[PATCH RESEND v5 1/2] KVM: X86: Introduce kvm_get_msr_feature()

[Wanpeng Li <kernellwp@gmail.com>]

From: Wanpeng Li <wanpengli@tencent.com>

Introduce kvm_get_msr_feature() to handle the msrs which are supported 
by different vendors and sharing the same emulation logic.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 arch/x86/kvm/x86.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d4985a9..efc8554 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1062,13 +1062,25 @@ static u32 msr_based_features[] = {
 
 static unsigned int num_msr_based_features;
 
+static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
+{
+	switch (msr->index) {
+	default:
+		if (kvm_x86_ops->get_msr_feature(msr))
+			return 1;
+	}
+	return 0;
+}
+
 static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
 {
 	struct kvm_msr_entry msr;
+	int r;
 
 	msr.index = index;
-	if (kvm_x86_ops->get_msr_feature(&msr))
-		return 1;
+	r = kvm_get_msr_feature(&msr);
+	if (r)
+		return r;
 
 	*data = msr.data;
 
@@ -4538,7 +4550,7 @@ static void kvm_init_msr_list(void)
 		struct kvm_msr_entry msr;
 
 		msr.index = msr_based_features[i];
-		if (kvm_x86_ops->get_msr_feature(&msr))
+		if (kvm_get_msr_feature(&msr))
 			continue;
 
 		if (j < i)
-- 
2.7.4