Re: [PATCH v2] kconfig: Add PCIe devices to s390x machines

[Philippe Mathieu-Daudé]

On 4/7/23 14:32, Cédric Le Goater wrote:
> On 7/4/23 14:09, Philippe Mathieu-Daudé wrote:
> > On 4/7/23 14:01, Cédric Le Goater wrote:
> > > It is useful to extend the number of available PCI devices to KVM guests
> > > for passthrough scenarios and also to expose these models to a different
> > > (big endian) architecture. Include models for Intel Ethernet adapters
> > > and one USB controller, which all support MSI-X. Devices only supporting
> > > INTx won't work on s390x.
> > >
> > > Signed-off-by: Cédric Le Goater <clg@redhat.com>
> > > ---
> > >
> > >   Tested under KVM as a machine device, under KVM nested as a 
> > > passthrough
> > >   device
> > >
> > >   hw/s390x/Kconfig | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > >
> > > diff --git a/hw/s390x/Kconfig b/hw/s390x/Kconfig
> > > index 5e7d8a2bae8b..7a82c58cdf6e 100644
> > > --- a/hw/s390x/Kconfig
> > > +++ b/hw/s390x/Kconfig
> > > @@ -10,3 +10,7 @@ config S390_CCW_VIRTIO
> > >       select SCLPCONSOLE
> > >       select VIRTIO_CCW
> > >       select MSI_NONBROKEN
> > > +    imply PCI_EXPRESS
> >
> > No, PCIe is a bus, which is implemented in s390-pci-bus.c;
> > S390_CCW_VIRTIO exposes this bus, so we Kconfig SELECT it.
> >
> > > +    imply E1000E_PCI_EXPRESS
> > > +    imply IGB_PCI_EXPRESS
> > > +    imply USB_XHCI_PCI
> >
> > These are devices you can plug on a PCIe bus, so Kconfig
> > IMPLY is correct.
>
> If I understand correctly, this should be ?
>
> @@ -5,8 +5,11 @@ config S390_CCW_VIRTIO
>       imply VFIO_AP
>       imply VFIO_CCW
>       imply WDT_DIAG288
> -    select PCI
> +    select PCI_EXPRESS
>       select S390_FLIC
>       select SCLPCONSOLE
>       select VIRTIO_CCW
>       select MSI_NONBROKEN
> +    imply E1000E_PCI_EXPRESS
> +    imply IGB_PCI_EXPRESS
> +    imply USB_XHCI_PCI

This is how I'd write this patch. Note I have zero knowledge of zPCI.