From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35675) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SRpYM-0004nU-B6 for qemu-devel@nongnu.org; Tue, 08 May 2012 14:54:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SRpYK-0000Da-F2 for qemu-devel@nongnu.org; Tue, 08 May 2012 14:54:29 -0400 Received: from e06smtp14.uk.ibm.com ([195.75.94.110]:49792) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SRpYK-0000D6-6e for qemu-devel@nongnu.org; Tue, 08 May 2012 14:54:28 -0400 Received: from /spool/local by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 8 May 2012 19:54:24 +0100 Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by d06nrmr1507.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q48Is8hw2662594 for ; Tue, 8 May 2012 19:54:08 +0100 Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q48Is7tK003083 for ; Tue, 8 May 2012 12:54:07 -0600 Message-ID: <4FA96BCE.1040100@de.ibm.com> Date: Tue, 08 May 2012 20:54:06 +0200 From: Christian Borntraeger MIME-Version: 1.0 References: <1336139040-16628-1-git-send-email-borntraeger@de.ibm.com> <1336139040-16628-2-git-send-email-borntraeger@de.ibm.com> <16456C5E-6C77-4976-8F09-A122C0FE0943@suse.de> <4FA3E108.9040204@de.ibm.com> <4FA3E15D.20804@de.ibm.com> <72DBB625-871D-4B0F-8139-A8F941448905@suse.de> <4FA91267.5050306@de.ibm.com> <9A5D5218-5E01-4D3D-B06E-25F83522E703@suse.de> <4FA930FA.4000305@de.ibm.com> <26FC36DC-33B0-4C38-B67E-20812F527046@suse.de> In-Reply-To: <26FC36DC-33B0-4C38-B67E-20812F527046@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/1] s390: IPL device for s390 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Cornelia Huck , Anthony Liguori , Heinz Graalfs , Jens Freimann , qemu-devel Developers > Well, the only shortcomings I'm aware of of the external IPL are: > > * You lose the boot menu. All you get is "entry 0", "entry 1", etc. as the description is not part of the boot map > * You can't choose different entries during runtime. Doing a reboot of a VM and selecting a different entry won't work. > > The former is pretty annoying if you don't know all of your VMs by heart. The latter is an issue when you don't own the qemu process, > but do own the VM. Think of a hosted environment. Those are valid points. Regarding the former, I see two things that we might do here: 1. have the current zipl-"bios" as a fallback if the user does not specify an s390-ipl device. That should be pretty easy and might even have the advantage to minimize the surprise to existing users of kvm on s390(are there any?). If the user provides an s390-ipl device then this is a conscious decision. (I will move the specific virtio-zipl bios code into the s390-ipl device nevertheless,see below for rationale) 2. I will check with the zipl maintainer if we could sneak in the necessary information in the boot map, the program table or something else (e.g. defining an component_description, after component_execute). It just have to be compatible with the layout that the firmware loader expects. Not sure yet, if this will work out I definitely want to concentrate all booting in this device: kernel, zipl-virtio, firmware loader and everything else, because on system_reset we have to reset the cpus and set the PSW accordingly. As a device we are being called during reset at the right time. Does that make sense? If yes I will try to refresh that patch as outlined above Christian