From: jbeulich@novell.com Subject: consolidate pmd/pud/pgd entry handling Patch-mainline: obsolete --- head-2011-03-17.orig/arch/x86/include/mach-xen/asm/hypervisor.h 2011-02-02 15:09:52.000000000 +0100 +++ head-2011-03-17/arch/x86/include/mach-xen/asm/hypervisor.h 2011-02-03 14:41:13.000000000 +0100 @@ -101,10 +101,12 @@ void xen_invlpg(unsigned long ptr); void xen_l1_entry_update(pte_t *ptr, pte_t val); void xen_l2_entry_update(pmd_t *ptr, pmd_t val); void xen_l3_entry_update(pud_t *ptr, pud_t val); /* x86_64/PAE */ -void xen_l4_entry_update(pgd_t *ptr, pgd_t val); /* x86_64 only */ +void xen_l4_entry_update(pgd_t *ptr, int user, pgd_t val); /* x86_64 only */ void xen_pgd_pin(unsigned long ptr); void xen_pgd_unpin(unsigned long ptr); +void xen_init_pgd_pin(void); + void xen_set_ldt(const void *ptr, unsigned int ents); #ifdef CONFIG_SMP @@ -337,6 +339,18 @@ MULTI_update_va_mapping( } static inline void +MULTI_mmu_update(multicall_entry_t *mcl, mmu_update_t *req, + unsigned int count, unsigned int *success_count, + domid_t domid) +{ + mcl->op = __HYPERVISOR_mmu_update; + mcl->args[0] = (unsigned long)req; + mcl->args[1] = count; + mcl->args[2] = (unsigned long)success_count; + mcl->args[3] = domid; +} + +static inline void MULTI_grant_table_op(multicall_entry_t *mcl, unsigned int cmd, void *uop, unsigned int count) { --- head-2011-03-17.orig/arch/x86/include/mach-xen/asm/pgalloc.h 2011-02-01 15:41:35.000000000 +0100 +++ head-2011-03-17/arch/x86/include/mach-xen/asm/pgalloc.h 2011-02-03 14:41:13.000000000 +0100 @@ -75,20 +75,16 @@ static inline void pmd_populate(struct m struct page *pte) { unsigned long pfn = page_to_pfn(pte); + pmd_t ent = __pmd(((pmdval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE); paravirt_alloc_pte(mm, pfn); - if (PagePinned(virt_to_page(mm->pgd))) { - if (!PageHighMem(pte)) - BUG_ON(HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - pfn_pte(pfn, PAGE_KERNEL_RO), 0)); -#ifndef CONFIG_X86_64 - else if (!TestSetPagePinned(pte)) - kmap_flush_unused(); + if (PagePinned(virt_to_page(pmd))) { +#ifndef CONFIG_HIGHPTE + BUG_ON(PageHighMem(pte)); #endif - set_pmd(pmd, __pmd(((pmdval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE)); + set_pmd(pmd, ent); } else - *pmd = __pmd(((pmdval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE); + *pmd = ent; } #define pmd_pgtable(pmd) pmd_page(pmd) @@ -116,39 +112,28 @@ extern void pud_populate(struct mm_struc #else /* !CONFIG_X86_PAE */ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) { + pud_t ent = __pud(_PAGE_TABLE | __pa(pmd)); + paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); - if (unlikely(PagePinned(virt_to_page((mm)->pgd)))) { - BUG_ON(HYPERVISOR_update_va_mapping( - (unsigned long)pmd, - pfn_pte(virt_to_phys(pmd)>>PAGE_SHIFT, - PAGE_KERNEL_RO), 0)); - set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd))); - } else - *pud = __pud(_PAGE_TABLE | __pa(pmd)); + if (PagePinned(virt_to_page(pud))) + set_pud(pud, ent); + else + *pud = ent; } #endif /* CONFIG_X86_PAE */ #if PAGETABLE_LEVELS > 3 #define __user_pgd(pgd) ((pgd) + PTRS_PER_PGD) -/* - * We need to use the batch mode here, but pgd_pupulate() won't be - * be called frequently. - */ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud) { + pgd_t ent = __pgd(_PAGE_TABLE | __pa(pud)); + paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT); - if (unlikely(PagePinned(virt_to_page((mm)->pgd)))) { - BUG_ON(HYPERVISOR_update_va_mapping( - (unsigned long)pud, - pfn_pte(virt_to_phys(pud)>>PAGE_SHIFT, - PAGE_KERNEL_RO), 0)); - set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pud))); - set_pgd(__user_pgd(pgd), __pgd(_PAGE_TABLE | __pa(pud))); - } else { - *(pgd) = __pgd(_PAGE_TABLE | __pa(pud)); - *__user_pgd(pgd) = *(pgd); - } + if (unlikely(PagePinned(virt_to_page(pgd)))) + xen_l4_entry_update(pgd, 1, ent); + else + *__user_pgd(pgd) = *pgd = ent; } static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) --- head-2011-03-17.orig/arch/x86/include/mach-xen/asm/pgtable.h 2011-02-01 15:55:04.000000000 +0100 +++ head-2011-03-17/arch/x86/include/mach-xen/asm/pgtable.h 2011-02-07 12:14:31.000000000 +0100 @@ -621,7 +621,7 @@ static inline pmd_t xen_local_pmdp_get_a { pmd_t res = *pmdp; - xen_pmd_clear(pmdp); + xen_set_pmd(pmdp, __pmd(0)); return res; } --- head-2011-03-17.orig/arch/x86/include/mach-xen/asm/pgtable-3level.h 2011-02-01 15:47:16.000000000 +0100 +++ head-2011-03-17/arch/x86/include/mach-xen/asm/pgtable-3level.h 2011-02-03 14:41:13.000000000 +0100 @@ -61,12 +61,15 @@ static inline void __xen_pte_clear(pte_t ptep->pte_high = 0; } -static inline void xen_pmd_clear(pmd_t *pmd) -{ - xen_l2_entry_update(pmd, __pmd(0)); -} +#define xen_pmd_clear(pmd) \ +({ \ + pmd_t *__pmdp = (pmd); \ + PagePinned(virt_to_page(__pmdp)) \ + ? set_pmd(__pmdp, __pmd(0)) \ + : (void)(*__pmdp = __pmd(0)); \ +}) -static inline void pud_clear(pud_t *pudp) +static inline void __xen_pud_clear(pud_t *pudp) { pgdval_t pgd; @@ -87,6 +90,14 @@ static inline void pud_clear(pud_t *pudp xen_tlb_flush(); } +#define xen_pud_clear(pudp) \ +({ \ + pud_t *__pudp = (pudp); \ + PagePinned(virt_to_page(__pudp)) \ + ? __xen_pud_clear(__pudp) \ + : (void)(*__pudp = __pud(0)); \ +}) + #ifdef CONFIG_SMP static inline pte_t xen_ptep_get_and_clear(pte_t *ptep, pte_t res) { --- head-2011-03-17.orig/arch/x86/include/mach-xen/asm/pgtable_64.h 2011-02-03 14:39:36.000000000 +0100 +++ head-2011-03-17/arch/x86/include/mach-xen/asm/pgtable_64.h 2011-02-03 14:41:13.000000000 +0100 @@ -70,10 +70,13 @@ static inline void xen_set_pmd(pmd_t *pm xen_l2_entry_update(pmdp, pmd); } -static inline void xen_pmd_clear(pmd_t *pmd) -{ - xen_set_pmd(pmd, xen_make_pmd(0)); -} +#define xen_pmd_clear(pmd) \ +({ \ + pmd_t *__pmdp = (pmd); \ + PagePinned(virt_to_page(__pmdp)) \ + ? set_pmd(__pmdp, xen_make_pmd(0)) \ + : (void)(*__pmdp = xen_make_pmd(0)); \ +}) #ifdef CONFIG_SMP static inline pte_t xen_ptep_get_and_clear(pte_t *xp, pte_t ret) @@ -100,23 +103,28 @@ static inline void xen_set_pud(pud_t *pu xen_l3_entry_update(pudp, pud); } -static inline void xen_pud_clear(pud_t *pud) -{ - xen_set_pud(pud, xen_make_pud(0)); -} +#define xen_pud_clear(pud) \ +({ \ + pud_t *__pudp = (pud); \ + PagePinned(virt_to_page(__pudp)) \ + ? set_pud(__pudp, xen_make_pud(0)) \ + : (void)(*__pudp = xen_make_pud(0)); \ +}) #define __user_pgd(pgd) ((pgd) + PTRS_PER_PGD) static inline void xen_set_pgd(pgd_t *pgdp, pgd_t pgd) { - xen_l4_entry_update(pgdp, pgd); + xen_l4_entry_update(pgdp, 0, pgd); } -static inline void xen_pgd_clear(pgd_t *pgd) -{ - xen_set_pgd(pgd, xen_make_pgd(0)); - xen_set_pgd(__user_pgd(pgd), xen_make_pgd(0)); -} +#define xen_pgd_clear(pgd) \ +({ \ + pgd_t *__pgdp = (pgd); \ + PagePinned(virt_to_page(__pgdp)) \ + ? xen_l4_entry_update(__pgdp, 1, xen_make_pgd(0)) \ + : (void)(*__user_pgd(__pgdp) = *__pgdp = xen_make_pgd(0)); \ +}) #define __pte_mfn(_pte) (((_pte).pte & PTE_PFN_MASK) >> PAGE_SHIFT) --- head-2011-03-17.orig/arch/x86/mm/hypervisor.c 2010-12-08 10:45:24.000000000 +0100 +++ head-2011-03-17/arch/x86/mm/hypervisor.c 2011-02-03 14:41:13.000000000 +0100 @@ -358,31 +358,91 @@ void xen_l1_entry_update(pte_t *ptr, pte } EXPORT_SYMBOL_GPL(xen_l1_entry_update); +static void do_lN_entry_update(mmu_update_t *mmu, unsigned int mmu_count, + struct page *page) +{ + if (likely(page)) { + multicall_entry_t mcl[2]; + unsigned long pfn = page_to_pfn(page); + + MULTI_update_va_mapping(mcl, + (unsigned long)__va(pfn << PAGE_SHIFT), + pfn_pte(pfn, PAGE_KERNEL_RO), 0); + SetPagePinned(page); + MULTI_mmu_update(mcl + 1, mmu, mmu_count, NULL, DOMID_SELF); + if (unlikely(HYPERVISOR_multicall_check(mcl, 2, NULL))) + BUG(); + } else if (unlikely(HYPERVISOR_mmu_update(mmu, mmu_count, + NULL, DOMID_SELF) < 0)) + BUG(); +} + void xen_l2_entry_update(pmd_t *ptr, pmd_t val) { mmu_update_t u; + struct page *page = NULL; + + if (likely(pmd_present(val)) && likely(!pmd_large(val)) + && likely(mem_map) + && likely(PagePinned(virt_to_page(ptr)))) { + page = pmd_page(val); + if (unlikely(PagePinned(page))) + page = NULL; + else if (PageHighMem(page)) { +#ifndef CONFIG_HIGHPTE + BUG(); +#endif + kmap_flush_unused(); + page = NULL; + } + } u.ptr = virt_to_machine(ptr); u.val = __pmd_val(val); - BUG_ON(HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF) < 0); + do_lN_entry_update(&u, 1, page); } #if defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64) void xen_l3_entry_update(pud_t *ptr, pud_t val) { mmu_update_t u; + struct page *page = NULL; + + if (likely(pud_present(val)) +#ifdef CONFIG_X86_64 + && likely(!pud_large(val)) +#endif + && likely(mem_map) + && likely(PagePinned(virt_to_page(ptr)))) { + page = pud_page(val); + if (unlikely(PagePinned(page))) + page = NULL; + } u.ptr = virt_to_machine(ptr); u.val = __pud_val(val); - BUG_ON(HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF) < 0); + do_lN_entry_update(&u, 1, page); } #endif #ifdef CONFIG_X86_64 -void xen_l4_entry_update(pgd_t *ptr, pgd_t val) +void xen_l4_entry_update(pgd_t *ptr, int user, pgd_t val) { - mmu_update_t u; - u.ptr = virt_to_machine(ptr); - u.val = __pgd_val(val); - BUG_ON(HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF) < 0); + mmu_update_t u[2]; + struct page *page = NULL; + + if (likely(pgd_present(val)) && likely(mem_map) + && likely(PagePinned(virt_to_page(ptr)))) { + page = pgd_page(val); + if (unlikely(PagePinned(page))) + page = NULL; + } + u[0].ptr = virt_to_machine(ptr); + u[0].val = __pgd_val(val); + if (user) { + u[1].ptr = virt_to_machine(__user_pgd(ptr)); + u[1].val = __pgd_val(val); + do_lN_entry_update(u, 2, page); + } else + do_lN_entry_update(u, 1, page); } #endif /* CONFIG_X86_64 */ --- head-2011-03-17.orig/arch/x86/mm/init_32-xen.c 2011-02-02 15:10:16.000000000 +0100 +++ head-2011-03-17/arch/x86/mm/init_32-xen.c 2011-02-03 14:41:13.000000000 +0100 @@ -689,6 +689,8 @@ static void __init zone_sizes_init(void) #endif free_area_init_nodes(max_zone_pfns); + + xen_init_pgd_pin(); } void __init setup_bootmem_allocator(void) @@ -908,8 +910,6 @@ void __init mem_init(void) if (boot_cpu_data.wp_works_ok < 0) test_wp_bit(); - - SetPagePinned(virt_to_page(init_mm.pgd)); } #ifdef CONFIG_MEMORY_HOTPLUG --- head-2011-03-17.orig/arch/x86/mm/init_64-xen.c 2011-02-02 15:10:16.000000000 +0100 +++ head-2011-03-17/arch/x86/mm/init_64-xen.c 2011-02-03 14:41:13.000000000 +0100 @@ -231,8 +231,11 @@ static pud_t *fill_pud(pgd_t *pgd, unsig { if (pgd_none(*pgd)) { pud_t *pud = (pud_t *)spp_getpage(); - make_page_readonly(pud, XENFEAT_writable_page_tables); - pgd_populate(&init_mm, pgd, pud); + if (!after_bootmem) { + make_page_readonly(pud, XENFEAT_writable_page_tables); + xen_l4_entry_update(pgd, __pgd(__pa(pud) | _PAGE_TABLE)); + } else + pgd_populate(&init_mm, pgd, pud); if (pud != pud_offset(pgd, 0)) printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", pud, pud_offset(pgd, 0)); @@ -244,8 +247,11 @@ static pmd_t *fill_pmd(pud_t *pud, unsig { if (pud_none(*pud)) { pmd_t *pmd = (pmd_t *) spp_getpage(); - make_page_readonly(pmd, XENFEAT_writable_page_tables); - pud_populate(&init_mm, pud, pmd); + if (!after_bootmem) { + make_page_readonly(pmd, XENFEAT_writable_page_tables); + xen_l3_entry_update(pud, __pud(__pa(pmd) | _PAGE_TABLE)); + } else + pud_populate(&init_mm, pud, pmd); if (pmd != pmd_offset(pud, 0)) printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud, 0)); @@ -578,7 +584,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned XENFEAT_writable_page_tables); *pmd = __pmd(pte_phys | _PAGE_TABLE); } else { - make_page_readonly(pte, XENFEAT_writable_page_tables); spin_lock(&init_mm.page_table_lock); pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); spin_unlock(&init_mm.page_table_lock); @@ -667,7 +672,6 @@ phys_pud_init(pud_t *pud_page, unsigned else *pud = __pud(pmd_phys | _PAGE_TABLE); } else { - make_page_readonly(pmd, XENFEAT_writable_page_tables); spin_lock(&init_mm.page_table_lock); pud_populate(&init_mm, pud, __va(pmd_phys)); spin_unlock(&init_mm.page_table_lock); @@ -843,7 +847,6 @@ kernel_physical_mapping_init(unsigned lo XENFEAT_writable_page_tables); xen_l4_entry_update(pgd, __pgd(pud_phys | _PAGE_TABLE)); } else { - make_page_readonly(pud, XENFEAT_writable_page_tables); spin_lock(&init_mm.page_table_lock); pgd_populate(&init_mm, pgd, __va(pud_phys)); spin_unlock(&init_mm.page_table_lock); @@ -892,7 +895,7 @@ void __init paging_init(void) free_area_init_nodes(max_zone_pfns); - SetPagePinned(virt_to_page(init_mm.pgd)); + xen_init_pgd_pin(); } /* --- head-2011-03-17.orig/arch/x86/mm/pgtable-xen.c 2011-03-17 14:26:03.000000000 +0100 +++ head-2011-03-17/arch/x86/mm/pgtable-xen.c 2011-03-17 14:34:34.000000000 +0100 @@ -66,16 +66,16 @@ early_param("userpte", setup_userpte); void __pte_free(pgtable_t pte) { if (!PageHighMem(pte)) { - unsigned long va = (unsigned long)page_address(pte); - unsigned int level; - pte_t *ptep = lookup_address(va, &level); - - BUG_ON(!ptep || level != PG_LEVEL_4K || !pte_present(*ptep)); - if (!pte_write(*ptep) - && HYPERVISOR_update_va_mapping(va, - mk_pte(pte, PAGE_KERNEL), - 0)) - BUG(); + if (PagePinned(pte)) { + unsigned long pfn = page_to_pfn(pte); + + if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), + pfn_pte(pfn, + PAGE_KERNEL), + 0)) + BUG(); + ClearPagePinned(pte); + } } else #ifdef CONFIG_HIGHPTE ClearPagePinned(pte); @@ -117,14 +117,15 @@ pmd_t *pmd_alloc_one(struct mm_struct *m void __pmd_free(pgtable_t pmd) { - unsigned long va = (unsigned long)page_address(pmd); - unsigned int level; - pte_t *ptep = lookup_address(va, &level); - - BUG_ON(!ptep || level != PG_LEVEL_4K || !pte_present(*ptep)); - if (!pte_write(*ptep) - && HYPERVISOR_update_va_mapping(va, mk_pte(pmd, PAGE_KERNEL), 0)) - BUG(); + if (PagePinned(pmd)) { + unsigned long pfn = page_to_pfn(pmd); + + if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), + pfn_pte(pfn, PAGE_KERNEL), + 0)) + BUG(); + ClearPagePinned(pmd); + } ClearPageForeign(pmd); init_page_count(pmd); @@ -212,21 +213,20 @@ static inline unsigned int pgd_walk_set_ { unsigned long pfn = page_to_pfn(page); - if (PageHighMem(page)) { - if (pgprot_val(flags) & _PAGE_RW) - ClearPagePinned(page); - else - SetPagePinned(page); - } else { - MULTI_update_va_mapping(per_cpu(pb_mcl, cpu) + seq, - (unsigned long)__va(pfn << PAGE_SHIFT), - pfn_pte(pfn, flags), 0); - if (unlikely(++seq == PIN_BATCH)) { - if (unlikely(HYPERVISOR_multicall_check(per_cpu(pb_mcl, cpu), - PIN_BATCH, NULL))) - BUG(); - seq = 0; - } + if (pgprot_val(flags) & _PAGE_RW) + ClearPagePinned(page); + else + SetPagePinned(page); + if (PageHighMem(page)) + return seq; + MULTI_update_va_mapping(per_cpu(pb_mcl, cpu) + seq, + (unsigned long)__va(pfn << PAGE_SHIFT), + pfn_pte(pfn, flags), 0); + if (unlikely(++seq == PIN_BATCH)) { + if (unlikely(HYPERVISOR_multicall_check(per_cpu(pb_mcl, cpu), + PIN_BATCH, NULL))) + BUG(); + seq = 0; } return