Re: [PATCH] arm64: errata: Mitigate AmpereOne erratum AC03_CPU_57 and AC04_CPU_29
From: Marc Zyngier
Date: Wed Jul 15 2026 - 08:33:59 EST
On Wed, 15 Jul 2026 00:06:00 +0100,
D Scott Phillips <scott@xxxxxxxxxxxxxxxxxxxxxx> 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.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.