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

[Wei Wang]

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?

Best,
Wei