On Fri, 16 Oct 2026 17:46:58 +0800 Jinjie Ruan <[email protected]> wrote:
> From: Jinjie Ruan <[email protected]> > > The MPAM ACPI table points at cache MSCs via a cache_reference that > the kernel resolves against a PPTT cache node carrying a Cache ID > (only present in PPTT revision 3, with the Cache ID valid flag). > Without it, a guest MPAM driver cannot associate cache MSCs with > caches and rejects them. > > Bump the PPTT to revision 3 and give every cache node an ID derived > from its type, level and the first CPU of the topology container it > belongs to. The virt machine's MPAM cache MSC creation uses the same > topology levels (L3 at socket, L2 at cluster) as the PPTT builder and > derives the same IDs, so MSC locators resolve to real cache nodes. Good. We dropped this from the last PPTT revision upgrade on basis we had no user without MPAM. Now we do indeed need an upgrade. PPTT is tested though so you need to add the two wrapping commits described at the top of tests/qtest/bios-tables-test.c and upgrade any effect tables in tests/data/acpi/arm/... Given the implementation defined aspect of this is how the cache IDs are derived, I'd add a description of that here. With that stuff tidied up. Reviewed-by: Jonathan Cameron <[email protected]> > > Signed-off-by: Jinjie Ruan <[email protected]>
