Message ID | 20240830011101.3189522-3-zhangchunyan@iscas.ac.cn (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | riscv: mm: Add soft-dirty and uffd-wp support | expand |
On 2024/8/30 9:11, Chunyan Zhang wrote: > The PTE bit(9) is reserved for software, now used by DEVMAP, > this patch reuse bit(9) for soft-dirty which is enabled only > if !CONFIG_ARCH_HAS_PTE_DEVMAP, in other words, soft-dirty > and devmap will be mutually exclusive on RISC-V. > > To add swap PTE soft-dirty tracking, we borrow bit (4) which is > available for swap PTEs on RISC-V systems. > > Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> > --- > arch/riscv/Kconfig | 27 ++++++++++- > arch/riscv/include/asm/pgtable-bits.h | 12 +++++ > arch/riscv/include/asm/pgtable.h | 69 ++++++++++++++++++++++++++- > 3 files changed, 106 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0f3cd7c3a436..f1460fc01cd4 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -39,7 +39,6 @@ config RISCV > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > select ARCH_HAS_PMEM_API > select ARCH_HAS_PREPARE_SYNC_CORE_CMD > - select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU > select ARCH_HAS_PTE_SPECIAL > select ARCH_HAS_SET_DIRECT_MAP if MMU > select ARCH_HAS_SET_MEMORY if MMU > @@ -948,6 +947,32 @@ config RANDOMIZE_BASE > > If unsure, say N. > > +choice > + prompt "PET RSW Bit(9) used for" > + default RISCV_HAS_PTE_DEVMEP > + depends on MMU && 64BIT > + help > + RISC-V PTE bit(9) is reserved for software, and used by more than > + one kernel features which cannot be supported at the same time. > + So we have to select one for it. > + > +config RISCV_HAS_PTE_DEVMEP > + bool "DEVMAP mark" > + select ARCH_HAS_PTE_DEVMAP > + help > + The PTE bit(9) is used for DEVMAP mark. ZONE_DEVICE pages need DEVMAP > + PTEs support to function. > + > + So if you want to use ZONE_DEVICE, select this. > + > +config RISCV_HAS_SOFT_DIRTY > + bool "soft dirty" > + select HAVE_ARCH_SOFT_DIRTY > + help > + The PTE bit(9) is used for soft-dirty tracking. > + > +endchoice > + Hi, ARCH_HAS_PTE_DEVMAP will be removed in following patch, I guess riscv will too: https://lore.kernel.org/all/47c26640cd85f3db2e0a2796047199bb984d1b3f.1719386613.git-series.apopple@nvidia.com/ > endmenu # "Kernel features" > > menu "Boot options" > diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h > index 5bcc73430829..c6d51fe9fc6f 100644 > --- a/arch/riscv/include/asm/pgtable-bits.h > +++ b/arch/riscv/include/asm/pgtable-bits.h > @@ -26,6 +26,18 @@ > #define _PAGE_DEVMAP 0 > #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ > > +#ifdef CONFIG_MEM_SOFT_DIRTY > +#define _PAGE_SOFT_DIRTY (1 << 9) /* RSW: 0x2 for software dirty tracking */ > +/* > + * BIT 4 is not involved into swap entry computation, so we > + * can borrow it for swap page soft-dirty tracking. > + */ > +#define _PAGE_SWP_SOFT_DIRTY _PAGE_USER > +#else > +#define _PAGE_SOFT_DIRTY 0 > +#define _PAGE_SWP_SOFT_DIRTY 0 > +#endif /* CONFIG_MEM_SOFT_DIRTY */ > + > #define _PAGE_TABLE _PAGE_PRESENT > > /* > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 089f3c9f56a3..d41507919ef2 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -428,7 +428,7 @@ static inline pte_t pte_mkwrite_novma(pte_t pte) > > static inline pte_t pte_mkdirty(pte_t pte) > { > - return __pte(pte_val(pte) | _PAGE_DIRTY); > + return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY); > } > > static inline pte_t pte_mkclean(pte_t pte) > @@ -461,6 +461,38 @@ static inline pte_t pte_mkhuge(pte_t pte) > return pte; > } > > +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY > +static inline int pte_soft_dirty(pte_t pte) > +{ > + return pte_val(pte) & _PAGE_SOFT_DIRTY; > +} > + > +static inline pte_t pte_mksoft_dirty(pte_t pte) > +{ > + return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY); > +} > + > +static inline pte_t pte_clear_soft_dirty(pte_t pte) > +{ > + return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY)); > +} > + > +static inline int pte_swp_soft_dirty(pte_t pte) > +{ > + return pte_val(pte) & _PAGE_SWP_SOFT_DIRTY; > +} > + > +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) > +{ > + return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY); > +} > + > +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) > +{ > + return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY)); > +} > +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ > + > #ifdef CONFIG_RISCV_ISA_SVNAPOT > #define pte_leaf_size(pte) (pte_napot(pte) ? \ > napot_cont_size(napot_cont_order(pte)) :\ > @@ -751,6 +783,40 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) > return pte_pmd(pte_mkdevmap(pmd_pte(pmd))); > } > > +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY > +static inline int pmd_soft_dirty(pmd_t pmd) > +{ > + return pte_soft_dirty(pmd_pte(pmd)); > +} > + > +static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) > +{ > + return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))); > +} > + > +static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) > +{ > + return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd))); > +} > + > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION > +static inline int pmd_swp_soft_dirty(pmd_t pmd) > +{ > + return pte_swp_soft_dirty(pmd_pte(pmd)); > +} > + > +static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) > +{ > + return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd))); > +} > + > +static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) > +{ > + return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd))); > +} > +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ > +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ > + > static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, > pmd_t *pmdp, pmd_t pmd) > { > @@ -841,6 +907,7 @@ extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, > * Format of swap PTE: > * bit 0: _PAGE_PRESENT (zero) > * bit 1 to 3: _PAGE_LEAF (zero) > + * bit 4: _PAGE_SWP_SOFT_DIRTY > * bit 5: _PAGE_PROT_NONE (zero) > * bit 6: exclusive marker > * bits 7 to 11: swap type
Hi Jinjie, On Fri, 30 Aug 2024 at 09:31, Jinjie Ruan <ruanjinjie@huawei.com> wrote: > > > > On 2024/8/30 9:11, Chunyan Zhang wrote: > > The PTE bit(9) is reserved for software, now used by DEVMAP, > > this patch reuse bit(9) for soft-dirty which is enabled only > > if !CONFIG_ARCH_HAS_PTE_DEVMAP, in other words, soft-dirty > > and devmap will be mutually exclusive on RISC-V. > > > > To add swap PTE soft-dirty tracking, we borrow bit (4) which is > > available for swap PTEs on RISC-V systems. > > > > Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> > > --- > > arch/riscv/Kconfig | 27 ++++++++++- > > arch/riscv/include/asm/pgtable-bits.h | 12 +++++ > > arch/riscv/include/asm/pgtable.h | 69 ++++++++++++++++++++++++++- > > 3 files changed, 106 insertions(+), 2 deletions(-) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 0f3cd7c3a436..f1460fc01cd4 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -39,7 +39,6 @@ config RISCV > > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > > select ARCH_HAS_PMEM_API > > select ARCH_HAS_PREPARE_SYNC_CORE_CMD > > - select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU > > select ARCH_HAS_PTE_SPECIAL > > select ARCH_HAS_SET_DIRECT_MAP if MMU > > select ARCH_HAS_SET_MEMORY if MMU > > @@ -948,6 +947,32 @@ config RANDOMIZE_BASE > > > > If unsure, say N. > > > > +choice > > + prompt "PET RSW Bit(9) used for" > > + default RISCV_HAS_PTE_DEVMEP > > + depends on MMU && 64BIT > > + help > > + RISC-V PTE bit(9) is reserved for software, and used by more than > > + one kernel features which cannot be supported at the same time. > > + So we have to select one for it. > > + > > +config RISCV_HAS_PTE_DEVMEP > > + bool "DEVMAP mark" > > + select ARCH_HAS_PTE_DEVMAP > > + help > > + The PTE bit(9) is used for DEVMAP mark. ZONE_DEVICE pages need DEVMAP > > + PTEs support to function. > > + > > + So if you want to use ZONE_DEVICE, select this. > > + > > +config RISCV_HAS_SOFT_DIRTY > > + bool "soft dirty" > > + select HAVE_ARCH_SOFT_DIRTY > > + help > > + The PTE bit(9) is used for soft-dirty tracking. > > + > > +endchoice > > + > > Hi, ARCH_HAS_PTE_DEVMAP will be removed in following patch, I guess > riscv will too: > > https://lore.kernel.org/all/47c26640cd85f3db2e0a2796047199bb984d1b3f.1719386613.git-series.apopple@nvidia.com/ Thanks for sharing, I didn't notice this. It looks like we should remove PTE_DEVMAP first and then add soft dirty and uffd_wp. Thanks, Chunyan > > > endmenu # "Kernel features" > > > > menu "Boot options" > > diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h > > index 5bcc73430829..c6d51fe9fc6f 100644 > > --- a/arch/riscv/include/asm/pgtable-bits.h > > +++ b/arch/riscv/include/asm/pgtable-bits.h > > @@ -26,6 +26,18 @@ > > #define _PAGE_DEVMAP 0 > > #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ > > > > +#ifdef CONFIG_MEM_SOFT_DIRTY > > +#define _PAGE_SOFT_DIRTY (1 << 9) /* RSW: 0x2 for software dirty tracking */ > > +/* > > + * BIT 4 is not involved into swap entry computation, so we > > + * can borrow it for swap page soft-dirty tracking. > > + */ > > +#define _PAGE_SWP_SOFT_DIRTY _PAGE_USER > > +#else > > +#define _PAGE_SOFT_DIRTY 0 > > +#define _PAGE_SWP_SOFT_DIRTY 0 > > +#endif /* CONFIG_MEM_SOFT_DIRTY */ > > + > > #define _PAGE_TABLE _PAGE_PRESENT > > > > /* > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > > index 089f3c9f56a3..d41507919ef2 100644 > > --- a/arch/riscv/include/asm/pgtable.h > > +++ b/arch/riscv/include/asm/pgtable.h > > @@ -428,7 +428,7 @@ static inline pte_t pte_mkwrite_novma(pte_t pte) > > > > static inline pte_t pte_mkdirty(pte_t pte) > > { > > - return __pte(pte_val(pte) | _PAGE_DIRTY); > > + return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY); > > } > > > > static inline pte_t pte_mkclean(pte_t pte) > > @@ -461,6 +461,38 @@ static inline pte_t pte_mkhuge(pte_t pte) > > return pte; > > } > > > > +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY > > +static inline int pte_soft_dirty(pte_t pte) > > +{ > > + return pte_val(pte) & _PAGE_SOFT_DIRTY; > > +} > > + > > +static inline pte_t pte_mksoft_dirty(pte_t pte) > > +{ > > + return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY); > > +} > > + > > +static inline pte_t pte_clear_soft_dirty(pte_t pte) > > +{ > > + return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY)); > > +} > > + > > +static inline int pte_swp_soft_dirty(pte_t pte) > > +{ > > + return pte_val(pte) & _PAGE_SWP_SOFT_DIRTY; > > +} > > + > > +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) > > +{ > > + return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY); > > +} > > + > > +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) > > +{ > > + return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY)); > > +} > > +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ > > + > > #ifdef CONFIG_RISCV_ISA_SVNAPOT > > #define pte_leaf_size(pte) (pte_napot(pte) ? \ > > napot_cont_size(napot_cont_order(pte)) :\ > > @@ -751,6 +783,40 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) > > return pte_pmd(pte_mkdevmap(pmd_pte(pmd))); > > } > > > > +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY > > +static inline int pmd_soft_dirty(pmd_t pmd) > > +{ > > + return pte_soft_dirty(pmd_pte(pmd)); > > +} > > + > > +static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) > > +{ > > + return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))); > > +} > > + > > +static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) > > +{ > > + return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd))); > > +} > > + > > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION > > +static inline int pmd_swp_soft_dirty(pmd_t pmd) > > +{ > > + return pte_swp_soft_dirty(pmd_pte(pmd)); > > +} > > + > > +static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) > > +{ > > + return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd))); > > +} > > + > > +static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) > > +{ > > + return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd))); > > +} > > +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ > > +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ > > + > > static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, > > pmd_t *pmdp, pmd_t pmd) > > { > > @@ -841,6 +907,7 @@ extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, > > * Format of swap PTE: > > * bit 0: _PAGE_PRESENT (zero) > > * bit 1 to 3: _PAGE_LEAF (zero) > > + * bit 4: _PAGE_SWP_SOFT_DIRTY > > * bit 5: _PAGE_PROT_NONE (zero) > > * bit 6: exclusive marker > > * bits 7 to 11: swap type
