diff options
Diffstat (limited to 'arch/arm/kvm/mmu.c')
| -rw-r--r-- | arch/arm/kvm/mmu.c | 850 |
1 files changed, 585 insertions, 265 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 99e07c7dd74..16f804938b8 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -19,8 +19,8 @@ #include <linux/mman.h> #include <linux/kvm_host.h> #include <linux/io.h> +#include <linux/hugetlb.h> #include <trace/events/kvm.h> -#include <asm/idmap.h> #include <asm/pgalloc.h> #include <asm/cacheflush.h> #include <asm/kvm_arm.h> @@ -28,28 +28,34 @@ #include <asm/kvm_mmio.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> -#include <asm/mach/map.h> -#include <trace/events/kvm.h> #include "trace.h" extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[]; +static pgd_t *boot_hyp_pgd; +static pgd_t *hyp_pgd; static DEFINE_MUTEX(kvm_hyp_pgd_mutex); -static void kvm_tlb_flush_vmid(struct kvm *kvm) -{ - kvm_call_hyp(__kvm_tlb_flush_vmid, kvm); -} +static void *init_bounce_page; +static unsigned long hyp_idmap_start; +static unsigned long hyp_idmap_end; +static phys_addr_t hyp_idmap_vector; + +#define pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t)) + +#define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x)) -static void kvm_set_pte(pte_t *pte, pte_t new_pte) +static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { - pte_val(*pte) = new_pte; /* - * flush_pmd_entry just takes a void pointer and cleans the necessary - * cache entries, so we can reuse the function for ptes. + * This function also gets called when dealing with HYP page + * tables. As HYP doesn't have an associated struct kvm (and + * the HYP page tables are fairly static), we don't do + * anything there. */ - flush_pmd_entry(pte); + if (kvm) + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); } static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, @@ -84,88 +90,282 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) return p; } -static void free_ptes(pmd_t *pmd, unsigned long addr) +static bool page_empty(void *ptr) { - pte_t *pte; - unsigned int i; + struct page *ptr_page = virt_to_page(ptr); + return page_count(ptr_page) == 1; +} - for (i = 0; i < PTRS_PER_PMD; i++, addr += PMD_SIZE) { - if (!pmd_none(*pmd) && pmd_table(*pmd)) { - pte = pte_offset_kernel(pmd, addr); - pte_free_kernel(NULL, pte); - } - pmd++; +static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) +{ + if (pud_huge(*pud)) { + pud_clear(pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + pmd_t *pmd_table = pmd_offset(pud, 0); + pud_clear(pud); + kvm_tlb_flush_vmid_ipa(kvm, addr); + pmd_free(NULL, pmd_table); } + put_page(virt_to_page(pud)); } -/** - * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables - * - * Assumes this is a page table used strictly in Hyp-mode and therefore contains - * only mappings in the kernel memory area, which is above PAGE_OFFSET. - */ -void free_hyp_pmds(void) +static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr) +{ + if (kvm_pmd_huge(*pmd)) { + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } else { + pte_t *pte_table = pte_offset_kernel(pmd, 0); + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + pte_free_kernel(NULL, pte_table); + } + put_page(virt_to_page(pmd)); +} + +static void clear_pte_entry(struct kvm *kvm, pte_t *pte, phys_addr_t addr) +{ + if (pte_present(*pte)) { + kvm_set_pte(pte, __pte(0)); + put_page(virt_to_page(pte)); + kvm_tlb_flush_vmid_ipa(kvm, addr); + } +} + +static void unmap_range(struct kvm *kvm, pgd_t *pgdp, + unsigned long long start, u64 size) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; - unsigned long addr; + pte_t *pte; + unsigned long long addr = start, end = start + size; + u64 next; - mutex_lock(&kvm_hyp_pgd_mutex); - for (addr = PAGE_OFFSET; addr != 0; addr += PGDIR_SIZE) { - pgd = hyp_pgd + pgd_index(addr); + while (addr < end) { + pgd = pgdp + pgd_index(addr); pud = pud_offset(pgd, addr); + pte = NULL; + if (pud_none(*pud)) { + addr = kvm_pud_addr_end(addr, end); + continue; + } - if (pud_none(*pud)) + if (pud_huge(*pud)) { + /* + * If we are dealing with a huge pud, just clear it and + * move on. + */ + clear_pud_entry(kvm, pud, addr); + addr = kvm_pud_addr_end(addr, end); continue; - BUG_ON(pud_bad(*pud)); + } pmd = pmd_offset(pud, addr); - free_ptes(pmd, addr); - pmd_free(NULL, pmd); - pud_clear(pud); + if (pmd_none(*pmd)) { + addr = kvm_pmd_addr_end(addr, end); + continue; + } + + if (!kvm_pmd_huge(*pmd)) { + pte = pte_offset_kernel(pmd, addr); + clear_pte_entry(kvm, pte, addr); + next = addr + PAGE_SIZE; + } + + /* + * If the pmd entry is to be cleared, walk back up the ladder + */ + if (kvm_pmd_huge(*pmd) || (pte && page_empty(pte))) { + clear_pmd_entry(kvm, pmd, addr); + next = kvm_pmd_addr_end(addr, end); + if (page_empty(pmd) && !page_empty(pud)) { + clear_pud_entry(kvm, pud, addr); + next = kvm_pud_addr_end(addr, end); + } + } + + addr = next; } - mutex_unlock(&kvm_hyp_pgd_mutex); } -static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, - unsigned long end) +static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd, + phys_addr_t addr, phys_addr_t end) { pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + hva_t hva = gfn_to_hva(kvm, addr >> PAGE_SHIFT); + kvm_flush_dcache_to_poc((void*)hva, PAGE_SIZE); + } + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud, + phys_addr_t addr, phys_addr_t end) +{ + pmd_t *pmd; + phys_addr_t next; + + pmd = pmd_offset(pud, addr); + do { + next = kvm_pmd_addr_end(addr, end); + if (!pmd_none(*pmd)) { + if (kvm_pmd_huge(*pmd)) { + hva_t hva = gfn_to_hva(kvm, addr >> PAGE_SHIFT); + kvm_flush_dcache_to_poc((void*)hva, PMD_SIZE); + } else { + stage2_flush_ptes(kvm, pmd, addr, next); + } + } + } while (pmd++, addr = next, addr != end); +} + +static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd, + phys_addr_t addr, phys_addr_t end) +{ + pud_t *pud; + phys_addr_t next; + + pud = pud_offset(pgd, addr); + do { + next = kvm_pud_addr_end(addr, end); + if (!pud_none(*pud)) { + if (pud_huge(*pud)) { + hva_t hva = gfn_to_hva(kvm, addr >> PAGE_SHIFT); + kvm_flush_dcache_to_poc((void*)hva, PUD_SIZE); + } else { + stage2_flush_pmds(kvm, pud, addr, next); + } + } + } while (pud++, addr = next, addr != end); +} + +static void stage2_flush_memslot(struct kvm *kvm, + struct kvm_memory_slot *memslot) +{ + phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT; + phys_addr_t end = addr + PAGE_SIZE * memslot->npages; + phys_addr_t next; + pgd_t *pgd; + + pgd = kvm->arch.pgd + pgd_index(addr); + do { + next = kvm_pgd_addr_end(addr, end); + stage2_flush_puds(kvm, pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + +/** + * stage2_flush_vm - Invalidate cache for pages mapped in stage 2 + * @kvm: The struct kvm pointer + * + * Go through the stage 2 page tables and invalidate any cache lines + * backing memory already mapped to the VM. + */ +void stage2_flush_vm(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int idx; + + idx = srcu_read_lock(&kvm->srcu); + spin_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) + stage2_flush_memslot(kvm, memslot); + + spin_unlock(&kvm->mmu_lock); + srcu_read_unlock(&kvm->srcu, idx); +} + +/** + * free_boot_hyp_pgd - free HYP boot page tables + * + * Free the HYP boot page tables. The bounce page is also freed. + */ +void free_boot_hyp_pgd(void) +{ + mutex_lock(&kvm_hyp_pgd_mutex); + + if (boot_hyp_pgd) { + unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE); + unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + free_pages((unsigned long)boot_hyp_pgd, pgd_order); + boot_hyp_pgd = NULL; + } + + if (hyp_pgd) + unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE); + + free_page((unsigned