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* Fix Makefile concurrency bug where we could run Sphinx twice
    in parallel on the same manual (which makes it crash)
  * Support handling hxtool doc fragments for rST manuals
  * Convert qemu-img docs to rST
  * Convert qemu-trace-stap docs to rST
  * Convert virtfs-proxy-helper docs to rST
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Merge remote-tracking branch 'remotes/pmaydell/tags/pull-docs-20200203' into staging

docs:
 * Fix Makefile concurrency bug where we could run Sphinx twice
   in parallel on the same manual (which makes it crash)
 * Support handling hxtool doc fragments for rST manuals
 * Convert qemu-img docs to rST
 * Convert qemu-trace-stap docs to rST
 * Convert virtfs-proxy-helper docs to rST

# gpg: Signature made Mon 03 Feb 2020 11:11:44 GMT
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-docs-20200203:
  virtfs-proxy-helper: Convert documentation to rST
  scripts/qemu-trace-stap: Convert documentation to rST
  qemu-img-cmds.hx: Remove texinfo document fragments
  qemu-img: Convert invocation documentation to rST
  qemu-img-cmds.hx: Add rST documentation fragments
  docs/sphinx: Add new hxtool Sphinx extension
  hxtool: Support SRST/ERST directives
  Makefile: Ensure we don't run Sphinx in parallel for manpages

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2020-02-03 11:14:24 +00:00
parent 035b21977c 78813586b0
commit f31160c7d1
16 changed files with 1386 additions and 1088 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
MAINTAINERS
View file

@ -1574,6 +1574,7 @@ S: Odd Fixes
F: hw/9pfs/
X: hw/9pfs/xen-9p*
F: fsdev/
F: docs/interop/virtfs-proxy-helper.rst
F: tests/qtest/virtio-9p-test.c
T: git https://github.com/gkurz/qemu.git 9p-next
@ -1834,6 +1835,7 @@ F: block/
F: hw/block/
F: include/block/
F: qemu-img*
F: docs/interop/qemu-img.rst
F: qemu-io*
F: tests/qemu-iotests/
F: util/qemu-progress.c
@ -2192,6 +2194,7 @@ F: qemu-option-trace.texi
F: scripts/tracetool.py
F: scripts/tracetool/
F: scripts/qemu-trace-stap*
F: docs/interop/qemu-trace-stap.rst
F: docs/devel/tracing.txt
T: git https://github.com/stefanha/qemu.git tracing

46
Makefile
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@ -344,7 +344,8 @@ MANUAL_BUILDDIR := docs
endif
ifdef BUILD_DOCS
DOCS=qemu-doc.html qemu-doc.txt qemu.1 qemu-img.1
DOCS=qemu-doc.html qemu-doc.txt qemu.1
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-img.1
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-nbd.8
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-ga.8
DOCS+=$(MANUAL_BUILDDIR)/system/qemu-block-drivers.7
@ -353,10 +354,10 @@ DOCS+=docs/interop/qemu-ga-ref.html docs/interop/qemu-ga-ref.txt docs/interop/qe
DOCS+=docs/qemu-cpu-models.7
DOCS+=$(MANUAL_BUILDDIR)/index.html
ifdef CONFIG_VIRTFS
DOCS+=fsdev/virtfs-proxy-helper.1
DOCS+=$(MANUAL_BUILDDIR)/interop/virtfs-proxy-helper.1
endif
ifdef CONFIG_TRACE_SYSTEMTAP
DOCS+=scripts/qemu-trace-stap.1
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-trace-stap.1
endif
else
DOCS=
@ -744,7 +745,7 @@ rm -f $(MANUAL_BUILDDIR)/$1/objects.inv $(MANUAL_BUILDDIR)/$1/searchindex.js $(M
endef
distclean: clean
rm -f config-host.mak config-host.h* config-host.ld $(DOCS) qemu-options.texi qemu-img-cmds.texi qemu-monitor.texi qemu-monitor-info.texi
rm -f config-host.mak config-host.h* config-host.ld $(DOCS) qemu-options.texi qemu-monitor.texi qemu-monitor-info.texi
rm -f tests/tcg/config-*.mak
rm -f config-all-devices.mak config-all-disas.mak config.status
rm -f $(SUBDIR_DEVICES_MAK)
@ -842,12 +843,12 @@ ifdef CONFIG_POSIX
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/system/qemu-block-drivers.7 "$(DESTDIR)$(mandir)/man7"
$(INSTALL_DATA) docs/qemu-cpu-models.7 "$(DESTDIR)$(mandir)/man7"
ifeq ($(CONFIG_TOOLS),y)
$(INSTALL_DATA) qemu-img.1 "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/qemu-img.1 "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DIR) "$(DESTDIR)$(mandir)/man8"
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/qemu-nbd.8 "$(DESTDIR)$(mandir)/man8"
endif
ifdef CONFIG_TRACE_SYSTEMTAP
$(INSTALL_DATA) scripts/qemu-trace-stap.1 "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/qemu-trace-stap.1 "$(DESTDIR)$(mandir)/man1"
endif
ifneq (,$(findstring qemu-ga,$(TOOLS)))
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/qemu-ga.8 "$(DESTDIR)$(mandir)/man8"
@ -858,7 +859,7 @@ endif
endif
ifdef CONFIG_VIRTFS
$(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DATA) fsdev/virtfs-proxy-helper.1 "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/virtfs-proxy-helper.1 "$(DESTDIR)$(mandir)/man1"
endif
install-datadir:
@ -1028,11 +1029,19 @@ build-manual = $(call quiet-command,CONFDIR="$(qemu_confdir)" sphinx-build $(if
manual-deps = $(wildcard $(SRC_PATH)/docs/$1/*.rst) \
$(wildcard $(SRC_PATH)/docs/$1/*.rst.inc) \
$(SRC_PATH)/docs/$1/conf.py $(SRC_PATH)/docs/conf.py
# Macro to write out the rule and dependencies for building manpages
# Usage: $(call define-manpage-rule,manualname,manpage1 manpage2...[,extradeps])
# 'extradeps' is optional, and specifies extra files (eg .hx files) that
# the manual page depends on.
define define-manpage-rule
$(call atomic,$(foreach manpage,$2,$(MANUAL_BUILDDIR)/$1/$(manpage)),$(call manual-deps,$1) $3)
$(call build-manual,$1,man)
endef
$(MANUAL_BUILDDIR)/devel/index.html: $(call manual-deps,devel)
$(call build-manual,devel,html)
$(MANUAL_BUILDDIR)/interop/index.html: $(call manual-deps,interop)
$(MANUAL_BUILDDIR)/interop/index.html: $(call manual-deps,interop) $(SRC_PATH)/qemu-img-cmds.hx
$(call build-manual,interop,html)
$(MANUAL_BUILDDIR)/specs/index.html: $(call manual-deps,specs)
@ -1041,14 +1050,11 @@ $(MANUAL_BUILDDIR)/specs/index.html: $(call manual-deps,specs)
$(MANUAL_BUILDDIR)/system/index.html: $(call manual-deps,system)
$(call build-manual,system,html)
$(MANUAL_BUILDDIR)/interop/qemu-ga.8: $(call manual-deps,interop)
$(call build-manual,interop,man)
$(call define-manpage-rule,interop,\
qemu-ga.8 qemu-img.1 qemu-nbd.8 qemu-trace-stap.1 virtfs-proxy-helper.1,\
$(SRC_PATH/qemu-img-cmds.hx))
$(MANUAL_BUILDDIR)/interop/qemu-nbd.8: $(call manual-deps,interop)
$(call build-manual,interop,man)
$(MANUAL_BUILDDIR)/system/qemu-block-drivers.7: $(call manual-deps,system)
$(call build-manual,system,man)
$(call define-manpage-rule,system,qemu-block-drivers.7)
$(MANUAL_BUILDDIR)/index.html: $(SRC_PATH)/docs/index.html.in qemu-version.h
@mkdir -p "$(MANUAL_BUILDDIR)"
@ -1064,9 +1070,6 @@ qemu-monitor.texi: $(SRC_PATH)/hmp-commands.hx $(SRC_PATH)/scripts/hxtool
qemu-monitor-info.texi: $(SRC_PATH)/hmp-commands-info.hx $(SRC_PATH)/scripts/hxtool
$(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -t < $< > $@,"GEN","$@")
qemu-img-cmds.texi: $(SRC_PATH)/qemu-img-cmds.hx $(SRC_PATH)/scripts/hxtool
$(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -t < $< > $@,"GEN","$@")
docs/interop/qemu-qmp-qapi.texi: qapi/qapi-doc.texi
@cp -p $< $@
@ -1075,10 +1078,7 @@ docs/interop/qemu-ga-qapi.texi: qga/qapi-generated/qga-qapi-doc.texi
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
docs/qemu-cpu-models.7: docs/qemu-cpu-models.texi
scripts/qemu-trace-stap.1: scripts/qemu-trace-stap.texi
html: qemu-doc.html docs/interop/qemu-qmp-ref.html docs/interop/qemu-ga-ref.html sphinxdocs
info: qemu-doc.info docs/interop/qemu-qmp-ref.info docs/interop/qemu-ga-ref.info
@ -1086,9 +1086,9 @@ pdf: qemu-doc.pdf docs/interop/qemu-qmp-ref.pdf docs/interop/qemu-ga-ref.pdf
txt: qemu-doc.txt docs/interop/qemu-qmp-ref.txt docs/interop/qemu-ga-ref.txt
qemu-doc.html qemu-doc.info qemu-doc.pdf qemu-doc.txt: \
qemu-img.texi qemu-options.texi \
qemu-options.texi \
qemu-tech.texi qemu-option-trace.texi \
qemu-deprecated.texi qemu-monitor.texi qemu-img-cmds.texi \
qemu-deprecated.texi qemu-monitor.texi \
qemu-monitor-info.texi \
docs/qemu-cpu-models.texi docs/security.texi

3
docs/conf.py
View file

@ -54,7 +54,7 @@ needs_sphinx = '1.3'
# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
# ones.
extensions = ['kerneldoc', 'qmp_lexer']
extensions = ['kerneldoc', 'qmp_lexer', 'hxtool']
# Add any paths that contain templates here, relative to this directory.
templates_path = ['_templates']
@ -221,3 +221,4 @@ texinfo_documents = [
# find everything.
kerneldoc_bin = os.path.join(qemu_docdir, '../scripts/kernel-doc')
kerneldoc_srctree = os.path.join(qemu_docdir, '..')
hxtool_srctree = os.path.join(qemu_docdir, '..')

