1 files changed, 744 insertions, 6 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 503c240e26c7..319bd40a57c2 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -47,6 +47,7 @@
 #include <asm/tlbflush.h>
 #include <asm/fixmap.h>
 #include <asm/mmu_context.h>
+#include <asm/setup.h>
 #include <asm/paravirt.h>
 #include <asm/linkage.h>
 
@@ -55,6 +56,8 @@
 
 #include <xen/page.h>
 #include <xen/interface/xen.h>
+#include <xen/interface/version.h>
+#include <xen/hvc-console.h>
 
 #include "multicalls.h"
 #include "mmu.h"
@@ -114,6 +117,37 @@ static inline void check_zero(void)
 
 #endif /* CONFIG_XEN_DEBUG_FS */
 
+
+/*
+ * Identity map, in addition to plain kernel map.  This needs to be
+ * large enough to allocate page table pages to allocate the rest.
+ * Each page can map 2MB.
+ */
+static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
+
+#ifdef CONFIG_X86_64
+/* l3 pud for userspace vsyscall mapping */
+static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
+#endif /* CONFIG_X86_64 */
+
+/*
+ * Note about cr3 (pagetable base) values:
+ *
+ * xen_cr3 contains the current logical cr3 value; it contains the
+ * last set cr3.  This may not be the current effective cr3, because
+ * its update may be being lazily deferred.  However, a vcpu looking
+ * at its own cr3 can use this value knowing that it everything will
+ * be self-consistent.
+ *
+ * xen_current_cr3 contains the actual vcpu cr3; it is set once the
+ * hypercall to set the vcpu cr3 is complete (so it may be a little
+ * out of date, but it will never be set early).  If one vcpu is
+ * looking at another vcpu's cr3 value, it should use this variable.
+ */
+DEFINE_PER_CPU(unsigned long, xen_cr3);  /* cr3 stored as physaddr */
+DEFINE_PER_CPU(unsigned long, xen_current_cr3);  /* actual vcpu cr3 */
+
+
 /*
  * Just beyond the highest usermode address.  STACK_TOP_MAX has a
  * redzone above it, so round it up to a PGD boundary.
@@ -458,28 +492,33 @@ pteval_t xen_pte_val(pte_t pte)
 {
         return pte_mfn_to_pfn(pte.pte);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
 
 pgdval_t xen_pgd_val(pgd_t pgd)
 {
         return pte_mfn_to_pfn(pgd.pgd);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
 
 pte_t xen_make_pte(pteval_t pte)
 {
         pte = pte_pfn_to_mfn(pte);
         return native_make_pte(pte);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
 
 pgd_t xen_make_pgd(pgdval_t pgd)
 {
         pgd = pte_pfn_to_mfn(pgd);
         return native_make_pgd(pgd);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd);
 
 pmdval_t xen_pmd_val(pmd_t pmd)
 {
         return pte_mfn_to_pfn(pmd.pmd);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
 
 void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 {
@@ -556,12 +595,14 @@ pmd_t xen_make_pmd(pmdval_t pmd)
         pmd = pte_pfn_to_mfn(pmd);
         return native_make_pmd(pmd);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
 
 #if PAGETABLE_LEVELS == 4
 pudval_t xen_pud_val(pud_t pud)
 {
         return pte_mfn_to_pfn(pud.pud);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
 
 pud_t xen_make_pud(pudval_t pud)
 {
@@ -569,6 +610,7 @@ pud_t xen_make_pud(pudval_t pud)
 
         return native_make_pud(pud);
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud);
 
 pgd_t *xen_get_user_pgd(pgd_t *pgd)
 {
@@ -1063,18 +1105,14 @@ static void drop_other_mm_ref(void *info)
         struct mm_struct *mm = info;
         struct mm_struct *active_mm;
 
-#ifdef CONFIG_X86_64
-        active_mm = read_pda(active_mm);
-#else
-        active_mm = __get_cpu_var(cpu_tlbstate).active_mm;
-#endif
+        active_mm = percpu_read(cpu_tlbstate.active_mm);
 
         if (active_mm == mm)
                 leave_mm(smp_processor_id());
 
