Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann <kraxel@redhat.com>]

Paul Brook wrote:
> On Wednesday 10 September 2008, Gerd Hoffmann wrote:
>> +extern uint16_t pci_default_sub_vendor_id;
>> +extern uint16_t pci_default_sub_device_id;
> 
> Why are these being exported?

So you can change the defaults.  Main user for that I have in mind is
Xen.  They have added a subsystem id (5853:0001, XenSource vendor ID) to
some of the devices (by patching the indiviudual drivers, not by adding
a global default like this patch does).

I expect they probably want to keep the XenSource subsystem ID instead
of going with the qemu default.  So the idea is that we can have "if
(using_xen) { make 5853:0001 the default }" in the initialization path
some day.

cheers,
  Gerd