On 06/06/19 03:18, Like Xu wrote: > Add support to expose Intel V2 Extended Topology Enumeration Leaf for > some new systems with multiple software-visible die within each package. > > Because unimplemented and unexposed leaves should be explicitly reported > as zero, there is no need to limit cpuid.0.eax to the maximum value of > feature configuration but limit it to the highest leaf implemented in > the current code. A single clamping seems sufficient and cheaper. > > Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxxxxxxxx> > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxxxxxxxx> > Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx> > > --- > > ==changelog== > > v4: > - Limited cpuid.0.eax to the highest leaf implemented in KVM > > v3: https://lkml.org/lkml/2019/5/26/64 > - Refine commit message and comment > > v2: https://lkml.org/lkml/2019/4/25/1246 > > - 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 | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index e18a9f9f65b5..f819011e6a13 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -426,7 +426,8 @@ 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)); > + /* Limited to the highest leaf implemented in KVM. */ > + entry->eax = min(entry->eax, 0x1f); > break; > case 1: > entry->edx &= kvm_cpuid_1_edx_x86_features; > @@ -546,7 +547,11 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > entry->edx = edx.full; > break; > } > - /* function 0xb has additional index. */ > + /* > + * Per Intel's SDM, the 0x1f is a superset of 0xb, > + * thus they can be handled by common code. > + */ > + case 0x1f: > case 0xb: { > int i, level_type; > > Queued, thanks. Paolo
