On Wed, 27 Sep 2017 18:25:00 +0800 Yi Min Zhao <zyi...@linux.vnet.ibm.com> wrote:
> 在 2017/9/27 下午5:47, Cornelia Huck 写道: > > On Tue, 26 Sep 2017 20:40:25 +0200 > > David Hildenbrand <da...@redhat.com> wrote: > >> I'd really really really (did I mention really?) favor something like a > >> dummy device, because we could easily handle the !CONFIG_PCI case then. > >> > >> All these compat options and conditions will kill us someday... we're > >> already patching around that whole stuff way too much. > >> > >> If we ever unconditionally created a device, we should keep doing so. > > Yes, that whole thing is horrible, especially interaction with compat > > machines. > > > > Do you have an idea on how to create such a dummy device (without > > having to effectively copy a lot of configured-out code)? > > > > > How about in s390_pcihost_hot_plug() we check s390_has_feat(zpci)? > If no zpci feature, we avoid plugging any pci device. > Then we could always create phb. > I think pcibus's vmstate is only data to migrate. That's still problematic if CONFIG_PCI is off. I currently don't have a better idea than either disallowing compat machines on builds without pci, or using a dummy device...
