Stefan Hajnoczi writes:
> Document the virtiofsd(1) program and its command-line options. This > man page is a rST conversion of the original texi documentation that I > wrote. > > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > Based-on: 20200124162606.8787-1-peter.mayd...@linaro.org > ("[PATCH v2 0/8] qemu-img, qemu-trace-stap, virtfs-proxy-helper: > convert to rST") > --- > MAINTAINERS | 1 + > Makefile | 8 ++- > docs/interop/conf.py | 5 +- > docs/interop/index.rst | 1 + > docs/interop/virtiofsd.rst | 123 +++++++++++++++++++++++++++++++++++++ > 5 files changed, 136 insertions(+), 2 deletions(-) > create mode 100644 docs/interop/virtiofsd.rst > > diff --git a/MAINTAINERS b/MAINTAINERS > index 83fb32b860..1da0709129 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1603,6 +1603,7 @@ S: Supported > F: tools/virtiofsd/* > F: hw/virtio/vhost-user-fs* > F: include/hw/virtio/vhost-user-fs.h > +F: docs/interop/virtiofsd.rst > > virtio-input > M: Gerd Hoffmann <kra...@redhat.com> > diff --git a/Makefile b/Makefile > index 539f9ef079..ecd26044bc 100644 > --- a/Makefile > +++ b/Makefile > @@ -348,6 +348,9 @@ DOCS=qemu-doc.html qemu-doc.txt qemu.1 > DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-img.1 > DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-nbd.8 > DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-ga.8 > +ifeq ($(CONFIG_LINUX)$(CONFIG_SECCOMP)$(CONFIG_LIBCAP_NG),yyy) > +DOCS+=$(MANUAL_BUILDDIR)/interop/virtiofsd.1 > +endif > DOCS+=$(MANUAL_BUILDDIR)/system/qemu-block-drivers.7 > DOCS+=docs/interop/qemu-qmp-ref.html docs/interop/qemu-qmp-ref.txt > docs/interop/qemu-qmp-ref.7 > DOCS+=docs/interop/qemu-ga-ref.html docs/interop/qemu-ga-ref.txt > docs/interop/qemu-ga-ref.7 > @@ -861,6 +864,9 @@ ifdef CONFIG_VIRTFS > $(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1" > $(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/virtfs-proxy-helper.1 > "$(DESTDIR)$(mandir)/man1" > endif > +ifeq ($(CONFIG_LINUX)$(CONFIG_SECCOMP)$(CONFIG_LIBCAP_NG),yyy) > + $(INSTALL_DATA) docs/interop/virtiofsd.1 "$(DESTDIR)$(mandir)/man1" > +endif > > install-datadir: > $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)" > @@ -1052,7 +1058,7 @@ $(MANUAL_BUILDDIR)/system/index.html: $(call > manual-deps,system) > > $(call define-manpage-rule,interop,\ > qemu-ga.8 qemu-img.1 qemu-nbd.8 qemu-trace-stap.1\ > - virtfs-proxy-helper.1,\ > + virtiofsd.1 virtfs-proxy-helper.1,\ > $(SRC_PATH/qemu-img-cmds.hx)) > > $(call define-manpage-rule,system,qemu-block-drivers.7) > diff --git a/docs/interop/conf.py b/docs/interop/conf.py > index b0f322207c..b3cda17042 100644 > --- a/docs/interop/conf.py > +++ b/docs/interop/conf.py > @@ -27,5 +27,8 @@ man_pages = [ > [], 1), > ('virtfs-proxy-helper', 'virtfs-proxy-helper', > u'QEMU 9p virtfs proxy filesystem helper', > - ['M. Mohan Kumar'], 1) > + ['M. Mohan Kumar'], 1), > + ('virtiofsd', 'virtiofsd', u'QEMU virtio-fs shared file system daemon', > + ['Stefan Hajnoczi <stefa...@redhat.com>', > + 'Masayoshi Mizuma <m.miz...@jp.fujitsu.com>'], 1), > ] > diff --git a/docs/interop/index.rst b/docs/interop/index.rst > index 3b763b1eeb..e8455b4270 100644 > --- a/docs/interop/index.rst > +++ b/docs/interop/index.rst > @@ -24,3 +24,4 @@ Contents: > vhost-user > vhost-user-gpu > virtfs-proxy-helper > + virtiofsd > diff --git a/docs/interop/virtiofsd.rst b/docs/interop/virtiofsd.rst > new file mode 100644 > index 0000000000..51a657ac0c > --- /dev/null > +++ b/docs/interop/virtiofsd.rst > @@ -0,0 +1,123 @@ > +QEMU virtio-fs shared file system daemon > +======================================== > + > +Synopsis > +-------- > + > +**virtiofsd** [*OPTIONS*] > + > +Description > +----------- > + > +Share a host directory tree with a guest through a virtio-fs device. This > +program is a vhost-user backend that implements the virtio-fs device. Each > +virtio-fs device instance requires its own virtiofsd process. > + > +This program is designed to work with QEMU's ``--device vhost-user-fs-pci`` > +but should work with any virtual machine monitor (VMM) that supports > +vhost-user. See the Examples section below. > + > +This program must be run as the root user. Upon startup the program will > +switch into a new file system namespace with the shared directory tree as its > +root. This prevents "file system escapes" due to symlinks and other file > +system objects that might lead to files outside the shared directory. The > +program also sandboxes itself using seccomp(2) to prevent ptrace(2) and other > +vectors that could allow an attacker to compromise the system after gaining > +control of the virtiofsd process. > + > +Options > +------- > + > +.. program:: virtiofsd > + > +.. option:: -h, --help > + > + Print help. > + > +.. option:: -V, --version > + > + Print version. > + > +.. option:: -d > + > + Enable debug output. > + > +.. option:: --syslog > + > + Print log messages to syslog instead of stderr. > + > +.. option:: -o OPTION > + > + * debug - > + Enable debug output. > + > + * flock|no_flock - > + Enable/disable flock. The default is ``no_flock``. > + > + * log_level=LEVEL - > + Print only log messages matching LEVEL or more severe. LEVEL is one of > + ``err``, ``warn``, ``info``, or ``debug``. The default is ``info``. > + > + * norace - > + Disable racy fallback. The default is false. It's not a problem with the doc, but seeing it exposes that options are not overly consistent in their spelling. "norace" has no _ but no_flock does (as does no_writeback). > + > + * posix_lock|no_posix_lock - > + Enable/disable remote POSIX locks. The default is ``posix_lock``. > + > + * readdirplus|no_readdirplus - > + Enable/disable readdirplus. The default is ``readdirplus``. > + > + * source=PATH - > + Share host directory tree located at PATH. This option is required. > + > + * timeout=TIMEOUT - > + I/O timeout in seconds. The default depends on cache= option. > + > + * vhost_user_socket=PATH - > + Listen on vhost-user UNIX domain socket at PATH. I believe that this option has been removed. > + > + * writeback|no_writeback - > + Enable/disable writeback cache. The cache alows the FUSE client to buffer > + and merge write requests. The default is ``no_writeback``. > + > + * xattr|no_xattr - > + Enable/disable extended attributes (xattr) on files and directories. The > + default is ``no_xattr``. > + > +.. option:: --socket-path=PATH > + > + Listen on vhost-user UNIX domain socket at PATH. Not related to the doc, but this looks like an option that might deserve a short form. > + > +.. option:: --fd=FDNUM > + > + Accept connections from vhost-user UNIX domain socket file descriptor > FDNUM. > + The file descriptor must already be listening for connections. Not directly related to the manual itself, but any reason why it's "socket-path" and "fd" (as opposed e.g. to "socket-path" and "socket-fd"? > + > +.. option:: --thread-pool-size=NUM > + > + Restrict the number of worker threads per request queue to NUM. The > default > + is 64. > + > +.. option:: --cache=none|auto|always > + > + Select the desired trade-off between coherency and performance. ``none`` > + forbids the FUSE client from caching to achieve best coherency at the cost > of > + performance. ``auto`` acts similar to NFS with a 1 second metadata cache > + timeout. ``always`` sets a long cache lifetime at the expense of > coherency. > + > +Examples > +-------- > + > +Export ``/var/lib/fs/vm001/`` on vhost-user UNIX domain socket > +``/var/run/vm001-vhost-fs.sock``: > + > +:: > + > + host# virtiofsd --socket-path=/var/run/vm001-vhost-fs.sock -o > source=/var/lib/fs/vm001 > + host# qemu-system-x86_64 \ > + -chardev socket,id=char0,path=/var/run/vm001-vhost-fs.sock \ > + -device vhost-user-fs-pci,chardev=char0,tag=myfs \ > + -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on \ > + -numa node,memdev=mem \ > + ... > + guest# mount -t virtio_fs myfs /mnt -- Cheers, Christophe de Dinechin (IRC c3d)