[RFC PATCH v2 5/5] dts: add functions for managing VFs to Node

[jspewock@iol.unh.edu]

From: Jeremy Spewock <jspewock@iol.unh.edu>

In order for test suites to create virtual functions there has to be
functions in the API that developers can use. This patch adds the
ability to create virtual functions to the Node API so that they are
reachable within test suites.

Bugzilla ID: 1500

Signed-off-by: Jeremy Spewock <jspewock@iol.unh.edu>
---
 dts/framework/testbed_model/node.py | 96 ++++++++++++++++++++++++++++-
 1 file changed, 94 insertions(+), 2 deletions(-)

diff --git a/dts/framework/testbed_model/node.py b/dts/framework/testbed_model/node.py
index 85d4eb1f7c..101a8edfbc 100644
--- a/dts/framework/testbed_model/node.py
+++ b/dts/framework/testbed_model/node.py
@@ -14,6 +14,7 @@
 """
 
 import os
+import re
 import tarfile
 from abc import ABC
 from ipaddress import IPv4Interface, IPv6Interface
@@ -24,9 +25,10 @@
     OS,
     BuildTargetConfiguration,
     NodeConfiguration,
+    PortConfig,
     TestRunConfiguration,
 )
-from framework.exception import ConfigurationError
+from framework.exception import ConfigurationError, InternalError
 from framework.logger import DTSLogger, get_dts_logger
 from framework.settings import SETTINGS
 
@@ -39,7 +41,7 @@
 )
 from .linux_session import LinuxSession
 from .os_session import OSSession
-from .port import Port
+from .port import Port, VirtualFunction
 
 
 class Node(ABC):
@@ -335,6 +337,96 @@ def _bind_port_to_driver(self, port: Port, for_dpdk: bool = True) -> None:
             verify=True,
         )
 
+    def create_virtual_functions(
+        self, num: int, pf_port: Port, dpdk_driver: str | None = None
+    ) -> list[VirtualFunction]:
+        """Create virtual functions (VFs) from a given physical function (PF) on the node.
+
+        Virtual functions will be created if there are not any currently configured on `pf_port`.
+        If there are greater than or equal to `num` VFs already configured on `pf_port`, those will
+        be used instead of creating more. In order to create VFs, the PF must be bound to its
+        kernel driver. This method will handle binding `pf_port` and any other ports in the test
+        run that reside on the same device back to their OS drivers if this was not done already.
+        VFs gathered in this method will be bound to `driver` if one is provided, or the DPDK
+        driver for `pf_port` and then added to `self.ports`.
+
+        Args:
+            num: The number of VFs to create. Must be greater than 0.
+            pf_port: The PF to create the VFs on.
+            dpdk_driver: Optional driver to bind the VFs to after they are created. Defaults to the
+                DPDK driver of `pf_port`.
+
+        Raises:
+            InternalError: If `num` is less than or equal to 0.
+        """
+        if num <= 0:
+            raise InternalError(
+                "Method for creating virtual functions received a non-positive value."
+            )
+        if not dpdk_driver:
+            dpdk_driver = pf_port.os_driver_for_dpdk
+        # Get any other port that is on the same device which DTS is aware of
+        all_device_ports = [
+            p for p in self.ports if p.pci.split(".")[0] == pf_port.pci.split(".")[0]
+        ]
+        # Ports must be bound to the kernel driver in order to create VFs from them
+        for port in all_device_ports:
+            self._bind_port_to_driver(port, False)
+            # Some PMDs require the interface being up in order to make VFs
+            self.configure_port_state(port)
+        created_vfs = self.main_session.set_num_virtual_functions(num, pf_port)
+        # We don't need more then `num` VFs from the list
+        vf_pcis = self.main_session.get_pci_addr_of_vfs(pf_port)[:num]
+        devbind_info = self.main_session.send_command(
+            f"{self.path_to_devbind_script} -s", privileged=True
+        ).stdout
+
+        ret = []
+
+        for pci in vf_pcis:
+            original_driver = re.search(f"{pci}.*drv=([\\d\\w-]*)", devbind_info)
+            os_driver = original_driver[1] if original_driver else pf_port.os_driver
+            vf_config = PortConfig(
+                self.name, pci, dpdk_driver, os_driver, pf_port.peer.node, pf_port.peer.pci
+            )
+            vf_port = VirtualFunction(self.name, vf_config, created_vfs, pf_port)
+            self.main_session.update_ports([vf_port])
+            self._bind_port_to_driver(vf_port)
+            self.ports.append(vf_port)
+            ret.append(vf_port)
+        return ret
+
+    def get_vfs_on_port(self, pf_port: Port) -> list[VirtualFunction]:
+        """Get all virtual functions (VFs) that DTS is aware of on `pf_port`.
+
+        Args:
+            pf_port: The port to search for the VFs on.
+
+        Returns:
+            A list of VFs in the framework that were created/gathered from `pf_port`.
+        """
+        return [p for p in self.ports if isinstance(p, VirtualFunction) and p.pf_port == pf_port]
+
+    def remove_virtual_functions(self, pf_port: Port) -> None:
+        """Removes all virtual functions (VFs) created on `pf_port` by DTS.
+
+        Finds all the VFs that were created from `pf_port` and either removes them if they were
+        created by the DTS framework or binds them back to their os_driver if they were preexisting
+        on the node.
+
+        Args:
+            pf_port: Port to remove the VFs from.
+        """
+        vf_ports = self.get_vfs_on_port(pf_port)
+        if any(vf.created_by_framework for vf in vf_ports):
+            self.main_session.set_num_virtual_functions(0, pf_port)
+        else:
+            self._logger.info("Skipping removing VFs since they were not created by DTS.")
+            # Bind all VFs that we are no longer using back to their original driver
+            for vf in vf_ports:
+                self._bind_port_to_driver(vf, for_dpdk=False)
+        self.ports = [p for p in self.ports if p not in vf_ports]
+
 
 def create_session(node_config: NodeConfiguration, name: str, logger: DTSLogger) -> OSSession:
     """Factory for OS-aware sessions.
-- 
2.46.0