diff options
Diffstat (limited to 'arch/x86/xen/mmu.c')
-rw-r--r-- | arch/x86/xen/mmu.c | 174 |
1 files changed, 33 insertions, 141 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 55c965b38c27..02d752460371 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1054,7 +1054,7 @@ void xen_mm_pin_all(void) * that's before we have page structures to store the bits. So do all * the book-keeping now. */ -static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page, +static int __init xen_mark_pinned(struct mm_struct *mm, struct page *page, enum pt_level level) { SetPagePinned(page); @@ -1187,7 +1187,7 @@ static void drop_other_mm_ref(void *info) active_mm = percpu_read(cpu_tlbstate.active_mm); - if (active_mm == mm) + if (active_mm == mm && percpu_read(cpu_tlbstate.state) != TLBSTATE_OK) leave_mm(smp_processor_id()); /* If this cpu still has a stale cr3 reference, then make sure @@ -1271,13 +1271,27 @@ 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 void __init xen_pagetable_setup_start(pgd_t *base) { } +static __init void xen_mapping_pagetable_reserve(u64 start, u64 end) +{ + /* reserve the range used */ + native_pagetable_reserve(start, end); + + /* set as RW the rest */ + printk(KERN_DEBUG "xen: setting RW the range %llx - %llx\n", end, + PFN_PHYS(pgt_buf_top)); + while (end < PFN_PHYS(pgt_buf_top)) { + make_lowmem_page_readwrite(__va(end)); + end += PAGE_SIZE; + } +} + static void xen_post_allocator_init(void); -static __init void xen_pagetable_setup_done(pgd_t *base) +static void __init xen_pagetable_setup_done(pgd_t *base) { xen_setup_shared_info(); xen_post_allocator_init(); @@ -1463,119 +1477,6 @@ static int xen_pgd_alloc(struct mm_struct *mm) return ret; } -#ifdef CONFIG_X86_64 -static __initdata u64 __last_pgt_set_rw = 0; -static __initdata u64 __pgt_buf_start = 0; -static __initdata u64 __pgt_buf_end = 0; -static __initdata u64 __pgt_buf_top = 0; -/* - * As a consequence of the commit: - * - * commit 4b239f458c229de044d6905c2b0f9fe16ed9e01e - * Author: Yinghai Lu <yinghai@kernel.org> - * Date: Fri Dec 17 16:58:28 2010 -0800 - * - * x86-64, mm: Put early page table high - * - * at some point init_memory_mapping is going to reach the pagetable pages - * area and map those pages too (mapping them as normal memory that falls - * in the range of addresses passed to init_memory_mapping as argument). - * Some of those pages are already pagetable pages (they are in the range - * pgt_buf_start-pgt_buf_end) therefore they are going to be mapped RO and - * everything is fine. - * Some of these pages are not pagetable pages yet (they fall in the range - * pgt_buf_end-pgt_buf_top; for example the page at pgt_buf_end) so they - * are going to be mapped RW. When these pages become pagetable pages and - * are hooked into the pagetable, xen will find that the guest has already - * a RW mapping of them somewhere and fail the operation. - * The reason Xen requires pagetables to be RO is that the hypervisor needs - * to verify that the pagetables are valid before using them. The validation - * operations are called "pinning". - * - * In order to fix the issue we mark all the pages in the entire range - * pgt_buf_start-pgt_buf_top as RO, however when the pagetable allocation - * is completed only the range pgt_buf_start-pgt_buf_end is reserved by - * init_memory_mapping. Hence the kernel is going to crash as soon as one - * of the pages in the range pgt_buf_end-pgt_buf_top is reused (b/c those - * ranges are RO). - * - * For this reason, 'mark_rw_past_pgt' is introduced which is called _after_ - * the init_memory_mapping has completed (in a perfect world we would - * call this function from init_memory_mapping, but lets ignore that). - * - * Because we are called _after_ init_memory_mapping the pgt_buf_[start, - * end,top] have all changed to new values (b/c init_memory_mapping - * is called and setting up another new page-table). Hence, the first time - * we enter this function, we save away the pgt_buf_start value and update - * the pgt_buf_[end,top]. - * - * When we detect that the "old" pgt_buf_start through pgt_buf_end - * PFNs have been reserved (so memblock_x86_reserve_range has been called), - * we immediately set out to RW the "old" pgt_buf_end through pgt_buf_top. - * - * And then we update those "old" pgt_buf_[end|top] with the new ones - * so that we can redo this on the next pagetable. - */ -static __init void mark_rw_past_pgt(void) { - - if (pgt_buf_end > pgt_buf_start) { - u64 addr, size; - - /* Save it away. */ - if (!__pgt_buf_start) { - __pgt_buf_start = pgt_buf_start; - __pgt_buf_end = pgt_buf_end; - __pgt_buf_top = pgt_buf_top; - return; - } - /* If we get the range that starts at __pgt_buf_end that means - * the range is reserved, and that in 'init_memory_mapping' - * the 'memblock_x86_reserve_range' has been called with the - * outdated __pgt_buf_start, __pgt_buf_end (the "new" - * pgt_buf_[start|end|top] refer now to a new pagetable. - * Note: we are called _after_ the pgt_buf_[..] have been - * updated.*/ - - addr = memblock_x86_find_in_range_size(PFN_PHYS(__pgt_buf_start), - &size, PAGE_SIZE); - - /* Still not reserved, meaning 'memblock_x86_reserve_range' - * hasn't been called yet. Update the _end and _top.