Re: [Qemu-devel] xen-pci-passthrough PCI Express support? (Re: [Xen-devel] [PATCH v2 4/5] pci: Add INTERFACE_CONVENTIONAL_PCI_DEVICE to Conventional PCI devices)

[Eduardo Habkost <ehabkost@redhat.com>]

On Wed, Oct 04, 2017 at 03:08:15AM -0600, Jan Beulich wrote:
> >>> On 03.10.17 at 02:12, <ehabkost@redhat.com> wrote:
> > On Thu, Sep 28, 2017 at 10:12:34AM -0300, Eduardo Habkost wrote:
> >> On Thu, Sep 28, 2017 at 02:33:57AM -0600, Jan Beulich wrote:
> >> > >>> On 27.09.17 at 21:56, <ehabkost@redhat.com> wrote:
> >> > > --- a/hw/xen/xen_pt.c
> >> > > +++ b/hw/xen/xen_pt.c
> >> > > @@ -964,6 +964,10 @@ static const TypeInfo xen_pci_passthrough_info = {
> >> > >      .instance_size = sizeof(XenPCIPassthroughState),
> >> > >      .instance_finalize = xen_pci_passthrough_finalize,
> >> > >      .class_init = xen_pci_passthrough_class_init,
> >> > > +    .interfaces = (InterfaceInfo[]) {
> >> > > +        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
> >> > > +        { },
> >> > > +    },
> >> > >  };
> >> > 
> >> > Passed through devices can be both PCI and PCIe, so following
> >> > the description of the patch I don't think these can be statically
> >> > given either property. Granted quite a bit of PCIe specific
> >> > functionality may be missing in the Xen code ...
> >> 
> >> This is just static data about what the device type supports, not
> >> about what a given device instance really is.  Deciding if the
> >> device is PCIe or Conventional at runtime is out of the scope of
> >> this series.
> >> 
> >> That said, if passed through PCI Express devices are really
> >> supported, it looks like this should be marked as hybrid.
> > 
> > Can anybody confirm if PCI Express devices are really supported
> > by xen-pci-passthrough?
> 
> I think I've clearly said they're supported, with some limitations.

Sorry, thanks.  I thought the possible missing PCIe functionality
could mean the device couldn't appear as PCI Express to the
guest.

I will submit a follow-up patch adding INTERFACE_PCIE_DEVICE to
xen-pci-passthrough.

-- 
Eduardo