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authorPaolo Bonzini <pbonzini@redhat.com>2019-08-14 12:07:34 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2019-08-22 10:08:45 +0200
commit4c6903a0f9d76be8a907d8238a5e86c829c8954d (patch)
treefaa90dbf0aa808f0610c8b0b652d47bfd1075fe0 /arch/x86/kvm
parente4427372398c31f57450565de277f861a4db5b3b (diff)
KVM: x86: fix reporting of AMD speculation bug CPUID leaf
The AMD_* bits have to be set from the vendor-independent feature and bug flags, because KVM_GET_SUPPORTED_CPUID does not care about the vendor and they should be set on Intel processors as well. On top of this, SSBD, STIBP and AMD_SSB_NO bit were not set, and VIRT_SSBD does not have to be added manually because it is a cpufeature that comes directly from the host's CPUID bit. Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/cpuid.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 22c2720cd948..43caeb6059b9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -729,18 +729,23 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
g_phys_as = phys_as;
entry->eax = g_phys_as | (virt_as << 8);
entry->edx = 0;
+ entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
+ cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
/*
- * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
- * hardware cpuid
+ * AMD has separate bits for each SPEC_CTRL bit.
+ * arch/x86/kernel/cpu/bugs.c is kind enough to
+ * record that in cpufeatures so use them.
*/
- if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
+ if (boot_cpu_has(X86_FEATURE_IBPB))
entry->ebx |= F(AMD_IBPB);
- if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
+ if (boot_cpu_has(X86_FEATURE_IBRS))
entry->ebx |= F(AMD_IBRS);
- if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
- entry->ebx |= F(VIRT_SSBD);
- entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
- cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ entry->ebx |= F(AMD_STIBP);
+ if (boot_cpu_has(X86_FEATURE_SSBD))
+ entry->ebx |= F(AMD_SSBD);
+ if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS))
+ entry->ebx |= F(AMD_SSB_NO);
/*
* The preference is to use SPEC CTRL MSR instead of the
* VIRT_SPEC MSR.