On Thu, 7 Sep 2017 12:21:50 +0200 Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
> On 09/07/2017 10:08 AM, Cornelia Huck wrote: > > On Thu, 7 Sep 2017 15:31:09 +0800 > > Dong Jia Shi <bjsdj...@linux.vnet.ibm.com> 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.
