Re: [Qemu-devel] Re: [PATCH] pci: initialize header type register.

[Gerd Hoffmann]

On 02/08/10 18:37, Michael S. Tsirkin wrote:
> On Mon, Feb 08, 2010 at 06:37:41PM +0100, Gerd Hoffmann wrote:
> > On 02/08/10 18:32, Michael S. Tsirkin wrote:
> > > On Mon, Feb 08, 2010 at 06:24:57PM +0100, Gerd Hoffmann wrote:
> > > > On 02/08/10 17:27, Michael S. Tsirkin wrote:
> > > > > On Mon, Feb 08, 2010 at 12:14:11PM +0100, Gerd Hoffmann wrote:
> > > > > > On 02/08/10 11:17, Michael S. Tsirkin wrote:
> > > > > > > On Mon, Feb 08, 2010 at 03:41:47PM +0900, Isaku Yamahata wrote:
> > > > > > > > initialize header type register in pci generic code.
> > > > > > > >
> > > > > > > > Cc: Blue Swirl<address@hidden>
> > > > > > > > Cc: "Michael S. Tsirkin"<address@hidden>
> > > > > > > > Signed-off-by: Isaku Yamahata<address@hidden>
> > > > > > >
> > > > > > > No objections here, I am assuming this will be followed
> > > > > > > by patches removing header type init from bridges?
> > > > > > >     From qdev perspective, it is probably cleaner to make
> > > > > > > multifunction bit a separate qdev property though, right?
> > > > > >
> > > > > >      From a qdev perspective it would make *alot* of sense to move a bunch of
> > > > > > pci config stuff (including, but not limited to header type) into
> > > > > > PCIDeviceInfo.
> > > > > >
> > > > > > cheers,
> > > > > >      Gerd
> > > > >
> > > > > Actually - won't this make it possible to create broken configurations
> > > > > by tweaking properties from command-line?
> > > >
> > > > Not as property, as struct element in PCIDeviceInfo.  i.e.
> > > >
> > > > static PCIDeviceInfo e1000_info = {
> > > >       [ stuff which is here right now ]
> > > >       .vendor_id = PCI_VENDOR_ID_INTEL,
> > > >       .device_id = E1000_DEVID,
> > > >       .class     = PCI_CLASS_NETWORK_ETHERNET,
> > > >       [ probably more stuff which makes sense ]
> > > > }
> > > >
> > > > Then setup this in generic pci code instead of having each driver doing
> > > > a bunch of pci_config_set_*() calls.
> > > >
> > > > cheers,
> > > >     Gerd
> > >
> > > We still end up with class, vendor etc duplicated in 2 places.
> >
> > No.  The info should be *only* in PCIDeviceInfo then.
>
> That would put a lot of code in pci config cycle path.  A single array
> mirroring the whole config space is much cleaner.
>
> > >   Why do
> > > we want stuff like vendor id in PCIDeviceInfo at all?  Why can't
> > > everyone just use pci_config_set/get calls?
> >
> > You can do nice stuff like printing vendor/device IDs in the '-device ?'
> > list then.
>
> That should use pci functions as well.

Hmm, do you mix up PCIDevice and PCIDeviceInfo structs?

cheers,
  Gerd