Re: [Qemu-devel] [PATCH v2 8/9] msix: Align MSI-X constants to libpci definitions and extend them

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

On Wed, Jun 08, 2011 at 11:02:44PM +0200, Jan Kiszka wrote:
> On 2011-06-08 23:00, Michael S. Tsirkin wrote:
> > On Wed, Jun 08, 2011 at 10:48:10PM +0200, Jan Kiszka wrote:
> >> On 2011-06-08 21:53, Michael S. Tsirkin wrote:
> >>> On Wed, Jun 08, 2011 at 06:21:51PM +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.
> >>>>
> >>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> >>>
> >>> Besides keeping pci_regs.h aligned with the original,
> >>> I also think ideally pci register banging should stay
> >>> within the pci subsystem.
> >>>
> >>> Could we add high-level APIs to help with that,
> >>> instead of having kvm look at config space directly?
> >>
> >> We could move the related static inlines from msi/msix.c to the headers
> >> in order to test for bits etc. Still, kvm needs to interpret the config
> >> space of the assigned device, so the abstraction will remain rather low.
> >>
> >> Jan
> >>
> > 
> > Hmm, at least for MSI/MSIX I thought this is done by kvm in kernel?
> > 
> 
> At least for the "traditional" assignment interface (VFIO may offload
> something), no. User space does the cap analysis, filtering, and in the
> MSI/MSI-X case the translation to QEMU msi/msix services. The latter is
> even WIP in my tree. Surrent assignment open-codes this, missing many
> corner cases.
> 
> Jan
> 

Anyway, if some defines need to be in a header, and aren't upstream
yet, let's create pci_ext_regs.h and add a comment there that we
should work on upstreaming them.


-- 
MST