*/ - if (addr == PFN_PHYS(__pgt_buf_start)) { - __pgt_buf_end = pgt_buf_end; - __pgt_buf_top = pgt_buf_top; - return; - } - - /* OK, the area is reserved, meaning it is time for us to - * set RW for the old end->top PFNs. */ - - /* ..unless we had already done this. */ - if (__pgt_buf_end == __last_pgt_set_rw) - return; - - addr = PFN_PHYS(__pgt_buf_end); - - /* set as RW the rest */ - printk(KERN_DEBUG "xen: setting RW the range %llx - %llx\n", - PFN_PHYS(__pgt_buf_end), PFN_PHYS(__pgt_buf_top)); - - while (addr < PFN_PHYS(__pgt_buf_top)) { - make_lowmem_page_readwrite(__va(addr)); - addr += PAGE_SIZE; - } - /* And update everything so that we are ready for the next - * pagetable (the one created for regions past 4GB) */ - __last_pgt_set_rw = __pgt_buf_end; - __pgt_buf_start = pgt_buf_start; - __pgt_buf_end = pgt_buf_end; - __pgt_buf_top = pgt_buf_top; - } - return; -} -#else -static __init void mark_rw_past_pgt(void) { } -#endif static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd) { #ifdef CONFIG_X86_64 @@ -1587,7 +1488,7 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd) } #ifdef CONFIG_X86_32 -static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte) +static pte_t __init 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) @@ -1597,19 +1498,11 @@ static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte) return pte; } #else /* CONFIG_X86_64 */ -static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte) +static pte_t __init mask_rw_pte(pte_t *ptep, pte_t pte) { unsigned long pfn = pte_pfn(pte); /* - * A bit of optimization. We do not need to call the workaround - * when xen_set_pte_init is called with a PTE with 0 as PFN. - * That is b/c the pagetable at that point are just being populated - * with empty values and we can save some cycles by not calling - * the 'memblock' code.*/ - if (pfn) - mark_rw_past_pgt(); - /* * If the new pfn is within the range of the newly allocated * kernel pagetable, and it isn't being mapped into an * early_ioremap fixmap slot as a freshly allocated page, make sure @@ -1626,7 +1519,7 @@ static __init pte_t mask_rw_pte(pte_t *ptep, pte_t 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) +static void __init xen_set_pte_init(pte_t *ptep, pte_t pte) { pte = mask_rw_pte(ptep, pte); @@ -1644,7 +1537,7 @@ static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn) /* 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) +static void __init xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn) { #ifdef CONFIG_FLATMEM BUG_ON(mem_map); /* should only be used early */ @@ -1654,7 +1547,7 @@ static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn) } /* Used for pmd and pud */ -static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn) +static void __init xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn) { #ifdef CONFIG_FLATMEM BUG_ON(mem_map); /* should only be used early */ @@ -1664,13 +1557,13 @@ static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn) /* Early release_pte assumes that all pts are pinned, since there's only init_mm and anything attached to that is pinned. */ -static __init void xen_release_pte_init(unsigned long pfn) +static void __init xen_release_pte_init(unsigned long pfn) { pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } -static __init void xen_release_pmd_init(unsigned long pfn) +static void __init xen_release_pmd_init(unsigned long pfn) { make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } @@ -1796,7 +1689,7 @@ static void set_page_prot(void *addr, pgprot_t prot) BUG(); } -static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) +static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) { unsigned pmdidx, pteidx; unsigned ident_pte; @@ -1879,7 +1772,7 @@ static void convert_pfn_mfn(void *v) * of the physical mapping once some sort of allocator has been set * up. */ -__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, +pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { pud_t *l3; @@ -1950,7 +1843,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD); static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD); -static __init void xen_write_cr3_init(unsigned long cr3) +static void __init xen_write_cr3_init(unsigned long cr3) { unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir)); @@ -1987,7 +1880,7 @@ static __init void xen_write_cr3_init(unsigned long cr3) pv_mmu_ops.write_cr3 = &xen_write_cr3; } -__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, +pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { pmd_t *kernel_pmd; @@ -2093,7 +1986,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) #endif } -__init void xen_ident_map_ISA(void) +void __init xen_ident_map_ISA(void) { unsigned long pa; @@ -2116,10 +2009,8 @@ __init void xen_ident_map_ISA(void) xen_flush_tlb(); } -static __init void xen_post_allocator_init(void) +static void __init xen_post_allocator_init(void) { - mark_rw_past_pgt(); - #ifdef CONFIG_XEN_DEBUG pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug); #endif @@ -2155,7 +2046,7 @@ static void xen_leave_lazy_mmu(void) preempt_enable(); } -static const struct pv_mmu_ops xen_mmu_ops __initdata = { +static const struct pv_mmu_ops xen_mmu_ops __initconst = { .read_cr2 = xen_read_cr2, .write_cr2 = xen_write_cr2, @@ -2228,6 +2119,7 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = { void __init xen_init_mmu_ops(void) { + x86_init.mapping.pagetable_reserve = xen_mapping_pagetable_reserve; x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start; x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done; pv_mmu_ops = xen_mmu_ops; |