1 files changed, 26 insertions, 6 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 27273ed24c41..83c7ab1bdad8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -571,6 +571,7 @@ static void init_vmcb(struct vcpu_svm *svm)
         control->intercept =    (1ULL << INTERCEPT_INTR) |
                                 (1ULL << INTERCEPT_NMI) |
                                 (1ULL << INTERCEPT_SMI) |
+                                (1ULL << INTERCEPT_SELECTIVE_CR0) |
                                 (1ULL << INTERCEPT_CPUID) |
                                 (1ULL << INTERCEPT_INVD) |
                                 (1ULL << INTERCEPT_HLT) |
@@ -963,6 +964,27 @@ static void svm_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
 {
 }
 
+static void update_cr0_intercept(struct vcpu_svm *svm)
+{
+        ulong gcr0 = svm->vcpu.arch.cr0;
+        u64 *hcr0 = &svm->vmcb->save.cr0;
+
+        if (!svm->vcpu.fpu_active)
+                *hcr0 |= SVM_CR0_SELECTIVE_MASK;
+        else
+                *hcr0 = (*hcr0 & ~SVM_CR0_SELECTIVE_MASK)
+                        | (gcr0 & SVM_CR0_SELECTIVE_MASK);
+
+
+        if (gcr0 == *hcr0 && svm->vcpu.fpu_active) {
+                svm->vmcb->control.intercept_cr_read &= ~INTERCEPT_CR0_MASK;
+                svm->vmcb->control.intercept_cr_write &= ~INTERCEPT_CR0_MASK;
+        } else {
+                svm->vmcb->control.intercept_cr_read |= INTERCEPT_CR0_MASK;
+                svm->vmcb->control.intercept_cr_write |= INTERCEPT_CR0_MASK;
+        }
+}
+
 static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
@@ -994,6 +1016,7 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
          */
         cr0 &= ~(X86_CR0_CD | X86_CR0_NW);
         svm->vmcb->save.cr0 = cr0;
+        update_cr0_intercept(svm);
 }
 
 static void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
@@ -1239,11 +1262,8 @@ static int ud_interception(struct vcpu_svm *svm)
 static int nm_interception(struct vcpu_svm *svm)
 {
         svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR);
-        if (!kvm_read_cr0_bits(&svm->vcpu, X86_CR0_TS))
-                svm->vmcb->save.cr0 &= ~X86_CR0_TS;
-        else
-                svm->vmcb->save.cr0 |= X86_CR0_TS;
         svm->vcpu.fpu_active = 1;
+        update_cr0_intercept(svm);
 
         return 1;
 }
@@ -2296,7 +2316,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
         [SVM_EXIT_READ_CR3]                     = emulate_on_interception,
         [SVM_EXIT_READ_CR4]                     = emulate_on_interception,
         [SVM_EXIT_READ_CR8]                     = emulate_on_interception,
-        /* for now: */
+        [SVM_EXIT_CR0_SEL_WRITE]                = emulate_on_interception,
         [SVM_EXIT_WRITE_CR0]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_CR3]                    = emulate_on_interception,
         [SVM_EXIT_WRITE_CR4]                    = emulate_on_interception,
@@ -2914,8 +2934,8 @@ static void svm_fpu_deactivate(struct kvm_vcpu *vcpu)
                 return;
         }
 
+        update_cr0_intercept(svm);
         svm->vmcb->control.intercept_exceptions |= 1 << NM_VECTOR;
-        svm->vmcb->save.cr0 |= X86_CR0_TS;
 }
 
 static struct kvm_x86_ops svm_x86_ops = {