Re: [PATCH 0/2] KVM: x86: CPUID tracepoint enhancements

From: Paolo Bonzini
Date: Wed Mar 18 2020 - 08:45:10 EST


On 17/03/20 20:53, Sean Christopherson wrote:
> Two enhancements to the CPUID tracepoint. Patch 01 was originally in the
> CPUID ranges series, but I unintentionally dropped it in v2.
>
> The final output looks like:
>
> kvm_cpuid: func 0 idx 0 rax d rbx 68747541 rcx 444d4163 rdx 69746e65, cpuid entry found
> kvm_cpuid: func d idx 444d4163 rax 0 rbx 0 rcx 0 rdx 0, cpuid entry not found
> kvm_cpuid: func 80000023 idx 1 rax f rbx 240 rcx 0 rdx 0, cpuid entry not found, used max basic
> kvm_cpuid: func 80000023 idx 2 rax 100 rbx 240 rcx 0 rdx 0, cpuid entry not found, used max basic
>
> I also considered appending "exact" to the "found" case, which is more
> directly what Jan suggested, but IMO "found exact" implies there's also a
> "found inexact", which is not true. AIUI, calling out that KVM is using
> the max basic leaf values is what's really important to avoid confusion.
>
> Ideally, the function of the max basic leaf would also be displayed, but
> doing that without printing garbage for the other cases is a lot of ugly
> code for marginal value.
>
> Sean Christopherson (2):
> KVM: x86: Add requested index to the CPUID tracepoint
> KVM: x86: Add blurb to CPUID tracepoint when using max basic leaf
> values
>
> arch/x86/kvm/cpuid.c | 9 ++++++---
> arch/x86/kvm/trace.h | 18 ++++++++++++------
> 2 files changed, 18 insertions(+), 9 deletions(-)
>

Queued, thanks.

Paolo