long)init_bounce_page); + init_bounce_page = NULL; + + mutex_unlock(&kvm_hyp_pgd_mutex); +} + +/** + * free_hyp_pgds - free Hyp-mode page tables + * + * Assumes hyp_pgd is a page table used strictly in Hyp-mode and + * therefore contains either mappings in the kernel memory area (above + * PAGE_OFFSET), or device mappings in the vmalloc range (from + * VMALLOC_START to VMALLOC_END). + * + * boot_hyp_pgd should only map two pages for the init code. + */ +void free_hyp_pgds(void) +{ unsigned long addr; - struct page *page; - for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { - pte = pte_offset_kernel(pmd, addr); - BUG_ON(!virt_addr_valid(addr)); - page = virt_to_page(addr); - kvm_set_pte(pte, mk_pte(page, PAGE_HYP)); + free_boot_hyp_pgd(); + + mutex_lock(&kvm_hyp_pgd_mutex); + + if (hyp_pgd) { + for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) + unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) + unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE); + + free_pages((unsigned long)hyp_pgd, pgd_order); + hyp_pgd = NULL; } + + mutex_unlock(&kvm_hyp_pgd_mutex); } -static void create_hyp_io_pte_mappings(pmd_t *pmd, unsigned long start, - unsigned long end, - unsigned long *pfn_base) +static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start, + unsigned long end, unsigned long pfn, + pgprot_t prot) { pte_t *pte; unsigned long addr; - for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) { + addr = start; + do { pte = pte_offset_kernel(pmd, addr); - BUG_ON(pfn_valid(*pfn_base)); - kvm_set_pte(pte, pfn_pte(*pfn_base, PAGE_HYP_DEVICE)); - (*pfn_base)++; - } + kvm_set_pte(pte, pfn_pte(pfn, prot)); + get_page(virt_to_page(pte)); + kvm_flush_dcache_to_poc(pte, sizeof(*pte)); + pfn++; + } while (addr += PAGE_SIZE, addr != end); } static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, - unsigned long end, unsigned long *pfn_base) + unsigned long end, unsigned long pfn, + pgprot_t prot) { pmd_t *pmd; pte_t *pte; unsigned long addr, next; - for (addr = start; addr < end; addr = next) { + addr = start; + do { pmd = pmd_offset(pud, addr); BUG_ON(pmd_sect(*pmd)); @@ -177,42 +377,34 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start, return -ENOMEM; } pmd_populate_kernel(NULL, pmd, pte); + get_page(virt_to_page(pmd)); + kvm_flush_dcache_to_poc(pmd, sizeof(*pmd)); } next = pmd_addr_end(addr, end); - /* - * If pfn_base is NULL, we map kernel pages into HYP with the - * virtual address. Otherwise, this is considered an I/O - * mapping and we map the physical region starting at - * *pfn_base to [start, end[. - */ - if (!pfn_base) - create_hyp_pte_mappings(pmd, addr, next); - else - create_hyp_io_pte_mappings(pmd, addr, next, pfn_base); - } + create_hyp_pte_mappings(pmd, addr, next, pfn, prot); + pfn += (next - addr) >> PAGE_SHIFT; + } while (addr = next, addr != end); return 0; } -static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) +static int __create_hyp_mappings(pgd_t *pgdp, + unsigned long start, unsigned long end, + unsigned long pfn, pgprot_t prot) { - unsigned long start = (unsigned long)from; - unsigned long end = (unsigned long)to; pgd_t *pgd; pud_t *pud; pmd_t *pmd; unsigned long addr, next; int err = 0; - BUG_ON(start > end); - if (start < PAGE_OFFSET) - return -EINVAL; - mutex_lock(&kvm_hyp_pgd_mutex); - for (addr = start; addr < end; addr = next) { - pgd = hyp_pgd + pgd_index(addr); + addr = start & PAGE_MASK; + end = PAGE_ALIGN(end); + do { + pgd = pgdp + pgd_index(addr); pud = pud_offset(pgd, addr); if (pud_none_or_clear_bad(pud)) { @@ -223,43 +415,86 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base) goto out; } pud_populate(NULL, pud, pmd); + get_page(virt_to_page(pud)); + kvm_flush_dcache_to_poc(pud, sizeof(*pud)); } next = pgd_addr_end(addr, end); - err = create_hyp_pmd_mappings(pud, addr, next, pfn_base); + err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot); if (err) goto out; - } + pfn += (next - addr) >> PAGE_SHIFT; + } while (addr = next, addr != end); out: mutex_unlock(&kvm_hyp_pgd_mutex); return err; } +static phys_addr_t kvm_kaddr_to_phys(void *kaddr) +{ + if (!is_vmalloc_addr(kaddr)) { + BUG_ON(!virt_addr_valid(kaddr)); + return __pa(kaddr); + } else { + return page_to_phys(vmalloc_to_page(kaddr)) + + offset_in_page(kaddr); + } +} + /** - * create_hyp_mappings - map a kernel virtual address range in Hyp mode + * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode * @from: The virtual kernel start address of the range * @to: The virtual kernel end address of the range (exclusive) * - * The same virtual address as the kernel virtual address is also used in - * Hyp-mode mapping to the same underlying physical pages. - * - * Note: Wrapping around zero in the "to" address is not supported. + * The same virtual address as the kernel virtual address is also used + * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying + * physical pages. */ int create_hyp_mappings(void *from, void *to) { - return __create_hyp_mappings(from, to, NULL); + phys_addr_t phys_addr; + unsigned long virt_addr; + unsigned long start = KERN_TO_HYP((unsigned long)from); + unsigned long end = KERN_TO_HYP((unsigned long)to); + + start = start & PAGE_MASK; + end = PAGE_ALIGN(end); + + for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { + int err; + + phys_addr = kvm_kaddr_to_phys(from + virt_addr - start); + err = __create_hyp_mappings(hyp_pgd, virt_addr, + virt_addr + PAGE_SIZE, + __phys_to_pfn(phys_addr), + PAGE_HYP); + if (err) + return err; + } + + return 0; } /** - * create_hyp_io_mappings - map a physical IO range in Hyp mode - * @from: The virtual HYP start address of the range - * @to: The virtual HYP end address of the range (exclusive) - * @addr: The physical start address which gets mapped + * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode + * @from: The kernel start VA of the range + * @to: The kernel end VA of the range (exclusive) + * @phys_addr: The physical start address which gets mapped + * + * The resulting HYP VA is the same as the kernel VA, modulo + * HYP_PAGE_OFFSET. */ -int create_hyp_io_mappings(void *from, void *to, phys_addr_t addr) +int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr) { - unsigned long pfn = __phys_to_pfn(addr); - return __create_hyp_mappings(from, to, &pfn); + unsigned long start = KERN_TO_HYP((unsigned long)from); + unsigned long end = KERN_TO_HYP((unsigned long)to); + + /* Check for a valid kernel IO mapping */ + if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1)) + return -EINVAL; + + return __create_hyp_mappings(hyp_pgd, start, end, + __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE); } /** @@ -286,52 +521,13 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) if (!pgd) return -ENOMEM; - /* stage-2 pgd must be aligned to its size */ - VM_BUG_ON((unsigned long)pgd & (S2_PGD_SIZE - 1)); - memset(pgd, 0, PTRS_PER_S2_PGD * sizeof(pgd_t)); - clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t)); + kvm_clean_pgd(pgd); kvm->arch.pgd = pgd; return 0; } -static void clear_pud_entry(pud_t *pud) -{ - pmd_t *pmd_table = pmd_offset(pud, 0); - pud_clear(pud); - pmd_free(NULL, pmd_table); - put_page(virt_to_page(pud)); -} - -static void clear_pmd_entry(pmd_t *pmd) -{ - pte_t *pte_table = pte_offset_kernel(pmd, 0); - pmd_clear(pmd); - pte_free_kernel(NULL, pte_table); - put_page(virt_to_page(pmd)); -} - -static bool pmd_empty(pmd_t *pmd) -{ - struct page *pmd_page = virt_to_page(pmd); - return page_count(pmd_page) == 1; -} - -static void clear_pte_entry(pte_t *pte) -{ - if (pte_present(*pte)) { - kvm_set_pte(pte, __pte(0)); - put_page(virt_to_page(pte)); - } -} - -static