From c119ecce894120790903ef535dac3e105f3d6cde Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Tue, 13 Feb 2007 13:26:21 +0100 Subject: [PATCH] MM: page allocation hooks for VMI backend The VMI backend uses explicit page type notification to track shadow page tables. The allocation of page table roots is especially tricky. We need to clone the root for non-PAE mode while it is protected under the pgd lock to correctly copy the shadow. We don't need to allocate pgds in PAE mode, (PDPs in Intel terminology) as they only have 4 entries, and are cached entirely by the processor, which makes shadowing them rather simple. For base page table level allocation, pmd_populate provides the exact hook point we need. Also, we need to allocate pages when splitting a large page, and we must release pages before returning the page to any free pool. Despite being required with these slightly odd semantics for VMI, Xen also uses these hooks to determine the exact moment when page tables are created or released. AK: All nops for other architectures Signed-off-by: Zachary Amsden Signed-off-by: Andi Kleen Cc: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Rusty Russell Cc: Chris Wright Signed-off-by: Andrew Morton --- include/asm-i386/pgalloc.h | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) (limited to 'include/asm-i386/pgalloc.h') diff --git a/include/asm-i386/pgalloc.h b/include/asm-i386/pgalloc.h index 4b1e61359f8..c8dc2d0141a 100644 --- a/include/asm-i386/pgalloc.h +++ b/include/asm-i386/pgalloc.h @@ -5,13 +5,31 @@ #include #include /* for struct page */ -#define pmd_populate_kernel(mm, pmd, pte) \ - set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte))) +#ifdef CONFIG_PARAVIRT +#include +#else +#define paravirt_alloc_pt(pfn) do { } while (0) +#define paravirt_alloc_pd(pfn) do { } while (0) +#define paravirt_alloc_pd(pfn) do { } while (0) +#define paravirt_alloc_pd_clone(pfn, clonepfn, start, count) do { } while (0) +#define paravirt_release_pt(pfn) do { } while (0) +#define paravirt_release_pd(pfn) do { } while (0) +#endif + +#define pmd_populate_kernel(mm, pmd, pte) \ +do { \ + paravirt_alloc_pt(__pa(pte) >> PAGE_SHIFT); \ + set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte))); \ +} while (0) #define pmd_populate(mm, pmd, pte) \ +do { \ + paravirt_alloc_pt(page_to_pfn(pte)); \ set_pmd(pmd, __pmd(_PAGE_TABLE + \ ((unsigned long long)page_to_pfn(pte) << \ - (unsigned long long) PAGE_SHIFT))) + (unsigned long long) PAGE_SHIFT))); \ +} while (0) + /* * Allocate and free page tables. */ @@ -32,7 +50,11 @@ static inline void pte_free(struct page *pte) } -#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte)) +#define __pte_free_tlb(tlb,pte) \ +do { \ + paravirt_release_pt(page_to_pfn(pte)); \ + tlb_remove_page((tlb),(pte)); \ +} while (0) #ifdef CONFIG_X86_PAE /* -- cgit v1.2.3