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SubjectRE: [PATCH 1/1] x86/hyper-V: Allocate the IDT entry early in boot
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> -----Original Message-----
> From: Ingo Molnar [mailto:mingo.kernel.org@gmail.com] On Behalf Of Ingo
> Molnar
> Sent: Wednesday, September 13, 2017 2:01 AM
> To: KY Srinivasan <kys@microsoft.com>
> Cc: Dan Carpenter <dan.carpenter@oracle.com>; x86@kernel.org;
> gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; tglx@linutronix.de; hpa@zytor.com
> Subject: Re: [PATCH 1/1] x86/hyper-V: Allocate the IDT entry early in boot
>
>
> * KY Srinivasan <kys@microsoft.com> wrote:
>
> >
> >
> > > -----Original Message-----
> > > From: Dan Carpenter [mailto:dan.carpenter@oracle.com]
> > > Sent: Saturday, September 9, 2017 4:04 AM
> > > To: KY Srinivasan <kys@microsoft.com>
> > > Cc: x86@kernel.org; gregkh@linuxfoundation.org; linux-
> > > kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de;
> > > apw@canonical.com; jasowang@redhat.com; tglx@linutronix.de;
> > > hpa@zytor.com; mingo@kernel.org
> > > Subject: Re: [PATCH 1/1] x86/hyper-V: Allocate the IDT entry early in boot
> > >
> > > On Fri, Sep 08, 2017 at 04:15:57PM -0700, kys@exchange.microsoft.com
> > > wrote:
> > > > From: "K. Y. Srinivasan" <kys@microsoft.com>
> > > >
> > > > Allocate the hypervisor callback IDT entry early in the boot sequence.
> > > >
> > >
> > > I'm guessing this fixes a NULL dereference or something? The changelog
> > > doesn't really say why we are doing this.
> >
> > The changelog does say what we are doing - allocating the IDT entry early in
> the boot sequence.
>
> But the question was the 'why', not the 'what' - so Dan's question is
> fully justified ...
>
> > The current code would allocate the entry as part of registering the handler
> > when vmbus driver loaded and this caused a problem for the cleanup
> Thomas had
> > implemented.
>
> I've put this explanation into the changelog.

You are right. Thanks, Ingo.

K. Y
>
> Thanks,
>
> Ingo

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