Re: [PATCH v3 1/1] irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection

From: Marc Zyngier
Date: Wed Mar 17 2021 - 10:05:36 EST


Hi Lorenzo,

Wed, 17 Mar 2021 10:07:19 +0000,
Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote:
>
> GIC CPU interfaces versions predating GIC v4.1 were not built to
> accommodate vINTID within the vSGI range; as reported in the GIC
> specifications (8.2 "Changes to the CPU interface"), it is
> CONSTRAINED UNPREDICTABLE to deliver a vSGI to a PE with
> ID_AA64PFR0_EL1.GIC < b0011.
>
> Check the GIC CPUIF version by reading the SYS_ID_AA64_PFR0_EL1.
>
> Disable vSGIs if a CPUIF version < 4.1 is detected to prevent using
> vSGIs on systems where they may misbehave.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>

Does it need to go in as a fix? or can it just be pushed into 5.13?
Given that there is no such HW in the wild just yet, I'm inclined to
do the latter...

Thanks,

M.

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