         /* If this cpu still has a stale cr3 reference, then make sure
            it has been flushed. */
-        if (x86_read_percpu(xen_current_cr3) == __pa(mm->pgd)) {
+        if (percpu_read(xen_current_cr3) == __pa(mm->pgd)) {
                 load_cr3(swapper_pg_dir);
                 arch_flush_lazy_cpu_mode();
         }
@@ -1156,6 +1194,706 @@ void xen_exit_mmap(struct mm_struct *mm)
         spin_unlock(&mm->page_table_lock);
 }
 
+static __init void xen_pagetable_setup_start(pgd_t *base)
+{
+}
+
+static __init void xen_pagetable_setup_done(pgd_t *base)
+{
+        xen_setup_shared_info();
+}
+
+static void xen_write_cr2(unsigned long cr2)
+{
+        percpu_read(xen_vcpu)->arch.cr2 = cr2;
+}
+
+static unsigned long xen_read_cr2(void)
+{
+        return percpu_read(xen_vcpu)->arch.cr2;
+}
+
+unsigned long xen_read_cr2_direct(void)
+{
+        return percpu_read(xen_vcpu_info.arch.cr2);
+}
+
+static void xen_flush_tlb(void)
+{
+        struct mmuext_op *op;
+        struct multicall_space mcs;
+
+        preempt_disable();
+
+        mcs = xen_mc_entry(sizeof(*op));
+
+        op = mcs.args;
+        op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+        preempt_enable();
+}
+
+static void xen_flush_tlb_single(unsigned long addr)
+{
+        struct mmuext_op *op;
+        struct multicall_space mcs;
+
+        preempt_disable();
+
+        mcs = xen_mc_entry(sizeof(*op));
+        op = mcs.args;
+        op->cmd = MMUEXT_INVLPG_LOCAL;
+        op->arg1.linear_addr = addr & PAGE_MASK;
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+        preempt_enable();
+}
+
+static void xen_flush_tlb_others(const struct cpumask *cpus,
+                                 struct mm_struct *mm, unsigned long va)
+{
+        struct {
+                struct mmuext_op op;
+                DECLARE_BITMAP(mask, NR_CPUS);
+        } *args;
+        struct multicall_space mcs;
+
+        BUG_ON(cpumask_empty(cpus));
+        BUG_ON(!mm);
+
+        mcs = xen_mc_entry(sizeof(*args));
+        args = mcs.args;
+        args->op.arg2.vcpumask = to_cpumask(args->mask);
+
+        /* Remove us, and any offline CPUS. */
+        cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
+        cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
+
+        if (va == TLB_FLUSH_ALL) {
+                args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
+        } else {
+                args->op.cmd = MMUEXT_INVLPG_MULTI;
+                args->op.arg1.linear_addr = va;
+        }
+
+        MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+
+static unsigned long xen_read_cr3(void)
+{
+        return percpu_read(xen_cr3);
+}
+
+static void set_current_cr3(void *v)
+{
+        percpu_write(xen_current_cr3, (unsigned long)v);
+}
+
+static void __xen_write_cr3(bool kernel, unsigned long cr3)
+{
+        struct mmuext_op *op;
+        struct multicall_space mcs;
+        unsigned long mfn;
+
+        if (cr3)
+                mfn = pfn_to_mfn(PFN_DOWN(cr3));
+        else
+                mfn = 0;
+
+        WARN_ON(mfn == 0 && kernel);
+
+        mcs = __xen_mc_entry(sizeof(*op));
+
+        op = mcs.args;
+        op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
+        op->arg1.mfn = mfn;
+
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        if (kernel) {
+                percpu_write(xen_cr3, cr3);
+
+                /* Update xen_current_cr3 once the batch has actually
+                   been submitted. */
+                xen_mc_callback(set_current_cr3, (void *)cr3);
+        }
+}
+
+static void xen_write_cr3(unsigned long cr3)
+{
+        BUG_ON(preemptible());
+
+        xen_mc_batch();  /* disables interrupts */
+
+        /* Update while interrupts are disabled, so its atomic with
+           respect to ipis */
+        percpu_write(xen_cr3, cr3);
+
+        __xen_write_cr3(true, cr3);
+
+#ifdef CONFIG_X86_64
+        {
+                pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
+                if (user_pgd)
+                        __xen_write_cr3(false, __pa(user_pgd));
+                else
+                        __xen_write_cr3(false, 0);
+        }
+#endif
+
+        xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
