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Stefan Hajnoczi 9f8d2fdcce aio: remove aio_context_acquire()/aio_context_release() API
Delete these functions because nothing calls these functions anymore.

I introduced these APIs in commit 98563fc3ec ("aio: add
aio_context_acquire() and aio_context_release()") in 2014. It's with a
sigh of relief that I delete these APIs almost 10 years later.

Thanks to Paolo Bonzini's vision for multi-queue QEMU, we got an
understanding of where the code needed to go in order to remove the
limitations that the original dataplane and the IOThread/AioContext
approach that followed it.

Emanuele Giuseppe Esposito had the splendid determination to convert
large parts of the codebase so that they no longer needed the AioContext
lock. This was a painstaking process, both in the actual code changes
required and the iterations of code review that Emanuele eked out of
Kevin and me over many months.

Kevin Wolf tackled multitudes of graph locking conversions to protect
in-flight I/O from run-time changes to the block graph as well as the
clang Thread Safety Analysis annotations that allow the compiler to
check whether the graph lock is being used correctly.

And me, well, I'm just here to add some pizzazz to the QEMU multi-queue
block layer :). Thank you to everyone who helped with this effort,
including Eric Blake, code reviewer extraordinaire, and others who I've
forgotten to mention.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20231205182011.1976568-11-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-12-21 22:49:27 +01:00
.github/workflows github: fix config mistake preventing repo lockdown commenting 2022-04-26 16:12:26 +01:00
.gitlab/issue_templates .gitlab/issue_templates: Move suggestions into comments 2022-12-15 15:19:24 +01:00
.gitlab-ci.d gitlab: add optional job to run flaky avocado tests 2023-12-01 17:47:20 +00:00
accel accel/kvm: Make kvm_has_guest_debug static 2023-12-19 17:57:38 +00:00
audio audio: Free consumed default audio devices 2023-11-24 16:21:55 +01:00
authz error: Drop superfluous #include "qapi/qmp/qerror.h" 2023-02-23 13:56:14 +01:00
backends backends/iommufd: Introduce the iommufd object 2023-12-19 19:03:38 +01:00
block block: remove AioContext locking 2023-12-21 22:49:27 +01:00
bsd-user bsd-user: spelling fixes: necesary, agrument, undocummented 2023-11-15 11:09:17 +03:00
chardev ui/input: Constify QemuInputHandler structure 2023-10-19 23:13:28 +02:00
common-user common-user/host/ppc: Implement safe-syscall.inc.S 2023-01-23 14:39:48 -10:00
configs default-configs: Add TARGET_XML_FILES definition 2023-11-08 15:15:23 +00:00
contrib plugins: fix win plugin tests on cross compile 2023-11-23 14:10:04 +00:00
crypto crypto/rsakey-builtin.c.inc: Clean up two error paths 2023-11-07 14:54:56 +00:00
disas disas/cris: Pass buffer size to format_dec() to avoid overflow warning 2023-11-24 16:21:55 +01:00
docs * Add compat machines for QEMU 9.0 2023-12-20 09:40:16 -05:00
dump dump: Add arch cleanup function 2023-11-14 10:42:32 +01:00
ebpf trace-events: Fix the name of the tracing.rst file 2023-09-08 13:08:51 +03:00
fpu fpu: Handle m68k extended precision denormals properly 2023-09-16 14:57:16 +00:00
fsdev fsdev: Use ThrottleDirection instread of bool is_write 2023-08-29 10:49:24 +02:00
gdb-xml gdb-xml: fix duplicate register in arm-neon.xml 2023-11-08 15:15:23 +00:00
gdbstub gdbstub: use a better signal when we halt for IO reasons 2023-12-01 14:00:52 +00:00
host/include host/include/generic/host/atomic128: Fix compilation problem with Clang 17 2023-11-13 11:35:47 +01:00
