Re: [PATCH 1/8] x86/irq: Ensure initial PIR loads are performed exactly once
From: Thomas Gleixner
Date: Mon Mar 17 2025 - 07:24:44 EST
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@xxxxxxxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>