KVM: Hoist SVM's get_cs_db_l_bits into core code.

SVM gets the DB and L bits for the cs by decoding the segment.  This
is in fact the completely generic code, so hoist it for kvm-lite to use.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/kvm.h

@@ -586,6 +586,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr0);
 void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr0);
 unsigned long get_cr8(struct kvm_vcpu *vcpu);
 void lmsw(struct kvm_vcpu *vcpu, unsigned long msw);
+void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l);
 
 int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
 int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data);

drivers/kvm/kvm_main.c

@@ -2270,6 +2270,16 @@ static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
+{
+	struct kvm_segment cs;
+
+	get_segment(vcpu, &cs, VCPU_SREG_CS);
+	*db = cs.db;
+	*l = cs.l;
+}
+EXPORT_SYMBOL_GPL(kvm_get_cs_db_l_bits);
+
 /*
  * List of msr numbers which we expose to userspace through KVM_GET_MSRS
  * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.

drivers/kvm/svm.c

@@ -724,14 +724,6 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
 	var->unusable = !var->present;
 }
 
-static void svm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
-{
-	struct vmcb_seg *s = svm_seg(vcpu, VCPU_SREG_CS);
-
-	*db = (s->attrib >> SVM_SELECTOR_DB_SHIFT) & 1;
-	*l = (s->attrib >> SVM_SELECTOR_L_SHIFT) & 1;
-}
-
 static void svm_get_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -1771,7 +1763,7 @@ static struct kvm_arch_ops svm_arch_ops = {
 	.get_segment_base = svm_get_segment_base,
 	.get_segment = svm_get_segment,
 	.set_segment = svm_set_segment,
-	.get_cs_db_l_bits = svm_get_cs_db_l_bits,
+	.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,
 	.set_cr3 = svm_set_cr3,