On Mon, 15 Jul 2019 13:04:28 +0200 Philippe Mathieu-Daudé <phi...@redhat.com> wrote:
> On 7/15/19 12:56 PM, Cornelia Huck wrote: > > On Mon, 15 Jul 2019 12:48:55 +0200 > > Thomas Huth <th...@redhat.com> wrote: > > > >> On 15/07/2019 12.19, Peter Maydell wrote: > >>> On Mon, 15 Jul 2019 at 11:15, Thomas Huth <th...@redhat.com> wrote: > >>>> > >>>> On 15/07/2019 11.55, Philippe Mathieu-Daudé wrote: > >>>>> If a controller device provides a PCI bus, we can plug any PCI > >>>>> daughter card on it. > >>>>> > >>>>> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> > >>>>> --- > >>> > >>>>> diff --git a/hw/pci/Kconfig b/hw/pci/Kconfig > >>>>> index 77f8b005ff..0f7267db35 100644 > >>>>> --- a/hw/pci/Kconfig > >>>>> +++ b/hw/pci/Kconfig > >>>>> @@ -1,5 +1,6 @@ > >>>>> config PCI > >>>>> bool > >>>>> + imply PCI_DEVICES > >>>> > >>>> No, please don't change this. This was done on purpose, since almost all > >>>> PCI_DEVICES do not work on s390x (so s390x does *not* imply > >>>> PCI_DEVICES). > >>> > >>> But that means that every board that provides PCI has to have an > >>> "imply PCI_DEVICES" line, which is pretty clunky just to work > >>> around an s390x limitation. > >>> > >>> Is there some way in the Kconfig syntax for s390x to say > >>> "no PCI_DEVICES" so we can have the corner-case be handled > >>> by the s390x Kconfig in one place rather than in 20 places > >>> affecting everywhere except s390x? > >> > >> IIRC the problem on s390x are the legacy IRQs. s390x has only MSIs. So I > >> guess the correct way to fix this would be to introduce some > >> PCI_LEGACY_IRQ switch and let all old devices that do not work with MSI > >> depend on it. > > > > s/MSI/MSI-X/, IIRC. Not sure how far 'legacy' would stretch. > > Maybe we can have something like PCI_LEGACY_DEVICES and PCI_MSI_DEVICES? > > So if s390x only selects PCI_LEGACY (not PCI_MSI) bus, then it only get > legacy devices? Wrong way around? We need MSI-X for s390x, not plain MSI or 'legacy' (whatever that is). > > Other MSI compliant should select PCI_MSI instead. PCI alone seems to > give troubles. > > > cc:ing Collin in case there's something else. > >
