Re: [PATCH v4 5/8] arch: introduce set_direct_map_valid_noflush()

From: Huacai Chen
Date: Mon Oct 07 2024 - 22:12:00 EST

Hi, Mike,

On Mon, Oct 7, 2024 at 2:30 PM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
>
> From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
>
> Add an API that will allow updates of the direct/linear map for a set of
> physically contiguous pages.
>
> It will be used in the following patches.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/set_memory.h | 1 +
> arch/arm64/mm/pageattr.c | 10 ++++++++++
> arch/loongarch/include/asm/set_memory.h | 1 +
> arch/loongarch/mm/pageattr.c | 21 +++++++++++++++++++++
> arch/riscv/include/asm/set_memory.h | 1 +
> arch/riscv/mm/pageattr.c | 15 +++++++++++++++
> arch/s390/include/asm/set_memory.h | 1 +
> arch/s390/mm/pageattr.c | 11 +++++++++++
> arch/x86/include/asm/set_memory.h | 1 +
> arch/x86/mm/pat/set_memory.c | 8 ++++++++
> include/linux/set_memory.h | 6 ++++++
> 11 files changed, 76 insertions(+)
>
> diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
> index 917761feeffd..98088c043606 100644
> --- a/arch/arm64/include/asm/set_memory.h
> +++ b/arch/arm64/include/asm/set_memory.h
> @@ -13,6 +13,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
>
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
> bool kernel_page_present(struct page *page);
>
> #endif /* _ASM_ARM64_SET_MEMORY_H */
> diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
> index 0e270a1c51e6..01225900293a 100644
> --- a/arch/arm64/mm/pageattr.c
> +++ b/arch/arm64/mm/pageattr.c
> @@ -192,6 +192,16 @@ int set_direct_map_default_noflush(struct page *page)
> PAGE_SIZE, change_page_range, &data);
> }
>
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
> +{
> + unsigned long addr = (unsigned long)page_address(page);
> +
> + if (!can_set_direct_map())
> + return 0;
> +
> + return set_memory_valid(addr, nr, valid);
> +}
> +
> #ifdef CONFIG_DEBUG_PAGEALLOC
> void __kernel_map_pages(struct page *page, int numpages, int enable)
> {
> diff --git a/arch/loongarch/include/asm/set_memory.h b/arch/loongarch/include/asm/set_memory.h
> index d70505b6676c..55dfaefd02c8 100644
> --- a/arch/loongarch/include/asm/set_memory.h
> +++ b/arch/loongarch/include/asm/set_memory.h
> @@ -17,5 +17,6 @@ int set_memory_rw(unsigned long addr, int numpages);
> bool kernel_page_present(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> int set_direct_map_invalid_noflush(struct page *page);
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
>
> #endif /* _ASM_LOONGARCH_SET_MEMORY_H */
> diff --git a/arch/loongarch/mm/pageattr.c b/arch/loongarch/mm/pageattr.c
> index ffd8d76021d4..f14b40c968b4 100644
> --- a/arch/loongarch/mm/pageattr.c
> +++ b/arch/loongarch/mm/pageattr.c
> @@ -216,3 +216,24 @@ int set_direct_map_invalid_noflush(struct page *page)
>
> return __set_memory(addr, 1, __pgprot(0), __pgprot(_PAGE_PRESENT | _PAGE_VALID));
> }
> +
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
> +{
> + unsigned long addr = (unsigned long)page_address(page);
> + pgprot_t set, clear;
> +
> + return __set_memory((unsigned long)page_address(page), nr, set, clear);
This line should be removed.

