Re: [Qemu-devel] [PATCH 6/7] msix: Align MSI-X constants to libpci definitions and extend them

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jun 08, 2011 at 04:46:13PM +0200, Jan Kiszka wrote:
> On 2011-06-08 16:43, Isaku Yamahata wrote:
> > On Wed, Jun 08, 2011 at 12:26:44PM +0200, Jan Kiszka wrote:
> >> Add PCI_MSIX_TABLE and PCI_MSIX_PBA, align other MSIX related constant
> >> names to libpci style. Will be used for device assignment code in
> >> qemu-kvm.
> > 
> > So since libpci would be used by qemu, you are claiming that
> > it should be switched to libpci style from Linux pci_regs.h?
> 
> No, libpci won't be used (I'm about to remove that dependency from
> qemu-kvm). We are just copying its definitions, so I think we should
> align to its style.
> 
> Jan

But why?

We are currently aligned with pci_regs.h from linux.
What is the benefit of switching styles?
It adds support overhead e.g. as backport becomes harder.

BTW, libpci doesn't seem to have pci_regs.h - it has pci/header.h

If some register definitions are missing in linux, what
we did in the past is:
- stick them in a C file that needs them meanwhile
- long term add them to linux and backport to our header

We could also add pci_ext_regs.h or something to this end
as an alternative, although this removes the pressure
to upstream definitions ...

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