On Mon, Mar 02, 2020 at 09:20:52PM +0100, Jan Kiszka wrote:
> On 02.03.20 20:57, Sean Christopherson wrote:
> >Rename "found" in kvm_cpuid() to "exact_entry_exists" to better convey
> >that the intent of the tracepoint's "found/not found" output is to trace
> >whether the output values are for the actual requested leaf or for some
> >other (likely unrelated) leaf that was found while processing entries to
> >emulate funky CPU behavior, e.g. the max basic leaf on Intel CPUs when
> >the requested CPUID leaf is out of range.
> >
> >Suggested-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> >Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> >---
> > arch/x86/kvm/cpuid.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> >diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> >index 869526930cf7..b0a4f3c17932 100644
> >--- a/arch/x86/kvm/cpuid.c
> >+++ b/arch/x86/kvm/cpuid.c
> >@@ -1002,10 +1002,10 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
> > {
> > const u32 function = *eax, index = *ecx;
> > struct kvm_cpuid_entry2 *entry;
> >- bool found;
> >+ bool exact_entry_exists;
> > entry = kvm_find_cpuid_entry(vcpu, function, index);
> >- found = entry;
> >+ exact_entry_exists = !!entry;
> > /*
> > * Intel CPUID semantics treats any query for an out-of-range
> > * leaf as if the highest basic leaf (i.e. CPUID.0H:EAX) were
> >@@ -1047,7 +1047,7 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
> > }
> > }
> > }
> >- trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, found);
> >+ trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, exact_entry_exists);
>
> Actually, I think we also what to change output in the tracepoint.
Oh, I definitely want to change it, but AIUI it's ABI and shouldn't be
changed. Paolo?