hw scsi: remove AioContext locking 2023-12-21 22:49:27 +01:00
include aio: remove aio_context_acquire()/aio_context_release() API 2023-12-21 22:49:27 +01:00
io io: Stop appending -listen to net listeners 2023-11-07 14:54:56 +00:00
libdecnumber libdecnumber/dpd/decimal64: Fix compiler warning from Clang 15 2022-11-11 09:13:52 +01:00
linux-headers linux-headers: Add iommufd.h 2023-10-18 10:10:49 +02:00
linux-user sh4: Coding style: Remove tabs 2023-12-04 15:12:57 +01:00
migration block: remove AioContext locking 2023-12-21 22:49:27 +01:00
monitor hmp: Improve sync-profile error message 2023-11-17 10:07:52 +01:00
nbd nbd/server: introduce NBDClient->lock to protect fields 2023-12-21 21:59:10 +01:00
net block: remove AioContext locking 2023-12-21 22:49:27 +01:00
pc-bios pseries: Update SLOF firmware image 2023-11-30 22:13:00 +10:00
plugins plugins: fix win plugin tests on cross compile 2023-11-23 14:10:04 +00:00
po po: add ukrainian translation 2022-07-05 10:15:49 +02:00
python buildsys: Bump known good meson version to v1.2.3 2023-11-24 16:21:55 +01:00
qapi backends/iommufd: Introduce the iommufd object 2023-12-19 19:03:38 +01:00
qga build-sys: fix meson project version usage 2023-11-25 19:23:38 +02:00
qobject docs/interop: Convert qmp-spec.txt to rST 2023-05-22 10:21:01 +02:00
qom qom/object: Limit type names to alphanumerical and some few special characters 2023-12-20 10:29:23 +01:00
replay block: remove AioContext locking 2023-12-21 22:49:27 +01:00
roms pseries: Update SLOF firmware image 2023-11-30 22:13:00 +10:00
scripts block: remove AioContext locking 2023-12-21 22:49:27 +01:00
scsi io: follow coroutine AioContext in qio_channel_yield() 2023-09-07 20:32:11 -05:00
semihosting semihosting: fix memleak at semihosting_arg_fallback 2023-10-31 14:10:21 +00:00
stats meson: Replace softmmu_ss -> system_ss 2023-06-20 10:01:30 +02:00
storage-daemon configure, meson: remove target OS symbols from config-host.mak 2023-09-07 13:32:37 +02:00
stubs migration: per-mode blockers 2023-11-01 16:13:59 +01:00
subprojects vhost-user: Fix protocol feature bit conflict 2023-10-22 05:18:17 -04:00
system scsi: assert that callbacks run in the correct AioContext 2023-12-21 22:49:27 +01:00
target * Add compat machines for QEMU 9.0 2023-12-20 09:40:16 -05:00
tcg tcg: Reduce serial context atomicity earlier 2023-12-12 13:35:19 -08:00
tests block: remove AioContext locking 2023-12-21 22:49:27 +01:00
tools ebpf: fix compatibility with libbpf 1.0+ 2023-03-10 17:26:47 +08:00
trace trace/control: Clean up global variable shadowing 2023-10-06 13:27:48 +02:00
ui ui/vnc-clipboard: fix inflate_buffer 2023-12-04 11:28:26 +04:00
util aio: remove aio_context_acquire()/aio_context_release() API 2023-12-21 22:49:27 +01:00
.dir-locals.el
.editorconfig .editorconfig: update the automatic mode setting for Emacs 2021-03-10 15:34:11 +00:00
.exrc
.gdbinit
.git-blame-ignore-revs metadata: add .git-blame-ignore-revs 2023-04-04 15:56:44 +01:00
.gitattributes gitattributes: Cover Objective-C source files 2022-03-29 00:15:14 +02:00
.gitignore configure: rename --enable-pypi to --enable-download, control subprojects too 2023-06-06 16:30:01 +02:00
.gitlab-ci.yml docs: Document GitLab custom CI/CD variables 2021-07-29 07:56:01 +02:00
.gitmodules meson: subprojects: replace berkeley-{soft,test}float-3 with wraps 2023-06-06 16:30:01 +02:00
.gitpublish
.mailmap mailmap: fixup some more corrupted author fields 2023-11-08 15:15:23 +00:00
.patchew.yml scripts/checkpatch: roll diff tweaking into checkpatch itself 2021-06-25 10:08:33 +01:00