9
docs/interop/conf.py
View file

@ -19,6 +19,13 @@ html_theme_options['description'] = u'System Emulation Management and Interopera
man_pages = [
('qemu-ga', 'qemu-ga', u'QEMU Guest Agent',
['Michael Roth <mdroth@linux.vnet.ibm.com>'], 8),
('qemu-img', 'qemu-img', u'QEMU disk image utility',
['Fabrice Bellard'], 1),
('qemu-nbd', 'qemu-nbd', u'QEMU Disk Network Block Device Server',
['Anthony Liguori <anthony@codemonkey.ws>'], 8)
['Anthony Liguori <anthony@codemonkey.ws>'], 8),
('qemu-trace-stap', 'qemu-trace-stap', u'QEMU SystemTap trace tool',
[], 1),
('virtfs-proxy-helper', 'virtfs-proxy-helper',
u'QEMU 9p virtfs proxy filesystem helper',
['M. Mohan Kumar'], 1)
]

3
docs/interop/index.rst
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@ -18,6 +18,9 @@ Contents:
live-block-operations
pr-helper
qemu-ga
qemu-img
qemu-nbd
qemu-trace-stap
vhost-user
vhost-user-gpu
virtfs-proxy-helper

825
docs/interop/qemu-img.rst Normal file
View file

@ -0,0 +1,825 @@
QEMU disk image utility
=======================
Synopsis
--------
**qemu-img** [*standard options*] *command* [*command options*]
Description
-----------
qemu-img allows you to create, convert and modify images offline. It can handle
all image formats supported by QEMU.
**Warning:** Never use qemu-img to 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-img
Standard options:
.. option:: -h, --help
Display this 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
The following commands are supported:
.. hxtool-doc:: qemu-img-cmds.hx
Command parameters:
*FILENAME* is a disk image filename.
*FMT* is the disk image format. It is guessed automatically in most
cases. See below for a description of the supported disk formats.
*SIZE* is the disk image size in bytes. Optional suffixes ``k`` or
``K`` (kilobyte, 1024) ``M`` (megabyte, 1024k) and ``G`` (gigabyte,
1024M) and T (terabyte, 1024G) are supported. ``b`` is ignored.
*OUTPUT_FILENAME* is the destination disk image filename.
*OUTPUT_FMT* is the destination format.
*OPTIONS* is a comma separated list of format specific options in a
name=value format. Use ``-o ?`` for an overview of the options supported
by the used format or see the format descriptions below for details.
*SNAPSHOT_PARAM* is param used for internal snapshot, format is
'snapshot.id=[ID],snapshot.name=[NAME]' or '[ID_OR_NAME]'.
..
Note the use of a new 'program'; otherwise Sphinx complains about
the -h option appearing both in the above option list and this one.
.. program:: qemu-img-common-opts
.. option:: --object OBJECTDEF
is a QEMU user creatable object definition. See the :manpage:`qemu(1)`
manual page for a description of the object properties. The most common
object type is a ``secret``, which is used to supply passwords and/or
encryption keys.
.. option:: --image-opts
Indicates that the source *FILENAME* parameter is to be interpreted as a
full option string, not a plain filename. This parameter is mutually
exclusive with the *-f* parameter.
.. option:: --target-image-opts
Indicates that the OUTPUT_FILENAME parameter(s) are to be interpreted as
a full option string, not a plain filename. This parameter is mutually
exclusive with the *-O* parameters. It is currently required to also use
the *-n* parameter to skip image creation. This restriction may be relaxed
in a future release.
.. option:: --force-share (-U)
If specified, ``qemu-img`` will open the image in shared mode, allowing
other QEMU processes to open it in write mode. For example, this can be used to
get the image information (with 'info' subcommand) when the image is used by a
running guest. Note that this could produce inconsistent results because of
concurrent metadata changes, etc. This option is only allowed when opening
images in read-only mode.
.. option:: --backing-chain
Will enumerate information about backing files in a disk image chain. Refer
below for further description.
.. option:: -c
Indicates that target image must be compressed (qcow format only).
.. option:: -h
With or without a command, shows help and lists the supported formats.
.. option:: -p
Display progress bar (compare, convert and rebase commands only).
If the *-p* option is not used for a command that supports it, the
progress is reported when the process receives a ``SIGUSR1`` or
``SIGINFO`` signal.
.. option:: -q
Quiet mode - do not print any output (except errors). There's no progress bar
in case both *-q* and *-p* options are used.
.. option:: -S SIZE
Indicates the consecutive number of bytes that must contain only zeros
for qemu-img to create a sparse image during conversion. This value is rounded
down to the nearest 512 bytes. You may use the common size suffixes like
``k`` for kilobytes.
.. option:: -t CACHE
Specifies the cache mode that should be used with the (destination) file. See
the documentation of the emulator's ``-drive cache=...`` option for allowed
values.
.. option:: -T SRC_CACHE
Specifies the cache mode that should be used with the source file(s). See
the documentation of the emulator's ``-drive cache=...`` option for allowed
values.
Parameters to snapshot subcommand:
.. program:: qemu-img-snapshot
.. option:: snapshot
Is the name of the snapshot to create, apply or delete
.. option:: -a
Applies a snapshot (revert disk to saved state)
.. option:: -c
Creates a snapshot
.. option:: -d
Deletes a snapshot
.. option:: -l
Lists all snapshots in the given image
Parameters to compare subcommand:
.. program:: qemu-img-compare
.. option:: -f
First image format
.. option:: -F
Second image format
.. option:: -s
Strict mode - fail on different image size or sector allocation
Parameters to convert subcommand:
.. program:: qemu-img-convert
.. option:: -n
Skip the creation of the target volume
.. option:: -m
Number of parallel coroutines for the convert process
.. option:: -W
Allow out-of-order writes to the destination. This option improves performance,
but is only recommended for preallocated devices like host devices or other
raw block devices.
.. option:: -C
Try to use copy offloading to move data from source image to target. This may
improve performance if the data is remote, such as with NFS or iSCSI backends,
but will not automatically sparsify zero sectors, and may result in a fully
allocated target image depending on the host support for getting allocation
information.
.. option:: --salvage
Try to ignore I/O errors when reading. Unless in quiet mode (``-q``), errors
will still be printed. Areas that cannot be read from the source will be
treated as containing only zeroes.
Parameters to dd subcommand:
.. program:: qemu-img-dd
.. option:: bs=BLOCK_SIZE
Defines the block size
.. option:: count=BLOCKS
Sets the number of input blocks to copy
.. option:: if=INPUT
Sets the input file
.. option:: of=OUTPUT
Sets the output file
.. option:: skip=BLOCKS
Sets the number of input blocks to skip
Command description:
.. program:: qemu-img-commands
.. option:: amend [--object OBJECTDEF] [--image-opts] [-p] [-q] [-f FMT] [-t CACHE] -o OPTIONS FILENAME
Amends the image format specific *OPTIONS* for the image file
*FILENAME*. Not all file formats support this operation.
.. option:: bench [-c COUNT] [-d DEPTH] [-f FMT] [--flush-interval=FLUSH_INTERVAL] [-n] [-i AIO] [--no-drain] [-o OFFSET] [--pattern=PATTERN] [-q] [-s BUFFER_SIZE] [-S STEP_SIZE] [-t CACHE] [-w] [-U] FILENAME
Run a simple sequential I/O benchmark on the specified image. If ``-w`` is
specified, a write test is performed, otherwise a read test is performed.
A total number of *COUNT* I/O requests is performed, each *BUFFER_SIZE*
bytes in size, and with *DEPTH* requests in parallel. The first request
starts at the position given by *OFFSET*, each following request increases
the current position by *STEP_SIZE*. If *STEP_SIZE* is not given,
*BUFFER_SIZE* is used for its value.
If *FLUSH_INTERVAL* is specified for a write test, the request queue is
drained and a flush is issued before new writes are made whenever the number of
remaining requests is a multiple of *FLUSH_INTERVAL*. If additionally
``--no-drain`` is specified, a flush is issued without draining the request
queue first.
If ``-n`` is specified, the native AIO backend is used if possible. On
Linux, this option only works if ``-t none`` or ``-t directsync`` is
specified as well.
if ``-i`` is specified, *AIO* option can be used to specify different
AIO backends: ``threads``, ``native`` or ``io_uring``.
For write tests, by default a buffer filled with zeros is written. This can be
overridden with a pattern byte specified by *PATTERN*.
.. option:: check [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [--output=OFMT] [-r [leaks | all]] [-T SRC_CACHE] [-U] FILENAME
Perform a consistency check on the disk image *FILENAME*. The command can
output in the format *OFMT* which is either ``human`` or ``json``.
The JSON output is an object of QAPI type ``ImageCheck``.
If ``-r`` is specified, qemu-img tries to repair any inconsistencies found
during the check. ``-r leaks`` repairs only cluster leaks, whereas
``-r all`` fixes all kinds of errors, with a higher risk of choosing the
wrong fix or hiding corruption that has already occurred.
Only the formats ``qcow2``, ``qed`` and ``vdi`` support
consistency checks.
In case the image does not have any inconsistencies, check exits with ``0``.
Other exit codes indicate the kind of inconsistency found or if another error
occurred. The following table summarizes all exit codes of the check subcommand:
0
Check completed, the image is (now) consistent
1
Check not completed because of internal errors
2
Check completed, image is corrupted
3
Check completed, image has leaked clusters, but is not corrupted
63
Checks are not supported by the image format
If ``-r`` is specified, exit codes representing the image state refer to the
state after (the attempt at) repairing it. That is, a successful ``-r all``
will yield the exit code 0, independently of the image state before.
.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-d] [-p] FILENAME
Commit the changes recorded in *FILENAME* in its base image or backing file.
If the backing file is smaller than the snapshot, then the backing file will be
resized to be the same size as the snapshot. If the snapshot is smaller than
the backing file, the backing file will not be truncated. If you want the
backing file to match the size of the smaller snapshot, you can safely truncate
it yourself once the commit operation successfully completes.
The image *FILENAME* is emptied after the operation has succeeded. If you do
not need *FILENAME* afterwards and intend to drop it, you may skip emptying
*FILENAME* by specifying the ``-d`` flag.
If the backing chain of the given image file *FILENAME* has more than one
layer, the backing file into which the changes will be committed may be
specified as *BASE* (which has to be part of *FILENAME*'s backing
chain). If *BASE* is not specified, the immediate backing file of the top
image (which is *FILENAME*) will be used. Note that after a commit operation
all images between *BASE* and the top image will be invalid and may return
garbage data when read. For this reason, ``-b`` implies ``-d`` (so that
the top image stays valid).
.. option:: compare [--object OBJECTDEF] [--image-opts] [-f FMT] [-F FMT] [-T SRC_CACHE] [-p] [-q] [-s] [-U] FILENAME1 FILENAME2
Check if two images have the same content. You can compare images with
different format or settings.
The format is probed unless you specify it by ``-f`` (used for
*FILENAME1*) and/or ``-F`` (used for *FILENAME2*) option.
By default, images with different size are considered identical if the larger
image contains only unallocated and/or zeroed sectors in the area after the end
of the other image. In addition, if any sector is not allocated in one image
and contains only zero bytes in the second one, it is evaluated as equal. You
can use Strict mode by specifying the ``-s`` option. When compare runs in
Strict mode, it fails in case image size differs or a sector is allocated in
one image and is not allocated in the second one.
By default, compare prints out a result message. This message displays
information that both images are same or the position of the first different
byte. In addition, result message can report different image size in case
Strict mode is used.
Compare exits with ``0`` in case the images are equal and with ``1``
in case the images differ. Other exit codes mean an error occurred during
execution and standard error output should contain an error message.
The following table sumarizes all exit codes of the compare subcommand:
0
Images are identical
1
Images differ
2
Error on opening an image
3
Error on checking a sector allocation
4
Error on reading data
.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
Convert the disk image *FILENAME* or a snapshot *SNAPSHOT_PARAM*
to disk image *OUTPUT_FILENAME* using format *OUTPUT_FMT*. It can
be optionally compressed (``-c`` option) or use any format specific
options like encryption (``-o`` option).
Only the formats ``qcow`` and ``qcow2`` support compression. The
compression is read-only. It means that if a compressed sector is
rewritten, then it is rewritten as uncompressed data.
Image conversion is also useful to get smaller image when using a
growable format such as ``qcow``: the empty sectors are detected and
suppressed from the destination image.
*SPARSE_SIZE* indicates the consecutive number of bytes (defaults to 4k)
that must contain only zeros for qemu-img to create a sparse image during
conversion. If *SPARSE_SIZE* is 0, the source will not be scanned for
unallocated or zero sectors, and the destination image will always be
fully allocated.
You can use the *BACKING_FILE* option to force the output image to be
created as a copy on write image of the specified base image; the
*BACKING_FILE* should have the same content as the input's base image,
however the path, image format, etc may differ.
If a relative path name is given, the backing file is looked up relative to
the directory containing *OUTPUT_FILENAME*.
If the ``-n`` option is specified, the target volume creation will be
skipped. This is useful for formats such as ``rbd`` if the target
volume has already been created with site specific options that cannot
be supplied through qemu-img.
Out of order writes can be enabled with ``-W`` to improve performance.
This is only recommended for preallocated devices like host devices or other
raw block devices. Out of order write does not work in combination with
creating compressed images.
*NUM_COROUTINES* specifies how many coroutines work in parallel during
the convert process (defaults to 8).
.. option:: create [--object OBJECTDEF] [-q] [-f FMT] [-b BACKING_FILE] [-F BACKING_FMT] [-u] [-o OPTIONS] FILENAME [SIZE]
Create the new disk image *FILENAME* of size *SIZE* and format
*FMT*. Depending on the file format, you can add one or more *OPTIONS*
that enable additional features of this format.
If the option *BACKING_FILE* is specified, then the image will record
only the differences from *BACKING_FILE*. No size needs to be specified in
this case. *BACKING_FILE* will never be modified unless you use the
``commit`` monitor command (or qemu-img commit).
If a relative path name is given, the backing file is looked up relative to
the directory containing *FILENAME*.
Note that a given backing file will be opened to check that it is valid. Use
the ``-u`` option to enable unsafe backing file mode, which means that the
image will be created even if the associated backing file cannot be opened. A
matching backing file must be created or additional options be used to make the
backing file specification valid when you want to use an image created this
