From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm@xmission.com (Eric W. Biederman)
Subject: Re: [PATCH 08/16] x86: Emergency virtualization disable function
Date: Thu, 06 Nov 2008 02:22:39 -0800
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Cc: Eduardo Habkost <ehabkost@redhat.com>, Ingo Molnar <mingo@elte.hu>,
	Simon Horman <horms@verge.net.au>,
	Andrew Morton <akpm@osdl.org>, Vivek Goyal <vgoyal@redhat.com>,
	Haren Myneni <hbabu@us.ibm.com>,
	Andrey Borzenkov <arvidjaar@mail.ru>, mingo@redhat.com,
	"Rafael J. Wysocki" <rjw@sisk.pl>, kexec@lists.infradead.org,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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In-Reply-To: <4912BD67.8000704@redhat.com> (Avi Kivity's message of "Thu, 06
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Avi Kivity <avi@redhat.com> writes:

> Eduardo Habkost wrote:
>> We could move the set_virt_disable_func() calls to vmx.c and svm.c (on
>> hardware_setup/hardware_unsetup). One could argue that it is sort of a
>> coincidence that we need the code for both vmx and svm.
>>
>
> I don't share this fear of function calls, but perhaps that's due to lack of
> experience with kdump.

Mostly I'm just afraid of extra complexity.

> If you want to be extra simple and safe, remove kvm from the equation.  Make the
> disabling code part of kdump/emergency_restart and only rely on the convention
> that cr3.vmxe == vmxon.
Convention?

> That has the advantage of working with other virtualization systems as well.

Sounds good.

Eric