Re: [PATCH v5 28/38] x86: Implement the new page table range API

[Peter Zijlstra]

On Mon, Jul 10, 2023 at 09:43:29PM +0100, Matthew Wilcox (Oracle) wrote:
> Add PFN_PTE_SHIFT and a noop update_mmu_cache_range().

And it silently removes set_pte_at() :/ What's happening here ?!?

-ENOCONTEXT

> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> ---
>  arch/x86/include/asm/pgtable.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
> index c6242bc58a71..9818f13bfa09 100644
> --- a/arch/x86/include/asm/pgtable.h
> +++ b/arch/x86/include/asm/pgtable.h
> @@ -185,6 +185,8 @@ static inline int pte_special(pte_t pte)
>  
>  static inline u64 protnone_mask(u64 val);
>  
> +#define PFN_PTE_SHIFT	PAGE_SHIFT
> +
>  static inline unsigned long pte_pfn(pte_t pte)
>  {
>  	phys_addr_t pfn = pte_val(pte);
> @@ -1020,13 +1022,6 @@ static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
>  	return res;
>  }
>  
> -static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> -			      pte_t *ptep, pte_t pte)
> -{
> -	page_table_check_ptes_set(mm, addr, ptep, pte, 1);
> -	set_pte(ptep, pte);
> -}
> -
>  static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
>  			      pmd_t *pmdp, pmd_t pmd)
>  {
> @@ -1292,6 +1287,11 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
>  		unsigned long addr, pte_t *ptep)
>  {
>  }
> +static inline void update_mmu_cache_range(struct vm_fault *vmf,
> +		struct vm_area_struct *vma, unsigned long addr,
> +		pte_t *ptep, unsigned int nr)
> +{
> +}
>  static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
>  		unsigned long addr, pmd_t *pmd)
>  {
> -- 
> 2.39.2
>