virtio-fs: add virtio_fs_extra_args for virtiofsd

Since virtio-fs is under active development, more
options will be added increasingly. To avaoid frequent
change on runtime side to handle option changes, use
one mingled arg to ease testing new option/feature of
virtiofsd.

See `virtiofsd -h` for more option details.

Fixes: #1999
Signed-off-by: Eric Ren <renzhen@linux.alibaba.com>

Makefile

@@ -174,6 +174,7 @@ DEFVIRTIOFSDAEMON := $(VIRTIOFSDBINDIR)/virtiofsd-x86_64
 # Default DAX mapping cache size in MiB
 DEFVIRTIOFSCACHESIZE := 1024
 DEFVIRTIOFSCACHE := always
+DEFVIRTIOFSEXTRAARGS := []
 DEFENABLEIOTHREADS := false
 DEFENABLEMEMPREALLOC := false
 DEFENABLEHUGEPAGES := false
@@ -414,6 +415,7 @@ USER_VARS += DEFSHAREDFS_NEMU
 USER_VARS += DEFVIRTIOFSDAEMON
 USER_VARS += DEFVIRTIOFSCACHESIZE
 USER_VARS += DEFVIRTIOFSCACHE
+USER_VARS += DEFVIRTIOFSEXTRAARGS
 USER_VARS += DEFENABLEIOTHREADS
 USER_VARS += DEFENABLEMEMPREALLOC
 USER_VARS += DEFENABLEHUGEPAGES
@@ -569,6 +571,7 @@ $(GENERATED_FILES): %: %.in $(MAKEFILE_LIST) VERSION .git-commit
 		-e "s|@DEFVIRTIOFSDAEMON@|$(DEFVIRTIOFSDAEMON)|g" \
 		-e "s|@DEFVIRTIOFSCACHESIZE@|$(DEFVIRTIOFSCACHESIZE)|g" \
 		-e "s|@DEFVIRTIOFSCACHE@|$(DEFVIRTIOFSCACHE)|g" \
+		-e "s|@DEFVIRTIOFSEXTRAARGS@|$(DEFVIRTIOFSEXTRAARGS)|g" \
 		-e "s|@DEFENABLEIOTHREADS@|$(DEFENABLEIOTHREADS)|g" \
 		-e "s|@DEFENABLEMEMPREALLOC@|$(DEFENABLEMEMPREALLOC)|g" \
 		-e "s|@DEFENABLEHUGEPAGES@|$(DEFENABLEHUGEPAGES)|g" \

cli/config/configuration-nemu.toml.in

@@ -123,6 +123,14 @@ virtio_fs_cache_size = @DEFVIRTIOFSCACHESIZE@
 #    Metadata, data, and pathname lookup are cached in guest and never expire.
 virtio_fs_cache = "@DEFVIRTIOFSCACHE@"
 
+# Extra args for virtiofsd daemon
+#
+# Format example:
+#   ["-o", "arg1=xxx,arg2", "-o", "hello world", "--arg3=yyy"]
+#
+# see `virtiofsd -h` for possible options.
+virtio_fs_extra_args = @DEFVIRTIOFSEXTRAARGS@
+
 # 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.

cli/config/configuration-qemu.toml.in

@@ -108,6 +108,14 @@ virtio_fs_daemon = "@DEFVIRTIOFSDAEMON@"
 # Default size of DAX cache in MiB
 virtio_fs_cache_size = @DEFVIRTIOFSCACHESIZE@
 
+# Extra args for virtiofsd daemon
+#
+# Format example:
+#   ["-o", "arg1=xxx,arg2", "-o", "hello world", "--arg3=yyy"]
+#
+# see `virtiofsd -h` for possible options.
+virtio_fs_extra_args = @DEFVIRTIOFSEXTRAARGS@
+
 # Cache mode:
 #
 #  - none

pkg/katautils/config.go

@@ -98,6 +98,7 @@ type hypervisor struct {
 	SharedFS                string   `toml:"shared_fs"`
 	VirtioFSDaemon          string   `toml:"virtio_fs_daemon"`
 	VirtioFSCache           string   `toml:"virtio_fs_cache"`
+	VirtioFSExtraArgs       []string `toml:"virtio_fs_extra_args"`
 	VirtioFSCacheSize       uint32   `toml:"virtio_fs_cache_size"`
 	BlockDeviceCacheSet     bool     `toml:"block_device_cache_set"`
 	BlockDeviceCacheDirect  bool     `toml:"block_device_cache_direct"`
@@ -617,6 +618,7 @@ func newQemuHypervisorConfig(h hypervisor) (vc.HypervisorConfig, error) {
 		VirtioFSDaemon:          h.VirtioFSDaemon,
 		VirtioFSCacheSize:       h.VirtioFSCacheSize,
 		VirtioFSCache:           h.VirtioFSCache,
+		VirtioFSExtraArgs:       h.VirtioFSExtraArgs,
 		MemPrealloc:             h.MemPrealloc,
 		HugePages:               h.HugePages,
 		FileBackedMemRootDir:    h.FileBackedMemRootDir,

virtcontainers/hypervisor.go

@@ -260,6 +260,9 @@ type HypervisorConfig struct {
 	// VirtioFSCache cache mode for fs version cache or "none"
 	VirtioFSCache string
 
+	// VirtioFSExtraArgs passes options to virtiofsd daemon
+	VirtioFSExtraArgs []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,

virtcontainers/qemu.go

@@ -613,6 +613,9 @@ func (q *qemu) virtiofsdArgs(sockPath string) []string {
 		args = append(args, "-f")
 	}
 
+	if len(q.config.VirtioFSExtraArgs) != 0 {
+		args = append(args, q.config.VirtioFSExtraArgs...)
+	}
 	return args
 }