PCI alias support

Add PCI alias support.

User may have specific device requirements for passthrough device, like
specific NIC card from specific vendor with specific network access.

It's too long and not straightforward to specify these requirements in
flavor directly, also cloud administrator may want to control what pci
requirements the user can specify and want to hide some device details
like the switch IP address a NIC is connected.

Pci alias is defined to specify the pci requirements and is specified in
the flavor extra specs. The API layer will translate the alias information
in flavor extra specs to pci requirement according to pci alias definition.

bp:pci-passthrough-base

Change-Id:I82a7826f72da8b41e95fb6d27cd03f68ed849880
Signed-off-by: Yongli He <yongli.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

etc/nova/nova.conf.sample

@@ -1663,6 +1663,20 @@
 #matchmaker_heartbeat_ttl=600
 
 
+#
+# Options defined in nova.pci.pci_request
+#
+
+# An alias for a PCI passthrough device requirement. This
+# allows users to specify the alias in the extra_spec for a
+# flavor, without needing to repeat all the PCI property
+# requirements. For example: pci_alias = { "name":
+# "QuicAssist",   "product_id": "0443",   "vendor_id": "8086",
+# "device_type": "ACCEL" } defines an alias for the Intel
+# QuickAssist card. (multi valued) (multi valued)
+#pci_alias=
+
+
 #
 # Options defined in nova.scheduler.driver
 #

nova/exception.py

@@ -1399,3 +1399,11 @@ class PciDevicePoolEmpty(NovaException):
     msg_fmt = _(
         "Attempt to consume PCI Device %(compute_node_id)s:%(address)s "
         "from empty pool")
+
+
+class PciInvalidAlias(NovaException):
+    msg_fmt = _("Invalid PCI alias definition: %(reason)s")
+
+
+class PciRequestAliasNotDefined(NovaException):
+    msg_fmt = _("PCI alias %(alias)s is not defined")

