Re: [Qemu-devel] [PATCH RFC 1/1] s390x/pci: Extend pci representation by new zpci device

[Alexander Graf]

On 26.02.15 12:59, Frank Blaschka wrote:
> This patch extends the current s390 pci implementation to
> provide more flexibility in configuration of s390 specific
> device handling. For this we had to introduce a new facility
> (and bus) to hold devices representing information actually
> provided by s390 firmware and I/O configuration.
> 
> On s390 the physical structure of the pci system (bridge, bus, slot)
> in not shown to the OS. For this the pci bridge and bus created
> in qemu can also not be shown to the guest. The new zpci device class
> represents this abstract view on the bare pci function and allows to
> provide s390 specific configuration attributes for it.
> 
> Sample qemu configuration:
> -device e1000,id=zpci1
> -device ne2k_pci,id=zpci2
> -device zpci,fid=2,uid=1248,pci_id=zpci1
> -device zpci,fid=17,uid=2244,pci_id=zpci2
> 
> A zpci device references the corresponding PCI device via device id.
> The new design allows to define multiple host bridges and support more
> pci devices.

Isn't this reverse? Shouldn't it rather be

  -device zpci,...,id=zpci1
  -device e1000,bus=zpci1.0

with a limit on each virtual zpci bus to only support one device?


Alex