diff mbox series

[net-next,7/8] devlink: Expose port function commands to control migratable

Message ID 20221130115217.7171-8-shayd@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series devlink: Add port function attribute to enable/disable Roce and migratable | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 383 this patch: 383
netdev/cc_maintainers warning 4 maintainers not CCed: linux-doc@vger.kernel.org edumazet@google.com pabeni@redhat.com corbet@lwn.net
netdev/build_clang success Errors and warnings before: 24 this patch: 24
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 528 this patch: 528
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 14 this patch: 14
netdev/source_inline success Was 0 now: 0

Commit Message

Shay Drori Nov. 30, 2022, 11:52 a.m. UTC
Expose port function commands to enable / disable migratable
capability, this is used to set the port function as migratable.

Live migration is the process of transferring a live virtual machine
from one physical host to another without disrupting its normal
operation.

In order for a VM to be able to perform LM, all the VM components must
be able to perform migration. e.g.: to be migratable.
In order for VF to be migratable, VF must be bound to VFIO driver with
migration support.

When migratable capability is enable for a function of the port, the
device is making the necessary preparations for the function to be
migratable, which might include disabling features which cannot be
migrated.

Example of LM with migratable function configuration:
Set migratable of the VF's port function.

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable disable

$ devlink port function set pci/0000:06:00.0/2 migratable enable

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable enable

Bind VF to VFIO driver with migration support:
$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
$ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/bind

Attach VF to the VM.
Start the VM.
Perform LM.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 .../networking/devlink/devlink-port.rst       | 45 ++++++++++++++++
 include/net/devlink.h                         | 21 ++++++++
 include/uapi/linux/devlink.h                  |  1 +
 net/core/devlink.c                            | 54 +++++++++++++++++++
 4 files changed, 121 insertions(+)

Comments

kernel test robot Dec. 1, 2022, 8:46 a.m. UTC | #1
Hi Shay,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Shay-Drory/devlink-Add-port-function-attribute-to-enable-disable-Roce-and-migratable/20221130-195607
patch link:    https://lore.kernel.org/r/20221130115217.7171-8-shayd%40nvidia.com
patch subject: [PATCH net-next 7/8] devlink: Expose port function commands to control migratable
reproduce:
        # https://github.com/intel-lab-lkp/linux/commit/e8458cc22a755577665ae67a15ca6b5d2166a04f
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Shay-Drory/devlink-Add-port-function-attribute-to-enable-disable-Roce-and-migratable/20221130-195607
        git checkout e8458cc22a755577665ae67a15ca6b5d2166a04f
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        make htmldocs

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> Documentation/networking/devlink/devlink-port.rst:234: WARNING: Bullet list ends without a blank line; unexpected unindent.

vim +234 Documentation/networking/devlink/devlink-port.rst

   225	
   226	    $ devlink port function set pci/0000:06:00.0/2 migratable enable
   227	
   228	    $ devlink port show pci/0000:06:00.0/2
   229	    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
   230	        function:
   231	            hw_addr 00:00:00:00:00:00 migratable enable
   232	
   233	- Bind VF to VFIO driver with migration support:
 > 234	$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
   235	$ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
   236	$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/bind
   237
diff mbox series

Patch

diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst
index 79f9c0390b47..b1b0ce50d9f1 100644
--- a/Documentation/networking/devlink/devlink-port.rst
+++ b/Documentation/networking/devlink/devlink-port.rst
@@ -125,6 +125,9 @@  this means a MAC address.
 Users may also set the RoCE capability of the function using
 'devlink port function set roce' command.
 
+Users may also set the function as migratable using
+'devlink port function set migratable' command.
+
 Function attributes
 ===================
 
@@ -194,6 +197,48 @@  VF/SF driver cannot override it.
         function:
             hw_addr 00:00:00:00:00:00 roce disable
 
+migratable capability setup
+---------------------------
+Live migration is the process of transferring a live virtual machine
+from one physical host to another without disrupting its normal
+operation.
+
+User who want PCI VFs to be able to perform live migration need to
+explicitly enable the VF migratable capability.
+
+When user enables migratable capability for a VF, and the HV binds the VF to VFIO driver
+with migration support, the user can migrate the VM with this VF from one HV to a
+different one.
+
+However, when migratable capability is enable, device will disable features which cannot
+be migrated. Thus migratable cap can impose limitations on a VF so let the user decide.
+
+Example of LM with migratable function configuration:
+- Get migratable capability of the VF device::
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 migratable disable
+
+- Set migratable capability of the VF device::
+
+    $ devlink port function set pci/0000:06:00.0/2 migratable enable
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 migratable enable
+
+- Bind VF to VFIO driver with migration support:
+$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
+$ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
+$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/bind
+
+Attach VF to the VM.
+Start the VM.
+Perform live migration.
+
 Subfunction
 ============
 
