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authorPaolo Bonzini <pbonzini@redhat.com>2021-10-28 19:26:38 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2022-03-21 14:28:40 +0100
commit58b3d12c0a860cda34ed9d2378078ea5134e6812 (patch)
tree6fd1c6194a2da0f1b04ffbdf4837d16a9ed8736a /arch/x86/kvm/cpuid.c
parentKVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask (diff)
downloadlinux-58b3d12c0a860cda34ed9d2378078ea5134e6812.tar.xz
linux-58b3d12c0a860cda34ed9d2378078ea5134e6812.zip
KVM: x86: add support for CPUID leaf 0x80000021
CPUID leaf 0x80000021 defines some features (or lack of bugs) of AMD processors. Expose the ones that make sense via KVM_GET_SUPPORTED_CPUID. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to '')
-rw-r--r--arch/x86/kvm/cpuid.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index afcdd4e693e5..f0d5ac7a12c9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -1068,7 +1068,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->edx = 0;
break;
case 0x80000000:
- entry->eax = min(entry->eax, 0x8000001f);
+ entry->eax = min(entry->eax, 0x80000021);
break;
case 0x80000001:
cpuid_entry_override(entry, CPUID_8000_0001_EDX);
@@ -1139,6 +1139,23 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->ebx &= ~GENMASK(11, 6);
}
break;
+ case 0x80000020:
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ case 0x80000021:
+ entry->ebx = entry->ecx = entry->edx = 0;
+ /*
+ * Pass down these bits:
+ * EAX 0 NNDBP, Processor ignores nested data breakpoints
+ * EAX 2 LAS, LFENCE always serializing
+ * EAX 6 NSCB, Null selector clear base
+ *
+ * Other defined bits are for MSRs that KVM does not expose:
+ * EAX 3 SPCL, SMM page configuration lock
+ * EAX 13 PCMSR, Prefetch control MSR
+ */
+ entry->eax &= BIT(0) | BIT(2) | BIT(6);
+ break;
/*Add support for Centaur's CPUID instruction*/
case 0xC0000000:
/*Just support up to 0xC0000004 now*/