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Date: Fri, 29 Jun 2018 17:18:21 +0200
From: Igor Mammedov <imammedo@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2] accel: forbid early use of
 kvm_enabled() and friends
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To: "Daniel P. =?UTF-8?B?QmVycmFuZ8Op?=" <berrange@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Greg Kurz <groug@kaod.org>, qemu-devel@nongnu.org, =?UTF-8?B?Q8OpZHJpYw==?= Le Goater <clg@kaod.org>, Richard Henderson <rth@twiddle.net>, David Gibson <david@gibson.dropbear.id.au>

On Fri, 29 Jun 2018 12:14:05 +0100
Daniel P. Berrang=C3=A9 <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: =20
> > >>>> Also asserting current_machine !=3D NULL is not necessary, since y=
ou're
> > >>>> immediately dereferencing it.   =20
> > >>> Is there a practical way to simply initialize the accelerators earl=
ier
> > >>> in startup sequence, so we just remove or at least reduce, the likl=
ihood
> > >>> of accessing it too early ?   =20
> > >> We can try, though not for 3.0 of course.
> > >> =20
> > > FWIW, the motivation for this patch was kvm_enabled() being called un=
der
> > > the class_init function of the machine TypeInfo. This happens way ear=
lier
> > > than accelerator init. Not sure this is doable, but I can have a look.
> > >  =20
> >=20
> > Probably not, that's way too early indeed. =20
>=20
> Yeah, doing anything non-trivial in class_init is just asking for trouble,
> as conceivably nothing is initialized at that point.=20
isn't class_init called lazily? (so it might actually work as far as type
isn't touched before kvm is initialized)

>=20
> Regards,
> Daniel