bridges: abstraction of bridge type

The abstraction of the bridge type to add additional types.

Fixes: kata-containers#1153

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

virtcontainers/qemu.go

@@ -61,7 +61,7 @@ type CPUDevice struct {
 
 // QemuState keeps Qemu's state
 type QemuState struct {
-	Bridges []types.PCIBridge
+	Bridges []types.Bridge
 	// HotpluggedCPUs is the list of CPUs that were hot-added
 	HotpluggedVCPUs      []CPUDevice
 	HotpluggedMemory     int
@@ -984,12 +984,12 @@ func (q *qemu) qmpShutdown() {
 	}
 }
 
-func (q *qemu) addDeviceToBridge(ID string) (string, types.PCIBridge, error) {
+func (q *qemu) addDeviceToBridge(ID string) (string, types.Bridge, error) {
 	var err error
 	var addr uint32
 
 	if len(q.state.Bridges) == 0 {
-		return "", types.PCIBridge{}, errors.New("failed to get available address from bridges")
+		return "", types.Bridge{}, errors.New("failed to get available address from bridges")
 	}
 
 	// looking for an empty address in the bridges
@@ -1000,7 +1000,7 @@ func (q *qemu) addDeviceToBridge(ID string) (string, types.PCIBridge, error) {
 		}
 	}
 
-	return "", types.PCIBridge{}, fmt.Errorf("no more bridge slots available")
+	return "", types.Bridge{}, fmt.Errorf("no more bridge slots available")
 }
 
 func (q *qemu) removeDeviceFromBridge(ID string) error {
@@ -1750,7 +1750,7 @@ func (q *qemu) resizeMemory(reqMemMB uint32, memoryBlockSizeMB uint32, probe boo
 
 // genericAppendBridges appends to devices the given bridges
 // nolint: unused, deadcode
-func genericAppendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge, machineType string) []govmmQemu.Device {
+func genericAppendBridges(devices []govmmQemu.Device, bridges []types.Bridge, machineType string) []govmmQemu.Device {
 	bus := defaultPCBridgeBus
 	switch machineType {
 	case QemuQ35, QemuVirt:
@@ -1782,9 +1782,9 @@ func genericAppendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge,
 }
 
 // nolint: unused, deadcode
-func genericBridges(number uint32, machineType string) []types.PCIBridge {
-	var bridges []types.PCIBridge
-	var bt types.PCIType
+func genericBridges(number uint32, machineType string) []types.Bridge {
+	var bridges []types.Bridge
+	var bt types.Type
 
 	switch machineType {
 	case QemuQ35:
@@ -1804,11 +1804,7 @@ func genericBridges(number uint32, machineType string) []types.PCIBridge {
 	}
 
 	for i := uint32(0); i < number; i++ {
-		bridges = append(bridges, types.PCIBridge{
-			Type:    bt,
-			ID:      fmt.Sprintf("%s-bridge-%d", bt, i),
-			Address: make(map[uint32]string),
-		})
+		bridges = append(bridges, types.NewBridge(bt, fmt.Sprintf("%s-bridge-%d", bt, i), make(map[uint32]string), 0))
 	}
 
 	return bridges
@@ -2010,7 +2006,7 @@ func (q *qemu) save() (s persistapi.HypervisorState) {
 
 	for _, bridge := range q.state.Bridges {
 		s.Bridges = append(s.Bridges, persistapi.Bridge{
-			DeviceAddr: bridge.Address,
+			DeviceAddr: bridge.Devices,
 			Type:       string(bridge.Type),
 			ID:         bridge.ID,
 			Addr:       bridge.Addr,
@@ -2032,12 +2028,8 @@ func (q *qemu) load(s persistapi.HypervisorState) {
 	q.state.VirtiofsdPid = s.VirtiofsdPid
 
 	for _, bridge := range s.Bridges {
-		q.state.Bridges = append(q.state.Bridges, types.PCIBridge{
-			Address: bridge.DeviceAddr,
-			Type:    types.PCIType(bridge.Type),
-			ID:      bridge.ID,
-			Addr:    bridge.Addr,
-		})
+		b := types.NewBridge(types.Type(bridge.Type), bridge.ID, bridge.DeviceAddr, bridge.Addr)
+		q.state.Bridges = append(q.state.Bridges, b)
 	}
 
 	for _, cpu := range s.HotpluggedVCPUs {

virtcontainers/qemu_amd64.go

@@ -122,7 +122,7 @@ func (q *qemuAmd64) capabilities() types.Capabilities {
 	return caps
 }
 
-func (q *qemuAmd64) bridges(number uint32) []types.PCIBridge {
+func (q *qemuAmd64) bridges(number uint32) []types.Bridge {
 	return genericBridges(number, q.machineType)
 }
 
@@ -173,6 +173,6 @@ func (q *qemuAmd64) appendImage(devices []govmmQemu.Device, path string) ([]govm
 }
 
