]> err.no Git - linux-2.6/blobdiff - drivers/kvm/paging_tmpl.h
KVM: MMU: Fold fix_read_pf() into set_pte_common()
[linux-2.6] / drivers / kvm / paging_tmpl.h
index 149fa45fd9a5a016955148fa6f24f8805e63f277..869582befaf1fec68768db822b1d642d922ab756 100644 (file)
@@ -128,8 +128,10 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
                        goto access_error;
 #endif
 
-               if (!(*ptep & PT_ACCESSED_MASK))
-                       *ptep |= PT_ACCESSED_MASK;      /* avoid rmw */
+               if (!(*ptep & PT_ACCESSED_MASK)) {
+                       mark_page_dirty(vcpu->kvm, table_gfn);
+                       *ptep |= PT_ACCESSED_MASK;
+               }
 
                if (walker->level == PT_PAGE_TABLE_LEVEL) {
                        walker->gfn = (*ptep & PT_BASE_ADDR_MASK)
@@ -146,8 +148,7 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
                        break;
                }
 
-               if (walker->level != 3 || is_long_mode(vcpu))
-                       walker->inherited_ar &= walker->table[index];
+               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);
@@ -185,40 +186,125 @@ static void FNAME(release_walker)(struct guest_walker *walker)
                kunmap_atomic(walker->table, KM_USER0);
 }
 
-static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 guest_pte,
-                          u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+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 write_fault,
+                                 gfn_t gfn)
+{
+       hpa_t paddr;
+       int dirty = *gpte & PT_DIRTY_MASK;
+
+       *shadow_pte |= access_bits << PT_SHADOW_BITS_OFFSET;
+       if (!dirty)
+               access_bits &= ~PT_WRITABLE_MASK;
+
+       paddr = gpa_to_hpa(vcpu, gaddr & PT64_BASE_ADDR_MASK);
+
+       *shadow_pte |= access_bits;
+
+       if (is_error_hpa(paddr)) {
+               *shadow_pte |= gaddr;
+               *shadow_pte |= PT_SHADOW_IO_MARK;
+               *shadow_pte &= ~PT_PRESENT_MASK;
+               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;
+       }
+
+       if (access_bits & PT_WRITABLE_MASK) {
+               struct kvm_mmu_page *shadow;
+
+               shadow = kvm_mmu_lookup_page(vcpu, 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 (access_bits & PT_WRITABLE_MASK)
+               mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
+
+       page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
+       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 write_fault, gfn_t gfn)
 {
        ASSERT(*shadow_pte == 0);
-       access_bits &= guest_pte;
-       *shadow_pte = (guest_pte & PT_PTE_COPY_MASK);
-       set_pte_common(vcpu, shadow_pte, guest_pte & PT_BASE_ADDR_MASK,
-                      guest_pte & PT_DIRTY_MASK, access_bits, gfn);
+       access_bits &= *gpte;
+       *shadow_pte = (*gpte & PT_PTE_COPY_MASK);
+       FNAME(set_pte_common)(vcpu, shadow_pte, *gpte & PT_BASE_ADDR_MASK,
+                             gpte, access_bits, write_fault, gfn);
+}
+
+static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
+                             u64 *spte, const void *pte, int bytes)
+{
+       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))
+               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,
+                      (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT);
 }
 
-static void FNAME(set_pde)(struct kvm_vcpu *vcpu, u64 guest_pde,
-                          u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t *gpde,
+                          u64 *shadow_pte, u64 access_bits, int write_fault,
+                          gfn_t gfn)
 {
        gpa_t gaddr;
 
        ASSERT(*shadow_pte == 0);
-       access_bits &= guest_pde;
+       access_bits &= *gpde;
        gaddr = (gpa_t)gfn << PAGE_SHIFT;
        if (PTTYPE == 32 && is_cpuid_PSE36())
-               gaddr |= (guest_pde & PT32_DIR_PSE36_MASK) <<
+               gaddr |= (*gpde & PT32_DIR_PSE36_MASK) <<
                        (32 - PT32_DIR_PSE36_SHIFT);
-       *shadow_pte = guest_pde & PT_PTE_COPY_MASK;
-       set_pte_common(vcpu, shadow_pte, gaddr,
-                      guest_pde & PT_DIRTY_MASK, access_bits, gfn);
+       *shadow_pte = *gpde & PT_PTE_COPY_MASK;
+       FNAME(set_pte_common)(vcpu, shadow_pte, gaddr,
+                             gpde, access_bits, write_fault, gfn);
 }
 
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
  */
 static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
-                             struct guest_walker *walker)
+                        struct guest_walker *walker, int write_fault)
 {
        hpa_t shadow_addr;
        int level;
+       u64 *shadow_ent;
        u64 *prev_shadow_ent = NULL;
        pt_element_t *guest_ent = walker->ptep;
 
@@ -235,12 +321,13 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 
        for (; ; level--) {
                u32 index = SHADOW_PT_INDEX(addr, level);
-               u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index;
                struct kvm_mmu_page *shadow_page;
                u64 shadow_pte;
                int metaphysical;
                gfn_t table_gfn;
+               unsigned hugepage_access = 0;
 
