lkml.org 
[lkml]   [2022]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v2 2/3] perf/x86/intel/pt: Introduce and export pt_get_curr_event()
On Thu, Sep 22, 2022 at 01:59:53PM +0000, Wang, Wei W wrote:
> On Thursday, September 22, 2022 9:35 PM, Peter Zijlstra
> > On Thu, Sep 22, 2022 at 12:58:49PM +0000, Wang, Wei W wrote:
> >
> > > Add a function to expose the current running PT event to users. One
> > > usage is in KVM, it needs to get and disable the running host PT event
> > > before VMEnter to the guest and resumes the event after VMexit to host.
> >
> > You cannot just kill a host event like that. If there is a host event, the guest
> > looses out.
>
> OK. The intention was to pause the event (that only profiles host info) when switching to guest,
> and resume when switching back to host.

If the even doesn't profile guest context, then yes. If it does profile
guest context, you can't.

\
 
 \ /
  Last update: 2022-09-22 16:10    [W:0.058 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site