 // appendBridges appends to devices the given bridges
-func (q *qemuAmd64) appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device {
+func (q *qemuAmd64) appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device {
 	return genericAppendBridges(devices, bridges, q.machineType)
 }

virtcontainers/qemu_amd64_test.go

@@ -47,7 +47,7 @@ func TestQemuAmd64Bridges(t *testing.T) {
 		id := fmt.Sprintf("%s-bridge-%d", types.PCI, i)
 		assert.Equal(types.PCI, b.Type)
 		assert.Equal(id, b.ID)
-		assert.NotNil(b.Address)
+		assert.NotNil(b.Devices)
 	}
 
 	amd64 = newTestQemu(QemuQ35)
@@ -58,7 +58,7 @@ func TestQemuAmd64Bridges(t *testing.T) {
 		id := fmt.Sprintf("%s-bridge-%d", types.PCI, i)
 		assert.Equal(types.PCI, b.Type)
 		assert.Equal(id, b.ID)
-		assert.NotNil(b.Address)
+		assert.NotNil(b.Devices)
 	}
 
 	amd64 = newTestQemu(QemuQ35 + QemuPC)

virtcontainers/qemu_arch_base.go

@@ -49,7 +49,7 @@ type qemuArch interface {
 	capabilities() types.Capabilities
 
 	// bridges returns the number bridges for the machine type
-	bridges(number uint32) []types.PCIBridge
+	bridges(number uint32) []types.Bridge
 
 	// cpuTopology returns the CPU topology for the given amount of vcpus
 	cpuTopology(vcpus, maxvcpus uint32) govmmQemu.SMP
@@ -70,7 +70,7 @@ type qemuArch interface {
 	appendSCSIController(devices []govmmQemu.Device, enableIOThreads bool) ([]govmmQemu.Device, *govmmQemu.IOThread)
 
 	// appendBridges appends bridges to devices
-	appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device
+	appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device
 
 	// append9PVolume appends a 9P volume to devices
 	append9PVolume(devices []govmmQemu.Device, volume types.Volume) []govmmQemu.Device
@@ -242,15 +242,11 @@ func (q *qemuArchBase) capabilities() types.Capabilities {
 	return caps
 }
 
-func (q *qemuArchBase) bridges(number uint32) []types.PCIBridge {
-	var bridges []types.PCIBridge
+func (q *qemuArchBase) bridges(number uint32) []types.Bridge {
+	var bridges []types.Bridge
 
 	for i := uint32(0); i < number; i++ {
-		bridges = append(bridges, types.PCIBridge{
-			Type:    types.PCI,
-			ID:      fmt.Sprintf("%s-bridge-%d", types.PCI, i),
-			Address: make(map[uint32]string),
-		})
+		bridges = append(bridges, types.NewBridge(types.PCI, fmt.Sprintf("%s-bridge-%d", types.PCI, i), make(map[uint32]string), 0))
 	}
 
 	return bridges
@@ -351,7 +347,7 @@ func (q *qemuArchBase) appendSCSIController(devices []govmmQemu.Device, enableIO
 }
 
 // appendBridges appends to devices the given bridges
-func (q *qemuArchBase) appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device {
+func (q *qemuArchBase) appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device {
 	for idx, b := range bridges {
 		t := govmmQemu.PCIBridge
 		if b.Type == types.PCIE {

virtcontainers/qemu_arch_base_test.go

@@ -154,7 +154,7 @@ func TestQemuArchBaseBridges(t *testing.T) {
 		id := fmt.Sprintf("%s-bridge-%d", types.PCI, i)
 		assert.Equal(types.PCI, b.Type)
 		assert.Equal(id, b.ID)
-		assert.NotNil(b.Address)
+		assert.NotNil(b.Devices)
 	}
 }
 

virtcontainers/qemu_arm64.go

@@ -162,12 +162,12 @@ func newQemuArch(config HypervisorConfig) qemuArch {
 	return q
 }
 
-func (q *qemuArm64) bridges(number uint32) []types.PCIBridge {
+func (q *qemuArm64) bridges(number uint32) []types.Bridge {
 	return genericBridges(number, q.machineType)
 }
 
 // appendBridges appends to devices the given bridges
-func (q *qemuArm64) appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device {
+func (q *qemuArm64) appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device {
 	return genericAppendBridges(devices, bridges, q.machineType)
 }
 

virtcontainers/qemu_ppc64le.go

@@ -105,7 +105,7 @@ func (q *qemuPPC64le) capabilities() types.Capabilities {
 	return caps
 }
 
-func (q *qemuPPC64le) bridges(number uint32) []types.PCIBridge {
+func (q *qemuPPC64le) bridges(number uint32) []types.Bridge {
 	return genericBridges(number, q.machineType)
 }
 
@@ -152,6 +152,6 @@ func (q *qemuPPC64le) appendImage(devices []govmmQemu.Device, path string) ([]go
 }
 
