virtcontainers: add a vm abstraction layer

As representation of a guest without actual sandbox attached to it.
This prepares for vm factory support.

Signed-off-by: Peng Tao <bergwolf@gmail.com>

virtcontainers/vm.go

@@ -0,0 +1,227 @@
+// Copyright (c) 2018 HyperHQ Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package virtcontainers
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/kata-containers/runtime/virtcontainers/pkg/uuid"
+	"github.com/sirupsen/logrus"
+)
+
+// VM is abstraction of a virtual machine.
+type VM struct {
+	id string
+
+	hypervisor hypervisor
+	agent      agent
+
+	cpu    uint32
+	memory uint32
+
+	cpuDelta uint32
+}
+
+// VMConfig is a collection of all info that a new blackbox VM needs.
+type VMConfig struct {
+	HypervisorType   HypervisorType
+	HypervisorConfig HypervisorConfig
+
+	AgentType   AgentType
+	AgentConfig interface{}
+}
+
+// Valid check VMConfig validity.
+func (c *VMConfig) Valid() error {
+	return c.HypervisorConfig.valid()
+}
+
+// NewVM creates a new VM based on provided VMConfig.
+func NewVM(config VMConfig) (*VM, error) {
+	hypervisor, err := newHypervisor(config.HypervisorType)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = config.Valid(); err != nil {
+		return nil, err
+	}
+
+	id := uuid.Generate().String()
+
+	virtLog.WithField("vm id", id).WithField("config", config).Info("create new vm")
+
+	defer func() {
+		if err != nil {
+			virtLog.WithField("vm id", id).WithError(err).Error("failed to create new vm")
+		}
+	}()
+
+	if err = hypervisor.init(id, &config.HypervisorConfig, Resources{}, &filesystem{}); err != nil {
+		return nil, err
+	}
+
+	if err = hypervisor.createSandbox(); err != nil {
+		return nil, err
+	}
+
+	agent := newAgent(config.AgentType)
+	agentConfig := newAgentConfig(config.AgentType, config.AgentConfig)
+	// do not keep connection for temp agent
+	if c, ok := agentConfig.(KataAgentConfig); ok {
+		c.LongLiveConn = false
+	}
+	vmSharePath := buildVMSharePath(id)
+	err = agent.configure(hypervisor, id, vmSharePath, true, agentConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = hypervisor.startSandbox(); err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if err != nil {
+			virtLog.WithField("vm id", id).WithError(err).Info("clean up vm")
+			hypervisor.stopSandbox()
+		}
+	}()
+
+	// VMs booted from template are paused, do not check
+	if !config.HypervisorConfig.BootFromTemplate {
+		err = hypervisor.waitSandbox(vmStartTimeout)
+		if err != nil {
+			return nil, err
+		}
+
+		virtLog.WithField("vm id", id).Info("check agent status")
+		err = agent.check()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &VM{
+		id:         id,
+		hypervisor: hypervisor,
+		agent:      agent,
+		cpu:        config.HypervisorConfig.DefaultVCPUs,
+		memory:     config.HypervisorConfig.DefaultMemSz,
+	}, nil
+}
+
+func buildVMSharePath(id string) string {
+	return filepath.Join(RunVMStoragePath, id, "shared")
+}
+
+func (v *VM) logger() logrus.FieldLogger {
+	return virtLog.WithField("vm id", v.id)
+}
+
+// Pause pauses a VM.
+func (v *VM) Pause() error {
+	v.logger().Info("pause vm")
+	return v.hypervisor.pauseSandbox()
+}
+
+// Save saves a VM to persistent disk.
+func (v *VM) Save() error {
+	v.logger().Info("save vm")
+	return v.hypervisor.saveSandbox()
+}
+
+// Resume resumes a paused VM.
+func (v *VM) Resume() error {
+	v.logger().Info("resume vm")
+	return v.hypervisor.resumeSandbox()
+}
+
+// Start kicks off a configured VM.
+func (v *VM) Start() error {
+	v.logger().Info("start vm")
+	return v.hypervisor.startSandbox()
+}
+
+// Stop stops a VM process.
+func (v *VM) Stop() error {
+	v.logger().Info("kill vm")
+	return v.hypervisor.stopSandbox()
+}
+
+// AddCPUs adds num of CPUs to the VM.
+func (v *VM) AddCPUs(num uint32) error {
+	if num > 0 {
+		v.logger().Infof("hot adding %d vCPUs", num)
+		if _, err := v.hypervisor.hotplugAddDevice(num, cpuDev); err != nil {
+			return err
+		}
+		v.cpuDelta += num
+		v.cpu += num
+	}
+
+	return nil
+}
+
+// AddMemory adds numMB of memory to the VM.
+func (v *VM) AddMemory(numMB uint32) error {
+	if numMB > 0 {
+		v.logger().Infof("hot adding %d MB memory", numMB)
+		dev := &memoryDevice{1, int(numMB)}
+		if _, err := v.hypervisor.hotplugAddDevice(dev, memoryDev); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// OnlineCPUMemory puts the hotplugged CPU and memory online.
+func (v *VM) OnlineCPUMemory() error {
+	v.logger().Infof("online CPU %d and memory", v.cpuDelta)
+	err := v.agent.onlineCPUMem(v.cpuDelta)
+	if err == nil {
+		v.cpuDelta = 0
+	}
+
+	return err
+}
+
+func (v *VM) assignSandbox(s *Sandbox) error {
+	// add vm symlinks
+	// - link vm socket from sandbox dir (/run/vc/vm/sbid/<kata.sock>) to vm dir (/run/vc/vm/vmid/<kata.sock>)
+	// - link 9pfs share path from sandbox dir (/run/kata-containers/shared/sandboxes/sbid/) to vm dir (/run/vc/vm/vmid/shared/)
+
+	vmSharePath := buildVMSharePath(v.id)
+	vmSockDir := v.agent.getVMPath(v.id)
+	sbSharePath := s.agent.getSharePath(s.id)
+	sbSockDir := s.agent.getVMPath(s.id)
+
+	v.logger().WithFields(logrus.Fields{
+		"vmSharePath": vmSharePath,
+		"vmSockDir":   vmSockDir,
+		"sbSharePath": sbSharePath,
+		"sbSockDir":   sbSockDir,
+	}).Infof("assign vm to sandbox %s", s.id)
+
+	// First make sure the symlinks do not exist
+	os.RemoveAll(sbSharePath)
+	os.RemoveAll(sbSockDir)
+
+	if err := os.Symlink(vmSharePath, sbSharePath); err != nil {
+		return err
+	}
+
+	if err := os.Symlink(vmSockDir, sbSockDir); err != nil {
+		os.Remove(sbSharePath)
+		return err
+	}
+
+	s.hypervisor = v.hypervisor
+
+	return nil
+}

