On Mon, Sep 04, 2023 at 09:53:40AM +0000, Manali Shukla wrote: >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; nit: no need to clear entry->eax to 0 because it will be overwritten right below. >+ 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 >
