On Fri, Mar 10, 2023 at 3:15 PM Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> wrote: > > This patchset intends to improve tlb utilization by using hugepages for > the linear mapping. > > As reported by Anup in v6, when STRICT_KERNEL_RWX is enabled, we must > take care of isolating the kernel text and rodata so that they are not > mapped with a PUD mapping which would then assign wrong permissions to > the whole region: it is achieved by introducing a new memblock API. > > Another patch makes use of this new API in arm64 which used some sort of > hack to solve this issue: it was built/boot tested successfully. > > base-commit-tag: v6.3-rc1 > > v7: > - Fix Anup bug report by introducing memblock_isolate_memory which > allows us to split the memblock mappings and then avoid to map the > the PUD which contains the kernel as read only > - Add a patch to arm64 to use this newly introduced API > > v6: > - quiet LLVM warning by casting phys_ram_base into an unsigned long > > v5: > - Fix nommu builds by getting rid of riscv_pfn_base in patch 1, thanks > Conor > - Add RB from Andrew > > v4: > - Rebase on top of v6.2-rc3, as noted by Conor > - Add Acked-by Rob > > v3: > - Change the comment about initrd_start VA conversion so that it fits > ARM64 and RISCV64 (and others in the future if needed), as suggested > by Rob > > v2: > - Add a comment on why RISCV64 does not need to set initrd_start/end that > early in the boot process, as asked by Rob > > Alexandre Ghiti (4): > riscv: Get rid of riscv_pfn_base variable > mm: Introduce memblock_isolate_memory > arm64: Make use of memblock_isolate_memory for the linear mapping > riscv: Use PUD/P4D/PGD pages for the linear mapping This works fine on QEMU RV64. I have tested on QEMU RV64 with busybox and Fedora rootfs. I also tested KVM RV64 which works fine as well. But, QEMU RV32 with busybox rootfs is broken so you might want to try that. In any case, I have reviewed and tested this series at my end. Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx> Tested-by: Anup Patel <anup@xxxxxxxxxxxxxx> Regards, Anup > > arch/arm64/mm/mmu.c | 4 ++-- > arch/riscv/include/asm/page.h | 19 +++++++++++++++-- > arch/riscv/mm/init.c | 39 ++++++++++++++++++++++++++--------- > arch/riscv/mm/physaddr.c | 16 ++++++++++++++ > drivers/of/fdt.c | 11 +++++----- > include/linux/memblock.h | 1 + > mm/memblock.c | 22 +++++++++++++++++++- > 7 files changed, 92 insertions(+), 20 deletions(-) > > -- > 2.37.2 >