+               shadow_ent = ((u64 *)__va(shadow_addr)) + index;
                if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) {
                        if (level == PT_PAGE_TABLE_LEVEL)
                                return shadow_ent;
@@ -249,26 +336,15 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                        continue;
                }
 
-               if (level == PT_PAGE_TABLE_LEVEL) {
-
-                       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,
-                                              walker->gfn);
-                       } else {
-                               ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
-                               FNAME(set_pte)(vcpu, *guest_ent, shadow_ent,
-                                              walker->inherited_ar,
-                                              walker->gfn);
-                       }
-                       return shadow_ent;
-               }
+               if (level == PT_PAGE_TABLE_LEVEL)
+                       break;
 
                if (level - 1 == PT_PAGE_TABLE_LEVEL
                    && walker->level == PT_DIRECTORY_LEVEL) {
                        metaphysical = 1;
+                       hugepage_access = *guest_ent;
+                       hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK;
+                       hugepage_access >>= PT_WRITABLE_SHIFT;
                        table_gfn = (*guest_ent & PT_BASE_ADDR_MASK)
                                >> PAGE_SHIFT;
                } else {
@@ -276,13 +352,27 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                        table_gfn = walker->table_gfn[level - 2];
                }
                shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
-                                              metaphysical, shadow_ent);
-               shadow_addr = shadow_page->page_hpa;
+                                              metaphysical, hugepage_access,
+                                              shadow_ent);
+               shadow_addr = __pa(shadow_page->spt);
                shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
                        | PT_WRITABLE_MASK | PT_USER_MASK;
                *shadow_ent = shadow_pte;
                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, write_fault, walker->gfn);
+       } else {
+               ASSERT(walker->level == PT_PAGE_TABLE_LEVEL);
+               FNAME(set_pte)(vcpu, guest_ent, shadow_ent,
+                              walker->inherited_ar,
+                              write_fault, walker->gfn);
+       }
+       return shadow_ent;
 }
 
 /*
@@ -348,12 +438,15 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
        } else if (kvm_mmu_lookup_page(vcpu, gfn)) {
                pgprintk("%s: found shadow page for %lx, marking ro\n",
                         __FUNCTION__, gfn);
+               mark_page_dirty(vcpu->kvm, gfn);
+               FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
                *guest_ent |= PT_DIRTY_MASK;
                *write_pt = 1;
                return 0;
        }
        mark_page_dirty(vcpu->kvm, gfn);
        *shadow_ent |= PT_WRITABLE_MASK;
+       FNAME(mark_pagetable_dirty)(vcpu->kvm, walker);
        *guest_ent |= PT_DIRTY_MASK;
        rmap_add(vcpu, shadow_ent);
 
@@ -406,10 +499,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                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;
        }
 
-       shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
+       shadow_pte = FNAME(fetch)(vcpu, addr, &walker, write_fault);
        pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
                 shadow_pte, *shadow_pte);
 
@@ -419,22 +513,22 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        if (write_fault)
                fixed = FNAME(fix_write_pf)(vcpu, shadow_pte, &walker, addr,
                                            user_fault, &write_pt);
-       else
-               fixed = fix_read_pf(shadow_pte);
 
        pgprintk("%s: updated shadow pte %p %llx\n", __FUNCTION__,
                 shadow_pte, *shadow_pte);
 
        FNAME(release_walker)(&walker);
 
+       if (!write_pt)
+               vcpu->last_pt_write_count = 0; /* reset fork detector */
+
        /*
         * mmio: emulate if accessible, otherwise its a guest fault.
         */
-       if (is_io_pte(*shadow_pte)) {
+       if (is_io_pte(*shadow_pte))
                return 1;
-       }
 
-       ++kvm_stat.pf_fixed;
+       ++vcpu->stat.pf_fixed;
        kvm_mmu_audit(vcpu, "post page fault (fixed)");
 
        return write_pt;
@@ -443,31 +537,17 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
 {
        struct guest_walker walker;
-       pt_element_t guest_pte;
-       gpa_t gpa;
-
-       FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
-       guest_pte = *walker.ptep;
-       FNAME(release_walker)(&walker);
-
-       if (!is_present_pte(guest_pte))
-               return UNMAPPED_GVA;
-
-       if (walker.level == PT_DIRECTORY_LEVEL) {
-               ASSERT((guest_pte & PT_PAGE_SIZE_MASK));
-               ASSERT(PTTYPE == 64 || is_pse(vcpu));
+       gpa_t gpa = UNMAPPED_GVA;
+       int r;
 
-               gpa = (guest_pte & PT_DIR_BASE_ADDR_MASK) | (vaddr &
-                       (PT_LEVEL_MASK(PT_PAGE_TABLE_LEVEL) | ~PAGE_MASK));
+       r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
 
-               if (PTTYPE == 32 && is_cpuid_PSE36())
-                       gpa |= (guest_pte & PT32_DIR_PSE36_MASK) <<
-                                       (32 - PT32_DIR_PSE36_SHIFT);
-       } else {
-               gpa = (guest_pte & PT_BASE_ADDR_MASK);
-               gpa |= (vaddr & ~PAGE_MASK);
+       if (r) {
+               gpa = (gpa_t)walker.gfn << PAGE_SHIFT;
+               gpa |= vaddr & ~PAGE_MASK;
        }
 
+       FNAME(release_walker)(&walker);
        return gpa;
 }