 Architectures Software Developer's
> > Manual, UMWAIT and TPAUSE instructions cause a VM exit if the
> > âRDTSC exitingâ and âenable user wait and pauseâ VM-execution controls
> > are both 1.
> >
> > This patch is to handle the vm-exit for UMWAIT and TPAUSE as invalid_op.
>
> KVM never enables RDTSC exiting, so this is not necessary.
>
> Paolo
OK, but should we just drop this patch?
Or add the VMX_EXIT_REASONS bits of UMWAIT and TPAUSE and handle like 
XSAVES/XRSTORS:
"kvm_skip_emulated_instruction(vcpu);"
"WARN(1, "this should never happen\n");"

Looking forward to your reply.

Tao