From 1982e1602d15313cd82f225e821c37733ece3404 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 9 Dec 2020 10:38:01 +0000 Subject: [PATCH] docs: add qemu-storage-daemon(1) man page Document the qemu-storage-daemon tool. Most of the command-line options are identical to their QEMU counterparts. Perhaps Sphinx hxtool integration could be extended to extract documentation for individual command-line options so they can be shared. For now the qemu-storage-daemon simply refers to the qemu(1) man page where the command-line options are identical. Signed-off-by: Stefan Hajnoczi Message-Id: <20201209103802.350848-3-stefanha@redhat.com> Signed-off-by: Kevin Wolf --- docs/tools/conf.py | 2 + docs/tools/index.rst | 1 + docs/tools/qemu-storage-daemon.rst | 148 +++++++++++++++++++++++++++++ 3 files changed, 151 insertions(+) create mode 100644 docs/tools/qemu-storage-daemon.rst diff --git a/docs/tools/conf.py b/docs/tools/conf.py index 4760d36ff2a6..7072d993246b 100644 --- a/docs/tools/conf.py +++ b/docs/tools/conf.py @@ -20,6 +20,8 @@ man_pages = [ ('qemu-img', 'qemu-img', u'QEMU disk image utility', ['Fabrice Bellard'], 1), + ('qemu-storage-daemon', 'qemu-storage-daemon', u'QEMU storage daemon', + [], 1), ('qemu-nbd', 'qemu-nbd', u'QEMU Disk Network Block Device Server', ['Anthony Liguori '], 8), ('qemu-pr-helper', 'qemu-pr-helper', 'QEMU persistent reservation helper', diff --git a/docs/tools/index.rst b/docs/tools/index.rst index b99f86c7c661..3a5829c17a54 100644 --- a/docs/tools/index.rst +++ b/docs/tools/index.rst @@ -11,6 +11,7 @@ Contents: :maxdepth: 2 qemu-img + qemu-storage-daemon qemu-nbd qemu-pr-helper qemu-trace-stap diff --git a/docs/tools/qemu-storage-daemon.rst b/docs/tools/qemu-storage-daemon.rst new file mode 100644 index 000000000000..f63627eaf60f --- /dev/null +++ b/docs/tools/qemu-storage-daemon.rst @@ -0,0 +1,148 @@ +QEMU Storage Daemon +=================== + +Synopsis +-------- + +**qemu-storage-daemon** [options] + +Description +----------- + +qemu-storage-daemon provides disk image functionality from QEMU, qemu-img, and +qemu-nbd in a long-running process controlled via QMP commands without running +a virtual machine. It can export disk images, run block job operations, and +perform other disk-related operations. The daemon is controlled via a QMP +monitor and initial configuration from the command-line. + +The daemon offers the following subset of QEMU features: + +* Block nodes +* Block jobs +* Block exports +* Throttle groups +* Character devices +* Crypto and secrets +* QMP +* IOThreads + +Commands can be sent over a QEMU Monitor Protocol (QMP) connection. See the +:manpage:`qemu-storage-daemon-qmp-ref(7)` manual page for a description of the +commands. + +The daemon runs until it is stopped using the ``quit`` QMP command or +SIGINT/SIGHUP/SIGTERM. + +**Warning:** Never modify images in use by a running virtual machine or any +other process; this may destroy the image. Also, be aware that querying an +image that is being modified by another process may encounter inconsistent +state. + +Options +------- + +.. program:: qemu-storage-daemon + +Standard options: + +.. option:: -h, --help + + Display help and exit + +.. option:: -V, --version + + Display version information and exit + +.. option:: -T, --trace [[enable=]PATTERN][,events=FILE][,file=FILE] + + .. include:: ../qemu-option-trace.rst.inc + +.. option:: --blockdev BLOCKDEVDEF + + is a block node definition. See the :manpage:`qemu(1)` manual page for a + description of block node properties and the :manpage:`qemu-block-drivers(7)` + manual page for a description of driver-specific