ccw: add ccw type as bridge

On IBM Z, CCW bus type can be additionally used.

Fixes: kata-containers#1153

Signed-off-by: Alice Frosi <afrosi@de.ibm.com>
Reviewed-by: Jan Schintag <jan.schintag@de.ibm.com>

virtcontainers/qemu.go

@@ -1764,6 +1764,9 @@ func genericAppendBridges(devices []govmmQemu.Device, bridges []types.Bridge, ma
 		if b.Type == types.PCIE {
 			t = govmmQemu.PCIEBridge
 		}
+		if b.Type == types.CCW {
+			continue
+		}
 
 		bridges[idx].Addr = bridgePCIStartAddr + idx
 
@@ -1783,7 +1786,6 @@ func genericAppendBridges(devices []govmmQemu.Device, bridges []types.Bridge, ma
 	return devices
 }
 
-// nolint: unused, deadcode
 func genericBridges(number uint32, machineType string) []types.Bridge {
 	var bridges []types.Bridge
 	var bt types.Type
@@ -1800,7 +1802,7 @@ func genericBridges(number uint32, machineType string) []types.Bridge {
 	case QemuPseries:
 		bt = types.PCI
 	case QemuCCWVirtio:
-		bt = types.PCI
+		bt = types.CCW
 	default:
 		return nil
 	}

virtcontainers/qemu_arch_base.go

@@ -362,6 +362,9 @@ func (q *qemuArchBase) appendSCSIController(devices []govmmQemu.Device, enableIO
 // appendBridges appends to devices the given bridges
 func (q *qemuArchBase) appendBridges(devices []govmmQemu.Device) []govmmQemu.Device {
 	for idx, b := range q.Bridges {
+		if b.Type == types.CCW {
+			continue
+		}
 		t := govmmQemu.PCIBridge
 		if b.Type == types.PCIE {
 			t = govmmQemu.PCIEBridge
@@ -618,6 +621,8 @@ func (q *qemuArchBase) addDeviceToBridge(ID string, t types.Type) (string, types
 		addr, err = b.AddDevice(ID)
 		if err == nil {
 			switch t {
+			case types.CCW:
+				return fmt.Sprintf("%04x", addr), b, nil
 			case types.PCI, types.PCIE:
 				return fmt.Sprintf("%02x", addr), b, nil
 			}

virtcontainers/qemu_s390x.go

@@ -11,6 +11,7 @@ import (
 
 	govmmQemu "github.com/intel/govmm/qemu"
 	"github.com/kata-containers/runtime/virtcontainers/device/config"
+	"github.com/kata-containers/runtime/virtcontainers/types"
 )
 
 type qemuS390x struct {
@@ -39,6 +40,8 @@ var kernelParams = []Param{
 
 var kernelRootParams = commonVirtioblkKernelRootParams
 
+var ccwbridge = types.NewBridge(types.CCW, "", make(map[uint32]string, types.CCWBridgeMaxCapacity), 0)
+
 var supportedQemuMachines = []govmmQemu.Machine{
 	{
 		Type:    QemuCCWVirtio,
@@ -71,6 +74,8 @@ func newQemuArch(config HypervisorConfig) qemuArch {
 			kernelParams:          kernelParams,
 		},
 	}
+	// Set first bridge type to CCW
+	q.Bridges = append(q.Bridges, ccwbridge)
 
 	if config.ImagePath != "" {
 		q.kernelParams = append(q.kernelParams, kernelRootParams...)

virtcontainers/types/bridges.go

@@ -10,7 +10,7 @@ import "fmt"
 // Type represents a type of bus and bridge.
 type Type string
 
-const pciBridgeMaxCapacity = 30
+const PCIBridgeMaxCapacity = 30
 
 const (
 	// PCI represents a PCI bus and bridge
@@ -20,6 +20,12 @@ const (
 	PCIE Type = "pcie"
 )
 
+const CCWBridgeMaxCapacity = 0xffff
+
+const (
+	CCW Type = "ccw"
+)
+
 type Bridge struct {
 	// Devices contains information about devices plugged and its address in the bridge
 	Devices map[uint32]string
@@ -43,7 +49,9 @@ func NewBridge(bt Type, id string, devices map[uint32]string, addr int) Bridge {
 	case PCI:
 		fallthrough
 	case PCIE:
-		maxCapacity = pciBridgeMaxCapacity
+		maxCapacity = PCIBridgeMaxCapacity
+	case CCW:
+		maxCapacity = CCWBridgeMaxCapacity
 	default:
 		maxCapacity = 0
 	}
@@ -88,3 +96,20 @@ func (b *Bridge) RemoveDevice(ID string) error {
 
 	return fmt.Errorf("Unable to hot unplug device %s: not present on bridge", ID)
 }
+
+// AddressFormatCCW returns the address format for the device number. The channel subsystem-ID 0xfe is reserved to the virtual channel and the address format is in the form fe.n.dddd, where n is subchannel set ID and ddd the device number. More details at https://www.ibm.com/support/knowledgecenter/en/linuxonibm/com.ibm.linux.z.ldva/ldva_t_configuringSCSIdevices.html
+func (b *Bridge) AddressFormatCCW(addr string) (string, error) {
+	if b.Type != CCW {
+		return "", fmt.Errorf("Expected bridge type %T, got %T (%+v)", CCW, b.Type, b)
+	}
+
+	return fmt.Sprintf("fe.%x.%s", b.Addr, addr), nil
+}
+
+// AddressFormatCCWForVirtServer returns the address format for the virtual server. The address format is in the form of 0.n.dddd
+func (b *Bridge) AddressFormatCCWForVirtServer(addr string) (string, error) {
+	if b.Type != CCW {
+		return "", fmt.Errorf("Wrong bridge type")
+	}
+	return fmt.Sprintf("0.%x.%s", b.Addr, addr), nil
+}

virtcontainers/types/bridges_test.go

@@ -46,7 +46,15 @@ func testAddRemoveDevice(t *testing.T, b *Bridge) {
 func TestAddRemoveDevicePCI(t *testing.T) {
 
 	// create a pci bridge
-	bridges := []*Bridge{{make(map[uint32]string), "rgb123", 5, PCI, pciBridgeMaxCapacity}}
+	bridges := []*Bridge{{make(map[uint32]string), "rgb123", 5, PCI, PCIBridgeMaxCapacity}}
+
+	testAddRemoveDevice(t, bridges[0])
+}
+
+func TestAddRemoveDeviceCCW(t *testing.T) {
+
+	// create a CCW bridge
+	bridges := []*Bridge{{make(map[uint32]string), "rgb123", 5, CCW, CCWBridgeMaxCapacity}}
 
 	testAddRemoveDevice(t, bridges[0])
 }