Re: [Qemu-devel] [PATCH v2] accel: forbid early use of kvm_enabled() and friends

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 29 Jun 2018 12:14:05 +0100
Daniel P. Berrangé <berrange@redhat.com> wrote:

> On Fri, Jun 29, 2018 at 01:08:38PM +0200, Paolo Bonzini wrote:
> > On 29/06/2018 13:07, Greg Kurz wrote:  
> > >>>> Also asserting current_machine != NULL is not necessary, since you're
> > >>>> immediately dereferencing it.    
> > >>> Is there a practical way to simply initialize the accelerators earlier
> > >>> in startup sequence, so we just remove or at least reduce, the liklihood
> > >>> of accessing it too early ?    
> > >> We can try, though not for 3.0 of course.
> > >>  
> > > FWIW, the motivation for this patch was kvm_enabled() being called under
> > > the class_init function of the machine TypeInfo. This happens way earlier
> > > than accelerator init. Not sure this is doable, but I can have a look.
> > >   
> > 
> > Probably not, that's way too early indeed.  
> 
> Yeah, doing anything non-trivial in class_init is just asking for trouble,
> as conceivably nothing is initialized at that point. 
isn't class_init called lazily? (so it might actually work as far as type
isn't touched before kvm is initialized)

> 
> Regards,
> Daniel