KVM: x86 emulator: unify two switches
[safe/jmp/linux-2.6] / drivers / kvm / paging_tmpl.h
index 35f264f..b24bc7c 100644 (file)
@@ -31,7 +31,7 @@
        #define PT_INDEX(addr, level) PT64_INDEX(addr, level)
        #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level)
-       #define PT_PTE_COPY_MASK PT64_PTE_COPY_MASK
+       #define PT_LEVEL_BITS PT64_LEVEL_BITS
        #ifdef CONFIG_X86_64
        #define PT_MAX_FULL_LEVELS 4
        #else
        #define PT_INDEX(addr, level) PT32_INDEX(addr, level)
        #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level)
-       #define PT_PTE_COPY_MASK PT32_PTE_COPY_MASK
+       #define PT_LEVEL_BITS PT32_LEVEL_BITS
        #define PT_MAX_FULL_LEVELS 2
 #else
        #error Invalid PTTYPE value
 #endif
 
+#define gpte_to_gfn FNAME(gpte_to_gfn)
+#define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde)
+
 /*
  * The guest_walker structure emulates the behavior of the hardware page
  * table walker.
 struct guest_walker {
        int level;
        gfn_t table_gfn[PT_MAX_FULL_LEVELS];
-       pt_element_t *table;
-       pt_element_t *ptep;
+       pt_element_t pte;
        pt_element_t inherited_ar;
        gfn_t gfn;
        u32 error_code;
 };
 
+static gfn_t gpte_to_gfn(pt_element_t gpte)
+{
+       return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
+}
+
+static gfn_t gpte_to_gfn_pde(pt_element_t gpte)
+{
+       return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+}
+
 /*
  * Fetch a guest pte for a guest virtual address
  */
@@ -73,94 +85,88 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
                            struct kvm_vcpu *vcpu, gva_t addr,
                            int write_fault, int user_fault, int fetch_fault)
 {
-       hpa_t hpa;
-       struct kvm_memory_slot *slot;
-       pt_element_t *ptep;
-       pt_element_t root;
+       pt_element_t pte;
        gfn_t table_gfn;
+       unsigned index;
+       gpa_t pte_gpa;
 
        pgprintk("%s: addr %lx\n", __FUNCTION__, addr);
        walker->level = vcpu->mmu.root_level;
-       walker->table = NULL;
-       root = vcpu->cr3;
+       pte = vcpu->cr3;
 #if PTTYPE == 64
        if (!is_long_mode(vcpu)) {
-               walker->ptep = &vcpu->pdptrs[(addr >> 30) & 3];
-               root = *walker->ptep;
-               if (!(root & PT_PRESENT_MASK))
+               pte = vcpu->pdptrs[(addr >> 30) & 3];
+               if (!is_present_pte(pte))
                        goto not_present;
                --walker->level;
        }
 #endif
-       table_gfn = (root & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
-       walker->table_gfn[walker->level - 1] = table_gfn;
-       pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__,
-                walker->level - 1, table_gfn);
-       slot = gfn_to_memslot(vcpu->kvm, table_gfn);
-       hpa = safe_gpa_to_hpa(vcpu, root & PT64_BASE_ADDR_MASK);
-       walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0);
-
        ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
-              (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0);
+              (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0);
 
        walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK;
 
        for (;;) {
-               int index = PT_INDEX(addr, walker->level);
-               hpa_t paddr;
+               index = PT_INDEX(addr, walker->level);
+
+               table_gfn = gpte_to_gfn(pte);
+               pte_gpa = gfn_to_gpa(table_gfn);
+               pte_gpa += index * sizeof(pt_element_t);
+               walker->table_gfn[walker->level - 1] = table_gfn;
+               pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__,
+                        walker->level - 1, table_gfn);
 
-               ptep = &walker->table[index];
-               ASSERT(((unsigned long)walker->table & PAGE_MASK) ==
-                      ((unsigned long)ptep & PAGE_MASK));
+               kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
 
