Support GetPreferredAllocation

README.md

@@ -51,6 +51,7 @@ which are available on a Kubernetes host
 - Supports devices with both Kernel and userspace (UIO and VFIO) drivers
 - Allows resource grouping using "selector(s)"
 - User configurable resourceName
+- User configurable policy for preferred device allocation
 - Detects Kubelet restarts and auto-re-register
 - Detects Link status (for Linux network devices) and updates associated VFs health accordingly
 - Extensible to support new device types with minimal effort if not already supported
@@ -269,17 +270,27 @@ This plugin creates device plugin endpoints based on the configurations given in
 
 `"resourceList"` should contain a list of config objects. Each config object may consist of following fields:
 
-|       Field       | Required |                                                              Description                                                               |                     Type/Defaults                     |                         Example/Accepted values                        |
-|-------------------|----------|----------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------|------------------------------------------------------------------------|
-| "resourceName"    | Y        | Endpoint resource name. Should not contain special characters including hyphens and must be unique in the scope of the resource prefix | string                                                | "sriov_net_A"                                                          |
-| "resourcePrefix"  | N        | Endpoint resource prefix name override. Should not contain special characters                                                          | string Default : "intel.com"                          | "yourcompany.com"                                                      |
-| "deviceType"      | N        | Device Type for a resource pool.                                                                                                       | string value of supported types. Default: "netDevice" | Currently supported values: "accelerator", "netDevice", "auxNetDevice" |
-| "excludeTopology" | N        | Exclude advertising of device's NUMA topology                                                                                          | bool Default: "false"                                 | "excludeTopology": true                                                |
-| "selectors"       | N        | Either a single device selector map or a list of maps. The list syntax is preferred. The "deviceType" value determines the device selector options.                                                  | json list of objects or json object. Default: null                   | Example: "selectors": [{"vendors": ["8086"],"devices": ["154c"]}]        |
-| "additionalInfo" | N | A map of map to add additional information to the pod via environment variables to devices                                             | json object as string Default: null  | Example: "additionalInfo": {"*": {"token": "3e49019f-412f-4f02-824e-4cd195944205"}} |
+| Field              | Required |                                                              Description                                                               |                     Type/Defaults                     |                         Example/Accepted values                        |
+|--------------------|----------|----------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------|------------------------------------------------------------------------|
+| "resourceName"     | Y        | Endpoint resource name. Should not contain special characters including hyphens and must be unique in the scope of the resource prefix | string                                                | "sriov_net_A"                                                          |
+| "resourcePrefix"   | N        | Endpoint resource prefix name override. Should not contain special characters                                                          | string Default : "intel.com"                          | "yourcompany.com"                                                      |
+| "deviceType"       | N        | Device Type for a resource pool.                                                                                                       | string value of supported types. Default: "netDevice" | Currently supported values: "accelerator", "netDevice", "auxNetDevice" |
+| "allocationPolicy" | N        | Preferred device allocation policy for a resource pool                                                                                 | string value of supported allocation policy. Default: "" | Currently supported values: "", "packed"                                            |
+| "excludeTopology"  | N        | Exclude advertising of device's NUMA topology                                                                                          | bool Default: "false"                                 | "excludeTopology": true                                                |
+| "selectors"        | N        | Either a single device selector map or a list of maps. The list syntax is preferred. The "deviceType" value determines the device selector options.                                                  | json list of objects or json object. Default: null                   | Example: "selectors": [{"vendors": ["8086"],"devices": ["154c"]}]        |
+| "additionalInfo"   | N        | A map of map to add additional information to the pod via environment variables to devices                                             | json object as string Default: null  | Example: "additionalInfo": {"*": {"token": "3e49019f-412f-4f02-824e-4cd195944205"}} |
 
 Note: "resourceName" must be unique only in the scope of a given prefix, including the one specified globally in the CLI params, e.g. "example.com/10G", "acme.com/10G" and "acme.com/40G" are perfectly valid names.
 
+#### Allocation Policy
+
+The "allocationPolicy" value determines which device in a resource pool is allocated. Each policy acts as following:
+
+| Policy   | Description                                       |
+|----------|---------------------------------------------------|
+| ""       | Disable preferred device allocation functionality |
+| "packed" | Try to allocate VFs from same PF                  |
+
 #### Device selectors
 
 The "selectors" field accepts both a single object and a list of selector objects. While both formats are supported, the list syntax is preferred. When using the list syntax, each selector object is evaluated in the order present in the list. For example, a single object would look like:

pkg/factory/factory.go

@@ -56,7 +56,12 @@ func (rf *resourceFactory) GetResourceServer(rp types.ResourcePool) (types.Resou
 		if prefixOverride := rp.GetResourcePrefix(); prefixOverride != "" {
 			prefix = prefixOverride
 		}
-		return resources.NewResourceServer(prefix, rf.endPointSuffix, rf.pluginWatch, rp), nil
+		policy := rp.GetAllocationPolicy()
+		allocator, err := rf.GetAllocator(policy)
+		if err != nil {
+			return nil, err
+		}
+		return resources.NewResourceServer(prefix, rf.endPointSuffix, rf.pluginWatch, rp, allocator), nil
 	}
 	return nil, fmt.Errorf("factory: unable to get resource pool object")
 }
@@ -221,3 +226,15 @@ func (rf *resourceFactory) GetDeviceFilter(rc *types.ResourceConfig) ([]interfac
 func (rf *resourceFactory) GetNadUtils() types.NadUtils {
 	return netdevice.NewNadUtils()
 }
+
+// GetAllocator returns an instance of Allocator using preferredAllocationPolicy
+func (rf *resourceFactory) GetAllocator(policy string) (types.Allocator, error) {
+	switch policy {
+	case "":
+		return nil, nil
+	case "packed":
+		return resources.NewPackedAllocator(), nil
+	default:
+		return nil, fmt.Errorf("GetAllocator(): invalid policy %s", policy)
+	}
+}

