From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NCu3c-0006I0-O6 for qemu-devel@nongnu.org; Tue, 24 Nov 2009 06:59:44 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NCu3Z-0006G3-0C for qemu-devel@nongnu.org; Tue, 24 Nov 2009 06:59:44 -0500 Received: from [199.232.76.173] (port=45708 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NCu3Y-0006Fy-NO for qemu-devel@nongnu.org; Tue, 24 Nov 2009 06:59:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:23138) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NCu3X-0004hi-SU for qemu-devel@nongnu.org; Tue, 24 Nov 2009 06:59:40 -0500 Message-ID: <4B0BCAA1.3090400@redhat.com> Date: Tue, 24 Nov 2009 12:59:29 +0100 From: Gerd Hoffmann MIME-Version: 1.0 Subject: Re: [Qemu-devel] [sneak preview] major scsi overhaul References: <4AF4ACA5.2090701@redhat.com> <200911111638.31288.paul@codesourcery.com> <4B017F46.4030700@redhat.com> <200911161853.34668.paul@codesourcery.com> In-Reply-To: <200911161853.34668.paul@codesourcery.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: qemu-devel@nongnu.org On 11/16/09 19:53, Paul Brook wrote: > Capping the amount of memory required for a transfer *is* implemented, in both > LSI and virtio-blk. The exception being SCSI passthrough where the kernel API > makes it impossible. Well. Figured while doing more testing: The allowed request size is limited by the kernel, so scsi-generic requests larger than (currently) 128k fail. Now, how to handle *that*? Is there some way to signal to the guest that the request was to big? At least for known commands such as READ+WRITE which are likely to be big we could split the request internally into two (or more) if needed. cheers, Gerd