KVM: x86: add functions to get the cpl of vcpu

Signed-off-by: NIzik Eidus <izike@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

arch/x86/kvm/svm.c

@@ -792,6 +792,13 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
 	var->unusable = !var->present;
 }
 
+static int svm_get_cpl(struct kvm_vcpu *vcpu)
+{
+	struct vmcb_save_area *save = &to_svm(vcpu)->vmcb->save;
+
+	return save->cpl;
+}
+
 static void svm_get_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -1822,6 +1829,7 @@ static struct kvm_x86_ops svm_x86_ops = {
 	.get_segment_base = svm_get_segment_base,
 	.get_segment = svm_get_segment,
 	.set_segment = svm_set_segment,
+	.get_cpl = svm_get_cpl,
 	.get_cs_db_l_bits = kvm_get_cs_db_l_bits,
 	.decache_cr4_guest_bits = svm_decache_cr4_guest_bits,
 	.set_cr0 = svm_set_cr0,

arch/x86/kvm/vmx.c

@@ -1395,6 +1395,20 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
 	var->unusable = (ar >> 16) & 1;
 }
 
+static int vmx_get_cpl(struct kvm_vcpu *vcpu)
+{
+	struct kvm_segment kvm_seg;
+
+	if (!(vcpu->arch.cr0 & X86_CR0_PE)) /* if real mode */
+		return 0;
+
+	if (vmx_get_rflags(vcpu) & X86_EFLAGS_VM) /* if virtual 8086 */
+		return 3;
+
+	vmx_get_segment(vcpu, &kvm_seg, VCPU_SREG_CS);
+	return kvm_seg.selector & 3;
+}
+
 static u32 vmx_segment_access_rights(struct kvm_segment *var)
 {
 	u32 ar;
@@ -2665,6 +2679,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
 	.get_segment_base = vmx_get_segment_base,
 	.get_segment = vmx_get_segment,
 	.set_segment = vmx_set_segment,
+	.get_cpl = vmx_get_cpl,
 	.get_cs_db_l_bits = vmx_get_cs_db_l_bits,
 	.decache_cr4_guest_bits = vmx_decache_cr4_guest_bits,
 	.set_cr0 = vmx_set_cr0,

include/asm-x86/kvm_host.h

@@ -388,6 +388,7 @@ struct kvm_x86_ops {
 	u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
 	void (*get_segment)(struct kvm_vcpu *vcpu,
 			    struct kvm_segment *var, int seg);
+	int (*get_cpl)(struct kvm_vcpu *vcpu);
 	void (*set_segment)(struct kvm_vcpu *vcpu,
 			    struct kvm_segment *var, int seg);
 	void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);