pkg/factory/factory_test.go

@@ -624,12 +624,35 @@ var _ = Describe("Factory", func() {
 			f := factory.NewResourceFactory("fake", "fake", true)
 			rp := mocks.ResourcePool{}
 			rp.On("GetResourcePrefix").Return("overridden").
-				On("GetResourceName").Return("fake")
+				On("GetResourceName").Return("fake").
+				On("GetAllocationPolicy").Return("")
 			rs, e := f.GetResourceServer(&rp)
 			It("should not fail", func() {
 				Expect(e).NotTo(HaveOccurred())
 				Expect(rs).NotTo(BeNil())
 			})
 		})
 	})
+	DescribeTable("getting allocator",
+		func(policy string, shouldSucceed bool, expected reflect.Type) {
+			f := factory.NewResourceFactory("fake", "fake", true)
+			allocator, error := f.GetAllocator(policy)
+
+			if shouldSucceed {
+				Expect(error).NotTo(HaveOccurred())
+			} else {
+				Expect(allocator).To(BeNil())
+			}
+
+			// if statement below because gomega refuses to do "nil == nil" assertions
+			if expected != nil {
+				Expect(reflect.TypeOf(allocator)).To(Equal(expected))
+			} else {
+				Expect(reflect.TypeOf(allocator)).To(BeNil())
+			}
+		},
+		Entry("packed", "packed", true, reflect.TypeOf(resources.NewPackedAllocator())),
+		Entry("empty", "", true, reflect.TypeOf(nil)),
+		Entry("invalid value", "invalid policy", false, reflect.TypeOf(nil)),
+	)
 })

pkg/resources/allocator.go

@@ -0,0 +1,112 @@
+// Copyright 2022 Intel Corp. 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.
+
+package resources
+
+import (
+	"sort"
+
+	"github.com/golang/glog"
+
+	pluginapi "k8s.io/kubelet/pkg/apis/deviceplugin/v1beta1"
+
+	"github.com/k8snetworkplumbingwg/sriov-network-device-plugin/pkg/types"
+)
+
+// DeviceSet is to hold and manipulate a set of HostDevice
+type DeviceSet map[string]types.HostDevice
+
+// PackedAllocator implements the Allocator interface
+type PackedAllocator struct {
+}
+
+// NewPackedAllocator create instance of PackedAllocator
+func NewPackedAllocator() *PackedAllocator {
+	return &PackedAllocator{}
+}
+
+// NewDeviceSet is to create an empty DeviceSet
+func NewDeviceSet() DeviceSet {
+	set := make(DeviceSet)
+	return set
+}
+
+// Insert is to add a HostDevice in DeviceSet
+func (ds *DeviceSet) Insert(pciAddr string, device types.HostDevice) {
+	(*ds)[pciAddr] = device
+}
+
+// Delete is to delete a HostDevice in DeviceSet
+func (ds *DeviceSet) Delete(pciAddr string) {
+	delete(*ds, pciAddr)
+}
+
+// AsSortedStrings is to sort the DeviceSet and return the sorted keys
+func (ds *DeviceSet) AsSortedStrings() []string {
+	keys := make([]string, 0, len(*ds))
+	for k := range *ds {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// Allocate return the preferred allocation
+func (pa *PackedAllocator) Allocate(rqt *pluginapi.ContainerPreferredAllocationRequest, rp types.ResourcePool) []string {
+	size := rqt.AllocationSize
+	preferredDevices := make([]string, 0)
+
+	if size <= 0 {
+		glog.Warningf("Allocator(): requested number of devices are negative. requested: %d", size)
+		return []string{}
+	}
+
+	if len(rqt.AvailableDeviceIDs) < int(size) {
+		glog.Warningf("Allocator(): not enough number of devices were available. available: %d, requested: %d", len(rqt.AvailableDeviceIDs), size)
+		return []string{}
+	}
+
+	if len(rqt.MustIncludeDeviceIDs) > int(size) {
+		glog.Warningf("Allocator(): allocated number of devices exceeded the number of requested devices. allocated: %d, requested: %d",
+			len(rqt.MustIncludeDeviceIDs),
+			size)
+	}
+
+	availableSet := NewDeviceSet()
+	for _, available := range rqt.AvailableDeviceIDs {
+		dev, ok := rp.GetDevicePool()[available]
+		if ok {
+			availableSet.Insert(available, dev)
+		} else {
+			glog.Warningf("Allocator(): not available device id was specified: %s", available)
+			return []string{}
+		}
+	}
+	for _, required := range rqt.MustIncludeDeviceIDs {
+		_, ok := rp.GetDevicePool()[required]
+		if ok {
+			availableSet.Delete(required)
+		} else {
+			glog.Warningf("Allocator(): not available device was included: %s", required)
+			return []string{}
+		}
+	}
+	sortedAvailableSet := availableSet.AsSortedStrings()
+
+	preferredDevices = append(preferredDevices, rqt.MustIncludeDeviceIDs...)
+	if len(preferredDevices) < int(size) {
+		preferredDevices = append(preferredDevices, sortedAvailableSet[:int(size)-len(preferredDevices)]...)
+	}
+	return preferredDevices
+}