parameters. + +.. option:: --chardev CHARDEVDEF + + is a character device definition. See the :manpage:`qemu(1)` manual page for + a description of character device properties. A common character device + definition configures a UNIX domain socket:: + + --chardev socket,id=char1,path=/tmp/qmp.sock,server,nowait + +.. option:: --export [type=]nbd,id=,node-name=[,name=][,writable=on|off][,bitmap=] + --export [type=]vhost-user-blk,id=,node-name=,addr.type=unix,addr.path=[,writable=on|off][,logical-block-size=][,num-queues=] + --export [type=]vhost-user-blk,id=,node-name=,addr.type=fd,addr.str=[,writable=on|off][,logical-block-size=][,num-queues=] + + is a block export definition. ``node-name`` is the block node that should be + exported. ``writable`` determines whether or not the export allows write + requests for modifying data (the default is off). + + The ``nbd`` export type requires ``--nbd-server`` (see below). ``name`` is + the NBD export name. ``bitmap`` is the name of a dirty bitmap reachable from + the block node, so the NBD client can use NBD_OPT_SET_META_CONTEXT with the + metadata context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap. + + The ``vhost-user-blk`` export type takes a vhost-user socket address on which + it accept incoming connections. Both + ``addr.type=unix,addr.path=`` for UNIX domain sockets and + ``addr.type=fd,addr.str=`` for file descriptor passing are supported. + ``logical-block-size`` sets the logical block size in bytes (the default is + 512). ``num-queues`` sets the number of virtqueues (the default is 1). + +.. option:: --monitor MONITORDEF + + is a QMP monitor definition. See the :manpage:`qemu(1)` manual page for + a description of QMP monitor properties. A common QMP monitor definition + configures a monitor on character device ``char1``:: + + --monitor chardev=char1 + +.. option:: --nbd-server addr.type=inet,addr.host=,addr.port=[,tls-creds=][,tls-authz=][,max-connections=] + --nbd-server addr.type=unix,addr.path=[,tls-creds=][,tls-authz=][,max-connections=] + + is a server for NBD exports. Both TCP and UNIX domain sockets are supported. + TLS encryption can be configured using ``--object`` tls-creds-* and authz-* + secrets (see below). + + To configure an NBD server on UNIX domain socket path ``/tmp/nbd.sock``:: + + --nbd-server addr.type=unix,addr.path=/tmp/nbd.sock + +.. option:: --object help + --object ,help + --object [,=...] + + is a QEMU user creatable object definition. List object types with ``help``. + List object properties with ``,help``. See the :manpage:`qemu(1)` + manual page for a description of the object properties. + +Examples +-------- +Launch the daemon with QMP monitor socket ``qmp.sock`` so clients can execute +QMP commands:: + + $ qemu-storage-daemon \ + --chardev socket,path=qmp.sock,server,nowait,id=char1 \ + --monitor chardev=char1 + +Export raw image file ``disk.img`` over NBD UNIX domain socket ``nbd.sock``:: + + $ qemu-storage-daemon \ + --blockdev driver=file,node-name=disk,filename=disk.img \ + --nbd-server addr.type=unix,addr.path=nbd.sock \ + --export type=nbd,id=export,node-name=disk,writable=on + +Export a qcow2 image file ``disk.qcow2`` as a vhosts-user-blk device over UNIX +domain socket ``vhost-user-blk.sock``:: + + $ qemu-storage-daemon \ + --blockdev driver=file,node-name=file,filename=disk.qcow2 \ + --blockdev driver=qcow2,node-name=qcow2,file=file \ + --export type=vhost-user-blk,id=export,addr.type=unix,addr.path=vhost-user-blk.sock,node-name=qcow2 + +See also +-------- + +:manpage:`qemu(1)`, :manpage:`qemu-block-drivers(7)`, :manpage:`qemu-storage-daemon-qmp-ref(7)`