Re: [RFC v2 1/4] hisi-acc-vfio-pci: add new vfio_pci driver for HiSilicon ACC devices

On Mon, Jul 05, 2021 at 03:32:47PM -0300, Jason Gunthorpe wrote:

On Mon, Jul 05, 2021 at 09:27:37PM +0300, Leon Romanovsky wrote:

quoted

quoted

I think, in any case, it would be good to update the Documentation based on
which way we end up doing this.

The request to update Documentation can be seen as an example of
choosing not-good API decisions. Expectation to see all drivers to
use same callbacks with same vfio-core function calls sounds strange
to me.

It is not vfio-core, it is vfio-pci-core. It is similar to how some of
the fops stuff works, eg the generic_file whatever functions everyone
puts in.

It doesn't really matter if it is vfio-core or vfio-pci-core. This looks
horrible and it is going to be repeated for every driver:

+       .release        = vfio_pci_core_release,
+       .ioctl          = vfio_pci_core_ioctl,
+       .read           = vfio_pci_core_read,
+       .write          = vfio_pci_core_write,
+       .mmap           = vfio_pci_core_mmap,
+       .request        = vfio_pci_core_request,
+       .match          = vfio_pci_core_match,
+       .reflck_attach  = vfio_pci_core_reflck_attach,
+};

At some point of time you will add new .XXX callback and will
find yourself changing all drivers to have something like
".XXX = vfio_pci_core_XXX,"

Thanks