Re: [Qemu-devel] [PATCH] xen: Restrict build to x86 targets

[Anthony PERARD]

On Mon, 29 Nov 2010, Alexander Graf wrote:

>
> On 29.11.2010, at 15:27, Jan Kiszka wrote:
>
> > Am 29.11.2010 15:15, Alexander Graf wrote:
> >>
> >> On 29.11.2010, at 13:44, Jan Kiszka wrote:
> >>
> >>> Am 29.11.2010 13:40, Alexander Graf wrote:
> >>>>
> >>>> On 29.11.2010, at 13:30, Jan Kiszka wrote:
> >>>>
> >>>>> Am 29.11.2010 13:24, Alexander Graf wrote:
> >>>>>>
> >>>>>> On 28.11.2010, at 16:59, Jan Kiszka wrote:
> >>>>>>
> >>>>>>> From: Jan Kiszka <address@hidden>
> >>>>>>>
> >>>>>>> Xen target bits in qemu are intended for x86. Let the build system
> >>>>>>> reflect this and avoid useless building/linking for other targets.
> >>>>>>
> >>>>>> Not sure I understand the split. Xen is x86 only, yes. But why split 
> >>>>>> it into host and target? Target usually defines the guest. The piece 
> >>>>>> you marked as _HOST are target specific.
> >>>>>
> >>>>> At least so far, the HOST part is build once for all targets into the
> >>>>> host backend library. As this step injected CONFIG_XEN into all target
> >>>>> builds, even non-x86 targets built xen_machine_pv and xen_domainbuild.
> >>>>> That's addressed by the patch.
> >>>>
> >>>> I still don't understand the need for that split.
> >>>
> >>> Enable Xen and build some non-x86 targets, then you see the need.
> >>>
> >>>> The device drivers should be built only once, as do the xen_machine_pv 
> >>>> parts. Both are useless on non-x86. CONFIG_XEN should simply always be a 
> >>>> target specific option.
> >>>
> >>> Maybe the split-up between the "generic" host-side interfaces and
> >>> xen_machine_pv/xen_domainbuild is the problem. You know the dependencies
> >>> better than me, maybe you find a better fix.
> >>
> >> Should be enough to just replace obj-$(CONFIG_XEN) by 
> >> obj-i386-$(CONFIG_XEN).
> >
> > Indeed (as long as qemu's xen remains x86-only).
>
> I'm 99.9% sure it will :).
>
> >> Unless it's very urgent, please wait with this patch until qemu-dm and 
> >> xenner are in. It's pretty suboptimal to have 3 patches flying around that 
> >> hit the exact same code spot :).
> >
> > It isn't urgent. If patches series refactor the stuff and fix the
> > dependency, I'm happy to wait for them.
>
> They don't really refactor it, but add a lot more dependencies. Anthony, 
> since you probably need yet another round for the 4.0 compile stuff, feel 
> like putting this on your TODO list too? (Sorry this takes so long :( - I'll 
> try to review stuff quicker next time around)

OK, but I will go a little further by putting all Xen stuff in x86 only
target, not only xenpv.

-- 
Anthony PERARD