way.
The size can also be specified using the *SIZE* option with ``-o``,
it doesn't need to be specified separately in this case.
.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT
dd copies from *INPUT* file to *OUTPUT* file converting it from
*FMT* format to *OUTPUT_FMT* format.
The data is by default read and written using blocks of 512 bytes but can be
modified by specifying *BLOCK_SIZE*. If count=\ *BLOCKS* is specified
dd will stop reading input after reading *BLOCKS* input blocks.
The size syntax is similar to :manpage:`dd(1)`'s size syntax.
.. option:: info [--object OBJECTDEF] [--image-opts] [-f FMT] [--output=OFMT] [--backing-chain] [-U] FILENAME
Give information about the disk image *FILENAME*. Use it in
particular to know the size reserved on disk which can be different
from the displayed size. If VM snapshots are stored in the disk image,
they are displayed too.
If a disk image has a backing file chain, information about each disk image in
the chain can be recursively enumerated by using the option ``--backing-chain``.
For instance, if you have an image chain like:
::
base.qcow2 <- snap1.qcow2 <- snap2.qcow2
To enumerate information about each disk image in the above chain, starting from top to base, do:
::
qemu-img info --backing-chain snap2.qcow2
The command can output in the format *OFMT* which is either ``human`` or
``json``. The JSON output is an object of QAPI type ``ImageInfo``; with
``--backing-chain``, it is an array of ``ImageInfo`` objects.
``--output=human`` reports the following information (for every image in the
chain):
*image*
The image file name
*file format*
The image format
*virtual size*
The size of the guest disk
*disk size*
How much space the image file occupies on the host file system (may be
shown as 0 if this information is unavailable, e.g. because there is no
file system)
*cluster_size*
Cluster size of the image format, if applicable
*encrypted*
Whether the image is encrypted (only present if so)
*cleanly shut down*
This is shown as ``no`` if the image is dirty and will have to be
auto-repaired the next time it is opened in qemu.
*backing file*
The backing file name, if present
*backing file format*
The format of the backing file, if the image enforces it
*Snapshot list*
A list of all internal snapshots
*Format specific information*
Further information whose structure depends on the image format. This
section is a textual representation of the respective
``ImageInfoSpecific*`` QAPI object (e.g. ``ImageInfoSpecificQCow2``
for qcow2 images).
.. option:: map [--object OBJECTDEF] [--image-opts] [-f FMT] [--output=OFMT] [-U] FILENAME
Dump the metadata of image *FILENAME* and its backing file chain.
In particular, this commands dumps the allocation state of every sector
of *FILENAME*, together with the topmost file that allocates it in
the backing file chain.
Two option formats are possible. The default format (``human``)
only dumps known-nonzero areas of the file. Known-zero parts of the
file are omitted altogether, and likewise for parts that are not allocated
throughout the chain. ``qemu-img`` output will identify a file
from where the data can be read, and the offset in the file. Each line
will include four fields, the first three of which are hexadecimal
numbers. For example the first line of:
::
Offset Length Mapped to File
0 0x20000 0x50000 /tmp/overlay.qcow2
0x100000 0x10000 0x95380000 /tmp/backing.qcow2
means that 0x20000 (131072) bytes starting at offset 0 in the image are
available in /tmp/overlay.qcow2 (opened in ``raw`` format) starting
at offset 0x50000 (327680). Data that is compressed, encrypted, or
otherwise not available in raw format will cause an error if ``human``
format is in use. Note that file names can include newlines, thus it is
not safe to parse this output format in scripts.
The alternative format ``json`` will return an array of dictionaries
in JSON format. It will include similar information in
the ``start``, ``length``, ``offset`` fields;
it will also include other more specific information:
- whether the sectors contain actual data or not (boolean field ``data``;
if false, the sectors are either unallocated or stored as optimized
all-zero clusters);
- whether the data is known to read as zero (boolean field ``zero``);
- in order to make the output shorter, the target file is expressed as
a ``depth``; for example, a depth of 2 refers to the backing file
of the backing file of *FILENAME*.
In JSON format, the ``offset`` field is optional; it is absent in
cases where ``human`` format would omit the entry or exit with an error.
If ``data`` is false and the ``offset`` field is present, the
corresponding sectors in the file are not yet in use, but they are
preallocated.
For more information, consult ``include/block/block.h`` in QEMU's
source code.
.. option:: measure [--output=OFMT] [-O OUTPUT_FMT] [-o OPTIONS] [--size N | [--object OBJECTDEF] [--image-opts] [-f FMT] [-l SNAPSHOT_PARAM] FILENAME]
Calculate the file size required for a new image. This information
can be used to size logical volumes or SAN LUNs appropriately for
the image that will be placed in them. The values reported are
guaranteed to be large enough to fit the image. The command can
output in the format *OFMT* which is either ``human`` or ``json``.
The JSON output is an object of QAPI type ``BlockMeasureInfo``.
If the size *N* is given then act as if creating a new empty image file
using ``qemu-img create``. If *FILENAME* is given then act as if
converting an existing image file using ``qemu-img convert``. The format
of the new file is given by *OUTPUT_FMT* while the format of an existing
file is given by *FMT*.
A snapshot in an existing image can be specified using *SNAPSHOT_PARAM*.
The following fields are reported:
::
required size: 524288
fully allocated size: 1074069504
The ``required size`` is the file size of the new image. It may be smaller
than the virtual disk size if the image format supports compact representation.
The ``fully allocated size`` is the file size of the new image once data has
been written to all sectors. This is the maximum size that the image file can
occupy with the exception of internal snapshots, dirty bitmaps, vmstate data,
and other advanced image format features.
.. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
List, apply, create or delete snapshots in image *FILENAME*.
.. option:: rebase [--object OBJECTDEF] [--image-opts] [-U] [-q] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-p] [-u] -b BACKING_FILE [-F BACKING_FMT] FILENAME
Changes the backing file of an image. Only the formats ``qcow2`` and
``qed`` support changing the backing file.
The backing file is changed to *BACKING_FILE* and (if the image format of
*FILENAME* supports this) the backing file format is changed to
*BACKING_FMT*. If *BACKING_FILE* is specified as "" (the empty
string), then the image is rebased onto no backing file (i.e. it will exist
independently of any backing file).
If a relative path name is given, the backing file is looked up relative to
the directory containing *FILENAME*.
*CACHE* specifies the cache mode to be used for *FILENAME*, whereas
*SRC_CACHE* specifies the cache mode for reading backing files.
There are two different modes in which ``rebase`` can operate:
Safe mode
This is the default mode and performs a real rebase operation. The
new backing file may differ from the old one and qemu-img rebase
will take care of keeping the guest-visible content of *FILENAME*
unchanged.
In order to achieve this, any clusters that differ between
*BACKING_FILE* and the old backing file of *FILENAME* are merged
into *FILENAME* before actually changing the backing file.
Note that the safe mode is an expensive operation, comparable to
converting an image. It only works if the old backing file still
exists.
Unsafe mode
qemu-img uses the unsafe mode if ``-u`` is specified. In this
mode, only the backing file name and format of *FILENAME* is changed
without any checks on the file contents. The user must take care of
specifying the correct new backing file, or the guest-visible
content of the image will be corrupted.
This mode is useful for renaming or moving the backing file to
somewhere else. It can be used without an accessible old backing
file, i.e. you can use it to fix an image whose backing file has
already been moved/renamed.
You can use ``rebase`` to perform a "diff" operation on two
disk images. This can be useful when you have copied or cloned
a guest, and you want to get back to a thin image on top of a
template or base image.
Say that ``base.img`` has been cloned as ``modified.img`` by
copying it, and that the ``modified.img`` guest has run so there
are now some changes compared to ``base.img``. To construct a thin
image called ``diff.qcow2`` that contains just the differences, do:
::
qemu-img create -f qcow2 -b modified.img diff.qcow2
qemu-img rebase -b base.img diff.qcow2
At this point, ``modified.img`` can be discarded, since
``base.img + diff.qcow2`` contains the same information.
.. option:: resize [--object OBJECTDEF] [--image-opts] [-f FMT] [--preallocation=PREALLOC] [-q] [--shrink] FILENAME [+ | -]SIZE
Change the disk image as if it had been created with *SIZE*.
Before using this command to shrink a disk image, you MUST use file system and
partitioning tools inside the VM to reduce allocated file systems and partition
sizes accordingly. Failure to do so will result in data loss!
When shrinking images, the ``--shrink`` option must be given. This informs
qemu-img that the user acknowledges all loss of data beyond the truncated
image's end.
After using this command to grow a disk image, you must use file system and
partitioning tools inside the VM to actually begin using the new space on the
device.
When growing an image, the ``--preallocation`` option may be used to specify
how the additional image area should be allocated on the host. See the format
description in the :ref:`notes` section which values are allowed. Using this
option may result in slightly more data being allocated than necessary.
.. _notes:
Notes
-----
Supported image file formats:
``raw``
Raw disk image format (default). This format has the advantage of
being simple and easily exportable to all other emulators. If your
file system supports *holes* (for example in ext2 or ext3 on
Linux or NTFS on Windows), then only the written sectors will reserve
space. Use ``qemu-img info`` to know the real size used by the
image or ``ls -ls`` on Unix/Linux.
Supported options:
``preallocation``
Preallocation mode (allowed values: ``off``, ``falloc``,
``full``). ``falloc`` mode preallocates space for image by
calling ``posix_fallocate()``. ``full`` mode preallocates space
for image by writing data to underlying storage. This data may or
may not be zero, depending on the storage location.
``qcow2``
QEMU image format, the most versatile format. Use it to have smaller
images (useful if your filesystem does not supports holes, for example
on Windows), optional AES encryption, zlib based compression and
support of multiple VM snapshots.
Supported options:
``compat``
Determines the qcow2 version to use. ``compat=0.10`` uses the
traditional image format that can be read by any QEMU since 0.10.
``compat=1.1`` enables image format extensions that only QEMU 1.1 and
newer understand (this is the default). Amongst others, this includes zero
clusters, which allow efficient copy-on-read for sparse images.
``backing_file``
File name of a base image (see ``create`` subcommand)
``backing_fmt``
Image format of the base image
``encryption``
If this option is set to ``on``, the image is encrypted with
128-bit AES-CBC.
The use of encryption in qcow and qcow2 images is considered to be
flawed by modern cryptography standards, suffering from a number
of design problems:
- The AES-CBC cipher is used with predictable initialization
vectors based on the sector number. This makes it vulnerable to
chosen plaintext attacks which can reveal the existence of
encrypted data.
- The user passphrase is directly used as the encryption key. A
poorly chosen or short passphrase will compromise the security
of the encryption.
- In the event of the passphrase being compromised there is no way
to change the passphrase to protect data in any qcow images. The
files must be cloned, using a different encryption passphrase in
the new file. The original file must then be securely erased
using a program like shred, though even this is ineffective with
many modern storage technologies.
- Initialization vectors used to encrypt sectors are based on the
guest virtual sector number, instead of the host physical
sector. When a disk image has multiple internal snapshots this
means that data in multiple physical sectors is encrypted with
the same initialization vector. With the CBC mode, this opens
the possibility of watermarking attacks if the attack can
collect multiple sectors encrypted with the same IV and some
predictable data. Having multiple qcow2 images with the same
passphrase also exposes this weakness since the passphrase is
directly used as the key.
Use of qcow / qcow2 encryption is thus strongly discouraged. Users are
recommended to use an alternative encryption technology such as the
Linux dm-crypt / LUKS system.
``cluster_size``
Changes the qcow2 cluster size (must be between 512 and
2M). Smaller cluster sizes can improve the image file size whereas
larger cluster sizes generally provide better performance.
``preallocation``
Preallocation mode (allowed values: ``off``, ``metadata``,
``falloc``, ``full``). An image with preallocated metadata is
initially larger but can improve performance when the image needs
to grow. ``falloc`` and ``full`` preallocations are like the same
options of ``raw`` format, but sets up metadata also.
``lazy_refcounts``
If this option is set to ``on``, reference count updates are
postponed with the goal of avoiding metadata I/O and improving
performance. This is particularly interesting with
``cache=writethrough`` which doesn't batch metadata
updates. The tradeoff is that after a host crash, the reference
count tables must be rebuilt, i.e. on the next open an (automatic)
``qemu-img check -r all`` is required, which may take some time.
This option can only be enabled if ``compat=1.1`` is specified.
``nocow``
If this option is set to ``on``, it will turn off COW of the file. It's
only valid on btrfs, no effect on other file systems.
Btrfs has low performance when hosting a VM image file, even more
when the guest on the VM also using btrfs as file system. Turning
off COW is a way to mitigate this bad performance. Generally there
are two ways to turn off COW on btrfs:
- Disable it by mounting with nodatacow, then all newly created files
will be NOCOW
- For an empty file, add the NOCOW file attribute. That's what this
option does.
Note: this option is only valid to new or empty files. If there is
an existing file which is COW and has data blocks already, it
couldn't be changed to NOCOW by setting ``nocow=on``. One can
issue ``lsattr filename`` to check if the NOCOW flag is set or not
(Capital 'C' is NOCOW flag).
``Other``
QEMU also supports various other image file formats for
compatibility with older QEMU versions or other hypervisors,
including VMDK, VDI, VHD (vpc), VHDX, qcow1 and QED. For a full list
of supported formats see ``qemu-img --help``. For a more detailed
description of these formats, see the QEMU block drivers reference
documentation.
The main purpose of the block drivers for these formats is image
conversion. For running VMs, it is recommended to convert the disk
images to either raw or qcow2 in order to achieve good performance.

