From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38037) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dwnuL-0000DT-Vn for qemu-devel@nongnu.org; Tue, 26 Sep 2017 07:20:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dwnuG-0007b1-Ld for qemu-devel@nongnu.org; Tue, 26 Sep 2017 07:20:09 -0400 Received: from mx1.mailbox.org ([80.241.60.212]:42527) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dwnuG-0007Zq-BS for qemu-devel@nongnu.org; Tue, 26 Sep 2017 07:20:04 -0400 Date: Tue, 26 Sep 2017 13:19:57 +0200 From: Cornelia Huck Message-ID: <20170926131957.2110cc1b.cornelia.huck@mailbox.org> In-Reply-To: References: <20170921180841.24490-1-pasic@linux.vnet.ibm.com> <20170926121800.1e9e1ac1.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 0/5] add CCW indirect data access support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Halil Pasic Cc: qemu-devel@nongnu.org, Dong Jia Shi , Pierre Morel [Restored cc:s] On Tue, 26 Sep 2017 12:45:11 +0200 Halil Pasic wrote: > On 09/26/2017 12:18 PM, Cornelia Huck wrote: > > On Thu, 21 Sep 2017 20:08:36 +0200 > > Halil Pasic wrote: > > > >> Abstract > >> -------- > >> > >> The objective of this series is introducing CCW IDA (indirect data > >> access) support to our virtual channel subsystem implementation. Briefly > >> CCW IDA can be thought of as a kind of a scatter gather support for a > >> single CCW. If certain flags are set, the cda is to be interpreted as an > >> address to a list which in turn holds further addresses designating the > >> actual data. Thus the scheme which we are currently using for accessing > >> CCW payload does not work in general case. Currently there is no > >> immediate need for proper IDA handling (no use case), but since it IDA is > >> a non-optional part of the architecture, the only way towards AR > >> compliance is actually implementing IDA. > >> > >> The focus of this patch set is introducing IDA support. There seems to be > >> a potential for further improvements based on the introduced > >> infrastructure, but such improvements are intended to be discusses > >> separately and realized as patches on top of this series. > > > > Hm, do you have a list of what you want to do as follow-on patches? > > (Checking return codes, ...) > > > > It's easy to lose track of all this :) > > > > These are the stuff I had in mind: > * handling errors (aka. checking error codes) in virtio-ccw > * using residual count > * converting 3270 (patches already sent) The 3270 stuff is next in line for me. > > And then some related stuff is the error reporting and handling > rework for the IO instruction handlers and for the ccw interpretation > emulation (later affects CcwDataStream). > > There is probably a lot of potential for making things prettier > in virtio-ccw.c too -- I've done some experiments but ended up changing > too many things at the same time. There's always potential for such things :) Let's get the previously identified stuff out of the door first (it's not that I lack patches to apply anyway...) > > Btw, do we still have open issues with this series? Currently going through my acceptance testing.