Re: [dpdk-dev] [RFC PATCH] bus/pci: avoid depending on private value in kernel source

[David Marchand <david.marchand@redhat.com>]

On Wed, Jul 3, 2019 at 9:35 AM Tiwei Bie <tiwei.bie@intel.com> wrote:

> Hi David,
>
> On Wed, Jul 03, 2019 at 09:02:59AM +0200, David Marchand wrote:
> > Hello,
> >
> > On Wed, Jul 3, 2019 at 7:47 AM Tiwei Bie <tiwei.bie@intel.com> wrote:
> >
> >     The value 40 used in VFIO_GET_REGION_ADDR() is a private value
> >     (VFIO_PCI_OFFSET_SHIFT) defined in Linux kernel source [1]. It
> >     is not part of VFIO API, and we should not depend on it.
> >
> >     [1]
> https://github.com/torvalds/linux/blob/6fbc7275c7a9/drivers/vfio/pci/
> >     vfio_pci_private.h#L19
> >
> >
> >
> > I did not follow linux kernel changes, is there something that would
> change
> > this offset?
> > It looks like a cleanup (did not look into the details yet), do we need
> this
> > now?
>
> In VFIO/mdev [1], the offset can be something different. It depends
> on the parent device. It's not just a cleanup. It's a preparation
> for the mdev support in DPDK.
>
> [1]
> https://github.com/torvalds/linux/blob/master/Documentation/vfio-mediated-device.txt
>
>
Ok, thanks.
So we can wait for mdev to be ready before working on this.


-- 
David Marchand