virtcontainers/vm_test.go

@@ -0,0 +1,83 @@
+// Copyright (c) 2018 HyperHQ Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+package virtcontainers
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewVM(t *testing.T) {
+	assert := assert.New(t)
+
+	testDir, _ := ioutil.TempDir("", "vmfactory-tmp-")
+	config := VMConfig{
+		HypervisorType: MockHypervisor,
+		AgentType:      NoopAgentType,
+	}
+	hyperConfig := HypervisorConfig{
+		KernelPath: testDir,
+		ImagePath:  testDir,
+	}
+
+	var vm *VM
+	_, err := NewVM(config)
+	assert.Error(err)
+
+	config.HypervisorConfig = hyperConfig
+	vm, err = NewVM(config)
+	assert.Nil(err)
+
+	// VM operations
+	err = vm.Pause()
+	assert.Nil(err)
+	err = vm.Resume()
+	assert.Nil(err)
+	err = vm.Start()
+	assert.Nil(err)
+	err = vm.Save()
+	assert.Nil(err)
+	err = vm.Stop()
+	assert.Nil(err)
+	err = vm.AddCPUs(2)
+	assert.Nil(err)
+	err = vm.AddMemory(128)
+	assert.Nil(err)
+	err = vm.OnlineCPUMemory()
+	assert.Nil(err)
+
+	// template VM
+	config.HypervisorConfig.BootFromTemplate = true
+	_, err = NewVM(config)
+	assert.Error(err)
+
+	config.HypervisorConfig.MemoryPath = testDir
+	_, err = NewVM(config)
+	assert.Error(err)
+
+	config.HypervisorConfig.DevicesStatePath = testDir
+	_, err = NewVM(config)
+	assert.Nil(err)
+}
+
+func TestVMConfigValid(t *testing.T) {
+	assert := assert.New(t)
+
+	config := VMConfig{}
+
+	err := config.Valid()
+	assert.Error(err)
+
+	testDir, _ := ioutil.TempDir("", "vmfactory-tmp-")
+	config.HypervisorConfig = HypervisorConfig{
+		KernelPath: testDir,
+		InitrdPath: testDir,
+	}
+	err = config.Valid()
+	assert.Nil(err)
+}