Re: [Qemu-devel] Re: [PATCH 0/6] Make hpet a compile time option

[Paul Brook]

> On 05/24/2010 11:32 AM, Paul Brook wrote:
> >> Notice that this patch was sent against hpet as one example, if we agree
> >> that this "way" of disabling devices is ok, we could disable more
> >> devices/have more flexibility.  Notice that in general, we (RHEL/KVM)
> >> are interested in a small subset of qemu devices.
> > 
> > IMO this patch is a backwards step.  The device models should be cleaned
> > up so that you don't need to make a compile time decision.
> 
> I disagree.  I think the device model should be cleaned up so that no
> CONFIG_HPET is required in code but I think it's still useful to be able
> to exclude device models from the build.  That should just be a matter
> of not building the object though (that's the point of device_init()).

I think we're saying the same thing.

We already have a mechanism for avoiding things at build time - specifically 
config-devices.mak. We don't have a nice UI for it, but it's there.
At worst your distro specific patch is a 1-line change to default-
configs/i386-softmmu.mak.

I have no objection to moving hpet.c into Makefile.objs, conditional on 
CONFIG_HPET (like e.g. CONFIG_SERIAL/serial.o).  However a necessary 
prerequisite is that you fix the device model and machine initialisation so 
that it's possible to omit hpet.o without rebuilding anything else.

Paul