From: Eduardo Habkost <ehabkost@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@osdl.org>,
kvm@vger.kernel.org, kexec@lists.infradead.org,
Haren Myneni <hbabu@us.ibm.com>,
Simon Horman <horms@verge.net.au>, Avi Kivity <avi@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH 0/2] kvm: disable virtualization on kdump
Date: Mon, 27 Oct 2008 13:50:03 -0200 [thread overview]
Message-ID: <20081027155003.GM23893@blackpad> (raw)
In-Reply-To: <m1skqi9iy9.fsf@frodo.ebiederm.org>
On Mon, Oct 27, 2008 at 08:05:50AM -0700, Eric W. Biederman wrote:
> Avi Kivity <avi@redhat.com> writes:
>
> > There's no way to query whether vmx is enabled or disabled, AFAICT. So we have
> > to execute vmxoff and ignore possible #UDs.
> >
> > If we trust the exception handlers, there's no problem. Otherwise we need to
> > replace the current #UD handler with an iret (perhaps switching temporarily to
> > another IDT).
>
> Ugh. We already change the IDT on that code path so that
> may be a way to go.
I don't see the IDT being changed on native_machine_shutdown(). It even
uses notifier chain registration (register_die_notifier()) to sneak a
NMI handler in.
--
Eduardo
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WARNING: multiple messages have this Message-ID (diff)
From: Eduardo Habkost <ehabkost-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Andrew Morton <akpm-3NddpPZAyC0@public.gmane.org>,
kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Haren Myneni <hbabu-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>,
Simon Horman <horms-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org>,
Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 0/2] kvm: disable virtualization on kdump
Date: Mon, 27 Oct 2008 13:50:03 -0200 [thread overview]
Message-ID: <20081027155003.GM23893@blackpad> (raw)
In-Reply-To: <m1skqi9iy9.fsf-B27657KtZYmhTnVgQlOflh2eb7JE58TQ@public.gmane.org>
On Mon, Oct 27, 2008 at 08:05:50AM -0700, Eric W. Biederman wrote:
> Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> writes:
>
> > There's no way to query whether vmx is enabled or disabled, AFAICT. So we have
> > to execute vmxoff and ignore possible #UDs.
> >
> > If we trust the exception handlers, there's no problem. Otherwise we need to
> > replace the current #UD handler with an iret (perhaps switching temporarily to
> > another IDT).
>
> Ugh. We already change the IDT on that code path so that
> may be a way to go.
I don't see the IDT being changed on native_machine_shutdown(). It even
uses notifier chain registration (register_die_notifier()) to sneak a
NMI handler in.
--
Eduardo
next prev parent reply other threads:[~2008-10-27 15:50 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-20 15:01 [PATCH 0/2] kvm: disable virtualization on kdump Eduardo Habkost
2008-10-20 15:01 ` Eduardo Habkost
2008-10-20 15:01 ` [PATCH 1/2] kdump: crash-time CPU halt notifier interface Eduardo Habkost
2008-10-20 15:01 ` Eduardo Habkost
2008-10-20 15:01 ` [PATCH 2/2] kvm: disable virtualization when halting CPUs on crash Eduardo Habkost
2008-10-20 15:01 ` Eduardo Habkost
2008-10-22 23:28 ` [PATCH 0/2] kvm: disable virtualization on kdump Simon Horman
2008-10-22 23:28 ` Simon Horman
2008-10-23 19:41 ` Eduardo Habkost
2008-10-23 19:41 ` Eduardo Habkost
2008-10-23 22:29 ` Simon Horman
2008-10-23 22:29 ` Simon Horman
2008-10-24 1:00 ` Eric W. Biederman
2008-10-24 1:00 ` Eric W. Biederman
2008-10-26 12:49 ` Avi Kivity
2008-10-26 12:49 ` Avi Kivity
2008-10-26 14:46 ` Eric W. Biederman
2008-10-26 14:46 ` Eric W. Biederman
2008-10-26 15:07 ` Avi Kivity
2008-10-26 15:07 ` Avi Kivity
2008-10-26 21:39 ` Eduardo Habkost
2008-10-26 21:39 ` Eduardo Habkost
2008-10-27 2:08 ` Eric W. Biederman
2008-10-27 2:08 ` Eric W. Biederman
2008-10-27 9:13 ` Avi Kivity
2008-10-27 9:13 ` Avi Kivity
2008-10-27 12:28 ` Eduardo Habkost
2008-10-27 12:28 ` Eduardo Habkost
2008-10-27 14:02 ` Avi Kivity
2008-10-27 14:02 ` Avi Kivity
2008-10-27 17:32 ` Eric W. Biederman
2008-10-27 17:32 ` Eric W. Biederman
2008-10-28 19:45 ` Eduardo Habkost
2008-10-28 19:45 ` Eduardo Habkost
2008-10-28 20:13 ` Eric W. Biederman
2008-10-28 20:13 ` Eric W. Biederman
2008-10-29 9:41 ` Avi Kivity
2008-10-29 9:41 ` Avi Kivity
2008-10-29 14:54 ` Eric W. Biederman
2008-10-29 14:54 ` Eric W. Biederman
2008-10-29 17:03 ` Avi Kivity
2008-10-29 17:03 ` Avi Kivity
2008-10-30 1:33 ` Eric W. Biederman
2008-10-30 1:33 ` Eric W. Biederman
2008-10-30 7:35 ` Chris Lalancette
2008-10-30 7:35 ` Chris Lalancette
2008-10-30 7:43 ` Avi Kivity
2008-10-30 7:43 ` Avi Kivity
2008-10-30 7:52 ` Avi Kivity
2008-10-30 7:52 ` Avi Kivity
2008-10-29 9:31 ` Avi Kivity
2008-10-29 9:31 ` Avi Kivity
2008-10-27 15:05 ` Eric W. Biederman
2008-10-27 15:05 ` Eric W. Biederman
2008-10-27 15:50 ` Eduardo Habkost [this message]
2008-10-27 15:50 ` Eduardo Habkost
2008-10-27 8:54 ` Avi Kivity
2008-10-27 8:54 ` Avi Kivity
2008-10-27 13:09 ` Vivek Goyal
2008-10-27 13:09 ` Vivek Goyal
2008-10-27 14:04 ` Avi Kivity
2008-10-27 14:04 ` Avi Kivity
2008-10-29 20:10 ` Eduardo Habkost
2008-10-29 20:10 ` Eduardo Habkost
2008-10-29 20:29 ` Avi Kivity
2008-10-29 20:29 ` Avi Kivity
2008-10-29 21:05 ` Vivek Goyal
2008-10-29 21:05 ` Vivek Goyal
2008-10-30 0:58 ` Eric W. Biederman
2008-10-30 0:58 ` Eric W. Biederman
2008-10-26 21:47 ` Eric W. Biederman
2008-10-26 21:47 ` Eric W. Biederman
2008-10-27 8:59 ` Avi Kivity
2008-10-27 8:59 ` Avi Kivity
2008-10-27 15:02 ` Eric W. Biederman
2008-10-27 15:02 ` Eric W. Biederman
2008-10-27 15:38 ` Eduardo Habkost
2008-10-27 15:38 ` Eduardo Habkost
2008-10-26 12:46 ` Avi Kivity
2008-10-26 12:46 ` Avi Kivity
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