[RFC PATCH v2 vfio 7/7] vfio/pds: Add Kconfig and documentation

Brett Creeley
2022-12-14T23:25:03Z

Add Kconfig entries and pds_vfio.rst. Also, add an entry in the
MAINTAINERS file for this new driver.

It's not clear where documentation for vendor specific VFIO
drivers should live, so just re-use the current Pensando
ethernet location.

Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
---
.../device_drivers/ethernet/index.rst | 1 +
.../ethernet/pensando/pds_vfio.rst | 88 +++++++++++++++++++
MAINTAINERS | 7 ++
drivers/vfio/pci/Kconfig | 2 +
drivers/vfio/pci/pds/Kconfig | 17 ++++
5 files changed, 115 insertions(+)
create mode 100644 Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst
create mode 100644 drivers/vfio/pci/pds/Kconfig

diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index 5196905582c5..0242bbc3bb2a 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -44,6 +44,7 @@ Contents:
neterion/s2io
netronome/nfp
pensando/ionic
+ pensando/pds_vfio
smsc/smc9
stmicro/stmmac
ti/cpsw
diff --git a/Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst b/Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst
new file mode 100644
index 000000000000..adc144a4a7b8
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst
@@ -0,0 +1,88 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. note: can be edited and viewed with /usr/bin/formiko-vim
+
+==========================================================
+PCI VFIO driver for the Pensando(R) DSC adapter family
+==========================================================
+
+Pensando Linux VFIO PCI Device Driver
+Copyright(c) 2022 Pensando Systems, Inc
+
+Overview
+========
+
+The ``pds_vfio`` driver is both a PCI and auxiliary bus driver. The
+PCI driver supports Live Migration capable NVMe Virtual Function (VF)
+devices and the auxiliary driver is used to communicate with the
+``pds_core`` driver and hardware.
+
+Using the device
+================
+
+The pds_vfio device is enabled via multiple configuration steps and
+depends on the ``pds_core`` driver to create and enable SR-IOV Virtual
+Function devices.
+
+Shown below are the steps to bind the driver to a VF and also to the
+associated auxiliary device created by the ``pds_core`` driver. This
+example assumes the pds_core and pds_vfio modules are already
+loaded.
+
+.. code-block:: bash
+ :name: example-setup-script
+
+ #!/bin/bash
+
+ PF_BUS="0000:60"
+ PF_BDF="0000:60:00.0"
+ VF_BDF="0000:60:00.1"
+
+ # Enable live migration VF auxiliary device(s)
+ devlink dev param set pci/$PF_BDF name enable_migration value true cmode runtime
+
+ # Prevent nvme driver from probing the NVMe VF device
+ echo 0 > /sys/class/pci_bus/$PF_BUS/device/$PF_BDF/sriov_drivers_autoprobe
+
+ # Create single VF for NVMe Live Migration via VFIO
+ echo 1 > /sys/bus/pci/drivers/pds_core/$PF_BDF/sriov_numvfs
+
+ # Allow the VF to be bound to the pds_vfio driver
+ echo "pds_vfio" > /sys/class/pci_bus/$PF_BUS/device/$VF_BDF/driver_override
+
+ # Bind the VF to the pds_vfio driver
+ echo "$VF_BDF" > /sys/bus/pci/drivers/pds_vfio/bind
+
+After performing the steps above the pds_vfio driver's PCI probe should
+have been called, the pds_vfio driver's auxiliary probe should have
+been called, and a file in /dev/vfio/<iommu_group> should have been created.
+There will also be an entry in /sys/bus/auxiliary/device/pds_core.LM.<nn>
+for the VF's auxiliary device and the associated driver registered by the
+pds_vfio module will be at /sys/bus/auxiliary/drivers/pds_vfio.LM.
+
+
+Enabling the driver
+===================
+
+The driver is enabled via the standard kernel configuration system,
+using the make command::
+
+ make oldconfig/menuconfig/etc.
+
+The driver is located in the menu structure at:
+
+ -> Device Drivers
+ -> VFIO Non-Privileged userspace driver framework
+ -> VFIO support for PDS PCI devices
+
+Support
+=======
+
+For general Linux networking support, please use the netdev mailing
+list, which is monitored by Pensando personnel::
+
+ netdev@vger.kernel.org
+
+For more specific support needs, please use the Pensando driver support
+email::
+
+ drivers@pensando.io
diff --git a/MAINTAINERS b/MAINTAINERS
index 50d7442e7f43..ba2d139ccee9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21623,6 +21623,13 @@ S: Maintained
P: Documentation/driver-api/vfio-pci-device-specific-driver-acceptance.rst
F: drivers/vfio/pci/*/

+VFIO PDS PCI DRIVER
+M: Brett Creeley <brett.creeley@amd.com>
+L: kvm@vger.kernel.org
+S: Maintained
+F: Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst
+F: drivers/vfio/pci/pds/
+
VFIO PLATFORM DRIVER
M: Eric Auger <eric.auger@redhat.com>
L: kvm@vger.kernel.org
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index f9d0c908e738..2c3831dd60ef 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -59,4 +59,6 @@ source "drivers/vfio/pci/mlx5/Kconfig"

source "drivers/vfio/pci/hisilicon/Kconfig"

+source "drivers/vfio/pci/pds/Kconfig"
+
endif
diff --git a/drivers/vfio/pci/pds/Kconfig b/drivers/vfio/pci/pds/Kconfig
new file mode 100644
index 000000000000..d9bc9734c3cf
--- /dev/null
+++ b/drivers/vfio/pci/pds/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+config PDS_VFIO_PCI
+ tristate "VFIO support for PDS PCI devices"
+ depends on PDS_CORE
+ depends on VFIO_PCI_CORE
+ help
+ This provides generic PCI support for PDS devices using the VFIO
+ framework.
+
+ More specific information on this driver can be
+ found in
+ <file:Documentation/networking/device_drivers/ethernet/pensando/pds_vfio.rst>.
+
+ To compile this driver as a module, choose M here. The module
+ will be called pds_vfio.
+
+ If you don't know what to do here, say N.
--
2.17.1