This patchset adds support for Svrsw60t59b [1] extension which is ratified now, also add soft dirty and userfaultfd write protect tracking for RISC-V. The patches 1 and 2 add macros to allow architectures to define their own checks if the soft-dirty / uffd_wp PTE bits are available, in other words for RISC-V, the Svrsw60t59b extension is supported on which device the kernel is running. This patchset has been tested with kselftest mm suite in which soft-dirty, madv_populate, test_unmerge_uffd_wp, and uffd-unit-tests run and pass, and no regressions are observed in any of the other tests. This patchset applies on top of v6.17-rc4. [1] https://github.com/riscv-non-isa/riscv-iommu/pull/543 V11: - Rename the macro API to pgtable_*_supported() since we also have PMD support; - Change the default implementations of two macros, make CONFIG_MEM_SOFT_DIRTY or CONFIG_HAVE_ARCH_USERFAULTFD_WP part of the macros; - Correct the order of insertion of RISCV_ISA_EXT_SVRSW60T59B; - Rephrase some comments. V10: https://lore.kernel.org/all/20250909095611.803898-1-zhangchunyan@xxxxxxxxxxx/ - Fixed the issue reported by kernel test irobot <lkp@xxxxxxxxx>. V9: https://lore.kernel.org/all/20250905103651.489197-1-zhangchunyan@xxxxxxxxxxx/ - Add pte_soft_dirty/uffd_wp_available() API to allow dynamically checking if the PTE bit is available for the platform on which the kernel is running. V8: https://lore.kernel.org/all/20250619065232.1786470-1-zhangchunyan@xxxxxxxxxxx/) - Rebase on v6.16-rc1; - Add dependencies to MMU && 64BIT for RISCV_ISA_SVRSW60T59B; - Use 'Svrsw60t59b' instead of 'SVRSW60T59B' in Kconfig help paragraph; - Add Alex's Reviewed-by tag in patch 1. V7: https://lore.kernel.org/all/20250409095320.224100-1-zhangchunyan@xxxxxxxxxxx/ - Add Svrsw60t59b [1] extension support; - Have soft-dirty and uffd-wp depending on the Svrsw60t59b extension to avoid crashes for the hardware which don't have this extension. V6: https://lore.kernel.org/all/20250408084301.68186-1-zhangchunyan@xxxxxxxxxxx/ - Changes to use bits 59-60 which are supported by extension Svrsw60t59b for soft dirty and userfaultfd write protect tracking. V5: https://lore.kernel.org/all/20241113095833.1805746-1-zhangchunyan@xxxxxxxxxxx/ - Fixed typos and corrected some words in Kconfig and commit message; - Removed pte_wrprotect() from pte_swp_mkuffd_wp(), this is a copy-paste error; - Added Alex's Reviewed-by tag in patch 2. V4: https://lore.kernel.org/all/20240830011101.3189522-1-zhangchunyan@xxxxxxxxxxx/ - Added bit(4) descriptions into "Format of swap PTE". V3: https://lore.kernel.org/all/20240805095243.44809-1-zhangchunyan@xxxxxxxxxxx/ - Fixed the issue reported by kernel test irobot <lkp@xxxxxxxxx>. V2: https://lore.kernel.org/all/20240731040444.3384790-1-zhangchunyan@xxxxxxxxxxx/ - Add uffd-wp supported; - Make soft-dirty uffd-wp and devmap mutually exclusive which all use the same PTE bit; - Add test results of CRIU in the cover-letter. Chunyan Zhang (5): mm: softdirty: Add pgtable_soft_dirty_supported() mm: userfaultfd: Add pgtable_uffd_wp_supported() riscv: Add RISC-V Svrsw60t59b extension support riscv: mm: Add soft-dirty page tracking support riscv: mm: Add userfaultfd write-protect support arch/riscv/Kconfig | 16 +++ arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/include/asm/pgtable-bits.h | 37 +++++++ arch/riscv/include/asm/pgtable.h | 143 +++++++++++++++++++++++++- arch/riscv/kernel/cpufeature.c | 1 + fs/proc/task_mmu.c | 17 ++- fs/userfaultfd.c | 23 +++-- include/asm-generic/pgtable_uffd.h | 11 ++ include/linux/mm_inline.h | 7 ++ include/linux/pgtable.h | 12 +++ include/linux/userfaultfd_k.h | 44 +++++--- mm/debug_vm_pgtable.c | 10 +- mm/huge_memory.c | 13 +-- mm/internal.h | 2 +- mm/memory.c | 6 +- mm/mremap.c | 13 +-- mm/userfaultfd.c | 10 +- 17 files changed, 310 insertions(+), 56 deletions(-) -- 2.34.1
