Add virtiofs device support

This makes it possible to share files with the VM. For now it's limited
to one shared directory, which should be enough for our initial needs.

Code-Hex/vz#28 is not merged yet, so this relies
on a Code-Hex/vz fork in my own GitHub namespace which has the shared
folder API.

This fixes crc-org#2

go.mod

@@ -12,3 +12,5 @@ require (
 	golang.org/x/sys v0.0.0-20220519141025-dcacdad47464
 	inet.af/tcpproxy v0.0.0-20210824174053-2e577fef49e2
 )
+
+replace github.com/Code-Hex/vz => github.com/cfergeau/vz v0.0.5-0.20220629154958-9aad23fce70e

go.sum

@@ -48,8 +48,6 @@ cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
-github.com/Code-Hex/vz v0.0.5-0.20220406150231-a2ebc854a261 h1:7cU//dP3rZzrIdk1ytc2h5/N3ikjVJljvb5KbU7+lGs=
-github.com/Code-Hex/vz v0.0.5-0.20220406150231-a2ebc854a261/go.mod h1:BMgSoDpuZx8xZe5Ycxf5DJ5OewlWadVu40v/O1ZmVuQ=
 github.com/DataDog/datadog-go v3.2.0+incompatible/go.mod h1:LButxg5PwREeZtORoXG3tL4fMGNddJ+vMq1mwgfaqoQ=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
@@ -72,6 +70,8 @@ github.com/census-instrumentation/opencensus-proto v0.3.0/go.mod h1:f6KPmirojxKA
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cespare/xxhash/v2 v2.1.2/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/cfergeau/vz v0.0.5-0.20220629154958-9aad23fce70e h1:W34omdFFqjYSMud3wFeomOWqG9fO6MJ8hcADzEK4RKk=
+github.com/cfergeau/vz v0.0.5-0.20220629154958-9aad23fce70e/go.mod h1:BMgSoDpuZx8xZe5Ycxf5DJ5OewlWadVu40v/O1ZmVuQ=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=

pkg/client/cmdline.go

@@ -45,6 +45,11 @@ type virtioSerial struct {
 	logFile string
 }
 
+type virtioFs struct {
+	sharedDir string
+	mountTag  string
+}
+
 func NewVirtualMachine(vcpus uint, memoryBytes uint64, bootloader *Bootloader) *VirtualMachine {
 	return &VirtualMachine{
 		vcpus:       vcpus,
@@ -194,3 +199,21 @@ func (dev *virtioSerial) ToCmdLine() ([]string, error) {
 	}
 	return []string{"--device", fmt.Sprintf("virtio-serial,logFilePath=%s", dev.logFile)}, nil
 }
+
+func VirtioFsNew(sharedDir string, mountTag string) (VirtioDevice, error) {
+	return &virtioFs{
+		sharedDir: sharedDir,
+		mountTag:  mountTag,
+	}, nil
+}
+
+func (dev *virtioFs) ToCmdLine() ([]string, error) {
+	if dev.sharedDir == "" {
+		return nil, fmt.Errorf("virtio-fs needs the path to the directory to share")
+	}
+	if dev.mountTag != "" {
+		return []string{"--device", fmt.Sprintf("virtio-fs,sharedDir=%s,mountTag=%s", dev.sharedDir, dev.mountTag)}, nil
+	} else {
+		return []string{"--device", fmt.Sprintf("virtio-fs,sharedDir=%s", dev.sharedDir)}, nil
+	}
+}

pkg/config/virtio.go

@@ -3,6 +3,7 @@ package config
 import (
 	"fmt"
 	"net"
+	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -73,6 +74,8 @@ func deviceFromCmdLine(deviceOpts string) (VirtioDevice, error) {
 	switch opts[0] {
 	case "virtio-blk":
 		dev = &virtioBlk{}
+	case "virtio-fs":
+		dev = &virtioFs{}
 	case "virtio-net":
 		dev = &virtioNet{}
 	case "virtio-rng":
@@ -249,3 +252,50 @@ func (dev *VirtioVsock) AddToVirtualMachineConfig(vmConfig *vz.VirtualMachineCon
 
 	return nil
 }
+
+type virtioFs struct {
+	sharedDir string
+	mountTag  string
+}
+
+func (dev *virtioFs) FromOptions(options []option) error {
+	for _, option := range options {
+		switch option.key {
+		case "sharedDir":
+			dev.sharedDir = option.value
+		case "mountTag":
+			dev.mountTag = option.value
+		default:
+			return fmt.Errorf("Unknown option for virtio-fs devices: %s", option.key)
+		}
+	}
+	return nil
+}
+
+func (dev *virtioFs) AddToVirtualMachineConfig(vmConfig *vz.VirtualMachineConfiguration) error {
+	log.Infof("Adding virtio-fs device")
+	if dev.sharedDir == "" {
+		return fmt.Errorf("missing mandatory 'sharedDir' option for virtio-fs device")
+	}
+	var mountTag string
+	if dev.mountTag != "" {
+		mountTag = dev.mountTag
+	} else {
+		mountTag = filepath.Base(dev.sharedDir)
+	}
+
+	sharedDir, err := vz.NewSharedDirectory(dev.sharedDir, false)
+	if err != nil {
+		return err
+	}
+	sharedDirConfig := vz.NewSingleDirectoryShare(sharedDir)
+	fileSystemDeviceConfig, err := vz.NewVirtioFileSystemDeviceConfiguration(mountTag)
+	if err != nil {
+		return err
+	}
+	fileSystemDeviceConfig.SetDirectoryShare(sharedDirConfig)
+	vmConfig.SetDirectorySharingDevicesVirtualMachineConfiguration([]vz.DirectorySharingDeviceConfiguration{
+		fileSystemDeviceConfig,
+	})
+	return nil
+}