5 files changed, 99 insertions, 76 deletions
diff --git a/docs/tools/index.rst b/docs/tools/index.rst
index 8e65ce0..1e88ae4 100644
--- a/docs/tools/index.rst
+++ b/docs/tools/index.rst
@@ -15,4 +15,4 @@ command line utilities and other standalone programs.
    qemu-nbd
    qemu-pr-helper
    qemu-trace-stap
-   virtfs-proxy-helper
+   qemu-vmsr-helper
diff --git a/docs/tools/qemu-nbd.rst b/docs/tools/qemu-nbd.rst
index 329f44d..f82ea5f 100644
--- a/docs/tools/qemu-nbd.rst
+++ b/docs/tools/qemu-nbd.rst
@@ -1,3 +1,5 @@
+.. _qemu-nbd:
+
 =====================================
 QEMU Disk Network Block Device Server
 =====================================
@@ -154,6 +156,11 @@ driver options if :option:`--image-opts` is specified.
   Set the NBD volume export description, as a human-readable
   string.
 
+.. option:: --handshake-limit=N
+
+  Set the timeout for a client to successfully complete its handshake
+  to N seconds (default 10), or 0 for no limit.
+
 .. option:: -L, --list
 
   Connect as a client and list all details about the exports exposed by
diff --git a/docs/tools/qemu-storage-daemon.rst b/docs/tools/qemu-storage-daemon.rst
index ea00149..35ab2d7 100644
--- a/docs/tools/qemu-storage-daemon.rst
+++ b/docs/tools/qemu-storage-daemon.rst
@@ -1,3 +1,5 @@
+.. _storage-daemon:
+
 ===================
 QEMU Storage Daemon
 ===================
diff --git a/docs/tools/qemu-vmsr-helper.rst b/docs/tools/qemu-vmsr-helper.rst
new file mode 100644
index 0000000..9ce10b9
--- /dev/null
+++ b/docs/tools/qemu-vmsr-helper.rst
@@ -0,0 +1,89 @@
+==================================
+QEMU virtual RAPL MSR helper
+==================================
+
+Synopsis
+--------
+
+**qemu-vmsr-helper** [*OPTION*]
+
+Description
+-----------
+
+Implements the virtual RAPL MSR helper for QEMU.
+
+Accessing the RAPL (Running Average Power Limit) MSR enables the RAPL powercap
+driver to advertise and monitor the power consumption or accumulated energy
+consumption of different power domains, such as CPU packages, DRAM, and other
+components when available.
+
+However those registers are accessible under privileged access (CAP_SYS_RAWIO).
+QEMU can use an external helper to access those privileged registers.
+
+:program:`qemu-vmsr-helper` is that external helper; it creates a listener
+socket which will accept incoming connections for communication with QEMU.
+
+If you want to run VMs in a setup like this, this helper should be started as a
+system service, and you should read the QEMU manual section on "RAPL MSR
+support" to find out how to configure QEMU to connect to the socket created by
+:program:`qemu-vmsr-helper`.
+
+After connecting to the socket, :program:`qemu-vmsr-helper` can
+optionally drop root privileges, except for those capabilities that
+are needed for its operation.
+
+:program:`qemu-vmsr-helper` can also use the systemd socket activation
+protocol.  In this case, the systemd socket unit should specify a
+Unix stream socket, like this::
+
+    [Socket]
+    ListenStream=/var/run/qemu-vmsr-helper.sock
+
+Options
+-------
+
+.. program:: qemu-vmsr-helper
+
+.. option:: -d, --daemon
+
+  run in the background (and create a PID file)
+
+.. option:: -q, --quiet
+
+  decrease verbosity
+
+.. option:: -v, --verbose
+
+  increase verbosity
+
+.. option:: -f, --pidfile=PATH
+
+  PID file when running as a daemon. By default the PID file
+  is created in the system runtime state directory, for example
+  :file:`/var/run/qemu-vmsr-helper.pid`.
+
+.. option:: -k, --socket=PATH
+
+  path to the socket. By default the socket is created in
+  the system runtime state directory, for example
+  :file:`/var/run/qemu-vmsr-helper.sock`.
+
+.. option:: -T, --trace [[enable=]PATTERN][,events=FILE][,file=FILE]
+
+  .. include:: ../qemu-option-trace.rst.inc
+
+.. option:: -u, --user=USER
+
+  user to drop privileges to
+
+.. option:: -g, --group=GROUP
+
+  group to drop privileges to
+
+.. option:: -h, --help
+
+  Display a help message and exit.
+
+.. option:: -V, --version
+
+  Display version information and exit.
diff --git a/docs/tools/virtfs-proxy-helper.rst b/docs/tools/virtfs-proxy-helper.rst
deleted file mode 100644
index bd310eb..0000000
--- a/docs/tools/virtfs-proxy-helper.rst
+++ /dev/null
@@ -1,75 +0,0 @@
-QEMU 9p virtfs proxy filesystem helper
-======================================
-
-Synopsis
---------
-
-**virtfs-proxy-helper** [*OPTIONS*]
-
-Description
------------
-
-NOTE: The 9p 'proxy' backend is deprecated (since QEMU 8.1) and will be
-removed, along with this daemon, in a future version of QEMU!
-
-Pass-through security model in QEMU 9p server needs root privilege to do
-few file operations (like chown, chmod to any mode/uid:gid).  There are two
-issues in pass-through security model:
-
-- TOCTTOU vulnerability: Following symbolic links in the server could
-  provide access to files beyond 9p export path.
-
-- Running QEMU with root privilege could be a security issue.
-
-To overcome above issues, following approach is used: A new filesystem
-type 'proxy' is introduced. Proxy FS uses chroot + socket combination
-for securing the vulnerability known with following symbolic links.
-Intention of adding a new filesystem type is to allow qemu to run
-in non-root mode, but doing privileged operations using socket IO.
-
-Proxy helper (a stand alone binary part of qemu) is invoked with
-root privileges. Proxy helper chroots into 9p export path and creates
-a socket pair or a named socket based on the command line parameter.
-QEMU and proxy helper communicate using this socket. QEMU proxy fs
-driver sends filesystem request to proxy helper and receives the
-response from it.
-
-The proxy helper is designed so that it can drop root privileges except
-for the capabilities needed for doing filesystem operations.
-
-Options
--------
-
-The following options are supported:
-
-.. program:: virtfs-proxy-helper
-
-.. option:: -h
-
-  Display help and exit
-
-.. option:: -p, --path PATH
-
-  Path to export for proxy filesystem driver
-
-.. option:: -f, --fd SOCKET_ID
-
-  Use given file descriptor as socket descriptor for communicating with
-  qemu proxy fs drier. Usually a helper like libvirt will create
-  socketpair and pass one of the fds as parameter to this option.
-
-.. option:: -s, --socket SOCKET_FILE
-
-  Creates named socket file for communicating with qemu proxy fs driver
-
-.. option:: -u, --uid UID
-
-  uid to give access to named socket file; used in combination with -g.
-
-.. option:: -g, --gid GID
-
-  gid to give access to named socket file; used in combination with -u.
-
-.. option:: -n, --nodaemon
-
-  Run as a normal program. By default program will run in daemon mode