.readthedocs.yml
.travis.yml travis-ci: Correct invalid mentions of 'softmmu' by 'system' 2023-10-07 19:02:33 +02:00
block.c block: remove bdrv_co_lock() 2023-12-21 22:49:27 +01:00
blockdev-nbd.c qapi block: Elide redundant has_FOO in generated C 2022-12-14 20:03:25 +01:00
blockdev.c block: remove bdrv_co_lock() 2023-12-21 22:49:27 +01:00
blockjob.c block: remove AioContext locking 2023-12-21 22:49:27 +01:00
configure configure: Make only once with pseudo-"in source tree" builds 2023-11-24 16:21:55 +01:00
COPYING
COPYING.LIB
cpu-common.c hw/cpu: Clean up global variable shadowing 2023-11-07 13:08:48 +01:00
cpu-target.c cpu: Call plugin hooks only when ready 2023-11-08 15:15:23 +00:00
event-loop-base.c util/event-loop-base: Introduce options to set the thread pool size 2022-05-09 10:43:23 +01:00
gitdm.config contrib/gitdm: add group map for AMD 2023-03-22 15:08:26 +00:00
hmp-commands-info.hx accel/tcg: remove CONFIG_PROFILER 2023-06-26 17:33:00 +02:00
hmp-commands.hx qmp/hmp: disable screendump if PIXMAN is missing 2023-11-07 14:04:25 +04:00
iothread.c iothread: Set the GSource "name" field 2023-09-07 14:01:25 -04:00
job-qmp.c qapi job: Elide redundant has_FOO in generated C 2022-12-14 20:04:47 +01:00
job.c block: remove AioContext locking 2023-12-21 22:49:27 +01:00
Kconfig meson: Introduce target-specific Kconfig 2021-07-09 18:21:34 +02:00
Kconfig.host build-sys: add a "pixman" feature 2023-11-07 14:04:24 +04:00
LICENSE
MAINTAINERS * Add compat machines for QEMU 9.0 2023-12-20 09:40:16 -05:00
Makefile build: Add update-linux-vdso makefile rule 2023-10-30 13:41:56 -07:00
memory_ldst.c.inc exec/memory_ldst: Use correct type sizes 2021-05-26 08:35:51 -07:00
meson_options.txt build-sys: add a "pixman" feature 2023-11-07 14:04:24 +04:00
meson.build Fix for building with Xen 4.18 2023-12-12 07:42:02 -05:00
module-common.c
os-posix.c os-posix: Clean up global variable shadowing 2023-10-06 13:27:48 +02:00
os-win32.c Remove qemu-common.h include from most units 2022-04-06 14:31:55 +02:00
page-vary-common.c Remove qemu-common.h include from most units 2022-04-06 14:31:55 +02:00
page-vary-target.c exec: Rename target specific page-vary.c -> page-vary-target.c 2023-10-04 11:03:54 -07:00
pythondeps.toml buildsys: Bump known good meson version to v1.2.3 2023-11-24 16:21:55 +01:00
qemu-bridge-helper.c
qemu-edid.c qemu-edid: Restrict input parameter -d to avoid division by zero 2022-10-12 13:38:15 +02:00
qemu-img-cmds.hx qemu-img: add compression option to rebase subcommand 2023-10-31 13:51:28 +01:00
qemu-img.c block: remove AioContext locking 2023-12-21 22:49:27 +01:00
qemu-io-cmds.c block: Mark bdrv_get_specific_info() and callers GRAPH_RDLOCK 2023-10-12 16:31:33 +02:00
qemu-io.c block: remove AioContext locking 2023-12-21 22:49:27 +01:00
qemu-keymap.c qemu-keymap: properly check return from xkb_keymap_mod_get_index 2023-07-03 12:51:21 +01:00
qemu-nbd.c block: remove AioContext locking 2023-12-21 22:49:27 +01:00
qemu-options.hx * Add compat machines for QEMU 9.0 2023-12-20 09:40:16 -05:00
qemu.nsi nsis installer: Fix mouse-over descriptions for emulators 2022-03-18 10:55:15 +00:00
qemu.sasl sasl: remove comment about obsolete kerberos versions 2021-06-14 13:28:50 +01:00
README.rst README.rst: fix link formatting 2022-08-04 13:44:21 +02:00
replication.c replication: move include out of root directory 2021-05-26 14:49:46 +02:00
trace-events trace-events: remove the remaining vcpu trace events 2023-06-01 11:05:05 -04:00
VERSION Open 9.0 development tree 2023-12-19 09:46:22 -05:00
version.rc

