From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:46907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjQcJ-0003EL-6f for qemu-devel@nongnu.org; Wed, 20 Jul 2011 02:50:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QjQcI-0006zC-2M for qemu-devel@nongnu.org; Wed, 20 Jul 2011 02:50:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:34969 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjQcH-0006z2-R3 for qemu-devel@nongnu.org; Wed, 20 Jul 2011 02:50:45 -0400 Message-ID: <4E267AC0.7060307@suse.de> Date: Wed, 20 Jul 2011 08:50:40 +0200 From: Hannes Reinecke MIME-Version: 1.0 References: <1311074364-3489-1-git-send-email-hare@suse.de> <20110719160843.GA3414@lst.de> In-Reply-To: <20110719160843.GA3414@lst.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH][v7] megasas: LSI Megaraid SAS emulation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoph Hellwig Cc: Paolo Bonzini , Alexander Graf , qemu-devel@nongnu.org, kvm@vger.kernel.org, Stefan Haynoczi On 07/19/2011 06:08 PM, Christoph Hellwig wrote: > I've mentioned this a few times before, but just to make sure it's not > lost: > > This is a really bad idea for adding to qemu. It's not a controller th= at > actually speaks a plain SCSI protocol to disks, but a RAID controller, = that > has it's own command set for data plan operation, and minimal support f= or > a few SCSI CDBs around it. I also supports passthrough channels for > CDROMs and other periphals, but using those with disks is not recommend= ed > by LSI, thus explicitly disabled in most drivers and most certainly not > tested. So it fits the qemu model, especially if using scsi-generic > undeneath pretty badly and I don't think it helps us in practice. > Hmm. This driver emulates an existing piece of hardware. If the OS driver has shortcomings, okay, so be it. But are there any rules which devices might be emulated and which=20 shouldn't? Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)