[Qemu-devel] Re: [PATCH 1/2] Move KVM init to arch_init.c, compile vl.c once

[Blue Swirl <blauwirbel@gmail.com>]

On 4/2/10, Anthony Liguori <anthony@codemonkey.ws> wrote:
> On 04/02/2010 10:01 AM, Paolo Bonzini wrote:
>
> > On 04/01/2010 10:27 PM, Blue Swirl wrote:
> >
> > > It will not be safe to use kvm_enabled() in vl.c, so there needs to be
> > > a target dependent helper. The call to kvm_init could remain in vl.c,
> > > likewise it's not strictly needed to move kvm_allowed to arch_init.c.
> > >
> >
> > Not really, because kvm_allowed _can_ be used from once-compiled files.
> The attached patch makes kvm-all.c be compiled always, even if !CONFIG_KVM;
> functions that require kvm are almost always omitted for now (so checking
> kvm_enabled() is required to call them).  However, kvm_init is stubbed so
> that vl.c can call it.
> >
> > In the future we could add more stubbing and ultimately do this
> unconditionally:
> >
> >   #define kvm_enabled() kvm_allowed
> >
> > With this patch vl.c can already be compiled once, but I did not include
> it because it would conflict with my balloon.c series; I'm doing enough
> rebasing these days.  Also, qemu-kvm is a bit behind qemu and all these
> patches are nightmares for the merges, so it's better IMO if things are left
> to calm down a bit.
> >
>
>  Having kvm-all.c compile with and without CONFIG_KVM is pretty ugly IMHO.
>
>  Is compiling vl.c once really that important of a goal?  Wouldn't it be
> better to split bits out of vl.c and have those compile once?  Ideally, vl.c
> should be so small that compiling per-target shouldn't matter.

But the only thing preventing compiling whole vl.c once is just KVM
init. I'll send a new patch, hopefully it's better.