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QEMU SystemTap trace tool
=========================
Synopsis
--------
**qemu-trace-stap** [*GLOBAL-OPTIONS*] *COMMAND* [*COMMAND-OPTIONS*] *ARGS*...
Description
-----------
The ``qemu-trace-stap`` program facilitates tracing of the execution
of QEMU emulators using SystemTap.
It is required to have the SystemTap runtime environment installed to use
this program, since it is a wrapper around execution of the ``stap``
program.
Options
-------
.. program:: qemu-trace-stap
The following global options may be used regardless of which command
is executed:
.. option:: --verbose, -v
Display verbose information about command execution.
The following commands are valid:
.. option:: list BINARY PATTERN...
List all the probe names provided by *BINARY* that match
*PATTERN*.
If *BINARY* is not an absolute path, it will be located by searching
the directories listed in the ``$PATH`` environment variable.
*PATTERN* is a plain string that is used to filter the results of
this command. It may optionally contain a ``*`` wildcard to facilitate
matching multiple probes without listing each one explicitly. Multiple
*PATTERN* arguments may be given, causing listing of probes that match
any of the listed names. If no *PATTERN* is given, the all possible
probes will be listed.
For example, to list all probes available in the ``qemu-system-x86_64``
binary:
::
$ qemu-trace-stap list qemu-system-x86_64
To filter the list to only cover probes related to QEMU's cryptographic
subsystem, in a binary outside ``$PATH``
::
$ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*'
.. option:: run OPTIONS BINARY PATTERN...
Run a trace session, printing formatted output any time a process that is
executing *BINARY* triggers a probe matching *PATTERN*.
If *BINARY* is not an absolute path, it will be located by searching
the directories listed in the ``$PATH`` environment variable.
*PATTERN* is a plain string that matches a probe name shown by the
*LIST* command. It may optionally contain a ``*`` wildcard to
facilitate matching multiple probes without listing each one explicitly.
Multiple *PATTERN* arguments may be given, causing all matching probes
to be monitored. At least one *PATTERN* is required, since stap is not
capable of tracing all known QEMU probes concurrently without overflowing
its trace buffer.
Invocation of this command does not need to be synchronized with
invocation of the QEMU process(es). It will match probes on all
existing running processes and all future launched processes,
unless told to only monitor a specific process.
Valid command specific options are:
.. program:: qemu-trace-stap-run
.. option:: --pid=PID, -p PID
Restrict the tracing session so that it only triggers for the process
identified by *PID*.
For example, to monitor all processes executing ``qemu-system-x86_64``
as found on ``$PATH``, displaying all I/O related probes:
::
$ qemu-trace-stap run qemu-system-x86_64 'qio*'
To monitor only the QEMU process with PID 1732
::
$ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*'
To monitor QEMU processes running an alternative binary outside of
``$PATH``, displaying verbose information about setup of the
tracing environment:
::
$ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*'
See also
--------
:manpage:`qemu(1)`, :manpage:`stap(1)`
..
Copyright (C) 2019 Red Hat, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

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QEMU 9p virtfs proxy filesystem helper
======================================
Synopsis
--------
**virtfs-proxy-helper** [*OPTIONS*]
Description
-----------
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

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# coding=utf-8
#
# QEMU hxtool .hx file parsing extension
#
# Copyright (c) 2020 Linaro
#
# This work is licensed under the terms of the GNU GPLv2 or later.
# See the COPYING file in the top-level directory.
"""hxtool is a Sphinx extension that implements the hxtool-doc directive"""
# The purpose of this extension is to read fragments of rST
# from .hx files, and insert them all into the current document.
# The rST fragments are delimited by SRST/ERST lines.
# The conf.py file must set the hxtool_srctree config value to
# the root of the QEMU source tree.
# Each hxtool-doc:: directive takes one argument which is the
# path of the .hx file to process, relative to the source tree.
import os
import re
from enum import Enum
from docutils import nodes
from docutils.statemachine import ViewList
from docutils.parsers.rst import directives, Directive
from sphinx.errors import ExtensionError
from sphinx.util.nodes import nested_parse_with_titles
import sphinx
# Sphinx up to 1.6 uses AutodocReporter; 1.7 and later
# use switch_source_input. Check borrowed from kerneldoc.py.
Use_SSI = sphinx.__version__[:3] >= '1.7'
if Use_SSI:
from sphinx.util.docutils import switch_source_input
else:
from sphinx.ext.autodoc import AutodocReporter
__version__ = '1.0'
# We parse hx files with a state machine which may be in one of three
# states: reading the C code fragment, inside a texi fragment,
# or inside a rST fragment.
class HxState(Enum):
CTEXT = 1
TEXI = 2
RST = 3
def serror(file, lnum, errtext):
"""Raise an exception giving a user-friendly syntax error message"""
raise ExtensionError('%s line %d: syntax error: %s' % (file, lnum, errtext))
def parse_directive(line):
"""Return first word of line, if any"""
return re.split('\W', line)[0]
def parse_defheading(file, lnum, line):
"""Handle a DEFHEADING directive"""
# The input should be "DEFHEADING(some string)", though note that
# the 'some string' could be the empty string. If the string is
# empty we ignore the directive -- these are used only to add
# blank lines in the plain-text content of the --help output.
#
# Return the heading text
match = re.match(r'DEFHEADING\((.*)\)', line)
if match is None:
serror(file, lnum, "Invalid DEFHEADING line")
return match.group(1)
def parse_archheading(file, lnum, line):
"""Handle an ARCHHEADING directive"""
# The input should be "ARCHHEADING(some string, other arg)",
# though note that the 'some string' could be the empty string.
# As with DEFHEADING, empty string ARCHHEADINGs will be ignored.
#
# Return the heading text
match = re.match(r'ARCHHEADING\((.*),.*\)', line)
if match is None:
serror(file, lnum, "Invalid ARCHHEADING line")
return match.group(1)
class HxtoolDocDirective(Directive):
"""Extract rST fragments from the specified .hx file"""
required_argument = 1
optional_arguments = 1
option_spec = {
'hxfile': directives.unchanged_required
}
has_content = False
def run(self):
env = self.state.document.settings.env
hxfile = env.config.hxtool_srctree + '/' + self.arguments[0]
# Tell sphinx of the dependency
env.note_dependency(os.path.abspath(hxfile))
state = HxState.CTEXT
# We build up lines of rST in this ViewList, which we will
# later put into a 'section' node.
rstlist = ViewList()
current_node = None
node_list = []
with open(hxfile) as f:
lines = (l.rstrip() for l in f)
for lnum, line in enumerate(lines, 1):
directive = parse_directive(line)
if directive == 'HXCOMM':
pass
elif directive == 'STEXI':
if state == HxState.RST:
serror(hxfile, lnum, 'expected ERST, found STEXI')
elif state == HxState.TEXI:
serror(hxfile, lnum, 'expected ETEXI, found STEXI')
else:
state = HxState.TEXI
elif directive == 'ETEXI':
if state == HxState.RST:
serror(hxfile, lnum, 'expected ERST, found ETEXI')
elif state == HxState.CTEXT:
serror(hxfile, lnum, 'expected STEXI, found ETEXI')
else:
state = HxState.CTEXT
elif directive == 'SRST':
if state == HxState.RST:
serror(hxfile, lnum, 'expected ERST, found SRST')
elif state == HxState.TEXI:
serror(hxfile, lnum, 'expected ETEXI, found SRST')
else:
state = HxState.RST
elif directive == 'ERST':
if state == HxState.TEXI:
serror(hxfile, lnum, 'expected ETEXI, found ERST')
elif state == HxState.CTEXT:
serror(hxfile, lnum, 'expected SRST, found ERST')
else:
state = HxState.CTEXT
elif directive == 'DEFHEADING' or directive == 'ARCHHEADING':
if directive == 'DEFHEADING':
heading = parse_defheading(hxfile, lnum, line)
else:
heading = parse_archheading(hxfile, lnum, line)
if heading == "":
continue
# Put the accumulated rST into the previous node,
# and then start a fresh section with this heading.
if len(rstlist) > 0:
if current_node is None:
# We had some rST fragments before the first
# DEFHEADING. We don't have a section to put
# these in, so rather than magicing up a section,
# make it a syntax error.
serror(hxfile, lnum,
'first DEFHEADING must precede all rST text')
self.do_parse(rstlist, current_node)
rstlist = ViewList()
if current_node is not None:
node_list.append(current_node)
section_id = 'hxtool-%d' % env.new_serialno('hxtool')
current_node = nodes.section(ids=[section_id])
current_node += nodes.title(heading, heading)
else:
# Not a directive: put in output if we are in rST fragment
if state == HxState.RST:
# Sphinx counts its lines from 0
rstlist.append(line, hxfile, lnum - 1)
if current_node is None:
# We don't have multiple sections, so just parse the rst
# fragments into a dummy node so we can return the children.
current_node = nodes.section()
self.do_parse(rstlist, current_node)
return current_node.children
else:
# Put the remaining accumulated rST into the last section, and
# return all the sections.
if len(rstlist) > 0:
self.do_parse(rstlist, current_node)
node_list.append(current_node)
return node_list
# This is from kerneldoc.py -- it works around an API change in
# Sphinx between 1.6 and 1.7. Unlike kerneldoc.py, we use
# sphinx.util.nodes.nested_parse_with_titles() rather than the
# plain self.state.nested_parse(), and so we can drop the saving
# of title_styles and section_level that kerneldoc.py does,
# because nested_parse_with_titles() does that for us.
def do_parse(self, result, node):
if Use_SSI:
with switch_source_input(self.state, result):
nested_parse_with_titles(self.state, result, node)
else:
save = self.state.memo.reporter
self.state.memo.reporter = AutodocReporter(result, self.state.memo.reporter)
try:
nested_parse_with_titles(self.state, result, node)
finally:
self.state.memo.reporter = save
def setup(app):
""" Register hxtool-doc directive with Sphinx"""
app.add_config_value('hxtool_srctree', None, 'env')
app.add_directive('hxtool-doc', HxtoolDocDirective)
return dict(
version = __version__,
parallel_read_safe = True,
parallel_write_safe = True
)