+}
+
+static int xen_pgd_alloc(struct mm_struct *mm)
+{
+        pgd_t *pgd = mm->pgd;
+        int ret = 0;
+
+        BUG_ON(PagePinned(virt_to_page(pgd)));
+
+#ifdef CONFIG_X86_64
+        {
+                struct page *page = virt_to_page(pgd);
+                pgd_t *user_pgd;
+
+                BUG_ON(page->private != 0);
+
+                ret = -ENOMEM;
+
+                user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+                page->private = (unsigned long)user_pgd;
+
+                if (user_pgd != NULL) {
+                        user_pgd[pgd_index(VSYSCALL_START)] =
+                                __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
+                        ret = 0;
+                }
+
+                BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
+        }
+#endif
+
+        return ret;
+}
+
+static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+#ifdef CONFIG_X86_64
+        pgd_t *user_pgd = xen_get_user_pgd(pgd);
+
+        if (user_pgd)
+                free_page((unsigned long)user_pgd);
+#endif
+}
+
+#ifdef CONFIG_HIGHPTE
+static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
+{
+        pgprot_t prot = PAGE_KERNEL;
+
+        if (PagePinned(page))
+                prot = PAGE_KERNEL_RO;
+
+        if (0 && PageHighMem(page))
+                printk("mapping highpte %lx type %d prot %s\n",
+                       page_to_pfn(page), type,
+                       (unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ");
+
+        return kmap_atomic_prot(page, type, prot);
+}
+#endif
+
+#ifdef CONFIG_X86_32
+static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
+{
+        /* If there's an existing pte, then don't allow _PAGE_RW to be set */
+        if (pte_val_ma(*ptep) & _PAGE_PRESENT)
+                pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
+                               pte_val_ma(pte));
+
+        return pte;
+}
+
+/* Init-time set_pte while constructing initial pagetables, which
+   doesn't allow RO pagetable pages to be remapped RW */
+static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
+{
+        pte = mask_rw_pte(ptep, pte);
+
+        xen_set_pte(ptep, pte);
+}
+#endif
+
+/* Early in boot, while setting up the initial pagetable, assume
+   everything is pinned. */
+static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
+{
+#ifdef CONFIG_FLATMEM
+        BUG_ON(mem_map);        /* should only be used early */
+#endif
+        make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
+}
+
+/* Early release_pte assumes that all pts are pinned, since there's
+   only init_mm and anything attached to that is pinned. */
+static void xen_release_pte_init(unsigned long pfn)
+{
+        make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
+}
+
+static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
+{
+        struct mmuext_op op;
+        op.cmd = cmd;
+        op.arg1.mfn = pfn_to_mfn(pfn);
+        if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
+                BUG();
+}
+
+/* This needs to make sure the new pte page is pinned iff its being
+   attached to a pinned pagetable. */
+static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)
+{
+        struct page *page = pfn_to_page(pfn);
+
+        if (PagePinned(virt_to_page(mm->pgd))) {
+                SetPagePinned(page);
+
+                vm_unmap_aliases();
+                if (!PageHighMem(page)) {
+                        make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
+                        if (level == PT_PTE && USE_SPLIT_PTLOCKS)
+                                pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
+                } else {
+                        /* make sure there are no stray mappings of
+                           this page */
+                        kmap_flush_unused();
+                }
+        }
+}
+
+static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn)
+{
+        xen_alloc_ptpage(mm, pfn, PT_PTE);
+}
+
+static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
+{
+        xen_alloc_ptpage(mm, pfn, PT_PMD);
+}
+
+/* This should never happen until we're OK to use struct page */
+static void xen_release_ptpage(unsigned long pfn, unsigned level)
+{
+        struct page *page = pfn_to_page(pfn);
+
+        if (PagePinned(page)) {
+                if (!PageHighMem(page)) {
+                        if (level == PT_PTE && USE_SPLIT_PTLOCKS)
+                                pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
+                        make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
+                }
+                ClearPagePinned(page);
+        }
+}
+
+static void xen_release_pte(unsigned long pfn)
+{
+        xen_release_ptpage(pfn, PT_PTE);
+}
+
+static void xen_release_pmd(unsigned long pfn)
+{
+        xen_release_ptpage(pfn, PT_PMD);
+}
+
+#if PAGETABLE_LEVELS == 4
+static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
+{
+        xen_alloc_ptpage(mm, pfn, PT_PUD);
+}
+
+static void xen_release_pud(unsigned long pfn)
+{
+        xen_release_ptpage(pfn, PT_PUD);
+}
+#endif
+
+void __init xen_reserve_top(void)
+{
+#ifdef CONFIG_X86_32
+        unsigned long top = HYPERVISOR_VIRT_START;
+        struct xen_platform_parameters pp;
+
+        if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
+                top = pp.virt_start;
+
+        reserve_top_address(-top);
+#endif  /* CONFIG_X86_32 */
+}
+
+/*
+ * Like __va(), but returns address in the kernel mapping (which is
+ * all we have until the physical memory mapping has been set up.
+ */
+static void *__ka(phys_addr_t paddr)
+{
+#ifdef CONFIG_X86_64
+        return (void *)(paddr + __START_KERNEL_map);
+#else
+        return __va(paddr);
+#endif
+}
+
+/* Convert a machine address to physical address */
+static unsigned long m2p(phys_addr_t maddr)
+{
+        phys_addr_t paddr;
+
+        maddr &= PTE_PFN_MASK;
+        paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
+
+        return paddr;
+}
+
+/* Convert a machine address to kernel virtual */
+static void *m2v(phys_addr_t maddr)
+{
+        return __ka(m2p(maddr));
+}
+
+static void set_page_prot(void *addr, pgprot_t prot)
+{
+        unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
+        pte_t pte = pfn_pte(pfn, prot);
+
+        if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
+                BUG();
+}
+
+static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
+{
+        unsigned pmdidx, pteidx;
+        unsigned ident_pte;
+        unsigned long pfn;
+
+        ident_pte = 0;
+        pfn = 0;
+        for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
+                pte_t *pte_page;
+
+                /* Reuse or allocate a page of ptes */
+                if (pmd_present(pmd[pmdidx]))
+                        pte_page = m2v(pmd[pmdidx].pmd);
+                else {
+                        /* Check for free pte pages */
+                        if (ident_pte == ARRAY_SIZE(level1_ident_pgt))
+                                break;
+
+                        pte_page = &level1_ident_pgt[ident_pte];
+                        ident_pte += PTRS_PER_PTE;
+
+                        pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
+                }
+
+                /* Install mappings */
+                for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
+                        pte_t pte;
+
+                        if (pfn > max_pfn_mapped)
+                                max_pfn_mapped = pfn;
+
+                        if (!pte_none(pte_page[pteidx]))
+                                continue;
+
+                        pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
+                        pte_page[pteidx] = pte;
+                }
+        }
+
+        for (pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
+                set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
+
+        set_page_prot(pmd, PAGE_KERNEL_RO);
+}
+
+#ifdef CONFIG_X86_64
+static void convert_pfn_mfn(void *v)
+{
+        pte_t *pte = v;
+        int i;
+
+        /* All levels are converted the same way, so just treat them
+           as ptes. */
+        for (i = 0; i < PTRS_PER_PTE; i++)
+                pte[i] = xen_make_pte(pte[i].pte);
+}
+
+/*
+ * Set up the inital kernel pagetable.
+ *
+ * We can construct this by grafting the Xen provided pagetable into
+ * head_64.S's preconstructed pagetables.  We copy the Xen L2's into
+ * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt.  This
+ * means that only the kernel has a physical mapping to start with -
+ * but that's enough to get __va working.  We need to fill in the rest
+ * of the physical mapping once some sort of allocator has been set
+ * up.
+ */
+__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+                                         unsigned long max_pfn)
+{
+        pud_t *l3;
+        pmd_t *l2;
+
+        /* Zap identity mapping */
+        init_level4_pgt[0] = __pgd(0);
+
+        /* Pre-constructed entries are in pfn, so convert to mfn */
+        convert_pfn_mfn(init_level4_pgt);
+        convert_pfn_mfn(level3_ident_pgt);
+        convert_pfn_mfn(level3_kernel_pgt);
+
+        l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
+        l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);
+
+        memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+        memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+
+        l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd);
+        l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud);
+        memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
+
+        /* Set up identity map */
+        xen_map_identity_early(level2_ident_pgt, max_pfn);
+
+        /* Make pagetable pieces RO */
+        set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
+        set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
+        set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
+        set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
+        set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
+        set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);
+
+        /* Pin down new L4 */
+        pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
+                          PFN_DOWN(__pa_symbol(init_level4_pgt)));
+
+        /* Unpin Xen-provided one */
+        pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+
+        /* Switch over */
+        pgd = init_level4_pgt;
+
+        /*
+         * At this stage there can be no user pgd, and no page
+         * structure to attach it to, so make sure we just set kernel
+         * pgd.
+         */
+        xen_mc_batch();
+        __xen_write_cr3(true, __pa(pgd));
+        xen_mc_issue(PARAVIRT_LAZY_CPU);
+
+        reserve_early(__pa(xen_start_info->pt_base),
+                      __pa(xen_start_info->pt_base +
+                           xen_start_info->nr_pt_frames * PAGE_SIZE),
+                      "XEN PAGETABLES");
+
+        return pgd;
+}
+#else   /* !CONFIG_X86_64 */
+static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss;
+
+__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
+                                         unsigned long max_pfn)
+{
+        pmd_t *kernel_pmd;
+
+        init_pg_tables_start = __pa(pgd);
+        init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
+        max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024);
+
+        kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
+        memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
+
+        xen_map_identity_early(level2_kernel_pgt, max_pfn);
+
+        memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
+        set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],
+                        __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));
+
+        set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
+        set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
+        set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
+
+        pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+
+        xen_write_cr3(__pa(swapper_pg_dir));
+
+        pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
+
+        return swapper_pg_dir;
+}
+#endif  /* CONFIG_X86_64 */
+
+static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot)
+{
+        pte_t pte;
+
+        phys >>= PAGE_SHIFT;
+
+        switch (idx) {
+        case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
+#ifdef CONFIG_X86_F00F_BUG
+        case FIX_F00F_IDT:
+#endif
+#ifdef CONFIG_X86_32
+        case FIX_WP_TEST:
