From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: vhost-scsi support for ANY_LAYOUT Date: Tue, 27 Jan 2015 09:56:01 +0100 Message-ID: <54C752A1.4040406@redhat.com> References: <1422340517.9532.26.camel@haakon3.risingtidesystems.com> <54C74F6E.6000805@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: kvm-devel , target-devel To: "Nicholas A. Bellinger" , "Michael S. Tsirkin" Return-path: In-Reply-To: <54C74F6E.6000805@redhat.com> Sender: target-devel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 27/01/2015 09:42, Paolo Bonzini wrote: > > *) When ANY_LAYOUT is negotiated by vhost-scsi, it's expected that > > virtio-scsi request + response headers may be (but not always..?) > > combined with data-out + data-in payloads into a single iovec. Note that request and data-out can be combined, and response + data-in can be combined, but there still have to be separate iovecs for at least outgoing and incoming buffers (so 2 buffers for the control and request queues; 1 buffer for the event queue since it's unidirectional. Paolo