63
fsdev/virtfs-proxy-helper.texi
View file

@ -1,63 +0,0 @@
@example
@c man begin SYNOPSIS
@command{virtfs-proxy-helper} @var{options}
@c man end
@end example
@c man begin DESCRIPTION
@table @description
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
1) TOCTTOU vulnerability: Following symbolic links in the server could
provide access to files beyond 9p export path.
2) 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.
@end table
@c man end
@c man begin OPTIONS
The following options are supported:
@table @option
@item -h
@findex -h
Display help and exit
@item -p|--path path
Path to export for proxy filesystem driver
@item -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 -f|--fd
@item -s|--socket socket-file
Creates named socket file for communicating with qemu proxy fs driver
@item -u|--uid uid -g|--gid gid
uid:gid combination to give access to named socket file
@item -n|--nodaemon
Run as a normal program. By default program will run in daemon mode
@end table
@c man end
@setfilename virtfs-proxy-helper
@settitle QEMU 9p virtfs proxy filesystem helper
@c man begin AUTHOR
M. Mohan Kumar
@c man end

10
qemu-doc.texi
View file

@ -632,7 +632,6 @@ encrypted disk images.
* disk_images_quickstart:: Quick start for disk image creation
* disk_images_snapshot_mode:: Snapshot mode
* vm_snapshots:: VM snapshots
* qemu_img_invocation:: qemu-img Invocation
@end menu
@node disk_images_quickstart
@ -646,7 +645,9 @@ where @var{myimage.img} is the disk image filename and @var{mysize} is its
size in kilobytes. You can add an @code{M} suffix to give the size in
megabytes and a @code{G} suffix for gigabytes.
See @ref{qemu_img_invocation} for more information.
@c When this document is converted to rst we should make this into
@c a proper linked reference to the qemu-img documentation again:
See the qemu-img invocation documentation for more information.
@node disk_images_snapshot_mode
@subsection Snapshot mode
@ -708,11 +709,6 @@ A few device drivers still have incomplete snapshot support so their
state is not saved or restored properly (in particular USB).
@end itemize
@node qemu_img_invocation
@subsection @code{qemu-img} Invocation
@include qemu-img.texi
@node pcsys_network
@section Network emulation

99
qemu-img-cmds.hx
View file

@ -1,102 +1,93 @@
HXCOMM Keep the list of subcommands sorted by name.
HXCOMM Use DEFHEADING() to define headings in both help text and texi
HXCOMM Text between STEXI and ETEXI are copied to texi version and
HXCOMM Text between SRST and ERST are copied to rST version and
HXCOMM discarded from C version
HXCOMM DEF(command, callback, arg_string) is used to construct
HXCOMM command structures and help message.
HXCOMM HXCOMM can be used for comments, discarded from both texi and C
HXCOMM HXCOMM can be used for comments, discarded from both rST and C
HXCOMM When amending the TEXI sections, please remember to copy the usage
HXCOMM When amending the rST sections, please remember to copy the usage
HXCOMM over to the per-command sections in qemu-img.texi.
STEXI
@table @option
ETEXI
DEF("amend", img_amend,
"amend [--object objectdef] [--image-opts] [-p] [-q] [-f fmt] [-t cache] -o options filename")
STEXI
@item amend [--object @var{objectdef}] [--image-opts] [-p] [-q] [-f @var{fmt}] [-t @var{cache}] -o @var{options} @var{filename}
ETEXI
SRST
.. option:: amend [--object OBJECTDEF] [--image-opts] [-p] [-q] [-f FMT] [-t CACHE] -o OPTIONS FILENAME
ERST
DEF("bench", img_bench,
"bench [-c count] [-d depth] [-f fmt] [--flush-interval=flush_interval] [-n] [--no-drain] [-o offset] [--pattern=pattern] [-q] [-s buffer_size] [-S step_size] [-t cache] [-i aio] [-w] [-U] filename")
STEXI
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-i @var{aio}] [-w] [-U] @var{filename}
ETEXI
SRST
.. option:: bench [-c COUNT] [-d DEPTH] [-f FMT] [--flush-interval=FLUSH_INTERVAL] [-n] [--no-drain] [-o OFFSET] [--pattern=PATTERN] [-q] [-s BUFFER_SIZE] [-S STEP_SIZE] [-t CACHE] [-i AIO] [-w] [-U] FILENAME
ERST
DEF("check", img_check,
"check [--object objectdef] [--image-opts] [-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] [-T src_cache] [-U] filename")
STEXI
@item check [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] [-U] @var{filename}
ETEXI
SRST
.. option:: check [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [--output=OFMT] [-r [leaks | all]] [-T SRC_CACHE] [-U] FILENAME
ERST
DEF("commit", img_commit,
"commit [--object objectdef] [--image-opts] [-q] [-f fmt] [-t cache] [-b base] [-d] [-p] filename")
STEXI
@item commit [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename}
ETEXI
SRST
.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-d] [-p] FILENAME
ERST
DEF("compare", img_compare,
"compare [--object objectdef] [--image-opts] [-f fmt] [-F fmt] [-T src_cache] [-p] [-q] [-s] [-U] filename1 filename2")
STEXI
@item compare [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-q] [-s] [-U] @var{filename1} @var{filename2}
ETEXI
SRST
.. option:: compare [--object OBJECTDEF] [--image-opts] [-f FMT] [-F FMT] [-T SRC_CACHE] [-p] [-q] [-s] [-U] FILENAME1 FILENAME2
ERST
DEF("convert", img_convert,
"convert [--object objectdef] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")
STEXI
@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] [--salvage] @var{filename} [@var{filename2} [...]] @var{output_filename}
ETEXI
SRST
.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] [--salvage] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
ERST
DEF("create", img_create,
"create [--object objectdef] [-q] [-f fmt] [-b backing_file] [-F backing_fmt] [-u] [-o options] filename [size]")
STEXI
@item create [--object @var{objectdef}] [-q] [-f @var{fmt}] [-b @var{backing_file}] [-F @var{backing_fmt}] [-u] [-o @var{options}] @var{filename} [@var{size}]
ETEXI
SRST
.. option:: create [--object OBJECTDEF] [-q] [-f FMT] [-b BACKING_FILE] [-F BACKING_FMT] [-u] [-o OPTIONS] FILENAME [SIZE]
ERST
DEF("dd", img_dd,
"dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks] [skip=blocks] if=input of=output")
STEXI
@item dd [--image-opts] [-U] [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] if=@var{input} of=@var{output}
ETEXI
SRST
.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT
ERST
DEF("info", img_info,
"info [--object objectdef] [--image-opts] [-f fmt] [--output=ofmt] [--backing-chain] [-U] filename")
STEXI
@item info [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain] [-U] @var{filename}
ETEXI
SRST
.. option:: info [--object OBJECTDEF] [--image-opts] [-f FMT] [--output=OFMT] [--backing-chain] [-U] FILENAME
ERST
DEF("map", img_map,
"map [--object objectdef] [--image-opts] [-f fmt] [--output=ofmt] [-U] filename")
STEXI
@item map [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--output=@var{ofmt}] [-U] @var{filename}
ETEXI
SRST
.. option:: map [--object OBJECTDEF] [--image-opts] [-f FMT] [--output=OFMT] [-U] FILENAME
ERST
DEF("measure", img_measure,
"measure [--output=ofmt] [-O output_fmt] [-o options] [--size N | [--object objectdef] [--image-opts] [-f fmt] [-l snapshot_param] filename]")
STEXI
@item measure [--output=@var{ofmt}] [-O @var{output_fmt}] [-o @var{options}] [--size @var{N} | [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [-l @var{snapshot_param}] @var{filename}]
ETEXI
SRST
.. option:: measure [--output=OFMT] [-O OUTPUT_FMT] [-o OPTIONS] [--size N | [--object OBJECTDEF] [--image-opts] [-f FMT] [-l SNAPSHOT_PARAM] FILENAME]
ERST
DEF("snapshot", img_snapshot,
"snapshot [--object objectdef] [--image-opts] [-U] [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename")
STEXI
@item snapshot [--object @var{objectdef}] [--image-opts] [-U] [-q] [-l | -a @var{snapshot} | -c @var{snapshot} | -d @var{snapshot}] @var{filename}
ETEXI
SRST
.. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
ERST
DEF("rebase", img_rebase,
"rebase [--object objectdef] [--image-opts] [-U] [-q] [-f fmt] [-t cache] [-T src_cache] [-p] [-u] -b backing_file [-F backing_fmt] filename")
STEXI
@item rebase [--object @var{objectdef}] [--image-opts] [-U] [-q] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-p] [-u] -b @var{backing_file} [-F @var{backing_fmt}] @var{filename}
ETEXI
SRST
.. option:: rebase [--object OBJECTDEF] [--image-opts] [-U] [-q] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-p] [-u] -b BACKING_FILE [-F BACKING_FMT] FILENAME
ERST
DEF("resize", img_resize,
"resize [--object objectdef] [--image-opts] [-f fmt] [--preallocation=prealloc] [-q] [--shrink] filename [+ | -]size")
STEXI
@item resize [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--preallocation=@var{prealloc}] [-q] [--shrink] @var{filename} [+ | -]@var{size}
ETEXI
STEXI
@end table
ETEXI
SRST
.. option:: resize [--object OBJECTDEF] [--image-opts] [-f FMT] [--preallocation=PREALLOC] [-q] [--shrink] FILENAME [+ | -]SIZE
ERST

