qemu/qmp: support query-memory-devices qmp command.

Implement query qemu memory devices function and testcase.

Signed-off-by: Clare Chen <clare.chenhui@huawei.com>

qemu/qmp.go

@@ -160,6 +160,24 @@ type HotpluggableCPU struct {
 	QOMPath    string        `json:"qom-path"`
 }
 
+// MemoryDevicesData cotains the data describes a memory device
+type MemoryDevicesData struct {
+	Slot         int    `json:"slot"`
+	Node         int    `json:"node"`
+	Addr         uint64 `json:"addr"`
+	Memdev       string `json:"memdev"`
+	ID           string `json:"id"`
+	Hotpluggable bool   `json:"hotpluggable"`
+	Hotplugged   bool   `json:"hotplugged"`
+	Size         uint64 `json:"size"`
+}
+
+// MemoryDevices represents memory devices of vm
+type MemoryDevices struct {
+	Data MemoryDevicesData `json:"data"`
+	Type string            `json:"type"`
+}
+
 func (q *QMP) readLoop(fromVMCh chan<- []byte) {
 	scanner := bufio.NewScanner(q.conn)
 	for scanner.Scan() {
@@ -989,6 +1007,28 @@ func (q *QMP) ExecSetMigrateArguments(ctx context.Context, url string) error {
 	return q.executeCommand(ctx, "migrate", args, nil)
 }
 
+// ExecQueryMemoryDevices returns a slice with the list of memory devices
+func (q *QMP) ExecQueryMemoryDevices(ctx context.Context) ([]MemoryDevices, error) {
+	response, err := q.executeCommandWithResponse(ctx, "query-memory-devices", nil, nil, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// convert response to json
+	data, err := json.Marshal(response)
+	if err != nil {
+		return nil, fmt.Errorf("Unable to extract memory devices information: %v", err)
+	}
+
+	var memoryDevices []MemoryDevices
+	// convert json to []MemoryDevices
+	if err = json.Unmarshal(data, &memoryDevices); err != nil {
+		return nil, fmt.Errorf("unable to convert json to memory devices: %v", err)
+	}
+
+	return memoryDevices, nil
+}
+
 // ExecHotplugMemory adds size of MiB memory to the guest
 func (q *QMP) ExecHotplugMemory(ctx context.Context, qomtype, id, mempath string, size int) error {
 	args := map[string]interface{}{

qemu/qmp_test.go

@@ -1055,6 +1055,42 @@ func TestQMPExecuteQueryHotpluggableCPUs(t *testing.T) {
 	<-disconnectedCh
 }
 
+// Checks that memory devices are listed correctly
+func TestQMPExecuteQueryMemoryDevices(t *testing.T) {
+	connectedCh := make(chan *QMPVersion)
+	disconnectedCh := make(chan struct{})
+	buf := newQMPTestCommandBuffer(t)
+	memoryDevices := MemoryDevices{
+		Type: "dimm",
+		Data: MemoryDevicesData{
+			Slot:         1,
+			Node:         0,
+			Addr:         1234,
+			Memdev:       "dimm1",
+			ID:           "mem1",
+			Hotpluggable: true,
+			Hotplugged:   false,
+			Size:         1234,
+		},
+	}
+	buf.AddCommand("query-memory-devices", nil, "return", []interface{}{memoryDevices})
+	cfg := QMPConfig{Logger: qmpTestLogger{}}
+	q := startQMPLoop(buf, cfg, connectedCh, disconnectedCh)
+	checkVersion(t, connectedCh)
+	memDevices, err := q.ExecQueryMemoryDevices(context.Background())
+	if err != nil {
+		t.Fatalf("Unexpected error: %v\n", err)
+	}
+	if len(memDevices) != 1 {
+		t.Fatalf("Expected memory devices length equals to 1\n")
+	}
+	if reflect.DeepEqual(memDevices[0], memoryDevices) == false {
+		t.Fatalf("Expected %v equals to %v\n", memDevices[0], memoryDevices)
+	}
+	q.Shutdown()
+	<-disconnectedCh
+}
+
 // Checks that migrate capabilities can be set
 func TestExecSetMigrationCaps(t *testing.T) {
 	connectedCh := make(chan *QMPVersion)