[Patch] KVM: SVM: Fix svm_xsaves_supported

From: Aaron Lewis <aaronlewis@google.com>
To: kvm@vger.kernel.org
Cc: Janakarajan.Natarajan@amd.com, jmattson@google.com,
	Aaron Lewis <aaronlewis@google.com>
Subject: [Patch] KVM: SVM: Fix svm_xsaves_supported
Date: Tue,  3 Sep 2019 17:14:22 -0700	[thread overview]
Message-ID: <20190904001422.11809-1-aaronlewis@google.com> (raw)

AMD allows guests to execute XSAVES/XRSTORS if supported by the host.  This is different than Intel as they have an additional control bit that determines if XSAVES/XRSTORS can be used by the guest. Intel also has intercept bits that might prevent the guest from intercepting the instruction as well. AMD has none of that, not even an Intercept mechanism.  AMD simply allows XSAVES/XRSTORS to be executed by the guest if also supported by the host.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
---
 arch/x86/kvm/svm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1f220a85514f..b681a89f4f7e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5985,7 +5985,7 @@ static bool svm_mpx_supported(void)
 
 static bool svm_xsaves_supported(void)
 {
-	return false;
+	return boot_cpu_has(X86_FEATURE_XSAVES);
 }
 
 static bool svm_umip_emulated(void)
-- 
2.23.0.187.g17f5b7556c-goog

