On Wed, Dec 4, 2024, at 17:37, H. Peter Anvin wrote: > On December 4, 2024 5:29:17 AM PST, Brian Gerst <brgerst@xxxxxxxxx> wrote: >>> >>> Removing this also drops the need for PHYS_ADDR_T_64BIT and SWIOTLB. >>> PAE mode is still required to get access to the 'NX' bit on Atom >>> 'Pentium M' and 'Core Duo' CPUs. > > By the way, there are 64-bit machines which require swiotlb. What I meant to write here was that CONFIG_X86_PAE no longer needs to select PHYS_ADDR_T_64BIT and SWIOTLB. I ended up splitting that change out to patch 06/11 with a better explanation, so the sentence above is just wrong now and I've removed it in my local copy now. Obviously 64-bit kernels still generally need swiotlb. Arnd