From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Kiper Subject: Re: kexec and kdump on Xen?? Date: Wed, 16 Apr 2014 13:10:05 +0200 Message-ID: <20140416111005.GA6251@router-fw-old.local.net-space.pl> References: <20140414081126.GA1632@router-fw-old.local.net-space.pl> <20140414132632.GA6173@router-fw-old.local.net-space.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "Zhang, Yang Z" Cc: "xen-devel@lists.xen.org" , Daniel Kiper List-Id: xen-devel@lists.xenproject.org On Tue, Apr 15, 2014 at 02:13:56AM +0000, Zhang, Yang Z wrote: > Daniel Kiper wrote on 2014-04-14: > > Hey, > > > > On Mon, Apr 14, 2014 at 08:15:35AM +0000, Zhang, Yang Z wrote: > >> Daniel Kiper wrote on 2014-04-14: > >>> Hi, > >>> > >>> On Mon, Apr 14, 2014 at 03:38:26AM +0000, Zhang, Yang Z wrote: > >>>> Hi Daniel > >>>> > >>>> Are kexec/kdump supported by latest Xen + upstream Linux? > >>>> I remember it only works with xen+2.6.18 linux. I know you are > >>>> working on enable it. So I wonder to know what the current status is. > > Thanks. > >>> > >>> Xen 4.4 has new kexec implementation written by David Vrabel. > >>> It does not require any specific Linux Kernel version because this > >>> implementation is self contained. However, please do not forget to > >>> use > >> > >> Cool.. > >> > >>> latest stable version of kexec-tools too. > >> > >> Is there any BKM to use it? I saw an old wiki page but not sure > >> whether it is still suitable. > > > > I assume that you are asking about kexec/kdump support in dom0. > > > > Just build kexec-tools with Xen support enabled (you must provide > > relevant Xen header files and libraries). > > Then add crashkernel argument to Xen (e.g. crashkernel=512m@64m) and > > reboot machine. Use kexec-tools like on bare metal machines. > > I am trying to kexec from Xen to Linux. But it fails to work. > ./kexec -l /boot/vmlinuz-2.6.32-358.el6.x86_64 What about --append or --command-line? > kexec_load failed: Invalid argument > entry = 0x7fff6760 flags = 0x3e0000 > nr_segments = 3 > segment[0].buf = 0x138f660 > segment[0].bufsz = 0x3641 > segment[0].mem = 0x3000 > segment[0].memsz = 0x4000 > segment[1].buf = 0x7fc68badf610 > segment[1].bufsz = 0x3d8110 > segment[1].mem = 0x1000000 > segment[1].memsz = 0x3d9000 > segment[2].buf = 0x1387540 > segment[2].bufsz = 0x80e0 > segment[2].mem = 0x7fff6000 > segment[2].memsz = 0xa000 Could you configure kexec-tools in following way: ./configure CFLAGS=-DDEBUG Then build it as usual. > Here is my environment: > Xen version: latest Xen > Xen boot command: > kernel (hd0,0)/boot/xen.gz dom0_mem=4096M loglvl=all guest_loglvl=all conring_size=4M crashkernel=128M@64M > module (hd0,0)/boot/vmlinuz-xen o root=UUID=03a5e7c4-b8d0-45b4-a090-c34b06821cea pci=noaer max_loop=64 3 debug > module (hd0,0)/boot/initrd-xen.img > kexec version with Xen enabled: kexec-tools 2.0.6 released 18 April 2014 > > Also, it shows error when trying to kexec (Xen -> Xen) > ./kexec -l /boot/xen.gz > Segmentation fault (core dumped) We were focusing more on kdump than on other scenarios. I suppose that kexec-tools assume that this compressed ELF file is Linux Kernel and tries load it as usual which of course is completely wrong. You should load Xen with at least "-t multiboot-x86" argument (read help printed by kexec). However, I am not sure that this loader is actively maintained and works. Daniel