-               if (!is_present_pte(*ptep))
+               if (!is_present_pte(pte))
                        goto not_present;
 
-               if (write_fault && !is_writeble_pte(*ptep))
+               if (write_fault && !is_writeble_pte(pte))
                        if (user_fault || is_write_protection(vcpu))
                                goto access_error;
 
-               if (user_fault && !(*ptep & PT_USER_MASK))
+               if (user_fault && !(pte & PT_USER_MASK))
                        goto access_error;
 
 #if PTTYPE == 64
-               if (fetch_fault && is_nx(vcpu) && (*ptep & PT64_NX_MASK))
+               if (fetch_fault && is_nx(vcpu) && (pte & PT64_NX_MASK))
                        goto access_error;
 #endif
 
-               if (!(*ptep & PT_ACCESSED_MASK)) {
+               if (!(pte & PT_ACCESSED_MASK)) {
                        mark_page_dirty(vcpu->kvm, table_gfn);
-                       *ptep |= PT_ACCESSED_MASK;
+                       pte |= PT_ACCESSED_MASK;
+                       kvm_write_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
                }
 
                if (walker->level == PT_PAGE_TABLE_LEVEL) {
-                       walker->gfn = (*ptep & PT_BASE_ADDR_MASK)
-                               >> PAGE_SHIFT;
+                       walker->gfn = gpte_to_gfn(pte);
                        break;
                }
 
                if (walker->level == PT_DIRECTORY_LEVEL
-                   && (*ptep & PT_PAGE_SIZE_MASK)
+                   && (pte & PT_PAGE_SIZE_MASK)
                    && (PTTYPE == 64 || is_pse(vcpu))) {
-                       walker->gfn = (*ptep & PT_DIR_BASE_ADDR_MASK)
-                               >> PAGE_SHIFT;
+                       walker->gfn = gpte_to_gfn_pde(pte);
                        walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL);
+                       if (PTTYPE == 32 && is_cpuid_PSE36())
+                               walker->gfn += pse36_gfn_delta(pte);
                        break;
                }
 
-               walker->inherited_ar &= walker->table[index];
-               table_gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
-               paddr = safe_gpa_to_hpa(vcpu, *ptep & PT_BASE_ADDR_MASK);
-               kunmap_atomic(walker->table, KM_USER0);
-               walker->table = kmap_atomic(pfn_to_page(paddr >> PAGE_SHIFT),
-                                           KM_USER0);
+               walker->inherited_ar &= pte;
                --walker->level;
-               walker->table_gfn[walker->level - 1 ] = table_gfn;
-               pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__,
-                        walker->level - 1, table_gfn);
        }
-       walker->ptep = ptep;
-       pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)*ptep);
+
+       if (write_fault && !is_dirty_pte(pte)) {
+               mark_page_dirty(vcpu->kvm, table_gfn);
+               pte |= PT_DIRTY_MASK;
+               kvm_write_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
+               kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte));
+       }
+
+       walker->pte = pte;
+       pgprintk("%s: pte %llx\n", __FUNCTION__, (u64)pte);
        return 1;
 
 not_present:
@@ -180,93 +186,66 @@ err:
        return 0;
 }
 
-static void FNAME(release_walker)(struct guest_walker *walker)
-{
-       if (walker->table)
-               kunmap_atomic(walker->table, KM_USER0);
-}
-
-static void FNAME(mark_pagetable_dirty)(struct kvm *kvm,
-                                       struct guest_walker *walker)
-{
-       mark_page_dirty(kvm, walker->table_gfn[walker->level - 1]);
-}
-
-static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,
-                                 u64 *shadow_pte,
-                                 gpa_t gaddr,
-                                 pt_element_t *gpte,
-                                 u64 access_bits,
-                                 int user_fault,
-                                 int write_fault,
-                                 int *ptwrite,
-                                 struct guest_walker *walker,
-                                 gfn_t gfn)
+static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t gpte,
+                          u64 *shadow_pte, u64 access_bits,
+                          int user_fault, int write_fault,
+                          int *ptwrite, struct guest_walker *walker,
+                          gfn_t gfn)
 {
-       hpa_t paddr;
-       int dirty = *gpte & PT_DIRTY_MASK;
+       int dirty = gpte & PT_DIRTY_MASK;
+       u64 spte;
        int was_rmapped = is_rmap_pte(*shadow_pte);
+       struct page *page;
 
