Re: [pci PATCH v7 0/5] Add support for unmanaged SR-IOV

[Don Dutile]

On 03/15/2018 02:40 PM, 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/
>
> 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
>
> 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 (5):
>        pci: Add pci_sriov_configure_simple for PFs that don't manage VF resources
>        virtio_pci: Add support for unmanaged SR-IOV on virtio_pci devices
>        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 ++++++++++++++++++++++++++
>   drivers/virtio/virtio_pci_common.c           |    1
>   include/linux/pci.h                          |    3 +
>   include/linux/pci_ids.h                      |    2 +
>   9 files changed, 107 insertions(+), 46 deletions(-)
>   create mode 100644 drivers/pci/pci-pf-stub.c
>
> --
For what it's worth.

Good, simpler start for this type of support/effort.
Thanks for the multiple versions to get to this point.

Reviewed-by: Donald Dutile <ddutile@xxxxxxxxxx>