[PATCH v7 08/15] KVM: x86: Report XSS as an MSR to be saved if there are supported features

[Yang Weijiang <weijiang.yang@intel.com>]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Add MSR_IA32_XSS to the list of MSRs reported to userspace if
supported_xss is non-zero, i.e. KVM supports at least one XSS based
feature.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Message-Id: <20210203113421.5759-2-weijiang.yang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/x86.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 08a58ef8bec2..2ebb05212652 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1328,6 +1328,7 @@ static const u32 msrs_to_save_all[] = {
 	MSR_ARCH_PERFMON_EVENTSEL0 + 14, MSR_ARCH_PERFMON_EVENTSEL0 + 15,
 	MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
 	MSR_ARCH_LBR_CTL, MSR_ARCH_LBR_DEPTH,
+	MSR_IA32_XSS,
 };
 
 static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
@@ -6238,6 +6239,10 @@ static void kvm_init_msr_list(void)
 			if (!kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR))
 				continue;
 			break;
+		case MSR_IA32_XSS:
+			if (!supported_xss)
+				continue;
+			break;
 		default:
 			break;
 		}
-- 
2.25.1