        pgprintk("%s: spte %llx gpte %llx access %llx write_fault %d"
                 " user_fault %d gfn %lx\n",
-                __FUNCTION__, *shadow_pte, (u64)*gpte, access_bits,
+                __FUNCTION__, *shadow_pte, (u64)gpte, access_bits,
                 write_fault, user_fault, gfn);
 
-       if (write_fault && !dirty) {
-               *gpte |= PT_DIRTY_MASK;
-               dirty = 1;
-               FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
-       }
-
-       *shadow_pte |= *gpte & PT_PTE_COPY_MASK;
-       *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET;
+       access_bits &= gpte;
+       /*
+        * We don't set the accessed bit, since we sometimes want to see
+        * whether the guest actually used the pte (in order to detect
+        * demand paging).
+        */
+       spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
+       spte |= gpte & PT64_NX_MASK;
        if (!dirty)
                access_bits &= ~PT_WRITABLE_MASK;
 
-       paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK);
+       page = gfn_to_page(vcpu->kvm, gfn);
 
-       *shadow_pte |= PT_PRESENT_MASK;
+       spte |= PT_PRESENT_MASK;
        if (access_bits & PT_USER_MASK)
-               *shadow_pte |= PT_USER_MASK;
+               spte |= PT_USER_MASK;
 
-       if (is_error_hpa(paddr)) {
-               *shadow_pte |= gaddr;
-               *shadow_pte |= PT_SHADOW_IO_MARK;
-               *shadow_pte &= ~PT_PRESENT_MASK;
+       if (is_error_page(page)) {
+               set_shadow_pte(shadow_pte,
+                              shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
+               kvm_release_page_clean(page);
                return;
        }
 
-       *shadow_pte |= paddr;
-
-       if (!write_fault && (*shadow_pte & PT_SHADOW_USER_MASK) &&
-           !(*shadow_pte & PT_USER_MASK)) {
-               /*
-                * If supervisor write protect is disabled, we shadow kernel
-                * pages as user pages so we can trap the write access.
-                */
-               *shadow_pte |= PT_USER_MASK;
-               *shadow_pte &= ~PT_WRITABLE_MASK;
-               access_bits &= ~PT_WRITABLE_MASK;
-       }
+       spte |= page_to_phys(page);
 
        if ((access_bits & PT_WRITABLE_MASK)
            || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
                struct kvm_mmu_page *shadow;
 
-               *shadow_pte |= PT_WRITABLE_MASK;
+               spte |= PT_WRITABLE_MASK;
                if (user_fault) {
-                       mmu_unshadow(vcpu, gfn);
+                       mmu_unshadow(vcpu->kvm, gfn);
                        goto unshadowed;
                }
 
-               shadow = kvm_mmu_lookup_page(vcpu, gfn);
+               shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
                if (shadow) {
                        pgprintk("%s: found shadow page for %lx, marking ro\n",
                                 __FUNCTION__, gfn);
                        access_bits &= ~PT_WRITABLE_MASK;
-                       if (is_writeble_pte(*shadow_pte)) {
-                               *shadow_pte &= ~PT_WRITABLE_MASK;
-                               kvm_arch_ops->tlb_flush(vcpu);
+                       if (is_writeble_pte(spte)) {
+                               spte &= ~PT_WRITABLE_MASK;
+                               kvm_x86_ops->tlb_flush(vcpu);
                        }
                        if (write_fault)
                                *ptwrite = 1;
@@ -276,55 +255,39 @@ static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu,
 unshadowed:
 
