linux-kernel - RE: [PATCH 0/7] KVM: VMX: Handle NMI VM-Exits in noinstr section

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Message-ID: <BN6PR1101MB216100DFFC7ACA0B63C2F40BA8E09@BN6PR1101MB2161.namprd11.prod.outlook.com>
Date:   Wed, 14 Dec 2022 17:09:41 +0000
From:   "Li, Xin3" <xin3.li@...el.com>
To:     "Christopherson,, Sean" <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "Lutomirski, Andy" <luto@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: RE: [PATCH 0/7] KVM: VMX: Handle NMI VM-Exits in noinstr section

> I kept the use of a direct call to a dedicated entry point for NMIs
> (doubled down really).  AFAICT, there are no issues with the direct call
> in the current code, and I don't know enough about FRED to know if using
> INT $2 would be better or worse, i.e. less churn seemed like the way to
> go.  And if reverting to INT $2 in the future is desirable, splitting NMI
> and IRQ handling makes it quite easy to do so as all the relevant code
> that needs to be ripped out is isolated.

Thanks for making this change.

There is no big difference between "int $2" and calling the NMI handler explicitly.

Xin