Re: [RESEND] Atomic switch of MSR_IA32_UMWAIT_CONTROL

[Paolo Bonzini]

On 23/01/20 16:45, Sean Christopherson wrote:
> cc'ing KVM and LKML this time...
> 
> Why does KVM use the atomic load/store lists to load MSR_IA32_UMWAIT_CONTROL
> on VM-Enter/VM-Exit?  Unless the host kernel is doing UWMAIT, which it
> really shouldn't and AFAICT doesn't, isn't it better to use the shared MSR
> mechanism to load the host value only when returning to userspace, and
> reload the guest value on demand?

Just laziness I guess.

Paolo