        if (access_bits & PT_WRITABLE_MASK)
-               mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
-
-       page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
-       if (!was_rmapped)
-               rmap_add(vcpu, shadow_pte);
-}
-
-static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t *gpte,
-                          u64 *shadow_pte, u64 access_bits,
-                          int user_fault, int write_fault, int *ptwrite,
-                          struct guest_walker *walker, gfn_t gfn)
-{
-       access_bits &= *gpte;
-       FNAME(set_pte_common)(vcpu, shadow_pte, *gpte & PT_BASE_ADDR_MASK,
-                             gpte, access_bits, user_fault, write_fault,
-                             ptwrite, walker, gfn);
+               mark_page_dirty(vcpu->kvm, gfn);
+
+       pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
+       set_shadow_pte(shadow_pte, spte);
+       page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
+       if (!was_rmapped) {
+               rmap_add(vcpu, shadow_pte, gfn);
+               if (!is_rmap_pte(*shadow_pte))
+                       kvm_release_page_clean(page);
+       }
+       else
+               kvm_release_page_clean(page);
+       if (!ptwrite || !*ptwrite)
+               vcpu->last_pte_updated = shadow_pte;
 }
 
 static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
-                             u64 *spte, const void *pte, int bytes)
+                             u64 *spte, const void *pte, int bytes,
+                             int offset_in_pte)
 {
        pt_element_t gpte;
 
-       if (bytes < sizeof(pt_element_t))
-               return;
        gpte = *(const pt_element_t *)pte;
-       if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK))
+       if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) {
+               if (!offset_in_pte && !is_present_pte(gpte))
+                       set_shadow_pte(spte, shadow_notrap_nonpresent_pte);
+               return;
+       }
+       if (bytes < sizeof(pt_element_t))
                return;
        pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte);
-       FNAME(set_pte)(vcpu, &gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0,
-                      0, NULL, NULL,
-                      (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT);
-}
-
-static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t *gpde,
-                          u64 *shadow_pte, u64 access_bits,
-                          int user_fault, int write_fault, int *ptwrite,
-                          struct guest_walker *walker, gfn_t gfn)
-{
-       gpa_t gaddr;
-
-       access_bits &= *gpde;
-       gaddr = (gpa_t)gfn << PAGE_SHIFT;
-       if (PTTYPE == 32 && is_cpuid_PSE36())
-               gaddr |= (*gpde & PT32_DIR_PSE36_MASK) <<
-                       (32 - PT32_DIR_PSE36_SHIFT);
-       FNAME(set_pte_common)(vcpu, shadow_pte, gaddr,
-                             gpde, access_bits, user_fault, write_fault,
-                             ptwrite, walker, gfn);
+       FNAME(set_pte)(vcpu, gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0,
+                      0, NULL, NULL, gpte_to_gfn(gpte));
 }
 
 /*
@@ -338,9 +301,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
        int level;
        u64 *shadow_ent;
        u64 *prev_shadow_ent = NULL;
-       pt_element_t *guest_ent = walker->ptep;
 
-       if (!is_present_pte(*guest_ent))
+       if (!is_present_pte(walker->pte))
                return NULL;
 
        shadow_addr = vcpu->mmu.root_hpa;
@@ -360,7 +322,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                unsigned hugepage_access = 0;
 
