Re: [PATCH v3 5/5] KVM/x86/lbr: lazy save the guest lbr stack

[Peter Zijlstra]

On Thu, Sep 20, 2018 at 08:58:16PM +0800, Wei Wang wrote:
> On 09/20/2018 08:37 PM, Peter Zijlstra wrote:
> > On Thu, Sep 20, 2018 at 06:05:59PM +0800, Wei Wang wrote:
> > >   /**
> > > + * lbr_select_user_callstack - check if the user callstack mode is set
> > > + *
> > > + * @lbr_select: the lbr select msr
> > > + *
> > > + * Returns: true if the msr is configured to the user callstack mode.
> > > + * Otherwise, false.
> > > + *
> > > + */
> > > +bool lbr_select_user_callstack(u64 lbr_select)
> > > +{
> > > +	return !!(lbr_select & LBR_USER_CALLSTACK);
> > > +}
> > > +EXPORT_SYMBOL_GPL(lbr_select_user_callstack);
> > That function is pure and tiny, wth is that an exported symbol and not
> > an inline?
> Thanks Peter for the comments.
> 
> Because this function uses the LBR_ macros which are defined in this lbr.c
> file.
> Do you think it would be OK to move all the above LBR_ macros to
> asm/perf_event.h?

Sure.