Huacai

> +
> + if (addr < vm_map_base)
> + return 0;
> +
> + if (valid) {
> + set = PAGE_KERNEL;
> + clear = __pgprot(0);
> + } else {
> + set = __pgprot(0);
> + clear = __pgprot(_PAGE_PRESENT | _PAGE_VALID);
> + }
> +
> + return __set_memory(addr, 1, set, clear);
> +}
> diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
> index ab92fc84e1fc..ea263d3683ef 100644
> --- a/arch/riscv/include/asm/set_memory.h
> +++ b/arch/riscv/include/asm/set_memory.h
> @@ -42,6 +42,7 @@ static inline int set_kernel_memory(char *startp, char *endp,
>
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
> bool kernel_page_present(struct page *page);
>
> #endif /* __ASSEMBLY__ */
> diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
> index 271d01a5ba4d..d815448758a1 100644
> --- a/arch/riscv/mm/pageattr.c
> +++ b/arch/riscv/mm/pageattr.c
> @@ -386,6 +386,21 @@ int set_direct_map_default_noflush(struct page *page)
> PAGE_KERNEL, __pgprot(_PAGE_EXEC));
> }
>
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
> +{
> + pgprot_t set, clear;
> +
> + if (valid) {
> + set = PAGE_KERNEL;
> + clear = __pgprot(_PAGE_EXEC);
> + } else {
> + set = __pgprot(0);
> + clear = __pgprot(_PAGE_PRESENT);
> + }
> +
> + return __set_memory((unsigned long)page_address(page), nr, set, clear);
> +}
> +
> #ifdef CONFIG_DEBUG_PAGEALLOC
> static int debug_pagealloc_set_page(pte_t *pte, unsigned long addr, void *data)
> {
> diff --git a/arch/s390/include/asm/set_memory.h b/arch/s390/include/asm/set_memory.h
> index 06fbabe2f66c..240bcfbdcdce 100644
> --- a/arch/s390/include/asm/set_memory.h
> +++ b/arch/s390/include/asm/set_memory.h
> @@ -62,5 +62,6 @@ __SET_MEMORY_FUNC(set_memory_4k, SET_MEMORY_4K)
>
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
>
> #endif
> diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
> index 5f805ad42d4c..4c7ee74aa130 100644
> --- a/arch/s390/mm/pageattr.c
> +++ b/arch/s390/mm/pageattr.c
> @@ -406,6 +406,17 @@ int set_direct_map_default_noflush(struct page *page)
> return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF);
> }
>
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
> +{
> + unsigned long flags;
> +
> + if (valid)
> + flags = SET_MEMORY_DEF;
> + else
> + flags = SET_MEMORY_INV;
> +
> + return __set_memory((unsigned long)page_to_virt(page), nr, flags);
> +}
> #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
>
> static void ipte_range(pte_t *pte, unsigned long address, int nr)
> diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
> index 4b2abce2e3e7..cc62ef70ccc0 100644
> --- a/arch/x86/include/asm/set_memory.h
> +++ b/arch/x86/include/asm/set_memory.h
> @@ -89,6 +89,7 @@ int set_pages_rw(struct page *page, int numpages);
>
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
> bool kernel_page_present(struct page *page);
>
> extern int kernel_set_to_readonly;
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index 44f7b2ea6a07..069e421c2247 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -2444,6 +2444,14 @@ int set_direct_map_default_noflush(struct page *page)
> return __set_pages_p(page, 1);
> }
>
> +int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
> +{
> + if (valid)
> + return __set_pages_p(page, nr);
> +
> + return __set_pages_np(page, nr);
> +}
> +
> #ifdef CONFIG_DEBUG_PAGEALLOC
> void __kernel_map_pages(struct page *page, int numpages, int enable)
> {
> diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
> index e7aec20fb44f..3030d9245f5a 100644
> --- a/include/linux/set_memory.h
> +++ b/include/linux/set_memory.h
> @@ -34,6 +34,12 @@ static inline int set_direct_map_default_noflush(struct page *page)
> return 0;
> }
>
> +static inline int set_direct_map_valid_noflush(struct page *page,
> + unsigned nr, bool valid)
> +{
> + return 0;
> +}
> +
> static inline bool kernel_page_present(struct page *page)
> {
> return true;
> --
> 2.43.0
>