On 07/19/2017 03:31 PM, Thomas Huth wrote: > On 19.07.2017 15:03, Cornelia Huck wrote: >> On Tue, 18 Jul 2017 16:24:46 +0200 >> Cornelia Huck <coh...@redhat.com> wrote: >> >>> Next try of the zPCI detangling, taking cpu models into account. >>> >>> The goal of this is twofold: >>> - Being able to disable PCI support in a build completely, as for v1. >>> - Properly fencing off PCI if the relevant facility bit is not provided. >>> >>> The second one leads to an interesting usability problem: -device help >>> still shows the various pci devices, but you cannot add them if the >>> cpu model does not include zpci, due to the phb not being instantiated. >>> The user is presented with >>> >>> qemu-system-s390x: -device virtio-rng-pci: No 'PCI' bus found for device >>> 'virtio-rng-pci' >>> >>> ...which is not very helpful, as it does not point to the root cause (no >>> zpci in the cpu model, and therefore no pci at all). Not sure how one can >>> communicate this root cause, ideas welcome. >> >> An idea on how to improve this would still be welcome :) > > IMHO it's ok to keep that error message ... but we should add a section > to http://wiki.qemu.org/Documentation/Platforms/S390X about PCI devices, > including a sample error message as above and a note what has to be done > to get a machine with PCI support, so that people can find that page via > Google in case they run into this problem.
I agree, the message is actually not that bad for an error message. With an wiki entry we should be fine.
