[PATCH] arm64: errata: Mitigate AmpereOne erratum AC03_CPU_57 and AC04_CPU_29

[D Scott Phillips]

Marc Zyngier <maz at kernel.org> writes:

> On Wed, 15 Jul 2026 00:06:00 +0100,
> D Scott Phillips <scott at os.amperecomputing.com> wrote:
>> 
>> > OK, that's pretty good news. Can I safely assume that your HW doesn't
>> > support VLPIs/VSGIs in any form (no GICv4+)?
>> 
>> AmpereOne AC04 does have gicv4.1 with vlpis/vsgis. Those take a
>> different enough path in the core that a deactivation of a pending
>> vlpi/vsgi won't cause the issue. The wording about "physical interrupt"
>> is meant to exclude vlpis/vsgis, sorry that it didn't come out clearly.
>
> Given that the write-up didn't mention direct injection at all, it
> wasn't totally obvious whether this was taken into account or not.
> Might be worth adding to the errata document for clarity.

Yep, makes sense. I'll work on getting that clarification added.