Re: [PATCH] KVM/VMX: Invoke NMI non-IST entry instead of IST entry

[Andy Lutomirski]

> On May 4, 2021, at 2:21 PM, Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> 
> On Tue, May 04, 2021, Paolo Bonzini wrote:
>>> On 04/05/21 23:05, Maxim Levitsky wrote:
>>> Does this mean that we still rely on hardware NMI masking to be activated?
>> 
>> No, the NMI code already handles reentrancy at both the assembly and C
>> levels.
>> 
>>> Or in other words, that is we still can't have an IRET between VM exit and
>>> the entry to the NMI handler?
>> 
>> No, because NMIs are not masked on VM exit.  This in fact makes things
>> potentially messy; unlike with AMD's CLGI/STGI, only MSRs and other things
>> that Intel thought can be restored atomically with the VM exit.
> 
> FWIW, NMIs are masked if the VM-Exit was due to an NMI.

Then this whole change is busted, since nothing will unmask NMIs. Revert it?