bool pte_empty(pte_t *pte) -{ - struct page *pte_page = virt_to_page(pte); - return page_count(pte_page) == 1; -} - /** * unmap_stage2_range -- Clear stage2 page table entries to unmap a range * @kvm: The VM pointer @@ -345,43 +541,7 @@ static bool pte_empty(pte_t *pte) */ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size) { - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - phys_addr_t addr = start, end = start + size; - u64 range; - - while (addr < end) { - pgd = kvm->arch.pgd + pgd_index(addr); - pud = pud_offset(pgd, addr); - if (pud_none(*pud)) { - addr += PUD_SIZE; - continue; - } - - pmd = pmd_offset(pud, addr); - if (pmd_none(*pmd)) { - addr += PMD_SIZE; - continue; - } - - pte = pte_offset_kernel(pmd, addr); - clear_pte_entry(pte); - range = PAGE_SIZE; - - /* If we emptied the pte, walk back up the ladder */ - if (pte_empty(pte)) { - clear_pmd_entry(pmd); - range = PMD_SIZE; - if (pmd_empty(pmd)) { - clear_pud_entry(pud); - range = PUD_SIZE; - } - } - - addr += range; - } + unmap_range(kvm, kvm->arch.pgd, start, size); } /** @@ -405,39 +565,81 @@ void kvm_free_stage2_pgd(struct kvm *kvm) kvm->arch.pgd = NULL; } - -static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr, const pte_t *new_pte, bool iomap) +static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pte_t *pte, old_pte; - /* Create 2nd stage page table mapping - Level 1 */ pgd = kvm->arch.pgd + pgd_index(addr); pud = pud_offset(pgd, addr); if (pud_none(*pud)) { if (!cache) - return 0; /* ignore calls from kvm_set_spte_hva */ + return NULL; pmd = mmu_memory_cache_alloc(cache); pud_populate(NULL, pud, pmd); - pmd += pmd_index(addr); get_page(virt_to_page(pud)); - } else - pmd = pmd_offset(pud, addr); + } + + return pmd_offset(pud, addr); +} + +static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache + *cache, phys_addr_t addr, const pmd_t *new_pmd) +{ + pmd_t *pmd, old_pmd; - /* Create 2nd stage page table mapping - Level 2 */ + pmd = stage2_get_pmd(kvm, cache, addr); + VM_BUG_ON(!pmd); + + /* + * Mapping in huge pages should only happen through a fault. If a + * page is merged into a transparent huge page, the individual + * subpages of that huge page should be unmapped through MMU + * notifiers before we get here. + * + * Merging of CompoundPages is not supported; they should become + * splitting first, unmapped, merged, and mapped back in on-demand. + */ + VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); + + old_pmd = *pmd; + kvm_set_pmd(pmd, *new_pmd); + if (pmd_present(old_pmd)) + kvm_tlb_flush_vmid_ipa(kvm, addr); + else + get_page(virt_to_page(pmd)); + return 0; +} + +static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, + phys_addr_t addr, const pte_t *new_pte, bool iomap) +{ + pmd_t *pmd; + pte_t *pte, old_pte; + + /* Create stage-2 page table mapping - Level 1 */ + pmd = stage2_get_pmd(kvm, cache, addr); + if (!pmd) { + /* + * Ignore calls from kvm_set_spte_hva for unallocated + * address ranges. + */ + return 0; + } + + /* Create stage-2 page mappings - Level 2 */ if (pmd_none(*pmd)) { if (!cache) return 0; /* ignore calls from kvm_set_spte_hva */ pte = mmu_memory_cache_alloc(cache); - clean_pte_table(pte); + kvm_clean_pte(pte); pmd_populate_kernel(NULL, pmd, pte); - pte += pte_index(addr); get_page(virt_to_page(pmd)); - } else - pte = pte_offset_kernel(pmd, addr); + } + + pte = pte_offset_kernel(pmd, addr); if (iomap && pte_present(*pte)) return -EFAULT; @@ -446,7 +648,7 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, old_pte = *pte; kvm_set_pte(pte, *new_pte); if (pte_present(old_pte)) - kvm_tlb_flush_vmid(kvm); + kvm_tlb_flush_vmid_ipa(kvm, addr); else get_page(virt_to_page(pte)); @@ -473,7 +675,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, pfn = __phys_to_pfn(pa); for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) { - pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE | L_PTE_S2_RDWR); + pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE); ret = mmu_topup_memory_cache(&cache, 2, 2); if (ret) @@ -492,46 +694,89 @@ out: return ret; } -static void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) +static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap) { - /* - * If we are going to insert an instruction page and the icache is - * either VIPT or PIPT, there is a potential problem where the host - * (or another VM) may have used the same page as this guest, and we - * read incorrect data from the icache. If we're using a PIPT cache, - * we can invalidate just that page, but if we are using a VIPT cache - * we need to invalidate the entire icache - damn shame - as written - * in the ARM ARM (DDI 0406C.b - Page B3-1393). - * - * VIVT caches are tagged using both the ASID and the VMID and doesn't - * need any kind of flushing (DDI 0406C.b - Page B3-1392). - */ - if (icache_is_pipt()) { - unsigned long hva = gfn_to_hva(kvm, gfn); - __cpuc_coherent_user_range(hva, hva + PAGE_SIZE); - } else if (!icache_is_vivt_asid_tagged()) { - /* any kind of VIPT cache */ - __flush_icache_all(); + pfn_t pfn = *pfnp; + gfn_t gfn = *ipap >> PAGE_SHIFT; + + if (PageTransCompound(pfn_to_page(pfn))) { + unsigned long mask; + /* + * The address we faulted on is backed by a transparent huge + * page. However, because we map the compound huge page and + * not the individual tail page, we need to transfer the + * refcount to the head page. We have to be careful that the + * THP doesn't start to split while we are adjusting the + * refcounts. + * + * We are sure this doesn't happen, because mmu_notifier_retry + * was successful and we are holding the mmu_lock, so if this + * THP is trying to split, it will be blocked in the mmu + * notifier before touching any of the pages, specifically + * before being able to call __split_huge_page_refcount(). + * + * We can therefore safely transfer the refcount from PG_tail + * to PG_head and switch the pfn from a tail page to the head + * page accordingly. + */ + mask = PTRS_PER_PMD - 1; + VM_BUG_ON((gfn & mask) != (pfn & mask)); + if (pfn & mask) { + *ipap &= PMD_MASK; + kvm_release_pfn_clean(pfn); + pfn &= ~mask; + kvm_get_pfn(pfn); + *pfnp = pfn; + } + + return true; } + + return false; } static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - gfn_t gfn, struct kvm_memory_slot *memslot, + struct kvm_memory_slot *memslot, unsigned long fault_status) { - pte_t new_pte; - pfn_t pfn; int ret; - bool write_fault, writable; + bool write_fault, writable, hugetlb = false, force_pte = false; unsigned long mmu_seq; + gfn_t gfn = fault_ipa >> PAGE_SHIFT; + unsigned long hva = gfn_to_hva(vcpu->kvm, gfn); + struct kvm *kvm = vcpu->kvm; struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; + struct vm_area_struct *vma; + pfn_t pfn; - write_fault = kvm_is_write_fault(vcpu->arch.hsr); + write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu)); if (fault_status == FSC_PERM && !write_fault) { kvm_err("Unexpected L2 read permission error\n"); return -EFAULT; } + /* Let's check if we will get back a huge page backed by hugetlbfs */ + down_read(¤t->mm->mmap_sem); + vma = find_vma_intersection(current->mm, hva, hva + 1); + if (is_vm_hugetlb_page(vma)) { + hugetlb = true; + gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; + } else { + /* + * Pages belonging to memslots that don't have the same + * alignment for userspace and IPA cannot be mapped using + * block descriptors even if the pages belong to a THP for + * the process, because the stage-2 block descriptor will + * cover more than a single THP and we loose atomicity for + * unmapping, updates, and splits of the THP or other pages + * in the stage-2 block range. + */ + if ((memslot->userspace_addr & ~PMD_MASK) != + ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK)) + force_pte = true; + } + up_read(¤t->mm->mmap_sem); + /* We need minimum second+third level pages */ ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS); if (ret) @@ -549,26 +794,40 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ smp_rmb(); - pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable); + pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable); if (is_error_pfn(pfn)) return -EFAULT; - new_pte = pfn_pte(pfn, PAGE_S2); - coherent_icache_guest_page(vcpu->kvm, gfn); - - spin_lock(&vcpu->kvm->mmu_lock); - if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) + spin_lock(&kvm->mmu_lock); + if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; - if (writable) { - pte_val(new_pte) |= L_PTE_S2_RDWR; - kvm_set_pfn_dirty(pfn); + if (!hugetlb && !force_pte) + hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); + + if (hugetlb) { + pmd_t new_pmd = pfn_pmd(pfn, PAGE_S2); + new_pmd = pmd_mkhuge(new_pmd); + if (writable) { + kvm_set_s2pmd_writable(&new_pmd); + kvm_set_pfn_dirty(pfn); + } + coherent_cache_guest_page(vcpu, hva & PMD_MASK, PMD_SIZE); + ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); + } else { + pte_t new_pte = pfn_pte(pfn, PAGE_S2); + if (writable) { + kvm_set_s2pte_writable(&new_pte); + kvm_set_pfn_dirty(pfn); + } + coherent_cache_guest_page(vcpu, hva, PAGE_SIZE); + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, false); } - stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false); + out_unlock: - spin_unlock(&vcpu->kvm->mmu_lock); + spin_unlock(&kvm->mmu_lock); kvm_release_pfn_clean(pfn); - return 0; + return ret; } /** @@ -585,7 +844,6 @@ out_unlock: */ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) { - unsigned long hsr_ec; unsigned long fault_status; phys_addr_t fault_ipa; struct kvm_memory_slot *memslot; @@ -593,18 +851,17 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) gfn_t gfn; int ret, idx; - hsr_ec = vcpu->arch.hsr >> HSR_EC_SHIFT; - is_iabt = (hsr_ec == HSR_EC_IABT); - fault_ipa = ((phys_addr_t)vcpu->arch.hpfar & HPFAR_MASK) << 8; + is_iabt = kvm_vcpu_trap_is_iabt(vcpu); + fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); - trace_kvm_guest_fault(*vcpu_pc(vcpu), vcpu->arch.hsr, - vcpu->arch.hxfar, fault_ipa); + trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu), + kvm_vcpu_get_hfar(vcpu), fault_ipa); /* Check the stage-2 fault is trans. fault or write fault */ - fault_status = (vcpu->arch.hsr & HSR_FSC_TYPE); + fault_status = kvm_vcpu_trap_get_fault(vcpu); if (fault_status != FSC_FAULT && fault_status != FSC_PERM) { - kvm_err("Unsupported fault status: EC=%#lx DFCS=%#lx\n", - hsr_ec, fault_status); + kvm_err("Unsupported fault status: EC=%#x DFCS=%#lx\n", + kvm_vcpu_trap_get_class(vcpu), fault_status); return -EFAULT; } @@ -614,7 +871,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) { if (is_iabt) { /* Prefetch Abort on I/O address */ - kvm_inject_pabt(vcpu, vcpu->arch.hxfar); + kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); ret = 1; goto out_unlock; } @@ -626,15 +883,20 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) goto out_unlock; } - /* Adjust page offset */ - fault_ipa |= vcpu->arch.hxfar & ~PAGE_MASK; + /* + * The IPA is reported as [MAX:12], so we need to + * complement it with the bottom 12 bits from the + * faulting VA. This is always 12 bits, irrespective + * of the page size. + */ + fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1); ret = io_mem_abort(vcpu, run, fault_ipa); goto out_unlock; } memslot = gfn_to_memslot(vcpu->kvm, gfn); - ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status); + ret = user_mem_abort(vcpu, fault_ipa, memslot, fault_status); if (ret == 0) ret = 1; out_unlock: @@ -682,7 +944,6 @@ static void