On Mon, Sep 08, 2025 at 08:22:59AM +0000, Shameer Kolothum wrote: > > nit: strictly speaking couldn't we have a stage2 being used at guest > > level implemented by a stage1 at physical level? > > but it is totally fair to restrict the support. > > Yeah it is possible I guess. But then we have to use the S2TTB to configure > Host SMMUv3 S1 instead of S1ContextPtr which is used now.
S1 and S2 have different PTE formats, you cannot take a guest S2 table with S2 PTEs and have the hypervisor program it to a S1. The guest must see a SMMU with no S2 support in the IDRs. Jason
