On Mon, 4 Dec 2017 18:56:00 +0100 David Hildenbrand <da...@redhat.com> wrote:
> On 04.12.2017 18:53, Cornelia Huck wrote: > > On Mon, 4 Dec 2017 18:34:36 +0100 > > David Hildenbrand <da...@redhat.com> wrote: > > > >> On 04.12.2017 18:22, Cornelia Huck wrote: > >>> On Mon, 4 Dec 2017 13:55:05 +0100 > >>> David Hildenbrand <da...@redhat.com> wrote: > >>> > >>>> We somehow missed that, new kernels require it. > >>> > >>> Why _new_ kernels? I think we have unconditionally issued stcrw since > >>> back in 2.2? > >> > >> Okay, the problem is then rather related to my setup. No ccw devices -> > >> no stcrw. > >> > >> How could we ever add ccw devices to a TCG guest then? > > > > Hotplug never worked before your patches. Coldplug does not create > > machine checks and thus does not trigger the guest to do STCRW. (Only > > STSCH, in keeping with "all channel I/O acronyms look the same".) > > > > But booting Fedora 26/27 without any involved hotplugs (therefore > machine checks) triggers a STCRW. > > That's how I originally found it. (I started playing with machine checks > after I had fedora 26/27 running) > Confused. Do you have a backtrace? (Guest/host)
