libct/cg/sd/v2: support cpu.max unified resource

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/cgroups/systemd/v2.go

@@ -45,7 +45,9 @@ func NewUnifiedManager(config *configs.Cgroup, path string, rootless bool) cgrou
 // For the list of keys, see https://www.kernel.org/doc/Documentation/cgroup-v2.txt
 //
 // For the list of systemd unit properties, see systemd.resource-control(5).
-func unifiedResToSystemdProps(res map[string]string) (props []systemdDbus.Property, _ error) {
+func unifiedResToSystemdProps(conn *systemdDbus.Conn, res map[string]string) (props []systemdDbus.Property, _ error) {
+	var err error
+
 	for k, v := range res {
 		if strings.Contains(k, "/") {
 			return nil, fmt.Errorf("unified resource %q must be a file name (no slashes)", k)
@@ -57,7 +59,32 @@ func unifiedResToSystemdProps(res map[string]string) (props []systemdDbus.Proper
 		// Kernel is quite forgiving to extra whitespace
 		// around the value, and so should we.
 		v = strings.TrimSpace(v)
+		// Please keep cases in alphabetical order.
 		switch k {
+		case "cpu.max":
+			// value: quota [period]
+			quota := int64(0) // 0 means "unlimited" for addCpuQuota, if period is set
+			period := defCPUQuotaPeriod
+			sv := strings.Fields(v)
+			if len(sv) < 1 || len(sv) > 2 {
+				return nil, fmt.Errorf("unified resource %q value invalid: %q", k, v)
+			}
+			// quota
+			if sv[0] != "max" {
+				quota, err = strconv.ParseInt(sv[0], 10, 64)
+				if err != nil {
+					return nil, fmt.Errorf("unified resource %q period value conversion error: %w", k, err)
+				}
+			}
+			// period
+			if len(sv) == 2 {
+				period, err = strconv.ParseUint(sv[1], 10, 64)
+				if err != nil {
+					return nil, fmt.Errorf("unified resource %q quota value conversion error: %w", k, err)
+				}
+			}
+			addCpuQuota(conn, &props, quota, period)
+
 		case "pids.max":
 			num := uint64(math.MaxUint64)
 			if v != "max" {
@@ -131,7 +158,7 @@ func genV2ResourcesProperties(c *configs.Cgroup, conn *systemdDbus.Conn) ([]syst
 
 	// convert Resources.Unified map to systemd properties
 	if r.Unified != nil {
-		unifiedProps, err := unifiedResToSystemdProps(r.Unified)
+		unifiedProps, err := unifiedResToSystemdProps(conn, r.Unified)
 		if err != nil {
 			return nil, err
 		}

tests/integration/cgroups.bats

@@ -218,6 +218,7 @@ function setup() {
 	echo "$output" | grep -q '^cpu.max:10000 100000$'
 
 	check_systemd_value "TasksMax" 99
+	check_cpu_quota 10000 100000 "100ms"
 }
 
 @test "runc run (cgroup v2 resources.unified override)" {
@@ -226,10 +227,15 @@ function setup() {
 	set_cgroups_path "$BUSYBOX_BUNDLE"
 	update_config '   .linux.resources.memory |= {"limit": 33554432}
 			| .linux.resources.memorySwap |= {"limit": 33554432}
+			| .linux.resources.cpu |= {
+				"quota": 40000,
+				"period": 100000
+			}
 			| .linux.resources.unified |= {
 				"memory.min": "131072",
 				"memory.max": "10485760",
-				"pids.max": "42"
+				"pids.max": "42",
+				"cpu.max": "5000 50000"
 			}' "$BUSYBOX_BUNDLE"
 
 	runc run -d --console-socket "$CONSOLE_SOCKET" test_cgroups_unified
@@ -247,4 +253,6 @@ function setup() {
 	[ "$status" -eq 0 ]
 	[ "$output" = '42' ]
 	check_systemd_value "TasksMax" 42
+
+	check_cpu_quota 5000 50000 "100ms"
 }