                shadow_ent = ((u64 *)__va(shadow_addr)) + index;
-               if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) {
+               if (is_shadow_present_pte(*shadow_ent)) {
                        if (level == PT_PAGE_TABLE_LEVEL)
                                break;
                        shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
@@ -374,11 +336,14 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                if (level - 1 == PT_PAGE_TABLE_LEVEL
                    && walker->level == PT_DIRECTORY_LEVEL) {
                        metaphysical = 1;
-                       hugepage_access = *guest_ent;
+                       hugepage_access = walker->pte;
                        hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK;
+                       if (!is_dirty_pte(walker->pte))
+                               hugepage_access &= ~PT_WRITABLE_MASK;
                        hugepage_access >>= PT_WRITABLE_SHIFT;
-                       table_gfn = (*guest_ent & PT_BASE_ADDR_MASK)
-                               >> PAGE_SHIFT;
+                       if (walker->pte & PT64_NX_MASK)
+                               hugepage_access |= (1 << 2);
+                       table_gfn = gpte_to_gfn(walker->pte);
                } else {
                        metaphysical = 0;
                        table_gfn = walker->table_gfn[level - 2];
@@ -393,18 +358,10 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                prev_shadow_ent = shadow_ent;
        }
 
-       if (walker->level == PT_DIRECTORY_LEVEL) {
-               if (prev_shadow_ent)
-                       *prev_shadow_ent |= PT_SHADOW_PS_MARK;
-               FNAME(set_pde)(vcpu, guest_ent, shadow_ent,
-                              walker->inherited_ar, user_fault, write_fault,
-                              ptwrite, walker, walker->gfn);
-       } else {
-               ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
-               FNAME(set_pte)(vcpu, guest_ent, shadow_ent,
-                              walker->inherited_ar, user_fault, write_fault,
-                              ptwrite, walker, walker->gfn);
-       }
+       FNAME(set_pte)(vcpu, walker->pte, shadow_ent,
+                      walker->inherited_ar, user_fault, write_fault,
+                      ptwrite, walker, walker->gfn);
+
        return shadow_ent;
 }
 
@@ -452,7 +409,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        if (!r) {
                pgprintk("%s: guest page fault\n", __FUNCTION__);
                inject_page_fault(vcpu, addr, walker.error_code);
-               FNAME(release_walker)(&walker);
                vcpu->last_pt_write_count = 0; /* reset fork detector */
                return 0;
        }
@@ -462,8 +418,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__,
                 shadow_pte, *shadow_pte, write_pt);
 
-       FNAME(release_walker)(&walker);
-
        if (!write_pt)
                vcpu->last_pt_write_count = 0; /* reset fork detector */
 
@@ -488,14 +442,39 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
        r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
 
        if (r) {
-               gpa = (gpa_t)walker.gfn << PAGE_SHIFT;
+               gpa = gfn_to_gpa(walker.gfn);
                gpa |= vaddr & ~PAGE_MASK;
        }
 
-       FNAME(release_walker)(&walker);
        return gpa;
 }
 
+static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
+                                struct kvm_mmu_page *sp)
+{
+       int i, offset = 0;
+       pt_element_t *gpt;
+       struct page *page;
+
+       if (sp->role.metaphysical
+           || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) {
+               nonpaging_prefetch_page(vcpu, sp);
+               return;
+       }
+
+       if (PTTYPE == 32)
+               offset = sp->role.quadrant << PT64_LEVEL_BITS;
+       page = gfn_to_page(vcpu->kvm, sp->gfn);
+       gpt = kmap_atomic(page, KM_USER0);
+       for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
+               if (is_present_pte(gpt[offset + i]))
+                       sp->spt[i] = shadow_trap_nonpresent_pte;
+               else
+                       sp->spt[i] = shadow_notrap_nonpresent_pte;
+       kunmap_atomic(gpt, KM_USER0);
+       kvm_release_page_clean(page);
+}
+
 #undef pt_element_t
 #undef guest_walker
 #undef FNAME
@@ -503,7 +482,8 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
 #undef PT_INDEX
 #undef SHADOW_PT_INDEX
 #undef PT_LEVEL_MASK
-#undef PT_PTE_COPY_MASK
-#undef PT_NON_PTE_COPY_MASK
 #undef PT_DIR_BASE_ADDR_MASK
+#undef PT_LEVEL_BITS
 #undef PT_MAX_FULL_LEVELS
+#undef gpte_to_gfn
+#undef gpte_to_gfn_pde