798
qemu-img.texi
View file

@ -1,798 +0,0 @@
@example
@c man begin SYNOPSIS
@command{qemu-img} [@var{standard} @var{options}] @var{command} [@var{command} @var{options}]
@c man end
@end example
@c man begin DESCRIPTION
qemu-img allows you to create, convert and modify images offline. It can handle
all image formats supported by QEMU.
@b{Warning:} Never use qemu-img to 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.
@c man end
@c man begin OPTIONS
Standard options:
@table @option
@item -h, --help
Display this help and exit
@item -V, --version
Display version information and exit
@item -T, --trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
@findex --trace
@include qemu-option-trace.texi
@end table
The following commands are supported:
@include qemu-img-cmds.texi
Command parameters:
@table @var
@item filename
is a disk image filename
@item fmt
is the disk image format. It is guessed automatically in most cases. See below
for a description of the supported disk formats.
@item size
is the disk image size in bytes. Optional suffixes @code{k} or @code{K}
(kilobyte, 1024) @code{M} (megabyte, 1024k) and @code{G} (gigabyte, 1024M)
and T (terabyte, 1024G) are supported. @code{b} is ignored.
@item output_filename
is the destination disk image filename
@item output_fmt
is the destination format
@item options
is a comma separated list of format specific options in a
name=value format. Use @code{-o ?} for an overview of the options supported
by the used format or see the format descriptions below for details.
@item snapshot_param
is param used for internal snapshot, format is
'snapshot.id=[ID],snapshot.name=[NAME]' or '[ID_OR_NAME]'
@end table
@table @option
@item --object @var{objectdef}
is a QEMU user creatable object definition. See the @code{qemu(1)} manual
page for a description of the object properties. The most common object
type is a @code{secret}, which is used to supply passwords and/or encryption
keys.
@item --image-opts
Indicates that the source @var{filename} parameter is to be interpreted as a
full option string, not a plain filename. This parameter is mutually
exclusive with the @var{-f} parameter.
@item --target-image-opts
Indicates that the @var{output_filename} parameter(s) are to be interpreted as
a full option string, not a plain filename. This parameter is mutually
exclusive with the @var{-O} parameters. It is currently required to also use
the @var{-n} parameter to skip image creation. This restriction may be relaxed
in a future release.
@item --force-share (-U)
If specified, @code{qemu-img} will open the image in shared mode, allowing
other QEMU processes to open it in write mode. For example, this can be used to
get the image information (with 'info' subcommand) when the image is used by a
running guest. Note that this could produce inconsistent results because of
concurrent metadata changes, etc. This option is only allowed when opening
images in read-only mode.
@item --backing-chain
will enumerate information about backing files in a disk image chain. Refer
below for further description.
@item -c
indicates that target image must be compressed (qcow format only)
@item -h
with or without a command shows help and lists the supported formats
@item -p
display progress bar (compare, convert and rebase commands only).
If the @var{-p} option is not used for a command that supports it, the
progress is reported when the process receives a @code{SIGUSR1} or
@code{SIGINFO} signal.
@item -q
Quiet mode - do not print any output (except errors). There's no progress bar
in case both @var{-q} and @var{-p} options are used.
@item -S @var{size}
indicates the consecutive number of bytes that must contain only zeros
for qemu-img to create a sparse image during conversion. This value is rounded
down to the nearest 512 bytes. You may use the common size suffixes like
@code{k} for kilobytes.
@item -t @var{cache}
specifies the cache mode that should be used with the (destination) file. See
the documentation of the emulator's @code{-drive cache=...} option for allowed
values.
@item -T @var{src_cache}
specifies the cache mode that should be used with the source file(s). See
the documentation of the emulator's @code{-drive cache=...} option for allowed
values.
@end table
Parameters to snapshot subcommand:
@table @option
@item snapshot
is the name of the snapshot to create, apply or delete
@item -a
applies a snapshot (revert disk to saved state)
@item -c
creates a snapshot
@item -d
deletes a snapshot
@item -l
lists all snapshots in the given image
@end table
Parameters to compare subcommand:
@table @option
@item -f
First image format
@item -F
Second image format
@item -s
Strict mode - fail on different image size or sector allocation
@end table
Parameters to convert subcommand:
@table @option
@item -n
Skip the creation of the target volume
@item -m
Number of parallel coroutines for the convert process
@item -W
Allow out-of-order writes to the destination. This option improves performance,
but is only recommended for preallocated devices like host devices or other
raw block devices.
@item -C
Try to use copy offloading to move data from source image to target. This may
improve performance if the data is remote, such as with NFS or iSCSI backends,
but will not automatically sparsify zero sectors, and may result in a fully
allocated target image depending on the host support for getting allocation
information.
@item --salvage
Try to ignore I/O errors when reading. Unless in quiet mode (@code{-q}), errors
will still be printed. Areas that cannot be read from the source will be
treated as containing only zeroes.
@end table
Parameters to dd subcommand:
@table @option
@item bs=@var{block_size}
defines the block size
@item count=@var{blocks}
sets the number of input blocks to copy
@item if=@var{input}
sets the input file
@item of=@var{output}
sets the output file
@item skip=@var{blocks}
sets the number of input blocks to skip
@end table
Command description:
@table @option
@item amend [--object @var{objectdef}] [--image-opts] [-p] [-q] [-f @var{fmt}] [-t @var{cache}] -o @var{options} @var{filename}
Amends the image format specific @var{options} for the image file
@var{filename}. Not all file formats support this operation.
@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [-i @var{aio}] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] [-U] @var{filename}
Run a simple sequential I/O benchmark on the specified image. If @code{-w} is
specified, a write test is performed, otherwise a read test is performed.
A total number of @var{count} I/O requests is performed, each @var{buffer_size}
bytes in size, and with @var{depth} requests in parallel. The first request
starts at the position given by @var{offset}, each following request increases
the current position by @var{step_size}. If @var{step_size} is not given,
@var{buffer_size} is used for its value.
If @var{flush_interval} is specified for a write test, the request queue is
drained and a flush is issued before new writes are made whenever the number of
remaining requests is a multiple of @var{flush_interval}. If additionally
@code{--no-drain} is specified, a flush is issued without draining the request
queue first.
If @code{-n} is specified, the native AIO backend is used if possible. On
Linux, this option only works if @code{-t none} or @code{-t directsync} is
specified as well.
If @code{-i} is specified, aio option can be used to specify different AIO
backends: @var{threads}, @var{native} or @var{io_uring}.
For write tests, by default a buffer filled with zeros is written. This can be
overridden with a pattern byte specified by @var{pattern}.
@item check [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] [-U] @var{filename}
Perform a consistency check on the disk image @var{filename}. The command can
output in the format @var{ofmt} which is either @code{human} or @code{json}.
The JSON output is an object of QAPI type @code{ImageCheck}.
If @code{-r} is specified, qemu-img tries to repair any inconsistencies found
during the check. @code{-r leaks} repairs only cluster leaks, whereas
@code{-r all} fixes all kinds of errors, with a higher risk of choosing the
wrong fix or hiding corruption that has already occurred.
Only the formats @code{qcow2}, @code{qed} and @code{vdi} support
consistency checks.
In case the image does not have any inconsistencies, check exits with @code{0}.
Other exit codes indicate the kind of inconsistency found or if another error
occurred. The following table summarizes all exit codes of the check subcommand:
@table @option
@item 0
Check completed, the image is (now) consistent
@item 1
Check not completed because of internal errors
@item 2
Check completed, image is corrupted
@item 3
Check completed, image has leaked clusters, but is not corrupted
@item 63
Checks are not supported by the image format
@end table
If @code{-r} is specified, exit codes representing the image state refer to the
state after (the attempt at) repairing it. That is, a successful @code{-r all}
will yield the exit code 0, independently of the image state before.
@item commit [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename}
Commit the changes recorded in @var{filename} in its base image or backing file.
If the backing file is smaller than the snapshot, then the backing file will be
resized to be the same size as the snapshot. If the snapshot is smaller than
the backing file, the backing file will not be truncated. If you want the
backing file to match the size of the smaller snapshot, you can safely truncate
it yourself once the commit operation successfully completes.
The image @var{filename} is emptied after the operation has succeeded. If you do
not need @var{filename} afterwards and intend to drop it, you may skip emptying
@var{filename} by specifying the @code{-d} flag.
If the backing chain of the given image file @var{filename} has more than one
layer, the backing file into which the changes will be committed may be
specified as @var{base} (which has to be part of @var{filename}'s backing
chain). If @var{base} is not specified, the immediate backing file of the top
image (which is @var{filename}) will be used. Note that after a commit operation
all images between @var{base} and the top image will be invalid and may return
garbage data when read. For this reason, @code{-b} implies @code{-d} (so that
the top image stays valid).
@item compare [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-q] [-s] [-U] @var{filename1} @var{filename2}
Check if two images have the same content. You can compare images with
different format or settings.
The format is probed unless you specify it by @var{-f} (used for
@var{filename1}) and/or @var{-F} (used for @var{filename2}) option.
By default, images with different size are considered identical if the larger
image contains only unallocated and/or zeroed sectors in the area after the end
of the other image. In addition, if any sector is not allocated in one image
and contains only zero bytes in the second one, it is evaluated as equal. You
can use Strict mode by specifying the @var{-s} option. When compare runs in
Strict mode, it fails in case image size differs or a sector is allocated in
one image and is not allocated in the second one.
By default, compare prints out a result message. This message displays
information that both images are same or the position of the first different
byte. In addition, result message can report different image size in case
Strict mode is used.
Compare exits with @code{0} in case the images are equal and with @code{1}
in case the images differ. Other exit codes mean an error occurred during
execution and standard error output should contain an error message.
The following table sumarizes all exit codes of the compare subcommand:
@table @option
@item 0
Images are identical
@item 1
Images differ
@item 2
Error on opening an image
@item 3
Error on checking a sector allocation
@item 4
Error on reading data
@end table
@item convert [--object @var{objectdef}] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-B @var{backing_file}] [-o @var{options}] [-l @var{snapshot_param}] [-S @var{sparse_size}] [-m @var{num_coroutines}] [-W] @var{filename} [@var{filename2} [...]] @var{output_filename}
Convert the disk image @var{filename} or a snapshot @var{snapshot_param}
to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c}
option) or use any format specific options like encryption (@code{-o} option).
Only the formats @code{qcow} and @code{qcow2} support compression. The
compression is read-only. It means that if a compressed sector is
rewritten, then it is rewritten as uncompressed data.
Image conversion is also useful to get smaller image when using a
growable format such as @code{qcow}: the empty sectors are detected and
suppressed from the destination image.
@var{sparse_size} indicates the consecutive number of bytes (defaults to 4k)
that must contain only zeros for qemu-img to create a sparse image during
conversion. If @var{sparse_size} is 0, the source will not be scanned for
unallocated or zero sectors, and the destination image will always be
fully allocated.
You can use the @var{backing_file} option to force the output image to be
created as a copy on write image of the specified base image; the
@var{backing_file} should have the same content as the input's base image,
however the path, image format, etc may differ.
If a relative path name is given, the backing file is looked up relative to
the directory containing @var{output_filename}.
If the @code{-n} option is specified, the target volume creation will be
skipped. This is useful for formats such as @code{rbd} if the target
volume has already been created with site specific options that cannot
be supplied through qemu-img.
Out of order writes can be enabled with @code{-W} to improve performance.
This is only recommended for preallocated devices like host devices or other
raw block devices. Out of order write does not work in combination with
creating compressed images.
@var{num_coroutines} specifies how many coroutines work in parallel during
the convert process (defaults to 8).
@item create [--object @var{objectdef}] [-q] [-f @var{fmt}] [-b @var{backing_file}] [-F @var{backing_fmt}] [-u] [-o @var{options}] @var{filename} [@var{size}]
Create the new disk image @var{filename} of size @var{size} and format
@var{fmt}. Depending on the file format, you can add one or more @var{options}
that enable additional features of this format.
If the option @var{backing_file} is specified, then the image will record
only the differences from @var{backing_file}. No size needs to be specified in
this case. @var{backing_file} will never be modified unless you use the
@code{commit} monitor command (or qemu-img commit).
If a relative path name is given, the backing file is looked up relative to
the directory containing @var{filename}.
Note that a given backing file will be opened to check that it is valid. Use
the @code{-u} option to enable unsafe backing file mode, which means that the
image will be created even if the associated backing file cannot be opened. A
matching backing file must be created or additional options be used to make the
backing file specification valid when you want to use an image created this
way.
The size can also be specified using the @var{size} option with @code{-o},
it doesn't need to be specified separately in this case.
@item dd [--image-opts] [-U] [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] if=@var{input} of=@var{output}
Dd copies from @var{input} file to @var{output} file converting it from
@var{fmt} format to @var{output_fmt} format.
The data is by default read and written using blocks of 512 bytes but can be
modified by specifying @var{block_size}. If count=@var{blocks} is specified
dd will stop reading input after reading @var{blocks} input blocks.
The size syntax is similar to dd(1)'s size syntax.
@item info [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain] [-U] @var{filename}
