Re: [PATCH v14 3/5] KVM: arm64: Manage GCS access and registers for guests

From: Marc Zyngier
Date: Sat Oct 05 2024 - 10:34:03 EST


On Sat, 05 Oct 2024 15:26:38 +0100,
Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> [1 <text/plain; us-ascii (7bit)>]
> On Sat, Oct 05, 2024 at 03:02:09PM +0100, Marc Zyngier wrote:
> > Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> > > Ah, I see. I'd been under the impression that the generic machinery was
> > > supposed to handle this already using the descriptions in
> > > emulate-nested.c and we only needed handlers for more specific actions.
>
> > From that very file:
>
> > /*
> > * Map encoding to trap bits for exception reported with EC=0x18.
> > [...]
> > */
>
> > Everything else needs special handling.
>
> I see. I had noticed that comment on that table but I didn't register
> that the comment wound up applying to the whole file rather than being
> about a specific part of the handling. I'm a bit confused about how
> things like the SVE traps I mentioned work here...

Like all ECs, the handling starts in handle_exit.c.

M.

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