kernel-fxtec-pro1x/arch/x86/xen/mmu.h
Jeremy Fitzhardinge e2426cf85f xen: avoid hypercalls when updating unpinned pud/pmd
When operating on an unpinned pagetable (ie, one under construction or
destruction), it isn't necessary to use a hypercall to update a
pud/pmd entry.  Jan Beulich observed that a similar optimisation
avoided many thousands of hypercalls while doing a kernel build.

One tricky part is that early in the kernel boot there's no page
structure, so we can't check to see if the page is pinned.  In that
case, we just always use the hypercall.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 13:24:40 +02:00

55 lines
1.6 KiB
C

#ifndef _XEN_MMU_H
#include <linux/linkage.h>
#include <asm/page.h>
enum pt_level {
PT_PGD,
PT_PUD,
PT_PMD,
PT_PTE
};
/*
* Page-directory addresses above 4GB do not fit into architectural %cr3.
* When accessing %cr3, or equivalent field in vcpu_guest_context, guests
* must use the following accessor macros to pack/unpack valid MFNs.
*
* Note that Xen is using the fact that the pagetable base is always
* page-aligned, and putting the 12 MSB of the address into the 12 LSB
* of cr3.
*/
#define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20))
#define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))
void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next);
void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm);
void xen_exit_mmap(struct mm_struct *mm);
void xen_pgd_pin(pgd_t *pgd);
//void xen_pgd_unpin(pgd_t *pgd);
pteval_t xen_pte_val(pte_t);
pmdval_t xen_pmd_val(pmd_t);
pgdval_t xen_pgd_val(pgd_t);
pte_t xen_make_pte(pteval_t);
pmd_t xen_make_pmd(pmdval_t);
pgd_t xen_make_pgd(pgdval_t);
void xen_set_pte(pte_t *ptep, pte_t pteval);
void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pteval);
void xen_set_pte_atomic(pte_t *ptep, pte_t pte);
void xen_set_pmd(pmd_t *pmdp, pmd_t pmdval);
void xen_set_pud(pud_t *ptr, pud_t val);
void xen_set_pmd_hyper(pmd_t *pmdp, pmd_t pmdval);
void xen_set_pud_hyper(pud_t *ptr, pud_t val);
void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
void xen_pmd_clear(pmd_t *pmdp);
#endif /* _XEN_MMU_H */