 // appendBridges appends to devices the given bridges
-func (q *qemuPPC64le) appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device {
+func (q *qemuPPC64le) appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device {
 	return genericAppendBridges(devices, bridges, q.machineType)
 }

virtcontainers/qemu_s390x.go

@@ -82,12 +82,12 @@ func newQemuArch(config HypervisorConfig) qemuArch {
 	return q
 }
 
-func (q *qemuS390x) bridges(number uint32) []types.PCIBridge {
+func (q *qemuS390x) bridges(number uint32) []types.Bridge {
 	return genericBridges(number, q.machineType)
 }
 
 // appendBridges appends to devices the given bridges
-func (q *qemuS390x) appendBridges(devices []govmmQemu.Device, bridges []types.PCIBridge) []govmmQemu.Device {
+func (q *qemuS390x) appendBridges(devices []govmmQemu.Device, bridges []types.Bridge) []govmmQemu.Device {
 	return genericAppendBridges(devices, bridges, q.machineType)
 }
 

virtcontainers/types/bridges.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2017 Intel Corporation
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package types
+
+import "fmt"
+
+// Type represents a type of bus and bridge.
+type Type string
+
+const pciBridgeMaxCapacity = 30
+
+const (
+	// PCI represents a PCI bus and bridge
+	PCI Type = "pci"
+
+	// PCIE represents a PCIe bus and bridge
+	PCIE Type = "pcie"
+)
+
+type Bridge struct {
+	// Devices contains information about devices plugged and its address in the bridge
+	Devices map[uint32]string
+
+	// ID is used to identify the bridge in the hypervisor
+	ID string
+
+	// Addr is the slot of the bridge
+	Addr int
+
+	// Type is the type of the bridge (pci, pcie, etc)
+	Type Type
+
+	// MaxCapacity is the max capacity of the bridge
+	MaxCapacity uint32
+}
+
+func NewBridge(bt Type, id string, devices map[uint32]string, addr int) Bridge {
+	var maxCapacity uint32
+	switch bt {
+	case PCI:
+		fallthrough
+	case PCIE:
+		maxCapacity = pciBridgeMaxCapacity
+	default:
+		maxCapacity = 0
+	}
+	return Bridge{
+		Devices:     devices,
+		ID:          id,
+		Addr:        addr,
+		Type:        bt,
+		MaxCapacity: maxCapacity,
+	}
+}
+
+func (b *Bridge) AddDevice(ID string) (uint32, error) {
+	var addr uint32
+
+	// looking for the first available address
+	for i := uint32(1); i <= b.MaxCapacity; i++ {
+		if _, ok := b.Devices[i]; !ok {
+			addr = i
+			break
+		}
+	}
+
+	if addr == 0 {
+		return 0, fmt.Errorf("Unable to hot plug device on bridge: there are no empty slots")
+	}
+
+	// save address and device
+	b.Devices[addr] = ID
+	return addr, nil
+}
+
+func (b *Bridge) RemoveDevice(ID string) error {
+	// check if the device was hot plugged in the bridge
+	for addr, devID := range b.Devices {
+		if devID == ID {
+			// free address to re-use the same slot with other devices
+			delete(b.Devices, addr)
+			return nil
+		}
+	}
+
+	return fmt.Errorf("Unable to hot unplug device %s: not present on bridge", ID)
+}

virtcontainers/types/pci_test.go → virtcontainers/types/bridges_test.go

@@ -12,15 +12,12 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestAddRemoveDevice(t *testing.T) {
+func testAddRemoveDevice(t *testing.T, b *Bridge) {
 	assert := assert.New(t)
 
-	// create a bridge
-	bridges := []*PCIBridge{{make(map[uint32]string), PCI, "rgb123", 5}}
-
 	// add device
 	devID := "abc123"
-	b := bridges[0]
+
 	addr, err := b.AddDevice(devID)
 	assert.NoError(err)
 	if addr < 1 {
@@ -35,13 +32,21 @@ func TestAddRemoveDevice(t *testing.T) {
 	assert.NoError(err)
 
 	// add device when the bridge is full
-	bridges[0].Address = make(map[uint32]string)
-	for i := uint32(1); i <= pciBridgeMaxCapacity; i++ {
-		bridges[0].Address[i] = fmt.Sprintf("%d", i)
+	b.Devices = make(map[uint32]string)
+	for i := uint32(1); i <= b.MaxCapacity; i++ {
+		b.Devices[i] = fmt.Sprintf("%d", i)
 	}
 	addr, err = b.AddDevice(devID)
 	assert.Error(err)
 	if addr != 0 {
 		assert.Fail("address should be 0")
 	}
 }
+
+func TestAddRemoveDevicePCI(t *testing.T) {
+
+	// create a pci bridge
+	bridges := []*Bridge{{make(map[uint32]string), "rgb123", 5, PCI, pciBridgeMaxCapacity}}
+
+	testAddRemoveDevice(t, bridges[0])
+}