source/custom: add rules for cpuid and kconfig

Signed-off-by: Mikko Ylinen <mikko.ylinen@intel.com>

README.md

@@ -390,6 +390,36 @@ loadedKMod : [<kernel module>, ...]
  Matching is done by performing logical _AND_ for each provided Element, i.e the Rule will match if all provided Elements (kernel modules) are loaded
  in the system.
 
+##### CpuId Rule
+###### Nomenclature
+```
+Element     :A CPUID flag
+```
+
+The Rule allows matching the available CPUID flags in the system against a provided list of Elements.
+
+###### Format
+```yaml
+cpuId : [<CPUID flag string>, ...]
+```
+ Matching is done by performing logical _AND_ for each provided Element, i.e the Rule will match if all provided Elements (CPUID flag strings) are available
+ in the system.
+
+##### Kconfig Rule
+###### Nomenclature
+```
+Element     :A Kconfig option
+```
+
+The Rule allows matching the kconfig options in the system against a provided list of Elements.
+
+###### Format
+```yaml
+kConfig: [<kernel config option ('y' or 'm') or '=<value>'>, ...]
+```
+ Matching is done by performing logical _AND_ for each provided Element, i.e the Rule will match if all provided Elements (kernel config options) are enabled ('y' or 'm') or matching '=<value>'.
+ in the kernel.
+
 #### Example
 
 ```yaml
@@ -419,6 +449,14 @@ custom:
       - pciId:
           vendor: ["15b3"]
           device: ["1014", "1017"]
+  - name: "my.kernel.featureneedscpu"
+    matchOn:
+      - kConfig: ["KVM_INTEL"]
+      - cpuId: ["VMX"]
+  - name: "my.kernel.modulecompiler"
+    matchOn:
+      - kConfig: ["GCC_VERSION=100101"]
+        loadedKMod: ["kmod1"]
 ```
 
 __In the example above:__
@@ -434,6 +472,9 @@ with a PCI vendor ID of `15b3` _AND_ PCI device ID of `1014` _or_ `1017`.
 - A node would contain the label: `feature.node.kubernetes.io/custom-my.accumulated.feature=true`
 if `some_kmod1` _AND_ `some_kmod2` kernel modules are loaded __OR__ the node contains a PCI device
 with a PCI vendor ID of `15b3` _AND_ PCI device ID of `1014` _OR_ `1017`.
+- A node would contain the label: `feature.node.kubernetes.io/custom-my.kernel.featureneedscpu=true`
+if `KVM_INTEL` kernel config is enabled __AND__ the node CPU supports `VMX` virtual machine extensions
+- A node would contain the label: `feature.node.kubernetes.io/custom-my.kernel.modulecompiler=true` if the in-tree `kmod1` kernel module is loaded __AND__ it's built with `GCC_VERSION=100101`.
 
 #### Statically defined features
 

source/custom/custom.go

@@ -28,6 +28,8 @@ type MatchRule struct {
 	PciID      *rules.PciIDRule      `json:"pciId,omitempty"`
 	UsbID      *rules.UsbIDRule      `json:"usbId,omitempty"`
 	LoadedKMod *rules.LoadedKModRule `json:"loadedKMod,omitempty"`
+	CpuID      *rules.CpuIDRule      `json:"cpuId,omitempty"`
+	Kconfig    *rules.KconfigRule    `json:"kConfig,omitempty"`
 }
 
 type FeatureSpec struct {
@@ -119,6 +121,26 @@ func (s Source) discoverFeature(feature FeatureSpec) (bool, error) {
 				continue
 			}
 		}
+		// cpuid rule
+		if rule.CpuID != nil {
+			match, err := rule.CpuID.Match()
+			if err != nil {
+				return false, err
+			}
+			if !match {
+				continue
+			}
+		}
+		// kconfig rule
+		if rule.Kconfig != nil {
+			match, err := rule.Kconfig.Match()
+			if err != nil {
+				return false, err
+			}
+			if !match {
+				continue
+			}
+		}
 		return true, nil
 	}
 	return false, nil

source/custom/rules/cpuid_rule.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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 rules
+
+import (
+	"sigs.k8s.io/node-feature-discovery/source/internal/cpuidutils"
+)
+
+// CpuIDRule implements Rule
+type CpuIDRule []string
+
+var cpuIdFlags map[string]struct{}
+
+func (cpuids *CpuIDRule) Match() (bool, error) {
+	for _, f := range *cpuids {
+		if _, ok := cpuIdFlags[f]; !ok {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func init() {
+	cpuIdFlags = make(map[string]struct{})
+	for _, f := range cpuidutils.GetCpuidFlags() {
+		cpuIdFlags[f] = struct{}{}
+	}
+}

source/custom/rules/kconfig_rule.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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 rules
+
+import (
+	"fmt"
+	"sigs.k8s.io/node-feature-discovery/source/internal/kernelutils"
+)
+
+// KconfigRule implements Rule
+type KconfigRule []string
+
+var kConfigs map[string]struct{}
+
+func (kconfigs *KconfigRule) Match() (bool, error) {
+	for _, f := range *kconfigs {
+		if _, ok := kConfigs[f]; !ok {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+func init() {
+	kConfigs = make(map[string]struct{})
+
+	kconfig, err := kernelutils.ParseKconfig("")
+	if err == nil {
+		for k, v := range kconfig {
+			if v != "true" {
+				kConfigs[fmt.Sprintf("%s=%s", k, v)] = struct{}{}
+			} else {
+				kConfigs[k] = struct{}{}
+			}
+		}
+	}
+}