KVM: X86: Report SVM bit to userspace only when supported

commit 4c62a2dc92518c5adf434df8e5c2283c6762672a upstream.

This patch fixes a bug in KVM where it _always_ reports the
support of the SVM feature to userspace. But KVM only
supports SVM on AMD hardware and only when it is enabled in
the kernel module. This patch fixes the wrong reporting.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8a3f9f64f86f9e7fee5bc5112bf50a04fbe37b15..66f7e5ea483668c1283706f7b9ca6e2448e78179 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3354,6 +3354,10 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
 static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
 {
        switch (func) {
+       case 0x80000001:
+               if (nested)
+                       entry->ecx |= (1 << 2); /* Set SVM bit */
+               break;
        case 0x8000000A:
                entry->eax = 1; /* SVM revision 1 */
                entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dd54779ccbeae7a54c355e799eb2b7fe044fb0a0..a4a427bea46e076e0eab143a038749b8b8a36a08 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1994,7 +1994,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                0 /* Reserved, AES */ | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX);
        /* cpuid 0x80000001.ecx */
        const u32 kvm_supported_word6_x86_features =
-               F(LAHF_LM) | F(CMP_LEGACY) | F(SVM) | 0 /* ExtApicSpace */ |
+               F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
                F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
                F(3DNOWPREFETCH) | 0 /* OSVW */ | 0 /* IBS */ | F(XOP) |
                0 /* SKINIT */ | 0 /* WDT */;