c119ecce89
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 <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
#ifndef _I386_PGALLOC_H
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#define _I386_PGALLOC_H
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#include <asm/fixmap.h>
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#include <linux/threads.h>
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#include <linux/mm.h> /* for struct page */
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#ifdef CONFIG_PARAVIRT
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#include <asm/paravirt.h>
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#else
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#define paravirt_alloc_pt(pfn) do { } while (0)
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#define paravirt_alloc_pd(pfn) do { } while (0)
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#define paravirt_alloc_pd(pfn) do { } while (0)
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#define paravirt_alloc_pd_clone(pfn, clonepfn, start, count) do { } while (0)
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#define paravirt_release_pt(pfn) do { } while (0)
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#define paravirt_release_pd(pfn) do { } while (0)
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#endif
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#define pmd_populate_kernel(mm, pmd, pte) \
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do { \
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paravirt_alloc_pt(__pa(pte) >> PAGE_SHIFT); \
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set_pmd(pmd, __pmd(_PAGE_TABLE + __pa(pte))); \
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} while (0)
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#define pmd_populate(mm, pmd, pte) \
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do { \
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paravirt_alloc_pt(page_to_pfn(pte)); \
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set_pmd(pmd, __pmd(_PAGE_TABLE + \
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((unsigned long long)page_to_pfn(pte) << \
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(unsigned long long) PAGE_SHIFT))); \
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} while (0)
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/*
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* Allocate and free page tables.
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*/
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extern pgd_t *pgd_alloc(struct mm_struct *);
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extern void pgd_free(pgd_t *pgd);
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extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
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extern struct page *pte_alloc_one(struct mm_struct *, unsigned long);
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static inline void pte_free_kernel(pte_t *pte)
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{
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free_page((unsigned long)pte);
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}
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static inline void pte_free(struct page *pte)
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{
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__free_page(pte);
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}
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#define __pte_free_tlb(tlb,pte) \
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do { \
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paravirt_release_pt(page_to_pfn(pte)); \
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tlb_remove_page((tlb),(pte)); \
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} while (0)
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#ifdef CONFIG_X86_PAE
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/*
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* In the PAE case we free the pmds as part of the pgd.
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*/
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#define pmd_alloc_one(mm, addr) ({ BUG(); ((pmd_t *)2); })
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#define pmd_free(x) do { } while (0)
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#define __pmd_free_tlb(tlb,x) do { } while (0)
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#define pud_populate(mm, pmd, pte) BUG()
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#endif
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#define check_pgt_cache() do { } while (0)
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#endif /* _I386_PGALLOC_H */
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