[PATCH v12 05/16] KVM: x86: Add Arch LBR MSRs to msrs_to_save_all list

[Yang Weijiang]

Arch LBR MSR_ARCH_LBR_DEPTH and MSR_ARCH_LBR_CTL are queried by
userspace application before it wants to {save|restore} the Arch LBR
data. Other LBR related data MSRs are omitted here intentionally due
to lengthy list(32*3). Userspace can still use KVM_{GET|SET}_MSRS to
access them if necessary.

Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
 arch/x86/kvm/x86.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 247c58f5c8af..93b027aed2f3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1458,6 +1458,7 @@ static const u32 msrs_to_save_all[] = {
 	MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5,
 	MSR_IA32_XFD, MSR_IA32_XFD_ERR,
 	MSR_IA32_XSS,
+	MSR_ARCH_LBR_CTL, MSR_ARCH_LBR_DEPTH,
 };
 
 static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
@@ -6741,6 +6742,11 @@ static void kvm_init_msr_list(void)
 			if (!supported_xss)
 				continue;
 			break;
+		case MSR_ARCH_LBR_DEPTH:
+		case MSR_ARCH_LBR_CTL:
+			if (!kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR))
+				continue;
+			break;
 		default:
 			break;
 		}
-- 
2.27.0