===========
QEMU README
===========

QEMU is a generic and open source machine & userspace emulator and
virtualizer.

QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).

QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.

QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.

QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.


Documentation
=============

Documentation can be found hosted online at
`<https://www.qemu.org/documentation/>`_. The documentation for the
current development version that is available at
`<https://www.qemu.org/docs/master/>`_ is generated from the ``docs/``
folder in the source tree, and is built by `Sphinx
<https://www.sphinx-doc.org/en/master/>`_.


Building
========

QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:


.. code-block:: shell

  mkdir build
  cd build
  ../configure
  make

Additional information can also be found online via the QEMU website:

* `<https://wiki.qemu.org/Hosts/Linux>`_
* `<https://wiki.qemu.org/Hosts/Mac>`_
* `<https://wiki.qemu.org/Hosts/W32>`_


Submitting patches
==================

The QEMU source code is maintained under the GIT version control system.

.. code-block:: shell

   git clone https://gitlab.com/qemu-project/qemu.git

When submitting patches, one common approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the `style section
<https://www.qemu.org/docs/master/devel/style.html>`_ of
the Developers Guide.

Additional information on submitting patches can be found online via
the QEMU website

* `<https://wiki.qemu.org/Contribute/SubmitAPatch>`_
* `<https://wiki.qemu.org/Contribute/TrivialPatches>`_

The QEMU website is also maintained under source control.

.. code-block:: shell

  git clone https://gitlab.com/qemu-project/qemu-web.git

* `<https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/>`_

A 'git-publish' utility was created to make above process less
cumbersome, and is highly recommended for making regular contributions,
or even just for sending consecutive patch series revisions. It also
requires a working 'git send-email' setup, and by default doesn't
automate everything, so you may want to go through the above steps
manually for once.

For installation instructions, please go to

*  `<https://github.com/stefanha/git-publish>`_

The workflow with 'git-publish' is:

.. code-block:: shell

  $ git checkout master -b my-feature
  $ # work on new commits, add your 'Signed-off-by' lines to each
  $ git publish

Your patch series will be sent and tagged as my-feature-v1 if you need to refer
back to it in the future.

Sending v2:

.. code-block:: shell

  $ git checkout my-feature # same topic branch
  $ # making changes to the commits (using 'git rebase', for example)
  $ git publish

Your patch series will be sent with 'v2' tag in the subject and the git tip
will be tagged as my-feature-v2.

Bug reporting
=============

The QEMU project uses GitLab issues to track bugs. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:

* `<https://gitlab.com/qemu-project/qemu/-/issues>`_

If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via GitLab.

For additional information on bug reporting consult:

* `<https://wiki.qemu.org/Contribute/ReportABug>`_


ChangeLog
=========

For version history and release notes, please visit
`<https://wiki.qemu.org/ChangeLog/>`_ or look at the git history for
more detailed information.


Contact
=======

The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC

* `<mailto:qemu-devel@nongnu.org>`_
* `<https://lists.nongnu.org/mailman/listinfo/qemu-devel>`_
* #qemu on irc.oftc.net

Information on additional methods of contacting the community can be
found online via the QEMU website:

* `<https://wiki.qemu.org/Contribute/StartHere>`_