Re: [Qemu-devel] [PATCH] Docs: Introduce multiport serial support in qemupciserial.inf

[Gerd Hoffmann <kraxel@redhat.com>]

On Mi, 2014-01-08 at 17:11 +0100, Paolo Bonzini wrote:
> Il 08/01/2014 16:07, Yan Vugenfirer ha scritto:
> >>>
> >>> +%QEMU-PCI_SERIAL_1_PORT%=ComPort_inst1,
> >>> PCI\VEN_1B36&DEV_0002&SUBSYS_11001AF4&REV_01
> >>> +%QEMU-PCI_SERIAL_2_PORT%=ComPort_inst2,
> >>> PCI\VEN_1B36&DEV_0003&SUBSYS_11001AF4&REV_01
> >>> +%QEMU-PCI_SERIAL_4_PORT%=ComPort_inst4,
> >>> PCI\VEN_1B36&DEV_0004&SUBSYS_11001AF4&REV_01
> >>
> >> I think checking the subsystem is not necessary (and I think downstreams
> >> could legitimately change it).  Can you check CC and REV but not SUBSYS?
> > 
> > PNP ID can be reduced to vendor and device ID only, for example:
> > PCI\VEN_1B36&DEV_0002 . But in this case we cannot check revision.
> 
> Gerd, Michael, what do you think is better?  Not check revision, or
> enforcing subsystem?

No need to check the revision.  There is only one, I doubt this will
ever change, and should we do a rev2 virtual hardware it is supposed to
be backward-compatible to rev1 (otherwise we should hand out a new pci
id to the device).

[ drivers which depend on few features of the hypothetical rev2 hardware
  and don't work with rev1 would need a revision check ]

cheers,
  Gerd