config: add virtio_fs_daemon string

Add a config option for the virtio-fs vhost-user daemon path.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Makefile

@@ -157,6 +157,7 @@ DEFENTROPYSOURCE := /dev/urandom
 
 DEFDISABLEBLOCK := false
 DEFSHAREDFS := virtio-9p
+DEFVIRTIOFSDAEMON :=
 DEFENABLEIOTHREADS := false
 DEFENABLEMEMPREALLOC := false
 DEFENABLEHUGEPAGES := false
@@ -322,6 +323,7 @@ USER_VARS += DEFDISABLEBLOCK
 USER_VARS += DEFBLOCKSTORAGEDRIVER_FC
 USER_VARS += DEFBLOCKSTORAGEDRIVER_QEMU
 USER_VARS += DEFSHAREDFS
+USER_VARS += DEFVIRTIOFSDAEMON
 USER_VARS += DEFENABLEIOTHREADS
 USER_VARS += DEFENABLEMEMPREALLOC
 USER_VARS += DEFENABLEHUGEPAGES
@@ -459,6 +461,7 @@ $(GENERATED_FILES): %: %.in $(MAKEFILE_LIST) VERSION .git-commit
 		-e "s|@DEFBLOCKSTORAGEDRIVER_FC@|$(DEFBLOCKSTORAGEDRIVER_FC)|g" \
 		-e "s|@DEFBLOCKSTORAGEDRIVER_QEMU@|$(DEFBLOCKSTORAGEDRIVER_QEMU)|g" \
 		-e "s|@DEFSHAREDFS@|$(DEFSHAREDFS)|g" \
+		-e "s|@DEFVIRTIOFSDAEMON@|$(DEFVIRTIOFSDAEMON)|g" \
 		-e "s|@DEFENABLEIOTHREADS@|$(DEFENABLEIOTHREADS)|g" \
 		-e "s|@DEFENABLEMEMPREALLOC@|$(DEFENABLEMEMPREALLOC)|g" \
 		-e "s|@DEFENABLEHUGEPAGES@|$(DEFENABLEHUGEPAGES)|g" \

cli/config/configuration-qemu.toml.in

@@ -102,6 +102,9 @@ disable_block_device_use = @DEFDISABLEBLOCK@
 #   - virtio-fs
 shared_fs = "@DEFSHAREDFS@"
 
+# Path to vhost-user-fs daemon.
+virtio_fs_daemon = "@DEFVIRTIOFSDAEMON@"
+
 # Block storage driver to be used for the hypervisor in case the container
 # rootfs is backed by a block device. This is virtio-scsi, virtio-blk
 # or nvdimm.

pkg/katautils/config.go

@@ -93,6 +93,7 @@ type hypervisor struct {
 	BlockDeviceDriver       string `toml:"block_device_driver"`
 	EntropySource           string `toml:"entropy_source"`
 	SharedFS                string `toml:"shared_fs"`
+	VirtioFSDaemon          string `toml:"virtio_fs_daemon"`
 	BlockDeviceCacheSet     bool   `toml:"block_device_cache_set"`
 	BlockDeviceCacheDirect  bool   `toml:"block_device_cache_direct"`
 	BlockDeviceCacheNoflush bool   `toml:"block_device_cache_noflush"`
@@ -543,6 +544,11 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		return vc.HypervisorConfig{}, err
 	}
 
+	if sharedFS == config.VirtioFS && h.VirtioFSDaemon == "" {
+		return vc.HypervisorConfig{},
+			errors.New("cannot enable virtio-fs without daemon path in configuration file")
+	}
+
 	useVSock := false
 	if h.useVSock() {
 		if utils.SupportsVsocks() {
@@ -571,6 +577,7 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		DefaultBridges:          h.defaultBridges(),
 		DisableBlockDeviceUse:   h.DisableBlockDeviceUse,
 		SharedFS:                sharedFS,
+		VirtioFSDaemon:          h.VirtioFSDaemon,
 		MemPrealloc:             h.MemPrealloc,
 		HugePages:               h.HugePages,
 		Mlock:                   !h.Swap,

virtcontainers/documentation/api/1.0/api.md

@@ -143,6 +143,9 @@ type HypervisorConfig struct {
 	//   - virtio-fs
 	SharedFS string
 
+	// VirtioFSDaemon is the virtio-fs vhost-user daemon path
+	VirtioFSDaemon string
+
 	// KernelParams are additional guest kernel parameters.
 	KernelParams []Param
 

virtcontainers/hypervisor.go

@@ -220,6 +220,9 @@ type HypervisorConfig struct {
 	//   - virtio-fs
 	SharedFS string
 
+	// VirtioFSDaemon is the virtio-fs vhost-user daemon path
+	VirtioFSDaemon string
+
 	// customAssets is a map of assets.
 	// Each value in that map takes precedence over the configured assets.
 	// For example, if there is a value for the "kernel" key in this map,