Some new systems have multiple software-visible die within each package. Add support to expose Intel V2 Extended Topology Enumeration Leaf CPUID.1F.
Co-developed-by: Xiaoyao Li <xiaoyao...@linux.intel.com> Signed-off-by: Xiaoyao Li <xiaoyao...@linux.intel.com> Signed-off-by: Like Xu <like...@linux.intel.com> --- ==changelog== v2: - Apply cpuid.1f check rule on Intel SDM page 3-222 Vol.2A - Add comment to handle 0x1f anf 0xb in common code - Reduce check time in a descending-break style v1: https://lkml.org/lkml/2019/4/22/28 arch/x86/kvm/cpuid.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index fd39516..f9b529e 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -425,6 +425,11 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, switch (function) { case 0: + /* Check if the cpuid leaf 0x1f is actually implemented */ + if (entry->eax >= 0x1f && (cpuid_ebx(0x1f) & 0x0000ffff)) { + entry->eax = 0x1f; + break; + } entry->eax = min(entry->eax, (u32)(f_intel_pt ? 0x14 : 0xd)); break; case 1: @@ -544,7 +549,12 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, entry->edx = edx.full; break; } - /* function 0xb has additional index. */ + /* + * Intel documentation states that 0x1f and 0xb have + * identical formats and thus can be handled by common code. + * (Intel SDM Vol. 2A - Instruction Set Reference - CPUID) + */ + case 0x1f: case 0xb: { int i, level_type; -- 1.8.3.1
