Date:   Tue, 31 Jan 2023 21:12:16 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Maxim Levitsky <mlevitsk@redhat.com>
Cc:     kvm@vger.kernel.org, Sandipan Das <sandipan.das@amd.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Jim Mattson <jmattson@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>,
        Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Daniel Sneddon <daniel.sneddon@linux.intel.com>,
        Jiaxi Chen <jiaxi.chen@linux.intel.com>,
        Babu Moger <babu.moger@amd.com>, linux-kernel@vger.kernel.org,
        Jing Liu <jing2.liu@intel.com>,
        Wyes Karny <wyes.karny@amd.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v2 07/11] KVM: x86: add a delayed hardware NMI injection
 interface
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References: <20221129193717.513824-1-mlevitsk@redhat.com>
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 <Y9R1w8kfQjCNnEfl@google.com>
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On Sat, Jan 28, 2023, Sean Christopherson wrote:
> On Tue, Nov 29, 2022, Maxim Levitsky wrote:
> > @@ -10015,13 +10022,34 @@ static void process_nmi(struct kvm_vcpu *vcpu)
> >  	 * Otherwise, allow two (and we'll inject the first one immediately).
> >  	 */
> >  	if (static_call(kvm_x86_get_nmi_mask)(vcpu) || vcpu->arch.nmi_injected)
> > -		limit = 1;
> > +		limit--;
> > +
> > +	/* Also if there is already a NMI hardware queued to be injected,
> > +	 * decrease the limit again
> > +	 */
> 
> 	/*
> 	 * Block comment ...
> 	 */
> 
> > +	if (static_call(kvm_x86_get_hw_nmi_pending)(vcpu))
> 
> I'd prefer "is_hw_nmi_pending()" over "get", even if it means not pairing with
> "set".  Though I think that's a good thing since they aren't perfect pairs.

Thinking more, I vote for s/hw_nmi/vnmi.  "hardware" usually means actual hardware,
i.e. a pending NMI for the host.