+        case FIX_VDSO:
+# ifdef CONFIG_HIGHMEM
+        case FIX_KMAP_BEGIN ... FIX_KMAP_END:
+# endif
+#else
+        case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
+#endif
+#ifdef CONFIG_X86_LOCAL_APIC
+        case FIX_APIC_BASE:     /* maps dummy local APIC */
+#endif
+                pte = pfn_pte(phys, prot);
+                break;
+
+        default:
+                pte = mfn_pte(phys, prot);
+                break;
+        }
+
+        __native_set_fixmap(idx, pte);
+
+#ifdef CONFIG_X86_64
+        /* Replicate changes to map the vsyscall page into the user
+           pagetable vsyscall mapping. */
+        if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
+                unsigned long vaddr = __fix_to_virt(idx);
+                set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
+        }
+#endif
+}
+
+__init void xen_post_allocator_init(void)
+{
+        pv_mmu_ops.set_pte = xen_set_pte;
+        pv_mmu_ops.set_pmd = xen_set_pmd;
+        pv_mmu_ops.set_pud = xen_set_pud;
+#if PAGETABLE_LEVELS == 4
+        pv_mmu_ops.set_pgd = xen_set_pgd;
+#endif
+
+        /* This will work as long as patching hasn't happened yet
+           (which it hasn't) */
+        pv_mmu_ops.alloc_pte = xen_alloc_pte;
+        pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
+        pv_mmu_ops.release_pte = xen_release_pte;
+        pv_mmu_ops.release_pmd = xen_release_pmd;
+#if PAGETABLE_LEVELS == 4
+        pv_mmu_ops.alloc_pud = xen_alloc_pud;
+        pv_mmu_ops.release_pud = xen_release_pud;
+#endif
+
+#ifdef CONFIG_X86_64
+        SetPagePinned(virt_to_page(level3_user_vsyscall));
+#endif
+        xen_mark_init_mm_pinned();
+}
+
+
+const struct pv_mmu_ops xen_mmu_ops __initdata = {
+        .pagetable_setup_start = xen_pagetable_setup_start,
+        .pagetable_setup_done = xen_pagetable_setup_done,
+
+        .read_cr2 = xen_read_cr2,
+        .write_cr2 = xen_write_cr2,
+
+        .read_cr3 = xen_read_cr3,
+        .write_cr3 = xen_write_cr3,
+
+        .flush_tlb_user = xen_flush_tlb,
+        .flush_tlb_kernel = xen_flush_tlb,
+        .flush_tlb_single = xen_flush_tlb_single,
+        .flush_tlb_others = xen_flush_tlb_others,
+
+        .pte_update = paravirt_nop,
+        .pte_update_defer = paravirt_nop,
+
+        .pgd_alloc = xen_pgd_alloc,
+        .pgd_free = xen_pgd_free,
+
+        .alloc_pte = xen_alloc_pte_init,
+        .release_pte = xen_release_pte_init,
+        .alloc_pmd = xen_alloc_pte_init,
+        .alloc_pmd_clone = paravirt_nop,
+        .release_pmd = xen_release_pte_init,
+
+#ifdef CONFIG_HIGHPTE
+        .kmap_atomic_pte = xen_kmap_atomic_pte,
+#endif
+
+#ifdef CONFIG_X86_64
+        .set_pte = xen_set_pte,
+#else
+        .set_pte = xen_set_pte_init,
+#endif
+        .set_pte_at = xen_set_pte_at,
+        .set_pmd = xen_set_pmd_hyper,
+
+        .ptep_modify_prot_start = __ptep_modify_prot_start,
+        .ptep_modify_prot_commit = __ptep_modify_prot_commit,
+
+        .pte_val = PV_CALLEE_SAVE(xen_pte_val),
+        .pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
+
+        .make_pte = PV_CALLEE_SAVE(xen_make_pte),
+        .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
+
+#ifdef CONFIG_X86_PAE
+        .set_pte_atomic = xen_set_pte_atomic,
+        .set_pte_present = xen_set_pte_at,
+        .pte_clear = xen_pte_clear,
+        .pmd_clear = xen_pmd_clear,
+#endif  /* CONFIG_X86_PAE */
+        .set_pud = xen_set_pud_hyper,
+
+        .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
+        .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
+
+#if PAGETABLE_LEVELS == 4
+        .pud_val = PV_CALLEE_SAVE(xen_pud_val),
+        .make_pud = PV_CALLEE_SAVE(xen_make_pud),
+        .set_pgd = xen_set_pgd_hyper,
+
+        .alloc_pud = xen_alloc_pte_init,
+        .release_pud = xen_release_pte_init,
+#endif  /* PAGETABLE_LEVELS == 4 */
+
+        .activate_mm = xen_activate_mm,
+        .dup_mmap = xen_dup_mmap,
+        .exit_mmap = xen_exit_mmap,
+
+        .lazy_mode = {
+                .enter = paravirt_enter_lazy_mmu,
+                .leave = xen_leave_lazy,
+        },
+
+        .set_fixmap = xen_set_fixmap,
+};
+
+
 #ifdef CONFIG_XEN_DEBUG_FS
 
 static struct dentry *d_mmu_debug;