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From: Thomas Gleixner <tglx@linutronix.de>
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To: Sean Christopherson <seanjc@google.com>, Ingo Molnar <mingo@redhat.com>,
 Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>,
 x86@kernel.org, Sean Christopherson <seanjc@google.com>, Paolo Bonzini
 <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Jacob Pan
 <jacob.jun.pan@linux.intel.com>, Jim Mattson <jmattson@google.com>
Subject: Re: [PATCH 1/8] x86/irq: Ensure initial PIR loads are performed
 exactly once
In-Reply-To: <20250315030630.2371712-2-seanjc@google.com>
References: <20250315030630.2371712-1-seanjc@google.com>
 <20250315030630.2371712-2-seanjc@google.com>
Date: Mon, 17 Mar 2025 12:23:31 +0100
Message-ID: <871puv6guk.ffs@tglx>
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On Fri, Mar 14 2025 at 20:06, Sean Christopherson wrote:
> Ensure the PIR is read exactly once at the start of handle_pending_pir(),
> to guarantee that checking for an outstanding posted interrupt in a given
> chuck doesn't reload the chunk from the "real" PIR.  Functionally, a reload
> is benign, but it would defeat the purpose of pre-loading into a copy.
>
> Fixes: 1b03d82ba15e ("x86/irq: Install posted MSI notification handler")
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>