commit 66a562f7e2576cde384ec813b481404d8f54f4c6
author Joerg Roedel <joerg.roedel@amd.com> Fri Feb 19 16:23:08 2010 +0100
committer Avi Kivity <avi@redhat.com> Sun Apr 25 12:34:28 2010 +0300
tree ea64df4f210caf8b0e375932a422174f95f658b8
parent 06fc7772690dec2a0e3814633357babf8f63af41

KVM: SVM: Make lazy FPU switching work with nested svm

The new lazy fpu switching code may disable cr0 intercepts
when running nested. This is a bug because the nested
hypervisor may still want to intercept cr0 which will break
in this situation. This patch fixes this issue and makes
lazy fpu switching working with nested svm.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/svm.c

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8ace0b0..a8ec53f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -979,6 +979,7 @@
 
 static void update_cr0_intercept(struct vcpu_svm *svm)
 {
+	struct vmcb *vmcb = svm->vmcb;
 	ulong gcr0 = svm->vcpu.arch.cr0;
 	u64 *hcr0 = &svm->vmcb->save.cr0;
 
@@ -990,11 +991,25 @@
 
 
 	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;
+		vmcb->control.intercept_cr_read &= ~INTERCEPT_CR0_MASK;
+		vmcb->control.intercept_cr_write &= ~INTERCEPT_CR0_MASK;
+		if (is_nested(svm)) {
+			struct vmcb *hsave = svm->nested.hsave;
+
+			hsave->control.intercept_cr_read  &= ~INTERCEPT_CR0_MASK;
+			hsave->control.intercept_cr_write &= ~INTERCEPT_CR0_MASK;
+			vmcb->control.intercept_cr_read  |= svm->nested.intercept_cr_read;
+			vmcb->control.intercept_cr_write |= svm->nested.intercept_cr_write;
+		}
 	} else {
 		svm->vmcb->control.intercept_cr_read |= INTERCEPT_CR0_MASK;
 		svm->vmcb->control.intercept_cr_write |= INTERCEPT_CR0_MASK;
+		if (is_nested(svm)) {
+			struct vmcb *hsave = svm->nested.hsave;
+
+			hsave->control.intercept_cr_read |= INTERCEPT_CR0_MASK;
+			hsave->control.intercept_cr_write |= INTERCEPT_CR0_MASK;
+		}
 	}
 }
 
@@ -1269,7 +1284,22 @@
 static void svm_fpu_activate(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
-	svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR);
+	u32 excp;
+
+	if (is_nested(svm)) {
+		u32 h_excp, n_excp;
+
+		h_excp  = svm->nested.hsave->control.intercept_exceptions;
+		n_excp  = svm->nested.intercept_exceptions;
+		h_excp &= ~(1 << NM_VECTOR);
+		excp    = h_excp | n_excp;
+	} else {
+		excp  = svm->vmcb->control.intercept_exceptions;
+	        excp &= ~(1 << NM_VECTOR);
+	}
+
+	svm->vmcb->control.intercept_exceptions = excp;
+
 	svm->vcpu.fpu_active = 1;
 	update_cr0_intercept(svm);
 }
@@ -1513,6 +1543,9 @@
 		if (!npt_enabled)
 			return NESTED_EXIT_HOST;
 		break;
+	case SVM_EXIT_EXCP_BASE + NM_VECTOR:
+		nm_interception(svm);
+		break;
 	default:
 		break;
 	}
@@ -2980,8 +3013,10 @@
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	update_cr0_intercept(svm);
 	svm->vmcb->control.intercept_exceptions |= 1 << NM_VECTOR;
+	if (is_nested(svm))
+		svm->nested.hsave->control.intercept_exceptions |= 1 << NM_VECTOR;
+	update_cr0_intercept(svm);
 }
 
 static struct kvm_x86_ops svm_x86_ops = {