Re: [PATCH v3] enable x2APIC without interrupt remapping under KVM

Gleb Natapov
2009-06-29T15:45:51Z

On Mon, Jun 29, 2009 at 08:15:05AM -0700, Suresh Siddha wrote:
> On Mon, 2009-06-29 at 08:10 -0700, Gleb Natapov wrote:
> > On Mon, Jun 29, 2009 at 07:58:39AM -0700, Suresh Siddha wrote:
> > > Thinking more, probably we shouldn't remove this dependency. This might
> > > encourage people (knowingly or unknowingly) to enable x2apic without
> > > interrupt-remapping. Can we remove this? KVM mode will still work even
> > > if we fail to enable interrupt-remapping. So this shouldn't be an issue,
> > > correct?
> > >
> > Yes, KVM will still work. I don't have strong fillings one way or the
> > other, but why mandate an option that is no longer mandatory. What
> > others think?
>
> Only under the presence of KVM we are breaking this dependency. And
> typically the same kernel runs natively and under the presence of kvm
> correct. So thats why we shouldn't break this dependency.
>
OK, I'll drop Kconfig part in the next version. Unless someone will
object till tomorrow.

>
> > > > ioapic_entries = alloc_ioapic_entries();
> > > > if (!ioapic_entries) {
> > > > - pr_info("Allocate ioapic_entries failed: %d\n", ret);
> > > > - goto end;
> > > > + pr_info("Allocate ioapic_entries failed\n");
> > > > + return;
> > >
> > >
> > > We should go to ir_failed ..
> > Why? There is not more ir_failed.
>
> oops. Not literally. We should goto the point where we should report the
> x2apic or ir enabling failed and check for x2apic pre-enabled etc at the
> end.
>
Ah, OK.

--
Gleb.