linux_dsm_epyc7002/arch/i386/xen/mmu.h
Jeremy Fitzhardinge f4f97b3ea9 xen: Complete pagetable pinning
Xen requires all active pagetables to be marked read-only.  When the
base of the pagetable is loaded into %cr3, the hypervisor validates
the entire pagetable and only allows the load to proceed if it all
checks out.

This is pretty slow, so to mitigate this cost Xen has a notion of
pinned pagetables.  Pinned pagetables are pagetables which are
considered to be active even if no processor's cr3 is pointing to is.
This means that it must remain read-only and all updates are validated
by the hypervisor.  This makes context switches much cheaper, because
the hypervisor doesn't need to revalidate the pagetable each time.

This also adds a new paravirt hook which is called during setup once
the zones and memory allocator have been initialized.  When the
init_mm pagetable is first built, the struct page array does not yet
exist, and so there's nowhere to put he init_mm pagetable's PG_pinned
flags.  Once the zones are initialized and the struct page array
exists, we can set the PG_pinned flags for those pages.

This patch also adds the Xen support for pte pages allocated out of
highmem (highpte) by implementing xen_kmap_atomic_pte.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Zach Amsden <zach@vmware.com>
2007-07-18 08:47:43 -07:00

48 lines
1.3 KiB
C

#ifndef _XEN_MMU_H
#include <linux/linkage.h>
#include <asm/page.h>
void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
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_pmd(pmd_t *pmdp, pmd_t pmdval);
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);
#ifdef CONFIG_X86_PAE
unsigned long long xen_pte_val(pte_t);
unsigned long long xen_pmd_val(pmd_t);
unsigned long long xen_pgd_val(pgd_t);
pte_t xen_make_pte(unsigned long long);
pmd_t xen_make_pmd(unsigned long long);
pgd_t xen_make_pgd(unsigned long long);
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_pud(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);
#else
unsigned long xen_pte_val(pte_t);
unsigned long xen_pmd_val(pmd_t);
unsigned long xen_pgd_val(pgd_t);
pte_t xen_make_pte(unsigned long);
pmd_t xen_make_pmd(unsigned long);
pgd_t xen_make_pgd(unsigned long);
#endif
#endif /* _XEN_MMU_H */