As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
of Netdev structure can collides with "type" field of SocketAddress),
we introduce a way to bypass qemu_opts_parse_noisily() and use directly
visit_type_Netdev() to parse the backend parameters.
More details from Markus:
qemu_init() passes the argument of -netdev, -nic, and -net to
net_client_parse().
net_client_parse() parses with qemu_opts_parse_noisily(), passing
QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
qemu_net_opts for -net. Their desc[] are all empty, which means any
keys are accepted. The result of the parse (a QemuOpts) is stored in
the QemuOptsList.
Note that QemuOpts is flat by design. In some places, we layer non-flat
on top using dotted keys convention, but not here.
net_init_clients() iterates over the stored QemuOpts, and passes them to
net_init_netdev(), net_param_nic(), or net_init_client(), respectively.
These functions pass the QemuOpts to net_client_init(). They also do
other things with the QemuOpts, which we can ignore here.
net_client_init() uses the opts visitor to convert the (flat) QemOpts to
a (non-flat) QAPI object Netdev. Netdev is also the argument of QMP
command netdev_add.
The opts visitor was an early attempt to support QAPI in
(QemuOpts-based) CLI. It restricts QAPI types to a certain shape; see
commit eb7ee2cbeb "qapi: introduce OptsVisitor".
A more modern way to support QAPI is qobject_input_visitor_new_str().
It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
it also supports JSON syntax. The former isn't quite as expressive as
JSON, but it's a lot closer than QemuOpts + opts visitor.
This commit paves the way to use of the modern way instead.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
===========
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>`_