KVM: MMU: Add EPT support

Enable kvm_set_spte() to generate EPT entries.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

2 files changed, 36 insertions, 10 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 20fb3c852db7..c28a36b4cbba 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -152,6 +152,12 @@ static struct kmem_cache *mmu_page_header_cache;
 
 static u64 __read_mostly shadow_trap_nonpresent_pte;
 static u64 __read_mostly shadow_notrap_nonpresent_pte;
+static u64 __read_mostly shadow_base_present_pte;
+static u64 __read_mostly shadow_nx_mask;
+static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
+static u64 __read_mostly shadow_user_mask;
+static u64 __read_mostly shadow_accessed_mask;
+static u64 __read_mostly shadow_dirty_mask;
 
 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 {
@@ -160,6 +166,23 @@ void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
 
+void kvm_mmu_set_base_ptes(u64 base_pte)
+{
+        shadow_base_present_pte = base_pte;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
+
+void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
+                u64 dirty_mask, u64 nx_mask, u64 x_mask)
+{
+        shadow_user_mask = user_mask;
+        shadow_accessed_mask = accessed_mask;
+        shadow_dirty_mask = dirty_mask;
+        shadow_nx_mask = nx_mask;
+        shadow_x_mask = x_mask;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
+
 static int is_write_protection(struct kvm_vcpu *vcpu)
 {
         return vcpu->arch.cr0 & X86_CR0_WP;
@@ -198,7 +221,7 @@ static int is_writeble_pte(unsigned long pte)
 
 static int is_dirty_pte(unsigned long pte)
 {
-        return pte & PT_DIRTY_MASK;
+        return pte & shadow_dirty_mask;
 }
 
 static int is_rmap_pte(u64 pte)
@@ -513,7 +536,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
                 return;
         sp = page_header(__pa(spte));
         pfn = spte_to_pfn(*spte);
-        if (*spte & PT_ACCESSED_MASK)
+        if (*spte & shadow_accessed_mask)
                 kvm_set_pfn_accessed(pfn);
         if (is_writeble_pte(*spte))
                 kvm_release_pfn_dirty(pfn);
@@ -1039,17 +1062,17 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
          * whether the guest actually used the pte (in order to detect
          * demand paging).
          */
-        spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
+        spte = shadow_base_present_pte | shadow_dirty_mask;
         if (!speculative)
                 pte_access |= PT_ACCESSED_MASK;
         if (!dirty)
                 pte_access &= ~ACC_WRITE_MASK;
-        if (!(pte_access & ACC_EXEC_MASK))
-                spte |= PT64_NX_MASK;
-
-        spte |= PT_PRESENT_MASK;
+        if (pte_access & ACC_EXEC_MASK)
+                spte |= shadow_x_mask;
+        else
+                spte |= shadow_nx_mask;
         if (pte_access & ACC_USER_MASK)
-                spte |= PT_USER_MASK;
+                spte |= shadow_user_mask;
         if (largepage)
                 spte |= PT_PAGE_SIZE_MASK;
 
@@ -1155,7 +1178,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
                         }
 
                         table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
-                                | PT_WRITABLE_MASK | PT_USER_MASK;
+                                | PT_WRITABLE_MASK | shadow_user_mask;
                 }
                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
         }
@@ -1599,7 +1622,7 @@ static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
 {
         u64 *spte = vcpu->arch.last_pte_updated;
 
-        return !!(spte && (*spte & PT_ACCESSED_MASK));
+        return !!(spte && (*spte & shadow_accessed_mask));
 }
 
 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0ce556372a4d..0735efbfa712 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2417,6 +2417,9 @@ int kvm_arch_init(void *opaque)
 
         kvm_x86_ops = ops;
         kvm_mmu_set_nonpresent_ptes(0ull, 0ull);
+        kvm_mmu_set_base_ptes(PT_PRESENT_MASK);
+        kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK,
+                        PT_DIRTY_MASK, PT64_NX_MASK, 0);
         return 0;
 
 out: