Re: [PATCH 0/2] KVM: x86: Fix incorrect VM-exit profiling

Wei Zhang
2022-05-11T16:46:45Z

Yes, the profiling is about finding out which instructions in the
guest trigger VM exits and the corresponding frequencies.

Basically this will give a histogram array in /proc/profile. So if
'array[A] == T', we know that the instruction at (_stext + A) triggers
VM exits T times. readprofile command could read the information and
show a summary.

On Tue, May 10, 2022 at 1:57 AM Sean Christopherson <seanjc@google.com> wrote:
>
> On Tue, Apr 12, 2022, Wei Zhang wrote:
> > The profile=kvm boot option has been useful because it provides a
> > convenient approach to profile VM exits.
>
> What exactly are you profiling? Where the guest executing at any given exit? Mostly
> out of curiosity, but also in the hope that we might be able to replace profiling with
> a dedicated KVM stat(s).