Re: Xen on AWS EC2 Graviton 2 metal instances (c6g.metal)

[Julien Grall <julien@xxxxxxx>]

On 03/10/2023 00:03, Stefano Stabellini wrote:
> On Mon, 2 Oct 2023, Julien Grall wrote:
> > On 29/09/2023 21:29, Stefano Stabellini wrote:
> > Now regarding whether the PPI is used. AFAICT, the secure timer PPI is still
> > present in the firmware tables (ACPI and DT) passed to dom0. So strictly
> > speaking we want to ensure the PPI value is reserved.
> >
> > That said, the ACPI spec suggests that the value will be ignored by the guest.
> > The Device-Tree binding doesn't have such statement, but I suspect this may be
> > the same. So it should be ok to skip reserving the PPI and therefore allow the
> > event channel interrupt to use if it is not reserved by someone else.
> You looked into this more deeply then I did. Your suggestion makes sense
> to me.
I have sent a patch [1]. This is not quite the same as I discussed 
before. See the commit message for more details.
Cheers,

[1] https://lore.kernel.org/20231005165454.18143-1-julien@xxxxxxx

--
Julien Grall