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From: "H. Peter Anvin" <hpa@zytor.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Daniel Kiper <daniel.kiper@oracle.com>,
	"jbeulich@suse.com" <jbeulich@suse.com>,
	"konrad.wilk@oracle.com" <konrad.wilk@oracle.com>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"x86@kernel.org" <x86@kernel.org>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: [PATCH v2 01/11] kexec: introduce kexec_ops struct
Date: Thu, 22 Nov 2012 17:34:56 -0800	[thread overview]
Message-ID: <a1f75604-1f52-4af1-9dd7-b469ed4ea7b6@email.android.com> (raw)
In-Reply-To: <50AEBF86.50501@citrix.com>

Ok... that *sort of* makes sense, but also underscores how utterly different this is from a normal kexec.

Andrew Cooper <andrew.cooper3@citrix.com> wrote:

>On 22/11/2012 17:47, H. Peter Anvin wrote:
>> The other thing that should be considered here is how utterly 
>> preposterous the notion of doing in-guest crash dumping is in a
>system 
>> that contains a hypervisor.  The reason for kdump is that on bare
>metal 
>> there are no other options, but in a hypervisor system the right
>thing 
>> should be for the hypervisor to do the dump (possibly spawning a
>clean 
>> I/O domain if the I/O domain is necessary to access the media.)
>>
>> There is absolutely no reason to have a crashkernel sitting around in
>
>> each guest, consuming memory, and possibly get corrupt.
>>
>> 	-hpa
>>
>
>(Your reply to my email which I can see on the xen devel archive
>appears
>to have gotten lost somewhere inside the citrix email system, so
>apologies for replying out of order)
>
>The kdump kernel loaded by dom0 is for when Xen crashes, not for when
>dom0 crashes (although a dom0 crash does admittedly lead to a Xen
>crash)
>
>There is no possible way it could be a separate domain; Xen completely
>ceases to function as soon as jumps to the entry point of the kdump
>image.
>
>~Andrew

-- 
Sent from my mobile phone. Please excuse brevity and lack of formatting.

  reply	other threads:[~2012-11-23  1:35 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-20 15:04 [PATCH v2 00/11] xen: Initial kexec/kdump implementation Daniel Kiper
2012-11-20 15:04 ` [PATCH v2 01/11] kexec: introduce kexec_ops struct Daniel Kiper
2012-11-20 15:04   ` [PATCH v2 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE Daniel Kiper
2012-11-20 15:04     ` [PATCH v2 03/11] xen: Introduce architecture independent data for kexec/kdump Daniel Kiper
2012-11-20 15:04       ` [PATCH v2 04/11] x86/xen: Introduce architecture dependent " Daniel Kiper
2012-11-20 15:04         ` [PATCH v2 05/11] x86/xen: Register resources required by kexec-tools Daniel Kiper
2012-11-20 15:04           ` [PATCH v2 06/11] x86/xen: Add i386 kexec/kdump implementation Daniel Kiper
2012-11-20 15:04             ` [PATCH v2 07/11] x86/xen: Add x86_64 " Daniel Kiper
2012-11-20 15:04               ` [PATCH v2 08/11] x86/xen: Add kexec/kdump makefile rules Daniel Kiper
2012-11-20 15:04                 ` [PATCH v2 09/11] x86/xen/enlighten: Add init and crash kexec/kdump hooks Daniel Kiper
2012-11-20 15:04                   ` [PATCH v2 10/11] drivers/xen: Export vmcoreinfo through sysfs Daniel Kiper
2012-11-20 15:04                     ` [PATCH v2 11/11] x86: Add Xen kexec control code size check to linker script Daniel Kiper
2012-11-20 15:52     ` [PATCH v2 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE Jan Beulich
2012-11-20 16:40   ` [PATCH v2 01/11] kexec: introduce kexec_ops struct Eric W. Biederman
2012-11-21 10:52     ` Daniel Kiper
2012-11-22 12:15       ` Eric W. Biederman
2012-11-22 17:37         ` H. Peter Anvin
2012-11-23  9:56           ` Jan Beulich
2012-11-23 10:53             ` [Xen-devel] " Ian Campbell
2012-11-22 17:47         ` H. Peter Anvin
2012-11-22 18:07           ` Andrew Cooper
2012-11-22 22:26             ` H. Peter Anvin
2014-03-31 10:50               ` Petr Tesarik
2012-11-23  0:12           ` Andrew Cooper
2012-11-23  1:34             ` H. Peter Anvin [this message]
2012-11-23  1:38             ` H. Peter Anvin
2012-11-23  1:56               ` Andrew Cooper
2012-11-23  9:53                 ` Jan Beulich
2012-11-23 10:37                   ` Daniel Kiper
2012-11-23 10:51                     ` [Xen-devel] " Ian Campbell
2012-11-23 11:13                       ` Daniel Kiper
2012-11-23 10:51                     ` Jan Beulich
2012-11-23 11:08                       ` Daniel Kiper
2012-11-23  9:47         ` Daniel Kiper
2012-11-23 20:24           ` Eric W. Biederman

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