From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1VrRMZ-0007WD-OI for mharc-grub-devel@gnu.org; Fri, 13 Dec 2013 06:56:59 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54374) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VrRMT-0007W4-S7 for grub-devel@gnu.org; Fri, 13 Dec 2013 06:56:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VrRMP-0007cP-8s for grub-devel@gnu.org; Fri, 13 Dec 2013 06:56:53 -0500 Received: from v6.chiark.greenend.org.uk ([2001:ba8:1e3::]:39309 helo=chiark.greenend.org.uk) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VrRMP-0007c9-2i for grub-devel@gnu.org; Fri, 13 Dec 2013 06:56:49 -0500 Received: from [172.20.153.9] (helo=riva.pelham.vpn.ucam.org) by chiark.greenend.org.uk (Debian Exim 4.72 #1) with esmtps (return-path cjwatson@ubuntu.com) id 1VrRMN-0005Yd-Ue; Fri, 13 Dec 2013 11:56:48 +0000 Received: from ns1.pelham.vpn.ucam.org ([172.20.153.2] helo=riva.ucam.org) by riva.pelham.vpn.ucam.org with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1VrRML-0006AO-6O; Fri, 13 Dec 2013 11:56:45 +0000 Date: Fri, 13 Dec 2013 11:56:43 +0000 From: Colin Watson To: grub-devel@gnu.org, xen-devel@lists.xen.org Subject: Re: [PATCH 3/4] Build grub.xen. Message-ID: <20131213115643.GJ1431@riva.ucam.org> References: <20131212153643.GA1431@riva.ucam.org> <20131212153741.GD1431@riva.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131212153741.GD1431@riva.ucam.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2001:ba8:1e3:: X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Dec 2013 11:56:58 -0000 On Thu, Dec 12, 2013 at 03:37:41PM +0000, Colin Watson wrote: > +if [ -z "$grub_xen_guest" ]; then > + # This is the copy of grub.xen installed in the dom0's filesystem. > + # Look for a copy in the domU's filesystem and chainload that. This > + # allows us to guarantee that GRUB will be in sync with the > + # configuration file in the domU. The file locations here must not > + # have any configure-generated substitutions applied, as the intent > + # is that a single grub.xen should be able to cope with a variety of > + # domU systems. > + if search --set=root --file /boot/grub/grub.xen; then > + linux /boot/grub/grub.xen grub_xen_guest=1 > + boot [...] I talked about this with Ian Jackson in the pub last night. We came to the same conclusion more or less at the same time, that this is in fact a new boot protocol; since it essentially just expects a bzImage here, there's nothing to stop somebody for example putting a bare kernel there. We'd like people to be able to set up PV-GRUB2 in their dom0s even for domUs that aren't new enough to have PV-GRUB2 inside them. Furthermore we'd like to be able to arrange that PV-GRUB (Legacy) and PyGRUB can at least in principle use the same boot protocol; in the case of PV-GRUB that would presumably involve a stub menu.lst, but it shouldn't take much more than that. As such the file name in the domU's filesystem shouldn't be GRUB-specific, although per Vladimir it'd be good for it to be distinct for each architecture. I'll put this patch series on hold for the time being (with the possible exception of "search --exclude", which I think has been uncontroversial so far and could perhaps be merged as a generally-useful gadget?) and write this up as a proper protocol document for inclusion in xen.git. Ian said he'd like to get this into Xen 4.4's documentation. No changes to Xen code are required as far as I know. -- Colin Watson [cjwatson@ubuntu.com]