CPUID leaf 0x8000001b (EAX) provides information about Instruction-Based sampling capabilities on AMD Platforms. Complete description about 0x8000001b CPUID leaf is available in AMD Programmer's Manual volume 3, Appendix E, section E.4.13. https://bugzilla.kernel.org/attachment.cgi?id=304655 Signed-off-by: Manali Shukla <manali.shukla@xxxxxxx> --- arch/x86/kvm/cpuid.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 0544e30b4946..1f4d505fb69d 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -771,6 +771,12 @@ void kvm_set_cpu_caps(void) F(PERFMON_V2) ); + /* + * Hide all IBS related features by default, it will be enabled + * automatically when IBS virtualization is enabled + */ + kvm_cpu_cap_init_kvm_defined(CPUID_8000_001B_EAX, 0); + /* * Synthesize "LFENCE is serializing" into the AMD-defined entry in * KVM's supported CPUID if the feature is reported as supported by the @@ -1252,6 +1258,11 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) entry->eax = entry->ebx = entry->ecx = 0; entry->edx = 0; /* reserved */ break; + /* AMD IBS capability */ + case 0x8000001B: + entry->eax = entry->ebx = entry->ecx = entry->edx = 0; + cpuid_entry_override(entry, CPUID_8000_001B_EAX); + break; case 0x8000001F: if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) { entry->eax = entry->ebx = entry->ecx = entry->edx = 0; -- 2.34.1