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 7f75100e8b26..8abffd9201d7 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1454,6 +1454,27 @@  struct devlink_ops {
 	int (*port_function_roce_set)(struct devlink_port *devlink_port,
 				      bool enable,
 				      struct netlink_ext_ack *extack);
+	/**
+	 * @port_function_mig_get: Port function's migratable get function.
+	 *
+	 * Query migratable state of a function managed by the devlink port.
+	 * Return -EOPNOTSUPP if port function migratable handling is not
+	 * supported.
+	 */
+	int (*port_function_mig_get)(struct devlink_port *devlink_port,
+				     bool *is_enable,
+				     struct netlink_ext_ack *extack);
+	/**
+	 * @port_function_mig_set: Port function's migratable set function.
+	 *
+	 * Enable/Disable migratable state of a function managed by the devlink
+	 * port.
+	 * Return -EOPNOTSUPP if port function migratable handling is not
+	 * supported.
+	 */
+	int (*port_function_mig_set)(struct devlink_port *devlink_port,
+				     bool enable,
+				     struct netlink_ext_ack *extack);
 	/**
 	 * port_new() - Add a new port function of a specified flavor
 	 * @devlink: Devlink instance
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index c6f1fbe54095..f70201be0479 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -658,6 +658,7 @@  enum devlink_resource_unit {
 
 enum devlink_port_fn_attr_cap {
 	DEVLINK_PORT_FN_ATTR_CAP_ROCE,
+	DEVLINK_PORT_FN_ATTR_CAP_MIGRATABLE,
 
 	/* Add new caps above */
 	__DEVLINK_PORT_FN_ATTR_CAPS_MAX,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 88846ad635a0..3fd47bbf891b 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -728,6 +728,29 @@  static int devlink_port_fn_roce_fill(const struct devlink_ops *ops,
 	return 0;
 }
 
+static int devlink_port_function_mig_fill(const struct devlink_ops *ops,
+					  struct devlink_port *devlink_port,
+					  struct nla_bitfield32 *caps,
+					  struct netlink_ext_ack *extack)
+{
+	bool is_enable;
+	int err;
+
+	if (!ops->port_function_mig_get ||
+	    devlink_port->attrs.flavour != DEVLINK_PORT_FLAVOUR_PCI_VF)
+		return 0;
+
+	err = ops->port_function_mig_get(devlink_port, &is_enable, extack);
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			return 0;
+		return err;
+	}
+
+	DEVLINK_PORT_FN_SET_CAP(caps, DEVLINK_PORT_FN_CAP(MIGRATABLE), is_enable);
+	return 0;
+}
+
 static int devlink_port_fn_caps_fill(const struct devlink_ops *ops,
 				     struct devlink_port *devlink_port,
 				     struct sk_buff *msg,
@@ -741,6 +764,10 @@  static int devlink_port_fn_caps_fill(const struct devlink_ops *ops,
 	if (err)
 		return err;
 
+	err = devlink_port_function_mig_fill(ops, devlink_port, &caps, extack);
+	if (err)
+		return err;
+
 	if (!caps.selector)
 		return 0;
 	err = nla_put_bitfield32(msg, DEVLINK_PORT_FN_ATTR_CAPS, caps.value,
@@ -1335,6 +1362,15 @@  static int devlink_port_fn_state_fill(const struct devlink_ops *ops,
 	return 0;
 }
 
+static int
+devlink_port_fn_mig_set(struct devlink_port *devlink_port, bool enable,
+			struct netlink_ext_ack *extack)
+{
+	const struct devlink_ops *ops = devlink_port->devlink->ops;
+
+	return ops->port_function_mig_set(devlink_port, enable, extack);
+}
+
 static int
 devlink_port_fn_roce_set(struct devlink_port *devlink_port, bool enable,
 			 struct netlink_ext_ack *extack)
@@ -1361,6 +1397,13 @@  static int devlink_port_fn_caps_set(struct devlink_port *devlink_port,
 		if (err)
 			return err;
 	}
+	if (caps.selector & DEVLINK_PORT_FN_CAP(MIGRATABLE)) {
+		err = devlink_port_fn_mig_set(devlink_port, caps_value &
+					      DEVLINK_PORT_FN_CAP(MIGRATABLE),
+					      extack);
+		if (err)
+			return err;
+	}
 	return 0;
 }
 
@@ -1781,6 +1824,17 @@  static int devlink_port_function_validate(struct devlink_port *devlink_port,
 					    "Port doesn't support RoCE function attribute");
 			return -EOPNOTSUPP;
 		}
+		if (caps.selector & DEVLINK_PORT_FN_CAP(MIGRATABLE)) {
+			if (!ops->port_function_mig_set) {
+				NL_SET_ERR_MSG_ATTR(extack, attr,
+						    "Port doesn't support migratable function attribute");
+			}
+			if (devlink_port->attrs.flavour != DEVLINK_PORT_FLAVOUR_PCI_VF) {
+				NL_SET_ERR_MSG_ATTR(extack, attr,
+						    "migratable function attribute supported for VFs only");
+				return -EOPNOTSUPP;
+			}
+		}
 	}
 	return 0;
 }