Re: [pci PATCH v8 0/4] Add support for unmanaged SR-IOV

[Randy Dunlap]

On 04/20/18 09:28, Alexander Duyck wrote:
> This series is meant to add support for SR-IOV on devices when the VFs are
> not managed by the kernel. Examples of recent patches attempting to do this
> include:
> virto - https://patchwork.kernel.org/patch/10241225/
> pci-stub - https://patchwork.kernel.org/patch/10109935/
> vfio - https://patchwork.kernel.org/patch/10103353/
> uio - https://patchwork.kernel.org/patch/9974031/

Hi,

Somewhere in this patch series it would be nice to tell us what the heck
a "PF" is.  :)

Thanks.

> Since this is quickly blowing up into a multi-driver problem it is probably
> best to implement this solution as generically as possible.
> 
> This series is an attempt to do that. What we do with this patch set is
> provide a generic framework to enable SR-IOV in the case that the PF driver
> doesn't support managing the VFs itself.
> 
> I based my patch set originally on the patch by Mark Rustad but there isn't
> much left after going through and cleaning out the bits that were no longer
> needed, and after incorporating the feedback from David Miller. At this point
> the only items to be fully reused was his patch description which is now
> present in patch 3 of the set.
> 
> This solution is limited in scope to just adding support for devices that
> provide no functionality for SR-IOV other than allocating the VFs by
> calling pci_enable_sriov. Previous sets had included patches for VFIO, but
> for now I am dropping that as the scope of that work is larger then I
> think I can take on at this time.
> 
> v2: Reduced scope back to just virtio_pci and vfio-pci
>     Broke into 3 patch set from single patch
>     Changed autoprobe behavior to always set when num_vfs is set non-zero
> v3: Updated Documentation to clarify when sriov_unmanaged_autoprobe is used
>     Wrapped vfio_pci_sriov_configure to fix build errors w/o SR-IOV in kernel
> v4: Dropped vfio-pci patch
>     Added ena and nvme to drivers now using pci_sriov_configure_unmanaged
>     Dropped pci_disable_sriov call in virtio_pci to be consistent with ena
> v5: Dropped sriov_unmanaged_autoprobe and pci_sriov_conifgure_unmanaged
>     Added new patch that enables pci_sriov_configure_simple
>     Updated drivers to use pci_sriov_configure_simple
> v6: Defined pci_sriov_configure_simple as NULL when SR-IOV is not enabled
>     Updated drivers to drop "#ifdef" checks for IOV
>     Added pci-pf-stub as place for PF-only drivers to add support
> v7: Dropped pci_id table explanation from pci-pf-stub driver
>     Updated pci_sriov_configure_simple to drop need for err value
>     Fixed comment explaining why pci_sriov_configure_simple is NULL
> v8: Dropped virtio from the set, support to be added later after TC approval
> 
> Cc: Mark Rustad <mark.d.rustad@xxxxxxxxx>
> Cc: Maximilian Heyne <mheyne@xxxxxxxxx>
> Cc: Liang-Min Wang <liang-min.wang@xxxxxxxxx>
> Cc: David Woodhouse <dwmw@xxxxxxxxxxxx>
> 
> ---
> 
> Alexander Duyck (4):
>       pci: Add pci_sriov_configure_simple for PFs that don't manage VF resources
>       ena: Migrate over to unmanaged SR-IOV support
>       nvme: Migrate over to unmanaged SR-IOV support
>       pci-pf-stub: Add PF driver stub for PFs that function only to enable VFs
> 
> 
>  drivers/net/ethernet/amazon/ena/ena_netdev.c |   28 -------------
>  drivers/nvme/host/pci.c                      |   20 ----------
>  drivers/pci/Kconfig                          |   12 ++++++
>  drivers/pci/Makefile                         |    2 +
>  drivers/pci/iov.c                            |   31 +++++++++++++++
>  drivers/pci/pci-pf-stub.c                    |   54 ++++++++++++++++++++++++++
>  include/linux/pci.h                          |    3 +
>  include/linux/pci_ids.h                      |    2 +
>  8 files changed, 106 insertions(+), 46 deletions(-)
>  create mode 100644 drivers/pci/pci-pf-stub.c
> 
> --
> 

-- 
~Randy