1 files changed, 142 insertions, 131 deletions

diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 73ffbffb1097..a7c5cb0319ea 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -31,7 +31,6 @@
         #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
         #ifdef CONFIG_X86_64
         #define PT_MAX_FULL_LEVELS 4
         #else
@@ -46,7 +45,6 @@
         #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_MAX_FULL_LEVELS 2
 #else
         #error Invalid PTTYPE value
@@ -192,40 +190,143 @@ static void FNAME(mark_pagetable_dirty)(struct kvm *kvm,
         mark_page_dirty(kvm, walker->table_gfn[walker->level - 1]);
 }
 
-static void FNAME(set_pte)(struct kvm_vcpu *vcpu, u64 guest_pte,
-                           u64 *shadow_pte, u64 access_bits, gfn_t gfn)
+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)
 {
-        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);
+        hpa_t paddr;
+        int dirty = *gpte & PT_DIRTY_MASK;
+        u64 spte = *shadow_pte;
+        int was_rmapped = is_rmap_pte(spte);
+
+        pgprintk("%s: spte %llx gpte %llx access %llx write_fault %d"
+                 " user_fault %d gfn %lx\n",
+                 __FUNCTION__, spte, (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);
+        }
+
+        spte |= PT_PRESENT_MASK | PT_ACCESSED_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);
+
+        spte |= PT_PRESENT_MASK;
+        if (access_bits & PT_USER_MASK)
+                spte |= PT_USER_MASK;
+
+        if (is_error_hpa(paddr)) {
+                spte |= gaddr;
+                spte |= PT_SHADOW_IO_MARK;
+                spte &= ~PT_PRESENT_MASK;
+                set_shadow_pte(shadow_pte, spte);
+                return;
+        }
+
+        spte |= paddr;
+
+        if ((access_bits & PT_WRITABLE_MASK)
+            || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
+                struct kvm_mmu_page *shadow;
+
+                spte |= PT_WRITABLE_MASK;
+                if (user_fault) {
+                        mmu_unshadow(vcpu, gfn);
+                        goto unshadowed;
+                }
+
+                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(spte)) {
+                                spte &= ~PT_WRITABLE_MASK;
+                                kvm_arch_ops->tlb_flush(vcpu);
+                        }
+                        if (write_fault)
+                                *ptwrite = 1;
+                }
+        }
+
+unshadowed:
+
+        if (access_bits & PT_WRITABLE_MASK)
+                mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
+
+        set_shadow_pte(shadow_pte, spte);
+        page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
+        if (!was_rmapped)
+                rmap_add(vcpu, shadow_pte);
 }
 
-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_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);
+}
+
+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,
+                       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;
 
-        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);
+        FNAME(set_pte_common)(vcpu, shadow_pte, gaddr,
+                              gpde, access_bits, user_fault, write_fault,
+                              ptwrite, walker, 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 user_fault, int write_fault, int *ptwrite)
 {
         hpa_t shadow_addr;
         int level;
+        u64 *shadow_ent;
         u64 *prev_shadow_ent = NULL;
         pt_element_t *guest_ent = walker->ptep;
 
@@ -242,37 +343,23 @@ 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;
+                                break;
                         shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
                         prev_shadow_ent = shadow_ent;
                         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) {
@@ -289,90 +376,24 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                 shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
                                                metaphysical, hugepage_access,
                                                shadow_ent);
-                shadow_addr = shadow_page->page_hpa;
+                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;
         }
-}
 
-/*
- * The guest faulted for write.  We need to
- *
- * - check write permissions
- * - update the guest pte dirty bit
- * - update our own dirty page tracking structures
- */
-static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
-                               u64 *shadow_ent,
-                               struct guest_walker *walker,
-                               gva_t addr,
-                               int user,
-                               int *write_pt)
-{
-        pt_element_t *guest_ent;
-        int writable_shadow;
-        gfn_t gfn;
-        struct kvm_mmu_page *page;
-
-        if (is_writeble_pte(*shadow_ent))
-                return !user || (*shadow_ent & PT_USER_MASK);
-
-        writable_shadow = *shadow_ent & PT_SHADOW_WRITABLE_MASK;
-        if (user) {
-                /*
-                 * User mode access.  Fail if it's a kernel page or a read-only
-                 * page.
-                 */
-                if (!(*shadow_ent & PT_SHADOW_USER_MASK) || !writable_shadow)
-                        return 0;
-                ASSERT(*shadow_ent & PT_USER_MASK);
-        } else
-                /*
-                 * Kernel mode access.  Fail if it's a read-only page and
-                 * supervisor write protection is enabled.
-                 */
-                if (!writable_shadow) {
-                        if (is_write_protection(vcpu))
-                                return 0;
-                        *shadow_ent &= ~PT_USER_MASK;
-                }
-
-        guest_ent = walker->ptep;
-
-        if (!is_present_pte(*guest_ent)) {
-                *shadow_ent = 0;
-                return 0;
+        if (walker->level == PT_DIRECTORY_LEVEL) {
+                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);
         }
-
-        gfn = walker->gfn;
-
-        if (user) {
-                /*
-                 * Usermode page faults won't be for page table updates.
-                 */
-                while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
-                        pgprintk("%s: zap %lx %x\n",
-                                 __FUNCTION__, gfn, page->role.word);
-                        kvm_mmu_zap_page(vcpu, page);
-                }
-        } 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);
-
-        return 1;
+        return shadow_ent;
 }
 
 /*
@@ -397,7 +418,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         int fetch_fault = error_code & PFERR_FETCH_MASK;
         struct guest_walker walker;
         u64 *shadow_pte;
-        int fixed;
         int write_pt = 0;
         int r;
 
@@ -421,27 +441,20 @@ 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);
-        pgprintk("%s: shadow pte %p %llx\n", __FUNCTION__,
-                 shadow_pte, *shadow_pte);
-
-        /*
-         * Update the shadow pte.
-         */
-        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);
+        shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+                                  &write_pt);
+        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 */
+
         /*
          * mmio: emulate if accessible, otherwise its a guest fault.
          */
@@ -478,7 +491,5 @@ 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_MAX_FULL_LEVELS