nova/pci/pci_request.py

@@ -0,0 +1,233 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 Intel Corporation
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+# @author: Yongli He, Intel Corporation.
+
+""" Example of a PCI alias:
+    pci_alias = '{
+        "name": "QuicAssist",
+        "product_id": "0443",
+        "vendor_id": "8086",
+        "device_type": "ACCEL",
+        }'
+
+    Aliases with the same name and the same device_type are OR operation:
+    pci_alias = '{
+        "name": "QuicAssist",
+        "product_id": "0442",
+        "vendor_id": "8086",
+        "device_type": "ACCEL",
+        }'
+    These 2 aliases define a device request meaning: vendor_id is "8086" and
+    product id is "0442" or "0443".
+    """
+
+import copy
+import jsonschema
+
+from nova import exception
+from nova.openstack.common import jsonutils
+from nova.openstack.common import log as logging
+from nova.pci import pci_utils
+from nova import utils
+from oslo.config import cfg
+
+pci_alias_opts = [
+    cfg.MultiStrOpt('pci_alias',
+                    default=[],
+                    help='An alias for a PCI passthrough device requirement. '
+                        'This allows users to specify the alias in the '
+                        'extra_spec for a flavor, without needing to repeat '
+                        'all the PCI property requirements. For example: '
+                        'pci_alias = '
+                          '{ "name": "QuicAssist", '
+                          '  "product_id": "0443", '
+                          '  "vendor_id": "8086", '
+                          '  "device_type": "ACCEL" '
+                          '} '
+                        'defines an alias for the Intel QuickAssist card. '
+                        '(multi valued)'
+                   )
+]
+
+CONF = cfg.CONF
+CONF.register_opts(pci_alias_opts)
+
+LOG = logging.getLogger(__name__)
+
+
+_ALIAS_DEV_TYPE = ['NIC', 'ACCEL', 'GPU']
+_ALIAS_CAP_TYPE = ['pci']
+_ALIAS_SCHEMA = {
+    "type": "object",
+    "additionalProperties": False,
+    "properties": {
+        "name": {
+            "type": "string",
+            "minLength": 1,
+            "maxLength": 256,
+        },
+        "capability_type": {
+            "type": "string",
+            "enum": _ALIAS_CAP_TYPE,
+        },
+        "product_id": {
+            "type": "string",
+            "pattern": pci_utils.PCI_VENDOR_PATTERN,
+        },
+        "vendor_id": {
+            "type": "string",
+            "pattern": pci_utils.PCI_VENDOR_PATTERN,
+        },
+        "device_type": {
+            "type": "string",
+            "enum": _ALIAS_DEV_TYPE,
+        },
+    },
+    "required": ["name"],
+}
+
+
+def _get_alias_from_config():
+    """Parse and validate PCI aliases from the nova config."""
+    jaliases = CONF.pci_alias
+    aliases = {}  # map alias name to alias spec list
+    try:
+        for jsonspecs in jaliases:
+            spec = jsonutils.loads(jsonspecs)
+            jsonschema.validate(spec, _ALIAS_SCHEMA)
+            name = spec.pop("name")
+            if name not in aliases:
+                aliases[name] = [spec]
+            else:
+                if aliases[name][0]["device_type"] == spec["device_type"]:
+                    aliases[name].append(spec)
+                else:
+                    reason = "Device type mismatch for alias '%s'" % name
+                    raise exception.PciInvalidAlias(reason=reason)
+
+    except exception.PciInvalidAlias:
+        raise
+    except Exception as e:
+        raise exception.PciInvalidAlias(reason=str(e))
+
+    return aliases
+
+
+def _translate_alias_to_requests(alias_spec):
+    """Generate complete pci requests from pci aliases in extra_spec."""
+
+    pci_aliases = _get_alias_from_config()
+
+    pci_requests = []  # list of a specs dict
+    alias_spec = alias_spec.replace(' ', '')
+    for name, count in [spec.split(':') for spec in alias_spec.split(',')]:
+        if name not in pci_aliases:
+            raise exception.PciRequestAliasNotDefined(alias=name)
+        else:
+            request = {'count': int(count),
+                       'spec': copy.deepcopy(pci_aliases[name]),
+                       'alias_name': name}
+            pci_requests.append(request)
+    return pci_requests
+
+
+def get_pci_requests_from_flavor(flavor):
+    """Get flavor's pci request.
+
+    The pci_passthrough:alias scope in flavor extra_specs
+    describes the flavor's pci requests, the key is
+    'pci_passthrough:alias' and the value has format
+    'alias_name_x:count, alias_name_y:count, ... '. The alias_name is
+    defined in 'pci_alias' configurations.
+
+    The flavor's requirement is translated into pci requests list,
+    each entry in the list is a dictionary. The dictionary has
+    three keys. The 'specs' gives the pci device properties
+    requirement, the 'count' gives the number of devices, and the
+    optional 'alias_name' is the corresponding alias definition name.
+
+    Example:
+    Assume alias configuration is:
+        {'vendor_id':'8086',
+         'device_id':'1502',
+         'name':'alias_1'}
+
+    The flavor extra specs includes: 'pci_passthrough:alias': 'alias_1:2'.
+
+    The returned pci_requests are:
+    pci_requests = [{'count':2,
+                     'specs': [{'vendor_id':'8086',
+                                'device_id':'1502'}],
+                     'alias_name': 'alias_1'}]
+
+    :param flavor: the flavor to be checked
+    :returns: a list of pci requests
+    """
+    if 'extra_specs' not in flavor:
+        return []
+
+    pci_requests = []
+    if 'pci_passthrough:alias' in flavor['extra_specs']:
+        pci_requests = _translate_alias_to_requests(
+            flavor['extra_specs']['pci_passthrough:alias'])
+    return pci_requests
+
+
+def get_instance_pci_requests(instance, prefix=""):
+    """Get instance's pci allocation requirement.
+
+    After a flavor's pci requirement is translated into pci requests,
+    the requests are kept in instance's system metadata to avoid
+    future flavor access and translation. This function get the
+    pci requests from instance system metadata directly.
+
+    As save_flavor_pci_info(), the prefix can be used to stash
+    information about another flavor for later use, like in resize.
+    """
+
+    if 'system_metadata' not in instance:
+        return []
+    system_metadata = utils.instance_sys_meta(instance)
+    pci_requests = system_metadata.get('%spci_requests' % prefix)
+
+    if not pci_requests:
+        return []
+    return jsonutils.loads(pci_requests)
+
+
+def save_flavor_pci_info(metadata, instance_type, prefix=''):
+    """Save flavor's pci information to metadata.
+
+    To reduce flavor access and pci request translation, the
+    translated pci requests are saved into instance's system
+    metadata.
+
+    As save_flavor_info(), the prefix can be used to stash information
+    about another flavor for later use, like in resize.
+    """
+    pci_requests = get_pci_requests_from_flavor(instance_type)
+    if pci_requests:
+        to_key = '%spci_requests' % prefix
+        metadata[to_key] = jsonutils.dumps(pci_requests)
+
+
+def delete_flavor_pci_info(metadata, *prefixes):
+    """Delete pci requests information from instance's system_metadata."""
+    for prefix in prefixes:
+        to_key = '%spci_requests' % prefix
+        if to_key in metadata:
+            del metadata[to_key]

nova/pci/pci_utils.py

@@ -22,6 +22,7 @@
 from nova import exception
 
 
+PCI_VENDOR_PATTERN = "^(hex{4})$".replace("hex", "[\da-fA-F]")
 _PCI_ADDRESS_PATTERN = ("^(hex{4}):(hex{2}):(hex{2}).(oct{1})$".
                                              replace("hex", "[\da-fA-F]").
                                              replace("oct", "[0-7]"))