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0f3cd7c3a436..f1460fc01cd4 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -39,7 +39,6 @@ config RISCV select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API select ARCH_HAS_PREPARE_SYNC_CORE_CMD - select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SET_DIRECT_MAP if MMU select ARCH_HAS_SET_MEMORY if MMU @@ -948,6 +947,32 @@ config RANDOMIZE_BASE If unsure, say N. +choice + prompt "PET RSW Bit(9) used for" + default RISCV_HAS_PTE_DEVMEP + depends on MMU && 64BIT + help + RISC-V PTE bit(9) is reserved for software, and used by more than + one kernel features which cannot be supported at the same time. + So we have to select one for it. + +config RISCV_HAS_PTE_DEVMEP + bool "DEVMAP mark" + select ARCH_HAS_PTE_DEVMAP + help + The PTE bit(9) is used for DEVMAP mark. ZONE_DEVICE pages need DEVMAP + PTEs support to function. + + So if you want to use ZONE_DEVICE, select this. + +config RISCV_HAS_SOFT_DIRTY + bool "soft dirty" + select HAVE_ARCH_SOFT_DIRTY + help + The PTE bit(9) is used for soft-dirty tracking. + +endchoice + endmenu # "Kernel features" menu "Boot options" diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h index 5bcc73430829..c6d51fe9fc6f 100644 --- a/arch/riscv/include/asm/pgtable-bits.h +++ b/arch/riscv/include/asm/pgtable-bits.h @@ -26,6 +26,18 @@ #define _PAGE_DEVMAP 0 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ +#ifdef CONFIG_MEM_SOFT_DIRTY +#define _PAGE_SOFT_DIRTY (1 << 9) /* RSW: 0x2 for software dirty tracking */ +/* + * BIT 4 is not involved into swap entry computation, so we + * can borrow it for swap page soft-dirty tracking. + */ +#define _PAGE_SWP_SOFT_DIRTY _PAGE_USER +#else +#define _PAGE_SOFT_DIRTY 0 +#define _PAGE_SWP_SOFT_DIRTY 0 +#endif /* CONFIG_MEM_SOFT_DIRTY */ + #define _PAGE_TABLE _PAGE_PRESENT /* diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 089f3c9f56a3..d41507919ef2 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -428,7 +428,7 @@ static inline pte_t pte_mkwrite_novma(pte_t pte) static inline pte_t pte_mkdirty(pte_t pte) { - return __pte(pte_val(pte) | _PAGE_DIRTY); + return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY); } static inline pte_t pte_mkclean(pte_t pte) @@ -461,6 +461,38 @@ static inline pte_t pte_mkhuge(pte_t pte) return pte; } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +static inline int pte_soft_dirty(pte_t pte) +{ + return pte_val(pte) & _PAGE_SOFT_DIRTY; +} + +static inline pte_t pte_mksoft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY); +} + +static inline pte_t pte_clear_soft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY)); +} + +static inline int pte_swp_soft_dirty(pte_t pte) +{ + return pte_val(pte) & _PAGE_SWP_SOFT_DIRTY; +} + +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY); +} + +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) +{ + return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY)); +} +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + #ifdef CONFIG_RISCV_ISA_SVNAPOT #define pte_leaf_size(pte) (pte_napot(pte) ? \ napot_cont_size(napot_cont_order(pte)) :\ @@ -751,6 +783,40 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) return pte_pmd(pte_mkdevmap(pmd_pte(pmd))); } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY +static inline int pmd_soft_dirty(pmd_t pmd) +{ + return pte_soft_dirty(pmd_pte(pmd)); +} + +static inline pmd_t pmd_mksoft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))); +} + +static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd))); +} + +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +static inline int pmd_swp_soft_dirty(pmd_t pmd) +{ + return pte_swp_soft_dirty(pmd_pte(pmd)); +} + +static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd))); +} + +static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd) +{ + return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd))); +} +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { @@ -841,6 +907,7 @@ extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, * Format of swap PTE: * bit 0: _PAGE_PRESENT (zero) * bit 1 to 3: _PAGE_LEAF (zero) + * bit 4: _PAGE_SWP_SOFT_DIRTY * bit 5: _PAGE_PROT_NONE (zero) * bit 6: exclusive marker * bits 7 to 11: swap type
The PTE bit(9) is reserved for software, now used by DEVMAP, this patch reuse bit(9) for soft-dirty which is enabled only if !CONFIG_ARCH_HAS_PTE_DEVMAP, in other words, soft-dirty and devmap will be mutually exclusive on RISC-V. To add swap PTE soft-dirty tracking, we borrow bit (4) which is available for swap PTEs on RISC-V systems. Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> --- arch/riscv/Kconfig | 27 ++++++++++- arch/riscv/include/asm/pgtable-bits.h | 12 +++++ arch/riscv/include/asm/pgtable.h | 69 ++++++++++++++++++++++++++- 3 files changed, 106 insertions(+), 2 deletions(-)