From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=51741 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Olkbs-00077B-HQ for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:31:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Olkbr-0004ct-Co for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:31:24 -0400 Received: from mail-fx0-f45.google.com ([209.85.161.45]:44853) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Olkbr-0004cl-65 for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:31:23 -0400 Received: by fxm7 with SMTP id 7so379867fxm.4 for ; Wed, 18 Aug 2010 08:31:22 -0700 (PDT) Message-ID: <4C6BFCBF.2030301@gmail.com> Date: Wed, 18 Aug 2010 23:31:11 +0800 From: Haishan Bai MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image References: <201008181608.55759.paul@codesourcery.com> <632E0D52-7618-4184-990D-2918E51A61BC@suse.de> In-Reply-To: <632E0D52-7618-4184-990D-2918E51A61BC@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Paul Brook , qemu-devel@nongnu.org On 08/18/2010 11:16 PM, Alexander Graf wrote: > On 18.08.2010, at 17:08, Paul Brook wrote: > > >>> The qemu-kvm could boot from SCSI disk image by utilizing seabios, this >>> patch ported codes >>> from qemu-kvm to let upstream qemu to support booting from SCSI disk image. >>> >> No. This has nothing to do with SCSI. >> >> What it does is add a really cheap and nasty block storage device that aliases >> one of the other block devices in the system. This is bad. The OS has no way >> of knowing which devices are aliased, and we really don't want yet another >> braindead guest visible interface (c.f. recent performance issues where - >> kernel/fw_cfg were being abused) >> >> This has been discussed several times before. The proper solution is to teach >> the bios how to boot off SCSI devices. IIRC support for virtio devices already >> exists, implementing support for the SCSI controller shouldn't be that much >> harder. >> > Couldn't we just have an option rom for the SCSI controller? The same way the VGABIOS is a rewrite of a VGA BIOS for the Cirrus Logic... > > In my opinion add SCSI support to seabios would be a choice. > Alex > >