Re: [Xen-devel] [PATCH 5/7] xen: Make event channel work with PV extension of HVM

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 02 March 2010 09:38:21 Jeremy Fitzhardinge wrote:
> On 03/01/2010 01:38 AM, Sheng Yang wrote:
> > +
> > +		x86_platform.calibrate_tsc = xen_tsc_khz;
> > +		x86_platform.get_wallclock = xen_get_wallclock;
> > +		x86_platform.set_wallclock = xen_set_wallclock;
> > +
> > +		pv_apic_ops = xen_apic_ops;
> > +#ifdef CONFIG_X86_LOCAL_APIC
> > +		/*
> > +		 * set up the basic apic ops.
> > +		 */
> > +		set_xen_basic_apic_ops();
> > +		apic->write = xen_hvm_pv_evtchn_apic_write;
> 
> I'd just change the xen_apic_write to remove the WARN_ON, since you
> don't seem to care about it either.

So which code base I should make these patches against? We expect the patchset 
can be accepted in the Linux upstream soon after you pick it up.
> 
> >
> > -	exit_idle();
> > -	irq_enter();
> > +	/*
> > +	 * If is PV featured HVM, these have already been done
> > +	 */
> > +	if (likely(!xen_hvm_pv_evtchn_enabled())) {
> > +		exit_idle();
> > +		irq_enter();
> > +	}
> 
> In that case, rather than putting this conditional in the hot path, make
> an inner __xen_evtchn_do_upcall which is wrapped by the PV and HVM
> variants which do the appropriate things.  (And drop the pt_regs arg, I
> think.)

Seems we still need pt_regs to for handle_irq()?

-- 
regards
Yang, Sheng