seq; @@ -273,6 +273,16 @@ static void pgd_walk(pgd_t *pgd_base, pg } } +#ifdef CONFIG_X86_PAE + for (; g < PTRS_PER_PGD; g++, pgd++) { + BUG_ON(pgd_none(*pgd)); + pud = pud_offset(pgd, 0); + BUG_ON(pud_none(*pud)); + pmd = pmd_offset(pud, 0); + seq = pgd_walk_set_prot(virt_to_page(pmd),flags,cpu,seq); + } +#endif + mcl = per_cpu(pb_mcl, cpu); #ifdef CONFIG_X86_64 if (unlikely(seq > PIN_BATCH - 2)) { @@ -308,6 +318,51 @@ static void pgd_walk(pgd_t *pgd_base, pg put_cpu(); } +void __init xen_init_pgd_pin(void) +{ + pgd_t *pgd = init_mm.pgd; + pud_t *pud; + pmd_t *pmd; + unsigned int g, u, m; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return; + + SetPagePinned(virt_to_page(pgd)); + for (g = 0; g < PTRS_PER_PGD; g++, pgd++) { +#ifndef CONFIG_X86_PAE + if (g >= pgd_index(HYPERVISOR_VIRT_START) + && g <= pgd_index(HYPERVISOR_VIRT_END - 1)) + continue; +#endif + if (!pgd_present(*pgd)) + continue; + pud = pud_offset(pgd, 0); + if (PTRS_PER_PUD > 1) /* not folded */ + SetPagePinned(virt_to_page(pud)); + for (u = 0; u < PTRS_PER_PUD; u++, pud++) { + if (!pud_present(*pud)) + continue; + pmd = pmd_offset(pud, 0); + if (PTRS_PER_PMD > 1) /* not folded */ + SetPagePinned(virt_to_page(pmd)); + for (m = 0; m < PTRS_PER_PMD; m++, pmd++) { +#ifdef CONFIG_X86_PAE + if (g == pgd_index(HYPERVISOR_VIRT_START) + && m >= pmd_index(HYPERVISOR_VIRT_START)) + continue; +#endif + if (!pmd_present(*pmd)) + continue; + SetPagePinned(pmd_page(*pmd)); + } + } + } +#ifdef CONFIG_X86_64 + SetPagePinned(virt_to_page(level3_user_pgt)); +#endif +} + static void __pgd_pin(pgd_t *pgd) { pgd_walk(pgd, PAGE_KERNEL_RO); @@ -506,21 +561,18 @@ static void pgd_dtor(pgd_t *pgd) void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd) { - struct page *page = virt_to_page(pmd); - unsigned long pfn = page_to_pfn(page); - - paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT); - /* Note: almost everything apart from _PAGE_PRESENT is reserved at the pmd (PDPT) level. */ - if (PagePinned(virt_to_page(mm->pgd))) { - BUG_ON(PageHighMem(page)); - BUG_ON(HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - pfn_pte(pfn, PAGE_KERNEL_RO), 0)); - set_pud(pudp, __pud(__pa(pmd) | _PAGE_PRESENT)); - } else - *pudp = __pud(__pa(pmd) | _PAGE_PRESENT); + pud_t pud = __pud(__pa(pmd) | _PAGE_PRESENT); + + paravirt_alloc_pmd(mm, page_to_pfn(virt_to_page(pmd))); + + if (likely(!PagePinned(virt_to_page(pudp)))) { + *pudp = pud; + return; + } + + set_pud(pudp, pud); /* * According to Intel App note "TLBs, Paging-Structure Caches, @@ -615,13 +667,10 @@ static void pgd_prepopulate_pmd(struct m i++, pud++, addr += PUD_SIZE) { pmd_t *pmd = pmds[i]; - if (i >= KERNEL_PGD_BOUNDARY) { + if (i >= KERNEL_PGD_BOUNDARY) memcpy(pmd, (pmd_t *)pgd_page_vaddr(swapper_pg_dir[i]), sizeof(pmd_t) * PTRS_PER_PMD); - make_lowmem_page_readonly( - pmd, XENFEAT_writable_page_tables); - } /* It is safe to poke machine addresses of pmds under the pgd_lock. */ pud_populate(mm, pud, pmd);