[PATCH v2 02/15] 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>
---
 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 f18f579ebde8..16726b44061b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1465,6 +1465,7 @@ 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,
 };
 
 static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
@@ -7061,6 +7062,10 @@ static void kvm_init_msr_list(void)
 			if (!kvm_cpu_cap_has(X86_FEATURE_XFD))
 				continue;
 			break;
+		case MSR_IA32_XSS:
+			if (!kvm_caps.supported_xss)
+				continue;
+			break;
 		default:
 			break;
 		}
-- 
2.27.0