Re: [Qemu-devel] [PATCH v2 1/2] ppc/pnv: Add model for Power8 PHB3 PCIe Host bridge

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2018-07-27 at 15:32 +1000, David Gibson wrote:
> 
> > > What is this pci bridge representing?  I know PCI-e PHBs typically
> > > have a pseudo P2P bridge right under them, but isn't that represnted
> > > by the root complex above?
> > 
> > This is the legacy pci bridge under the pcie bus.
> 
> Ah, ok.  Didn't realise there was a vanilla PCI bridge built in.

There isn't. That should probably be created by the machine.

> > Here is is the qdev hierarchy :
> > 
> >   dev: pnv-phb3, id ""
> >     index = 0 (0x0)
> >     chip-id = 0 (0x0)
> >     bus: phb3-root-bus
> >       type pnv-phb3-root-bus
> >       dev: pnv-phb3-rc, id ""
> >         power_controller_present = true
> >         chassis = 0 (0x0)
> >         slot = 1 (0x1)
> >         port = 0 (0x0)
> >         aer_log_max = 8 (0x8)
> >         addr = 00.0
> >         romfile = ""
> >         rombar = 1 (0x1)
> >         multifunction = false
> >         command_serr_enable = true
> >         x-pcie-lnksta-dllla = true
> >         x-pcie-extcap-init = true
> >         class PCI bridge, addr 00:00.0, pci id 1014:03dc (sub 0000:0000)
> >         bus: pcie.0
> >           type PCIE
> >           dev: pci-bridge, id ""
> >             chassis_nr = 128 (0x80)
> >             msi = "off"
> >             shpc = false
> >             addr = 00.0
> >             romfile = ""
> >             rombar = 1 (0x1)
> >             multifunction = false
> >             command_serr_enable = true
> >             x-pcie-lnksta-dllla = true
> >             x-pcie-extcap-init = true
> >             class PCI bridge, addr 00:00.0, pci id 1b36:0001 (sub 0000:0000)
> >             bus: pci.0
> >               type PCI
> > 
> > [ ... ]
> > 
> > >> +static const PropertyInfo pnv_phb3_phb_id_propinfo = {
> > >> +    .name = "irq",
> > >> +    .get = pnv_phb3_get_phb_id,
> > >> +    .set = pnv_phb3_set_phb_id,
> > >> +};
> > > 
> > > Can't you use a static DeviceProps style property for this, which is a
> > > bit simpler?
> > 
> > OK. We will address user creatable PHBs in some other way. Most
> > certainly in the realize routine like you suggested.
> > 
> > Thanks,
> > 
> > C. 
> > 
>