Hi Suzuki, On Mon, Apr 04, 2016 at 05:26:00PM +0100, Suzuki K Poulose wrote: > This series adds support for stage2 page table helpers and makes > the core kvm-arm MMU code make use of it. At the moment we assume > that the host/hyp and the stage2 page tables have same number of > levels and hence use the host level accessors (except for some > hooks, e.g kvm_p.d_addr_end) and shares the routines for unmapping > the page table ranges. > > On arm32, the only change w.r.t the page tables is dealing > with > 32bit physical addresses. > > However on arm64, the hardware supports concatenation of tables (upto 16) > at the entry level, which could affect : > 1) number of entries in the PGD table (upto 16 * PTRS_PER_PTE) > 2) number of page table levels (reduced number of page table levels). > > Also depending on the VA_BITS for the host kernel, the number of page table > levels for both host and stage2(40bit IPA) could differ. At present, we insert > (upto) one fake software page table(as the hardware is not aware of it and is > only used by the OS to walk the table) level to bring the number of levels to > that of the host/hyp table. However, with 16K + 48bit, and 40bit IPA, we could > end up in 2 fake levels, which complicates the code. > > This series introduces explicit stage2 page table helpers and also defines > separate set of routines for unmapping hyp and stage2 tables. > > On arm64 stage2 page table helpers are defined based on the number of levels > required to map the IPA bits. See patch 15 for more details. > > Tested on TC2 (arm32), Fast models(with VHE) and real hardwares. > This looks pretty good overall. Could you rebase it on kvmarm/master where Marc addressed the 36 bits PA size of the foundation model and have a look at the interactions there? If we can solve that bit and address the cosmetic issues I had in this series, then I think we can queue this real soon. Thanks a lot for going the extra mile on this with rewriting the whole KVM page table handling! Best, -Christoffer _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
