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

On Fri, Mar 16, 2018 at 2:42 PM, Don Dutile [off-list ref] wrote:

On 03/15/2018 02:40 PM, Alexander Duyck wrote:

quoted

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 <redacted>
Cc: Maximilian Heyne <redacted>
Cc: Liang-Min Wang <redacted>
Cc: David Woodhouse <redacted>

---

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 <redacted>

Any issues with getting this pulled into the linux-pci tree? When I
submitted these that was the original target for this set, or do I
need to look at breaking them up and/or submitting them submitted
somewhere else?

Thanks.

- Alex