From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp02.citrix.com ([66.165.176.63]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TbbBl-0004lS-OM for kexec@lists.infradead.org; Thu, 22 Nov 2012 18:07:50 +0000 Message-ID: <50AE69EF.4060909@citrix.com> Date: Thu, 22 Nov 2012 18:07:43 +0000 From: Andrew Cooper MIME-Version: 1.0 Subject: Re: [PATCH v2 01/11] kexec: introduce kexec_ops struct References: <1353423893-23125-1-git-send-email-daniel.kiper@oracle.com> <1353423893-23125-2-git-send-email-daniel.kiper@oracle.com> <87lidwtego.fsf@xmission.com> <20121121105221.GA2925@host-192-168-1-59.local.net-space.pl> <87txshx28b.fsf@xmission.com> <50AE6542.3020302@zytor.com> In-Reply-To: <50AE6542.3020302@zytor.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: "H. Peter Anvin" Cc: "xen-devel@lists.xensource.com" , "konrad.wilk@oracle.com" , Daniel Kiper , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "mingo@redhat.com" , "Eric W. Biederman" , "jbeulich@suse.com" , "tglx@linutronix.de" On 22/11/12 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 > I agree that regular guests should not be using the kexec/kdump. However, this patch series is required for allowing a pvops kernel to be a crash kernel for Xen, which is very important from dom0/Xen's point of view. -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932278Ab2KVSt3 (ORCPT ); Thu, 22 Nov 2012 13:49:29 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:63565 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932251Ab2KVStZ (ORCPT ); Thu, 22 Nov 2012 13:49:25 -0500 X-IronPort-AV: E=Sophos;i="4.83,302,1352073600"; d="scan'208";a="215291704" Message-ID: <50AE69EF.4060909@citrix.com> Date: Thu, 22 Nov 2012 18:07:43 +0000 From: Andrew Cooper User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121028 Thunderbird/16.0.2 MIME-Version: 1.0 To: "H. Peter Anvin" CC: "Eric W. Biederman" , Daniel Kiper , "jbeulich@suse.com" , "konrad.wilk@oracle.com" , "mingo@redhat.com" , "tglx@linutronix.de" , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "xen-devel@lists.xensource.com" Subject: Re: [PATCH v2 01/11] kexec: introduce kexec_ops struct References: <1353423893-23125-1-git-send-email-daniel.kiper@oracle.com> <1353423893-23125-2-git-send-email-daniel.kiper@oracle.com> <87lidwtego.fsf@xmission.com> <20121121105221.GA2925@host-192-168-1-59.local.net-space.pl> <87txshx28b.fsf@xmission.com> <50AE6542.3020302@zytor.com> In-Reply-To: <50AE6542.3020302@zytor.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/11/12 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 > I agree that regular guests should not be using the kexec/kdump. However, this patch series is required for allowing a pvops kernel to be a crash kernel for Xen, which is very important from dom0/Xen's point of view. -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2 01/11] kexec: introduce kexec_ops struct Date: Thu, 22 Nov 2012 18:07:43 +0000 Message-ID: <50AE69EF.4060909@citrix.com> References: <1353423893-23125-1-git-send-email-daniel.kiper@oracle.com> <1353423893-23125-2-git-send-email-daniel.kiper@oracle.com> <87lidwtego.fsf@xmission.com> <20121121105221.GA2925@host-192-168-1-59.local.net-space.pl> <87txshx28b.fsf@xmission.com> <50AE6542.3020302@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50AE6542.3020302-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kexec-bounces-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: "H. Peter Anvin" Cc: "xen-devel-GuqFBffKawuULHF6PoxzQEEOCMrvLtNR@public.gmane.org" , "konrad.wilk-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org" , Daniel Kiper , "x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , "Eric W. Biederman" , "jbeulich-IBi9RG/b67k@public.gmane.org" , "tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org" List-Id: xen-devel@lists.xenproject.org On 22/11/12 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 > I agree that regular guests should not be using the kexec/kdump. However, this patch series is required for allowing a pvops kernel to be a crash kernel for Xen, which is very important from dom0/Xen's point of view. -- Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer T: +44 (0)1223 225 900, http://www.citrix.com