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Date:   Wed, 23 Nov 2022 19:18:50 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     "Li, Xin3" <xin3.li@intel.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "hpa@zytor.com" <hpa@zytor.com>,
        "Tian, Kevin" <kevin.tian@intel.com>
Subject: Re: [RESEND PATCH 5/6] KVM: x86/VMX: add kvm_vmx_reinject_nmi_irq()
 for NMI/IRQ reinjection
Message-ID: <Y35yGltCxrwueOqn@google.com>
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On Wed, Nov 23, 2022, Peter Zijlstra wrote:
> On Tue, Nov 22, 2022 at 08:52:35PM +0000, Sean Christopherson wrote:
> 
> > Another wart that needs to be addressed is trace_kvm_exit().  IIRC, tracepoints
> > must be outside of noinstr, though maybe I'm misremembering that.
> 
> You are not, that is correct. Another point to be careful with is usage
> of jump_label and static_call, both can be used in noinstr *provided*
> they don't actually ever change -- so boot time setup only.
> 
> If either of them were to change, text_poke_bp() has a clue in the name.

I think we're mostly ok on that front.  kvm_wait_lapic_expire() consumes multiple
static keys that can change at will, but that can be kept outside of the noinstr
section.  

Thanks!