On 5/31/19 10:52 AM, Christian Svensson wrote: > Hi, > > On Fri, May 31, 2019 at 10:08 AM Hannes Reinecke <hare@xxxxxxx> wrote: >> There are easier ways for this ... I'd start with virtio-ccw and >> implement a virtual PUNCHER there ... > > The larger project scope is making FICON accessories more available > for people as crazy as I, that is wanting to run a mainframe as a > hobbyist, but maybe not want to buy a metric ton worth of disks or > tape robots (a 700 kg mainframe is hard enough by itself to house). > > I will take a look, but from the name of it it sounds like it will not > help me much getting FICON targets supported. > Maybe it will help if I ever want FICON initiator. > Right. >> Still, an uphill struggle; IBM is notorious for not giving out details >> about the internals, and simulating a puncher is one of these things. >> (And slightly pointless, but who am I to judge ...) > > It's a low-speed peripheral that has been emulated successfully in > Hercules, and there are some petty detailed documents around the CCWs > for 3505 around. I figured it would > be a good start getting a FICON user-space thing implemented, before I > try to tackle e.g. ECKDs or tapes. > Oh. Sure. You might want to ask on the s390 mailing lists, too; they typically have a quite good idea on what's going on. The biggest problem, however, will be to get the documentation from the HBAs themselves. All FC HBAs will present you with some version of cooked frames, and not allow you to access the frames themselves. So in the end you'd have to see to get hold of the HBA documentation itself, as you need to figure out how to pass FICON frames into the HBA. It might be easier when you'd be working with FCoE cards, as there you _do_ have access to the full frame, and do whatever you like with thems. Sadly you'd need an FCoE bridge then to hook up the mainframe. But as you have gotten hold of an FC analyser, getting an FCoE bridge shouldn't be too hard, too :-) Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)
