Add list-vgpu-types action

Change-Id: Ibd927191006152c82216974ac6ba0122aed8fd8d

actions.yaml

@@ -0,0 +1,2 @@
+list-vgpu-types:
+  description: List all vGPU types registered by the NVIDIA driver.

src/charm.py

@@ -25,6 +25,7 @@ from charm_utils import (
     is_nvidia_software_to_be_installed,
     set_principal_unit_relation_data,
 )
+from nvidia_utils import list_vgpu_types
 
 
 class NovaComputeNvidiaVgpuCharm(ops_openstack.core.OSBaseCharm):
@@ -46,6 +47,9 @@ class NovaComputeNvidiaVgpuCharm(ops_openstack.core.OSBaseCharm):
         self.framework.observe(self.on.nova_vgpu_relation_changed,
                                self._on_nova_vgpu_relation_joined_or_changed)
 
+        self.framework.observe(self.on.list_vgpu_types_action,
+                               self._list_vgpu_types_action)
+
         # hash of the last successfully installed NVIDIA vGPU software passed
         # as resource to the charm:
         self._stored.set_default(last_installed_resource_hash=None)
@@ -101,6 +105,13 @@ class NovaComputeNvidiaVgpuCharm(ops_openstack.core.OSBaseCharm):
         """
         return check_status(self.config, self.services())
 
+    def _list_vgpu_types_action(self, event):
+        """List all vGPU types registered by the NVIDIA driver.
+
+        :type event: ops.charm.ActionEvent
+        """
+        event.set_results({'output': list_vgpu_types()})
+
 
 if __name__ == '__main__':
     main(NovaComputeNvidiaVgpuCharm)

src/nvidia_utils.py

@@ -17,6 +17,7 @@
 
 import logging
 import os
+from pathlib import Path
 
 from charmhelpers.core.hookenv import cached
 from charmhelpers.core.kernel import update_initramfs
@@ -59,6 +60,44 @@ def disable_nouveau_driver():
     update_initramfs()
 
 
+def list_vgpu_types():
+    """Human-readable list of all vGPU types registered by the NVIDIA driver.
+
+    :rtype: str
+    """
+    # NOTE(lourot): we are reinventing `mdevctl types` here. Unfortunately
+    # `mdevctl` is not available on Bionic.
+
+    vgpu_types_dirname = 'mdev_supported_types'
+    found_pci_addr_dirs = []
+    for root, dirs, files in os.walk('/sys/devices'):
+        if vgpu_types_dirname in dirs:
+            # At this point root looks like
+            # /sys/devices/pci0000:40/0000:40:03.1/0000:41:00.0
+            found_pci_addr_dirs.append(root)
+
+    output_lines = []
+    for pci_addr_dir in found_pci_addr_dirs:
+        root = os.path.join(pci_addr_dir, vgpu_types_dirname)
+        for vgpu_type in sorted(os.listdir(root)):
+            output_line = vgpu_type
+            output_line += ', ' + os.path.basename(pci_addr_dir)
+            output_line += (
+                ', ' + Path(os.path.join(root, vgpu_type, 'name')
+                            ).read_text().rstrip())
+            output_line += (
+                ', ' + Path(os.path.join(root, vgpu_type, 'description')
+                            ).read_text().rstrip())
+
+            # At this point output_line looks like
+            # nvidia-256, 0000:41:00.0, GRID RTX6000-1Q, num_heads=4,
+            #   frl_config=60, framebuffer=1024M, max_resolution=5120x2880,
+            #   max_instance=24
+            output_lines.append(output_line)
+
+    return '\n'.join(output_lines)
+
+
 @cached
 def has_nvidia_gpu_hardware():
     """Search for NVIDIA GPU hardware.

unit_tests/test_nvidia_utils.py

@@ -15,7 +15,7 @@
 import sys
 import unittest
 
-from mock import patch
+from mock import MagicMock, patch
 
 sys.path.append('src')  # noqa
 
@@ -61,3 +61,44 @@ class TestNvidiaUtils(unittest.TestCase):
         lspci_parser_mock.return_value.run.return_value = (
             self._PCI_DEVICES_LIST_WITHOUT_GPU)
         self.assertFalse(nvidia_utils._has_nvidia_gpu_hardware_notcached())
+
+    @patch('nvidia_utils.Path')
+    @patch('nvidia_utils.os.listdir')
+    @patch('nvidia_utils.os.walk')
+    def test_list_vgpu_types(self, os_walk_mock, os_listdir_mock, path_mock):
+        os_walk_mock.return_value = [
+            ('/sys/devices/pci0000:40/0000:40:03.1/0000:41:00.0',
+             ['mdev_supported_types'], []),
+            ('/sys/devices/pci0000:c0/0000:c0:03.1/0000:c1:00.0',
+             ['mdev_supported_types'], []),
+        ]
+        os_listdir_mock.side_effect = [
+            ['nvidia-256', 'nvidia-257'],
+            ['nvidia-301'],
+        ]
+        path_mock_obj = MagicMock()
+        path_mock.return_value = path_mock_obj
+        path_mock_obj.read_text.side_effect = [
+            'GRID RTX6000-1Q',
+            ('num_heads=4, frl_config=60, framebuffer=1024M, '
+             'max_resolution=5120x2880, max_instance=24'),
+            'GRID RTX6000-2Q',
+            ('num_heads=4, frl_config=60, framebuffer=2048M, '
+             'max_resolution=7680x4320, max_instance=12'),
+            'GRID V100-16C',
+            ('num_heads=1, frl_config=60, framebuffer=16384M, '
+             'max_resolution=4096x2160, max_instance=1'),
+        ]
+
+        expected_output = '\n'.join([
+            ('nvidia-256, 0000:41:00.0, GRID RTX6000-1Q, num_heads=4, '
+             'frl_config=60, framebuffer=1024M, max_resolution=5120x2880, '
+             'max_instance=24'),
+            ('nvidia-257, 0000:41:00.0, GRID RTX6000-2Q, num_heads=4, '
+             'frl_config=60, framebuffer=2048M, max_resolution=7680x4320, '
+             'max_instance=12'),
+            ('nvidia-301, 0000:c1:00.0, GRID V100-16C, num_heads=1, '
+             'frl_config=60, framebuffer=16384M, max_resolution=4096x2160, '
+             'max_instance=1'),
+        ])
+        self.assertEqual(nvidia_utils.list_vgpu_types(), expected_output)