qemu: add support for device loaders

Devices loaders can be used to load some firmwares.

Signed-off-by: Julio Montes <julio.montes@intel.com>

qemu/qemu.go

@@ -131,6 +131,9 @@ const (
 
 	// PCIeRootPort is a PCIe Root Port, the PCIe device should be hotplugged to this port.
 	PCIeRootPort DeviceDriver = "pcie-root-port"
+
+	// Loader is the Loader device driver.
+	Loader DeviceDriver = "loader"
 )
 
 func isDimmSupported(config *Config) bool {
@@ -1138,6 +1141,40 @@ func (dev PVPanicDevice) QemuParams(config *Config) []string {
 	return []string{"-device", "pvpanic"}
 }
 
+// LoaderDevice represents a qemu loader device.
+type LoaderDevice struct {
+	File string
+	ID   string
+}
+
+// Valid returns true if there is a valid structure defined for LoaderDevice
+func (dev LoaderDevice) Valid() bool {
+	if dev.File == "" {
+		return false
+	}
+
+	if dev.ID == "" {
+		return false
+	}
+
+	return true
+}
+
+// QemuParams returns the qemu parameters built out of this loader device.
+func (dev LoaderDevice) QemuParams(config *Config) []string {
+	var qemuParams []string
+	var devParams []string
+
+	devParams = append(devParams, "loader")
+	devParams = append(devParams, fmt.Sprintf("file=%s", dev.File))
+	devParams = append(devParams, fmt.Sprintf("id=%s", dev.ID))
+
+	qemuParams = append(qemuParams, "-device")
+	qemuParams = append(qemuParams, strings.Join(devParams, ","))
+
+	return qemuParams
+}
+
 // VhostUserDevice represents a qemu vhost-user device meant to be passed
 // in to the guest
 type VhostUserDevice struct {

qemu/qemu_test.go

@@ -1240,3 +1240,20 @@ func TestAppendPVPanicDevice(t *testing.T) {
 		testAppend(tc.dev, tc.out, t)
 	}
 }
+
+func TestLoaderDevice(t *testing.T) {
+	testCases := []struct {
+		dev Device
+		out string
+	}{
+		{nil, ""},
+		{LoaderDevice{}, ""},
+		{LoaderDevice{File: "f"}, ""},
+		{LoaderDevice{ID: "id"}, ""},
+		{LoaderDevice{File: "f", ID: "id"}, "-device loader,file=f,id=id"},
+	}
+
+	for _, tc := range testCases {
+		testAppend(tc.dev, tc.out, t)
+	}
+}