On Mon, Apr 22, 2019 at 02:40:34PM +0800, Like Xu wrote: > Expose Intel V2 Extended Topology Enumeration Leaf to guest only when > host system has multiple software-visible die within each package. Is there some doc on this? The https://software.intel.com/en-us/articles/intel-64-architecture-processor-topology-enumeration has a date of 2012. > > Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx> > --- > arch/x86/kvm/cpuid.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index fd39516..9fc14f2 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -65,6 +65,16 @@ u64 kvm_supported_xcr0(void) > return xcr0; > } > > +/* We need to check if the host cpu has multi-chip packaging technology. */ > +static bool kvm_supported_intel_mcp(void) > +{ > + u32 eax, ignored; > + > + cpuid_count(0x1f, 0, &eax, &ignored, &ignored, &ignored); > + > + return boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && (eax != 0); > +} > + > #define F(x) bit(X86_FEATURE_##x) > > int kvm_update_cpuid(struct kvm_vcpu *vcpu) > @@ -426,6 +436,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > switch (function) { > case 0: > entry->eax = min(entry->eax, (u32)(f_intel_pt ? 0x14 : 0xd)); > + entry->eax = kvm_supported_intel_mcp() ? 0x1f : entry->eax; > break; > case 1: > entry->edx &= kvm_cpuid_1_edx_x86_features; > @@ -544,6 +555,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > entry->edx = edx.full; > break; > } > + /* function 0x1f has additional index. */ > + case 0x1f: > /* function 0xb has additional index. */ > case 0xb: { > int i, level_type; > -- > 1.8.3.1 >
