On Fri, Oct 31, 2025 at 09:52:16AM +0000, Duan, Zhenzhong wrote: > >> + /* > >> + * When guest enables scalable mode and sets up first stage page > >table, > >> + * we stick to system MR for IOMMUFD backed host device. Then its > >> + * default hwpt contains GPA->HPA mappings which is used directly if > >> + * PGTT=PT and used as nesting parent if PGTT=FST. Otherwise fall > >back > >> + * to original processing. > >According to the above comment you have a S1 translation in place but > >you set use_iommu = false and use system MR? > > Yes, we have extended the usages of MRs under IOMMU AS with nesting. > In nesting mode, system MR on/off isn't aligned with S1 translation anymore.
Does Intel vIOMMU need S1 translation when the working in the HW accelerated mode? I thought everything is handled by the HW..no? Nicolin
