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

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.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 36e6c88913dcbd39260c45528141106d06b6ede6..e0f4da07f9874026e43238e5936fbb90bb186cad 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3469,6 +3469,10 @@ 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 bbd9f4af4449963ff2260af03770693986b9667f..3ff0a8ff275c5c719cc2338bdc20d8a7b9dcb681 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2209,7 +2209,7 @@ 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(SSE5) |
                0 /* SKINIT */ | 0 /* WDT */;