Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751355AbWEZJ3R (ORCPT ); Fri, 26 May 2006 05:29:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751356AbWEZJ3R (ORCPT ); Fri, 26 May 2006 05:29:17 -0400 Received: from wr-out-0506.google.com ([64.233.184.227]:43317 "EHLO wr-out-0506.google.com") by vger.kernel.org with ESMTP id S1751355AbWEZJ3Q convert rfc822-to-8bit (ORCPT ); Fri, 26 May 2006 05:29:16 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Z4JQ/Ms2COz7FF24/IrgOaoFGaZiWGZGTJ5YLJqxNATEmz2N8VDXPZ2PB26q7Qhmzr5IPy4Ss5LNwbbhAoOw3fdm6PQSmDYTeVPjvdWbya0SJCYGtsRETCULJAgojgsJzCLj4oTGNTP/9WUk3hSN+AASlAoIKTwhXGBEId5bCV0= Message-ID: Date: Fri, 26 May 2006 18:29:15 +0900 From: "Magnus Damm" To: "Eric W. Biederman" Subject: Re: [Fastboot] [PATCH 03/03] kexec: Avoid overwriting the current pgd (V2, x86_64) Cc: "Gerd Hoffmann" , "Magnus Damm" , "Andrew Morton" , fastboot@lists.osdl.org, linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20060524044232.14219.68240.sendpatchset@cherry.local> <20060524044247.14219.13579.sendpatchset@cherry.local> <1148545616.5793.180.camel@localhost> <4476B0F6.2000708@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 36 On 5/26/06, Eric W. Biederman wrote: > "Magnus Damm" writes: > > > On 5/26/06, Gerd Hoffmann wrote: > >> > 1a. The C-code in xen_machine_kexec() performs a hypercall. > >> > > >> > 1b. The hypervisor jumps to the assembly code. > >> > After prepare we've created a NX-safe mapping for the control page. We > >> > jump to that NX-safe address to transfer control to the assembly code. > >> > >> This is about kexec'ing the physical machine, not the virtual machine, > >> right? > > > > Correct, kexec:ing from dom0. > > And staying in dom0? Or does Xen go away? You replace what's running on the physical machine. You can chose to kexec into a new "regular" Linux kernel (Xen goes away), or kexec into a new Xen hypervisor with a new dom0 kernel (Xen is replaced). Kexec behaves exactly the same as Linux today - no patches are needed to kexec-tools. Kdump is a little different though, we reserve the physical ram range in the hypervisor and our hypervisor code is currently using a differen format for the command line options. With Kdump under Xen it is possible to take a memory snapshot of the entire machine - both the hypervisor and dom0. / magnus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/