Re: [PATCH V2 5/6] perf kvm report: Add guest_code support

Andi Kleen
2022-05-23T15:56:12Z

On 5/17/2022 6:10 AM, Adrian Hunter wrote:
> Add an option to indicate that guest code can be found in the hypervisor
> process

Sorry for harping on this, but is it correct that this assumes that the
code is still at the original location at decode time?

If yes we need some warnings for this, something like:

This only works when the code is still available in the riginal memory
location at decode time. This is typically the case for kernel code
(unless modules are unloaded). For user programs it only works as long
as there is no memory pressure which might cause the memory to be
reused. For dynamically generated (JITed) code it might be rather
unreliable unless the hypervisor is SIGSTOPed during decoding.