Give information about the disk image @var{filename}. Use it in
particular to know the size reserved on disk which can be different
from the displayed size. If VM snapshots are stored in the disk image,
they are displayed too.
If a disk image has a backing file chain, information about each disk image in
the chain can be recursively enumerated by using the option @code{--backing-chain}.
For instance, if you have an image chain like:
@example
base.qcow2 <- snap1.qcow2 <- snap2.qcow2
@end example
To enumerate information about each disk image in the above chain, starting from top to base, do:
@example
qemu-img info --backing-chain snap2.qcow2
@end example
The command can output in the format @var{ofmt} which is either @code{human} or
@code{json}. The JSON output is an object of QAPI type @code{ImageInfo}; with
@code{--backing-chain}, it is an array of @code{ImageInfo} objects.
@code{--output=human} reports the following information (for every image in the
chain):
@table @var
@item image
The image file name
@item file format
The image format
@item virtual size
The size of the guest disk
@item disk size
How much space the image file occupies on the host file system (may be shown as
0 if this information is unavailable, e.g. because there is no file system)
@item cluster_size
Cluster size of the image format, if applicable
@item encrypted
Whether the image is encrypted (only present if so)
@item cleanly shut down
This is shown as @code{no} if the image is dirty and will have to be
auto-repaired the next time it is opened in qemu.
@item backing file
The backing file name, if present
@item backing file format
The format of the backing file, if the image enforces it
@item Snapshot list
A list of all internal snapshots
@item Format specific information
Further information whose structure depends on the image format. This section
is a textual representation of the respective @code{ImageInfoSpecific*} QAPI
object (e.g. @code{ImageInfoSpecificQCow2} for qcow2 images).
@end table
@item map [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--output=@var{ofmt}] [-U] @var{filename}
Dump the metadata of image @var{filename} and its backing file chain.
In particular, this commands dumps the allocation state of every sector
of @var{filename}, together with the topmost file that allocates it in
the backing file chain.
Two option formats are possible. The default format (@code{human})
only dumps known-nonzero areas of the file. Known-zero parts of the
file are omitted altogether, and likewise for parts that are not allocated
throughout the chain. @command{qemu-img} output will identify a file
from where the data can be read, and the offset in the file. Each line
will include four fields, the first three of which are hexadecimal
numbers. For example the first line of:
@example
Offset Length Mapped to File
0 0x20000 0x50000 /tmp/overlay.qcow2
0x100000 0x10000 0x95380000 /tmp/backing.qcow2
@end example
@noindent
means that 0x20000 (131072) bytes starting at offset 0 in the image are
available in /tmp/overlay.qcow2 (opened in @code{raw} format) starting
at offset 0x50000 (327680). Data that is compressed, encrypted, or
otherwise not available in raw format will cause an error if @code{human}
format is in use. Note that file names can include newlines, thus it is
not safe to parse this output format in scripts.
The alternative format @code{json} will return an array of dictionaries
in JSON format. It will include similar information in
the @code{start}, @code{length}, @code{offset} fields;
it will also include other more specific information:
@itemize @minus
@item
whether the sectors contain actual data or not (boolean field @code{data};
if false, the sectors are either unallocated or stored as optimized
all-zero clusters);
@item
whether the data is known to read as zero (boolean field @code{zero});
@item
in order to make the output shorter, the target file is expressed as
a @code{depth}; for example, a depth of 2 refers to the backing file
of the backing file of @var{filename}.
@end itemize
In JSON format, the @code{offset} field is optional; it is absent in
cases where @code{human} format would omit the entry or exit with an error.
If @code{data} is false and the @code{offset} field is present, the
corresponding sectors in the file are not yet in use, but they are
preallocated.
For more information, consult @file{include/block/block.h} in QEMU's
source code.
@item measure [--output=@var{ofmt}] [-O @var{output_fmt}] [-o @var{options}] [--size @var{N} | [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [-l @var{snapshot_param}] @var{filename}]
Calculate the file size required for a new image. This information can be used
to size logical volumes or SAN LUNs appropriately for the image that will be
placed in them. The values reported are guaranteed to be large enough to fit
the image. The command can output in the format @var{ofmt} which is either
@code{human} or @code{json}. The JSON output is an object of QAPI type
@code{BlockMeasureInfo}.
If the size @var{N} is given then act as if creating a new empty image file
using @command{qemu-img create}. If @var{filename} is given then act as if
converting an existing image file using @command{qemu-img convert}. The format
of the new file is given by @var{output_fmt} while the format of an existing
file is given by @var{fmt}.
A snapshot in an existing image can be specified using @var{snapshot_param}.
The following fields are reported:
@example
required size: 524288
fully allocated size: 1074069504
@end example
The @code{required size} is the file size of the new image. It may be smaller
than the virtual disk size if the image format supports compact representation.
The @code{fully allocated size} is the file size of the new image once data has
been written to all sectors. This is the maximum size that the image file can
occupy with the exception of internal snapshots, dirty bitmaps, vmstate data,
and other advanced image format features.
@item snapshot [--object @var{objectdef}] [--image-opts] [-U] [-q] [-l | -a @var{snapshot} | -c @var{snapshot} | -d @var{snapshot}] @var{filename}
List, apply, create or delete snapshots in image @var{filename}.
@item rebase [--object @var{objectdef}] [--image-opts] [-U] [-q] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-p] [-u] -b @var{backing_file} [-F @var{backing_fmt}] @var{filename}
Changes the backing file of an image. Only the formats @code{qcow2} and
@code{qed} support changing the backing file.
The backing file is changed to @var{backing_file} and (if the image format of
@var{filename} supports this) the backing file format is changed to
@var{backing_fmt}. If @var{backing_file} is specified as ``'' (the empty
string), then the image is rebased onto no backing file (i.e. it will exist
independently of any backing file).
If a relative path name is given, the backing file is looked up relative to
the directory containing @var{filename}.
@var{cache} specifies the cache mode to be used for @var{filename}, whereas
@var{src_cache} specifies the cache mode for reading backing files.
There are two different modes in which @code{rebase} can operate:
@table @option
@item Safe mode
This is the default mode and performs a real rebase operation. The new backing
file may differ from the old one and qemu-img rebase will take care of keeping
the guest-visible content of @var{filename} unchanged.
In order to achieve this, any clusters that differ between @var{backing_file}
and the old backing file of @var{filename} are merged into @var{filename}
before actually changing the backing file.
Note that the safe mode is an expensive operation, comparable to converting
an image. It only works if the old backing file still exists.
@item Unsafe mode
qemu-img uses the unsafe mode if @code{-u} is specified. In this mode, only the
backing file name and format of @var{filename} is changed without any checks
on the file contents. The user must take care of specifying the correct new
backing file, or the guest-visible content of the image will be corrupted.
This mode is useful for renaming or moving the backing file to somewhere else.
It can be used without an accessible old backing file, i.e. you can use it to
fix an image whose backing file has already been moved/renamed.
@end table
You can use @code{rebase} to perform a ``diff'' operation on two
disk images. This can be useful when you have copied or cloned
a guest, and you want to get back to a thin image on top of a
template or base image.
Say that @code{base.img} has been cloned as @code{modified.img} by
copying it, and that the @code{modified.img} guest has run so there
are now some changes compared to @code{base.img}. To construct a thin
image called @code{diff.qcow2} that contains just the differences, do:
@example
qemu-img create -f qcow2 -b modified.img diff.qcow2
qemu-img rebase -b base.img diff.qcow2
@end example
At this point, @code{modified.img} can be discarded, since
@code{base.img + diff.qcow2} contains the same information.
@item resize [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--preallocation=@var{prealloc}] [-q] [--shrink] @var{filename} [+ | -]@var{size}
Change the disk image as if it had been created with @var{size}.
Before using this command to shrink a disk image, you MUST use file system and
partitioning tools inside the VM to reduce allocated file systems and partition
sizes accordingly. Failure to do so will result in data loss!
When shrinking images, the @code{--shrink} option must be given. This informs
qemu-img that the user acknowledges all loss of data beyond the truncated
image's end.
After using this command to grow a disk image, you must use file system and
partitioning tools inside the VM to actually begin using the new space on the
device.
When growing an image, the @code{--preallocation} option may be used to specify
how the additional image area should be allocated on the host. See the format
description in the @code{NOTES} section which values are allowed. Using this
option may result in slightly more data being allocated than necessary.
@end table
@c man end
@ignore
@c man begin NOTES
Supported image file formats:
@table @option
@item raw
Raw disk image format (default). This format has the advantage of
being simple and easily exportable to all other emulators. If your
file system supports @emph{holes} (for example in ext2 or ext3 on
Linux or NTFS on Windows), then only the written sectors will reserve
space. Use @code{qemu-img info} to know the real size used by the
image or @code{ls -ls} on Unix/Linux.
Supported options:
@table @code
@item preallocation
Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}).
@code{falloc} mode preallocates space for image by calling posix_fallocate().
@code{full} mode preallocates space for image by writing data to underlying
storage. This data may or may not be zero, depending on the storage location.
@end table
@item qcow2
QEMU image format, the most versatile format. Use it to have smaller
images (useful if your filesystem does not supports holes, for example
on Windows), optional AES encryption, zlib based compression and
support of multiple VM snapshots.
Supported options:
@table @code
@item compat
Determines the qcow2 version to use. @code{compat=0.10} uses the
traditional image format that can be read by any QEMU since 0.10.
@code{compat=1.1} enables image format extensions that only QEMU 1.1 and
newer understand (this is the default). Amongst others, this includes zero
clusters, which allow efficient copy-on-read for sparse images.
@item backing_file
File name of a base image (see @option{create} subcommand)
@item backing_fmt
Image format of the base image
@item encryption
If this option is set to @code{on}, the image is encrypted with 128-bit AES-CBC.
The use of encryption in qcow and qcow2 images is considered to be flawed by
modern cryptography standards, suffering from a number of design problems:
@itemize @minus
@item
The AES-CBC cipher is used with predictable initialization vectors based
on the sector number. This makes it vulnerable to chosen plaintext attacks
which can reveal the existence of encrypted data.
@item
The user passphrase is directly used as the encryption key. A poorly
chosen or short passphrase will compromise the security of the encryption.
@item
In the event of the passphrase being compromised there is no way to
change the passphrase to protect data in any qcow images. The files must
be cloned, using a different encryption passphrase in the new file. The
original file must then be securely erased using a program like shred,
though even this is ineffective with many modern storage technologies.
@item
Initialization vectors used to encrypt sectors are based on the
guest virtual sector number, instead of the host physical sector. When
a disk image has multiple internal snapshots this means that data in
multiple physical sectors is encrypted with the same initialization
vector. With the CBC mode, this opens the possibility of watermarking
attacks if the attack can collect multiple sectors encrypted with the
same IV and some predictable data. Having multiple qcow2 images with
the same passphrase also exposes this weakness since the passphrase
is directly used as the key.
@end itemize
Use of qcow / qcow2 encryption is thus strongly discouraged. Users are
recommended to use an alternative encryption technology such as the
Linux dm-crypt / LUKS system.
@item cluster_size
Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster
sizes can improve the image file size whereas larger cluster sizes generally
provide better performance.
@item preallocation
Preallocation mode (allowed values: @code{off}, @code{metadata}, @code{falloc},
@code{full}). An image with preallocated metadata is initially larger but can
improve performance when the image needs to grow. @code{falloc} and @code{full}
preallocations are like the same options of @code{raw} format, but sets up
metadata also.
@item lazy_refcounts
If this option is set to @code{on}, reference count updates are postponed with
the goal of avoiding metadata I/O and improving performance. This is
particularly interesting with @option{cache=writethrough} which doesn't batch
metadata updates. The tradeoff is that after a host crash, the reference count
tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img
check -r all} is required, which may take some time.
This option can only be enabled if @code{compat=1.1} is specified.
@item nocow
If this option is set to @code{on}, it will turn off COW of the file. It's only
valid on btrfs, no effect on other file systems.
Btrfs has low performance when hosting a VM image file, even more when the guest
on the VM also using btrfs as file system. Turning off COW is a way to mitigate
this bad performance. Generally there are two ways to turn off COW on btrfs:
a) Disable it by mounting with nodatacow, then all newly created files will be
NOCOW. b) For an empty file, add the NOCOW file attribute. That's what this option
does.
Note: this option is only valid to new or empty files. If there is an existing
file which is COW and has data blocks already, it couldn't be changed to NOCOW
by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
@end table
@item Other
QEMU also supports various other image file formats for compatibility with
older QEMU versions or other hypervisors, including VMDK, VDI, VHD (vpc), VHDX,
qcow1 and QED. For a full list of supported formats see @code{qemu-img --help}.
For a more detailed description of these formats, see the QEMU Emulation User
Documentation.
The main purpose of the block drivers for these formats is image conversion.
For running VMs, it is recommended to convert the disk images to either raw or
qcow2 in order to achieve good performance.
@end table
@c man end
@setfilename qemu-img
@settitle QEMU disk image utility
@c man begin SEEALSO
The HTML documentation of QEMU for more precise information and Linux
user mode emulator invocation.
@c man end
@c man begin AUTHOR
Fabrice Bellard
@c man end
@end ignore