handle_hva_to_gpa(struct kvm *kvm, static void kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data) { unmap_stage2_range(kvm, gpa, PAGE_SIZE); - kvm_tlb_flush_vmid(kvm); } int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) @@ -736,47 +997,106 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu) phys_addr_t kvm_mmu_get_httbr(void) { - VM_BUG_ON(!virt_addr_valid(hyp_pgd)); return virt_to_phys(hyp_pgd); } +phys_addr_t kvm_mmu_get_boot_httbr(void) +{ + return virt_to_phys(boot_hyp_pgd); +} + +phys_addr_t kvm_get_idmap_vector(void) +{ + return hyp_idmap_vector; +} + int kvm_mmu_init(void) { - if (!hyp_pgd) { + int err; + + hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start); + hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end); + hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init); + + if ((hyp_idmap_start ^ hyp_idmap_end) & PAGE_MASK) { + /* + * Our init code is crossing a page boundary. Allocate + * a bounce page, copy the code over and use that. + */ + size_t len = __hyp_idmap_text_end - __hyp_idmap_text_start; + phys_addr_t phys_base; + + init_bounce_page = (void *)__get_free_page(GFP_KERNEL); + if (!init_bounce_page) { + kvm_err("Couldn't allocate HYP init bounce page\n"); + err = -ENOMEM; + goto out; + } + + memcpy(init_bounce_page, __hyp_idmap_text_start, len); + /* + * Warning: the code we just copied to the bounce page + * must be flushed to the point of coherency. + * Otherwise, the data may be sitting in L2, and HYP + * mode won't be able to observe it as it runs with + * caches off at that point. + */ + kvm_flush_dcache_to_poc(init_bounce_page, len); + + phys_base = kvm_virt_to_phys(init_bounce_page); + hyp_idmap_vector += phys_base - hyp_idmap_start; + hyp_idmap_start = phys_base; + hyp_idmap_end = phys_base + len; + + kvm_info("Using HYP init bounce page @%lx\n", + (unsigned long)phys_base); + } + + hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order); + boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, pgd_order); + + if (!hyp_pgd || !boot_hyp_pgd) { kvm_err("Hyp mode PGD not allocated\n"); - return -ENOMEM; + err = -ENOMEM; + goto out; } - return 0; -} + /* Create the idmap in the boot page tables */ + err = __create_hyp_mappings(boot_hyp_pgd, + hyp_idmap_start, hyp_idmap_end, + __phys_to_pfn(hyp_idmap_start), + PAGE_HYP); -/** - * kvm_clear_idmap - remove all idmaps from the hyp pgd - * - * Free the underlying pmds for all pgds in range and clear the pgds (but - * don't free them) afterwards. - */ -void kvm_clear_hyp_idmap(void) -{ - unsigned long addr, end; - unsigned long next; - pgd_t *pgd = hyp_pgd; - pud_t *pud; - pmd_t *pmd; + if (err) { + kvm_err("Failed to idmap %lx-%lx\n", + hyp_idmap_start, hyp_idmap_end); + goto out; + } - addr = virt_to_phys(__hyp_idmap_text_start); - end = virt_to_phys(__hyp_idmap_text_end); + /* Map the very same page at the trampoline VA */ + err = __create_hyp_mappings(boot_hyp_pgd, + TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE, + __phys_to_pfn(hyp_idmap_start), + PAGE_HYP); + if (err) { + kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n", + TRAMPOLINE_VA); + goto out; + } - pgd += pgd_index(addr); - do { - next = pgd_addr_end(addr, end); - if (pgd_none_or_clear_bad(pgd)) - continue; - pud = pud_offset(pgd, addr); - pmd = pmd_offset(pud, addr); + /* Map the same page again into the runtime page tables */ + err = __create_hyp_mappings(hyp_pgd, + TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE, + __phys_to_pfn(hyp_idmap_start), + PAGE_HYP); + if (err) { + kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n", + TRAMPOLINE_VA); + goto out; + } - pud_clear(pud); - clean_pmd_entry(pmd); - pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK)); - } while (pgd++, addr = next, addr < end); + return 0; +out: + free_hyp_pgds(); + return err; } |
