Add support for nvme devices

This also seems to avoid the disk corruption that we see
with virtio-blk; it reportedly has a small performance hit
for raw speed, but I think avoiding the double caching (guest and host)
is much better from a performance perspective.

Signed-off-by: Colin Walters <walters@verbum.org>

pkg/config/json.go

@@ -25,6 +25,7 @@ const (
 	vfGpu          vmComponentKind = "virtiogpu"
 	vfInput        vmComponentKind = "virtioinput"
 	usbMassStorage vmComponentKind = "usbmassstorage"
+	nvme           vmComponentKind = "nvme"
 	rosetta        vmComponentKind = "rosetta"
 )
 
@@ -109,6 +110,10 @@ func unmarshalDevice(rawMsg json.RawMessage) (VirtioDevice, error) {
 		var newDevice VirtioBlk
 		err = json.Unmarshal(rawMsg, &newDevice)
 		dev = &newDevice
+	case nvme:
+		var newDevice NVMExpressController
+		err = json.Unmarshal(rawMsg, &newDevice)
+		dev = &newDevice
 	case vfFs:
 		var newDevice VirtioFs
 		err = json.Unmarshal(rawMsg, &newDevice)
@@ -258,6 +263,17 @@ func (dev *VirtioFs) MarshalJSON() ([]byte, error) {
 	})
 }
 
+func (dev *NVMExpressController) MarshalJSON() ([]byte, error) {
+	type devWithKind struct {
+		jsonKind
+		NVMExpressController
+	}
+	return json.Marshal(devWithKind{
+		jsonKind:             kind(nvme),
+		NVMExpressController: *dev,
+	})
+}
+
 func (dev *RosettaShare) MarshalJSON() ([]byte, error) {
 	type devWithKind struct {
 		jsonKind

pkg/config/virtio.go

@@ -77,6 +77,11 @@ type RosettaShare struct {
 	InstallRosetta bool
 }
 
+// NVMExpressController configures a NVMe controller in the guest
+type NVMExpressController struct {
+	StorageConfig
+}
+
 // virtioRng configures a random number generator (RNG) device.
 type VirtioRng struct {
 }
@@ -143,6 +148,8 @@ func deviceFromCmdLine(deviceOpts string) (VirtioDevice, error) {
 	switch opts[0] {
 	case "rosetta":
 		dev = &RosettaShare{}
+	case "nvme":
+		dev = nvmExpressControllerNewEmpty()
 	case "virtio-blk":
 		dev = virtioBlkNewEmpty()
 	case "virtio-fs":
@@ -452,6 +459,28 @@ func (dev *VirtioRng) FromOptions(options []option) error {
 	return nil
 }
 
+func nvmExpressControllerNewEmpty() *NVMExpressController {
+	return &NVMExpressController{
+		StorageConfig: StorageConfig{
+			DevName: "nvme",
+		},
+	}
+}
+
+func NVMExpressControllerNew(imagePath string) (*NVMExpressController, error) {
+	r := nvmExpressControllerNewEmpty()
+	r.ImagePath = imagePath
+	return r, nil
+}
+
+func (dev *NVMExpressController) FromOptions(options []option) error {
+	return dev.StorageConfig.FromOptions(options)
+}
+
+func (dev *NVMExpressController) ToCmdLine() ([]string, error) {
+	return dev.StorageConfig.ToCmdLine()
+}
+
 func virtioBlkNewEmpty() *VirtioBlk {
 	return &VirtioBlk{
 		StorageConfig: StorageConfig{

pkg/config/virtio_test.go

@@ -45,6 +45,16 @@ var virtioDevTests = map[string]virtioDevTest{
 		expectedCmdLine:  []string{"--device", "virtio-blk,path=/foo/bar,deviceId=test"},
 		alternateCmdLine: []string{"--device", "virtio-blk,deviceId=test,path=/foo/bar"},
 	},
+	"NewNVMe": {
+		newDev: func() (VirtioDevice, error) { return NVMExpressControllerNew("/foo/bar") },
+		expectedDev: &NVMExpressController{
+			StorageConfig: StorageConfig{
+				DevName:   "nvme",
+				ImagePath: "/foo/bar",
+			},
+		},
+		expectedCmdLine: []string{"--device", "nvme,path=/foo/bar"},
+	},
 	"NewVirtioFs": {
 		newDev: func() (VirtioDevice, error) { return VirtioFsNew("/foo/bar", "") },
 		expectedDev: &VirtioFs{

pkg/vf/virtio.go

@@ -14,6 +14,7 @@ import (
 )
 
 type RosettaShare config.RosettaShare
+type NVMExpressController config.NVMExpressController
 type VirtioBlk config.VirtioBlk
 type VirtioFs config.VirtioFs
 type VirtioRng config.VirtioRng
@@ -22,6 +23,31 @@ type VirtioVsock config.VirtioVsock
 type VirtioInput config.VirtioInput
 type VirtioGPU config.VirtioGPU
 
+func (dev *NVMExpressController) toVz() (vz.StorageDeviceConfiguration, error) {
+	var storageConfig StorageConfig = StorageConfig(dev.StorageConfig)
+	attachment, err := storageConfig.toVz()
+	if err != nil {
+		return nil, err
+	}
+	devConfig, err := vz.NewNVMExpressControllerDeviceConfiguration(attachment)
+	if err != nil {
+		return nil, err
+	}
+
+	return devConfig, nil
+}
+
+func (dev *NVMExpressController) AddToVirtualMachineConfig(vmConfig *vzVirtualMachineConfiguration) error {
+	storageDeviceConfig, err := dev.toVz()
+	if err != nil {
+		return err
+	}
+	log.Infof("Adding nvme device (imagePath: %s)", dev.ImagePath)
+	vmConfig.storageDevicesConfiguration = append(vmConfig.storageDevicesConfiguration, storageDeviceConfig)
+
+	return nil
+}
+
 func (dev *VirtioBlk) toVz() (vz.StorageDeviceConfiguration, error) {
 	var storageConfig StorageConfig = StorageConfig(dev.StorageConfig)
 	attachment, err := storageConfig.toVz()
@@ -251,6 +277,8 @@ func AddToVirtualMachineConfig(dev config.VirtioDevice, vmConfig *vzVirtualMachi
 		return (*VirtioBlk)(d).AddToVirtualMachineConfig(vmConfig)
 	case *config.RosettaShare:
 		return (*RosettaShare)(d).AddToVirtualMachineConfig(vmConfig)
+	case *config.NVMExpressController:
+		return (*NVMExpressController)(d).AddToVirtualMachineConfig(vmConfig)
 	case *config.VirtioFs:
 		return (*VirtioFs)(d).AddToVirtualMachineConfig(vmConfig)
 	case *config.VirtioNet: