From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpuQ9-0000f6-6G for qemu-devel@nongnu.org; Thu, 07 Sep 2017 06:52:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpuQ5-0008A9-Ay for qemu-devel@nongnu.org; Thu, 07 Sep 2017 06:52:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51276) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dpuQ5-00089v-5U for qemu-devel@nongnu.org; Thu, 07 Sep 2017 06:52:25 -0400 Date: Thu, 7 Sep 2017 12:52:20 +0200 From: Cornelia Huck Message-ID: <20170907125220.0d78d285.cohuck@redhat.com> In-Reply-To: References: <20170905111645.18068-1-pasic@linux.vnet.ibm.com> <20170905111645.18068-6-pasic@linux.vnet.ibm.com> <20170906151821.1a77afe5.cohuck@redhat.com> <20170907073108.GD31680@bjsdjshi@linux.vnet.ibm.com> <20170907100817.08ddae29.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 5/5] s390x/ccs: add ccw-tester emulated device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Halil Pasic Cc: Dong Jia Shi , Pierre Morel , qemu-devel@nongnu.org On Thu, 7 Sep 2017 12:21:50 +0200 Halil Pasic wrote: > On 09/07/2017 10:08 AM, Cornelia Huck wrote: > > On Thu, 7 Sep 2017 15:31:09 +0800 > > Dong Jia Shi wrote: > >> I'm thinking of a method these days: > >> Could passing through an fully emulated ccw device (e.g. 3270), or a > >> virtio ccw device, in the level 1 kvm guest to a level 2 guest be a test > >> method for this? > >> > >> All of the CCWs will be translated to IDAL CCWs by vfio-ccw in the level > >> 1 guest (which is the level 2 kvm host) and issued to the level 1 kvm > >> host. So, those IDALs will eventually be handled by the emulated device, > >> or the virtio ccw device, on the level 1 kvm host... > >> > >> Some days ago, one of my colleague tried the emulated 3270 passing > >> through. She stucked with the problem that the level 1 kvm host handling > >> a senseid IDAL ccw as a Direct ccw. > >> > >> Maybe I could try to pass through a virtio ccw device. I don't think of > >> any obvious problem that would lead to fail. Any comment? > >> > > > > That actually looks like a good thing to try! Cool idea. > > > > I'm afraid that it would not work without some extra work. > AFAIR Connie we said that the 3270 does not use any IDA, so > I did not touch the 3270 emulation code in QEMU. To make > the scenario viable one should convert the 3270 emulation > to ccw data stream (unless the original implementation > already took care of IDA, which I doubt). But the vfio-ccw code uses idals... no need to touch the 3270 emulation.