Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- Makefile | 7 +++ contrib/virtiofsd/virtiofsd.texi | 85 ++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) create mode 100644 contrib/virtiofsd/virtiofsd.texi
diff --git a/Makefile b/Makefile index a3dfdd6fa8..cc18025753 100644 --- a/Makefile +++ b/Makefile @@ -334,6 +334,9 @@ DOCS+=docs/qemu-cpu-models.7 ifdef CONFIG_VIRTFS DOCS+=fsdev/virtfs-proxy-helper.1 endif +ifdef CONFIG_LINUX +DOCS+=contrib/virtiofsd/virtiofsd.1 +endif ifdef CONFIG_TRACE_SYSTEMTAP DOCS+=scripts/qemu-trace-stap.1 endif @@ -834,6 +837,9 @@ ifdef CONFIG_VIRTFS $(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1" $(INSTALL_DATA) fsdev/virtfs-proxy-helper.1 "$(DESTDIR)$(mandir)/man1" endif +ifdef CONFIG_LINUX + $(INSTALL_DATA) contrib/virtiofsd.1 "$(DESTDIR)$(mandir)/man1" +endif install-datadir: $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)" @@ -1018,6 +1024,7 @@ qemu.1: qemu-doc.texi qemu-options.texi qemu-monitor.texi qemu-monitor-info.texi qemu.1: qemu-option-trace.texi qemu-img.1: qemu-img.texi qemu-option-trace.texi qemu-img-cmds.texi fsdev/virtfs-proxy-helper.1: fsdev/virtfs-proxy-helper.texi +contrib/virtiofsd/virtiofsd.1: contrib/virtiofsd/virtiofsd.texi qemu-nbd.8: qemu-nbd.texi qemu-option-trace.texi qemu-ga.8: qemu-ga.texi docs/qemu-block-drivers.7: docs/qemu-block-drivers.texi diff --git a/contrib/virtiofsd/virtiofsd.texi b/contrib/virtiofsd/virtiofsd.texi new file mode 100644 index 0000000000..eec7fbf4e6 --- /dev/null +++ b/contrib/virtiofsd/virtiofsd.texi @@ -0,0 +1,85 @@ +@example +@c man begin SYNOPSIS +@command{virtiofsd} [OPTION] @option{--socket-path=}@var{path}|@option{--fd=}@var{fdnum} @option{-o source=}@var{path} +@c man end +@end example + +@c man begin 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 @code{--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. + +@c man end + +@c man begin OPTIONS +@table @option +@item -h, --help +Print help. +@item -V, --version +Print version. +@item -d, -o debug +Enable debug output. +@item --syslog +Print log messages to syslog instead of stderr. +@item -o log_level=@var{level} +Print only log messages matching @var{level} or more severe. @var{level} is +one of @code{err}, @code{warn}, @code{info}, or @code{debug}. The default is +@var{info}. +@item -o source=@var{path} +Share host directory tree located at @var{path}. This option is required. +@item --socket-path=@var{path}, -o vhost_user_socket=@var{path} +Listen on vhost-user UNIX domain socket at @var{path}. +@item --fd=@var{fdnum} +Accept connections from vhost-user UNIX domain socket file descriptor @var{fdnum}. The file descriptor must already be listening for connections. +@item --thread-pool-size=@var{num} +Restrict the number of worker threads per request queue to @var{num}. The default is 64. +@item --cache=@code{none}|@code{auto}|@code{always} +Select the desired trade-off between coherency and performance. @code{none} +forbids the FUSE client from caching to achieve best coherency at the cost of +performance. @code{auto} acts similar to NFS with a 1 second metadata cache +timeout. @code{always} sets a long cache lifetime at the expense of coherency. +@item --writeback +Enable writeback cache, allowing the FUSE client to buffer and merge write requests. +@end table +@c man end + +@c man begin EXAMPLES +Export @code{/var/lib/fs/vm001/} on vhost-user UNIX domain socket @code{/var/run/vm001-vhost-fs.sock}: + +@example +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 \ + -o default_permissions,allow_other,user_id=0,group_id=0,rootmode=040000,dax \ + myfs /mnt +@end example +@c man end + +@ignore +@setfilename virtiofsd +@settitle QEMU virtio-fs shared file system daemon + +@c man begin AUTHOR +Copyright (C) 2019 Red Hat, Inc. +This is free software; see the source for copying conditions. There is NO +warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +@c man end +@end ignore -- 2.21.0