From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=34704 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OlkGI-0002hQ-8c for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:09:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OlkGD-0000x7-HE for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:09:06 -0400 Received: from mail.codesourcery.com ([38.113.113.100]:52823) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OlkGD-0000wZ-9A for qemu-devel@nongnu.org; Wed, 18 Aug 2010 11:09:01 -0400 From: Paul Brook Subject: Re: [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image Date: Wed, 18 Aug 2010 16:08:55 +0100 References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201008181608.55759.paul@codesourcery.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Hai Shan Bai > 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. Paul