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 93730fe9f7e97ea67f4ae05002123baf4fe2cfd5..965a7fa071b6a3bb4767af6da8836ede1288f919 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3253,6 +3253,10 @@ 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 7b32ddb05a54c68c5f6d06038caa90d36a80a8bd..be9251193d2a9001b0f1ceaf98083eaabc557269 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1910,7 +1910,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                0 /* Reserved, XSAVE, OSXSAVE */;
        /* 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 */;