36
rules.mak
View file

@ -399,3 +399,39 @@ GEN_SUBST = $(call quiet-command, \
%.json: %.json.in
$(call GEN_SUBST)
# Support for building multiple output files by atomically executing
# a single rule which depends on several input files (so the rule
# will be executed exactly once, not once per output file, and
# not multiple times in parallel.) For more explanation see:
# https://www.cmcrossroads.com/article/atomic-rules-gnu-make
# Given a space-separated list of filenames, create the name of
# a 'sentinel' file to use to indicate that they have been built.
# We use fixed text on the end to avoid accidentally triggering
# automatic pattern rules, and . on the start to make the file
# not show up in ls output.
sentinel = .$(subst $(SPACE),_,$(subst /,_,$1)).sentinel.
# Define an atomic rule that builds multiple outputs from multiple inputs.
# To use:
# $(call atomic,out1 out2 ...,in1 in2 ...)
# <TAB>rule to do the operation
#
# Make 4.3 will have native support for this, and you would be able
# to instead write:
# out1 out2 ... &: in1 in2 ...
# <TAB>rule to do the operation
#
# The way this works is that it creates a make rule
# "out1 out2 ... : sentinel-file ; @:" which says that the sentinel
# depends on the dependencies, and the rule to do that is "do nothing".
# Then we have a rule
# "sentinel-file : in1 in2 ..."
# whose commands start with "touch sentinel-file" and then continue
# with the rule text provided by the user of this 'atomic' function.
# The foreach... is there to delete the sentinel file if any of the
# output files don't exist, so that we correctly rebuild in that situation.
atomic = $(eval $1: $(call sentinel,$1) ; @:) \
$(call sentinel,$1) : $2 ; @touch $$@ \
$(foreach t,$1,$(if $(wildcard $t),,$(shell rm -f $(call sentinel,$1))))

33
scripts/hxtool
View file

@ -7,7 +7,7 @@ hxtoh()
case $str in
HXCOMM*)
;;
STEXI*|ETEXI*) flag=$(($flag^1))
STEXI*|ETEXI*|SRST*|ERST*) flag=$(($flag^1))
;;
*)
test $flag -eq 1 && printf "%s\n" "$str"
@ -27,12 +27,17 @@ print_texi_heading()
hxtotexi()
{
flag=0
rstflag=0
line=1
while read -r str; do
case "$str" in
HXCOMM*)
;;
STEXI*)
if test $rstflag -eq 1 ; then
printf "line %d: syntax error: expected ERST, found '%s'\n" "$line" "$str" >&2
exit 1
fi
if test $flag -eq 1 ; then
printf "line %d: syntax error: expected ETEXI, found '%s'\n" "$line" "$str" >&2
exit 1
@ -40,12 +45,38 @@ hxtotexi()
flag=1
;;
ETEXI*)
if test $rstflag -eq 1 ; then
printf "line %d: syntax error: expected ERST, found '%s'\n" "$line" "$str" >&2
exit 1
fi
if test $flag -ne 1 ; then
printf "line %d: syntax error: expected STEXI, found '%s'\n" "$line" "$str" >&2
exit 1
fi
flag=0
;;
SRST*)
if test $rstflag -eq 1 ; then
printf "line %d: syntax error: expected ERST, found '%s'\n" "$line" "$str" >&2
exit 1
fi
if test $flag -eq 1 ; then
printf "line %d: syntax error: expected ETEXI, found '%s'\n" "$line" "$str" >&2
exit 1
fi
rstflag=1
;;
ERST*)
if test $flag -eq 1 ; then
printf "line %d: syntax error: expected ETEXI, found '%s'\n" "$line" "$str" >&2
exit 1
fi
if test $rstflag -ne 1 ; then
printf "line %d: syntax error: expected SRST, found '%s'\n" "$line" "$str" >&2
exit 1
fi
rstflag=0
;;
DEFHEADING*)
print_texi_heading "$(expr "$str" : "DEFHEADING(\(.*\))")"
;;

140
scripts/qemu-trace-stap.texi
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@ -1,140 +0,0 @@
@example
@c man begin SYNOPSIS
@command{qemu-trace-stap} @var{GLOBAL-OPTIONS} @var{COMMAND} @var{COMMAND-OPTIONS} @var{ARGS...}
@c man end
@end example
@c man begin DESCRIPTION
The @command{qemu-trace-stap} program facilitates tracing of the execution
of QEMU emulators using SystemTap.
It is required to have the SystemTap runtime environment installed to use
this program, since it is a wrapper around execution of the @command{stap}
program.
@c man end
@c man begin OPTIONS
The following global options may be used regardless of which command
is executed:
@table @option
@item @var{--verbose}, @var{-v}
Display verbose information about command execution.
@end table
The following commands are valid:
@table @option
@item @var{list} @var{BINARY} @var{PATTERN...}
List all the probe names provided by @var{BINARY} that match
@var{PATTERN}.
If @var{BINARY} is not an absolute path, it will be located by searching
the directories listed in the @code{$PATH} environment variable.
@var{PATTERN} is a plain string that is used to filter the results of
this command. It may optionally contain a @code{*} wildcard to facilitate
matching multiple probes without listing each one explicitly. Multiple
@var{PATTERN} arguments may be given, causing listing of probes that match
any of the listed names. If no @var{PATTERN} is given, the all possible
probes will be listed.
For example, to list all probes available in the @command{qemu-system-x86_64}
binary:
@example
$ qemu-trace-stap list qemu-system-x86_64
@end example
To filter the list to only cover probes related to QEMU's cryptographic
subsystem, in a binary outside @code{$PATH}
@example
$ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*'
@end example
@item @var{run} @var{OPTIONS} @var{BINARY} @var{PATTERN...}
Run a trace session, printing formatted output any time a process that is
executing @var{BINARY} triggers a probe matching @var{PATTERN}.
If @var{BINARY} is not an absolute path, it will be located by searching
the directories listed in the @code{$PATH} environment variable.
@var{PATTERN} is a plain string that matches a probe name shown by the
@var{list} command. It may optionally contain a @code{*} wildcard to
facilitate matching multiple probes without listing each one explicitly.
Multiple @var{PATTERN} arguments may be given, causing all matching probes
to be monitored. At least one @var{PATTERN} is required, since stap is not
capable of tracing all known QEMU probes concurrently without overflowing
its trace buffer.
Invocation of this command does not need to be synchronized with
invocation of the QEMU process(es). It will match probes on all
existing running processes and all future launched processes,
unless told to only monitor a specific process.
Valid command specific options are:
@table @option
@item @var{--pid=PID}, @var{-p PID}
Restrict the tracing session so that it only triggers for the process
identified by @code{PID}.
@end table
For example, to monitor all processes executing @command{qemu-system-x86_64}
as found on $PATH, displaying all I/O related probes:
@example
$ qemu-trace-stap run qemu-system-x86_64 'qio*'
@end example
To monitor only the QEMU process with PID 1732
@example
$ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*'
@end example
To monitor QEMU processes running an alternative binary outside of
@code{$PATH}, displaying verbose information about setup of the
tracing environment:
@example
$ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*'
@end example
@end table
@c man end
@ignore
@setfilename qemu-trace-stap
@settitle QEMU SystemTap trace tool
@c man begin LICENSE
Copyright (C) 2019 Red Hat, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
@c man end
@c man begin SEEALSO
qemu(1), stap(1)
@c man end
@end ignore