Re: [RESPIN PATCH] irqchip/gic-v4.1:Fix VSYNC referencing an unmapped VPE

From: Marc Zyngier
Date: Sat Apr 06 2024 - 05:58:21 EST


On Sat, 06 Apr 2024 03:27:37 +0100,
Nianyao Tang <tangnianyao@xxxxxxxxxx> wrote:
>
> As per the GICv4.1 spec (Arm IHI 0069H, 5.3.19):
>
> "A VMAPP with {V, Alloc}=={0, x} is self-synchronizing, This means the
> ITS command queue does not show the command as consumed until all of
> its effects are completed."
>
> Furthermore, VSYNC is allowed to deliver an SError when referencing a
> non existent VPE.
>
> By these definitions, a VMAPP followed by a VSYNC is a bug, as the
> later references a VPE that has been unmapped by the former.
>
> Fix it by eliding the VSYNC in this scenario.
>
> Fixes: 64edfaa9a234 ("irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP")
>
> Signed-off-by: Nianyao Tang <tangnianyao@xxxxxxxxxx>
> Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>

Thanks for having taken my remarks into account, it looks good now.

Thomas, can you please take this as a fix for 6.9?

Thanks,

M.

--
Without deviation from the norm, progress is not possible.