QEMU With E2K User Support
5bb0474778
bs->file and bs->backing are a kind of duplication of part of
bs->children. But very useful diplication, so let's not drop them at
all:)
We should manage bs->file and bs->backing in same place, where we
manage bs->children, to keep them in sync.
Moreover, generic io paths are unprepared to BdrvChild without a bs, so
it's double good to clear bs->file / bs->backing when we detach the
child.
Detach is simple: if we detach bs->file or bs->backing child, just
set corresponding field to NULL.
Attach is a bit more complicated. But we still can precisely detect
should we set one of bs->file / bs->backing or not:
- if role is BDRV_CHILD_COW, we definitely deal with bs->backing
- else, if role is BDRV_CHILD_FILTERED (it must be also
BDRV_CHILD_PRIMARY), it's a filtered child. Use
bs->drv->filtered_child_is_backing to chose the pointer field to
modify.
- else, if role is BDRV_CHILD_PRIMARY, we deal with bs->file
- in all other cases, it's neither bs->backing nor bs->file. It's some
other child and we shouldn't care
OK. This change brings one more good thing: we can (and should) get rid
of all indirect pointers in the block-graph-change transactions:
bdrv_attach_child_common() stores BdrvChild** into transaction to clear
it on abort.
bdrv_attach_child_common() has two callers: bdrv_attach_child_noperm()
just pass-through this feature, bdrv_root_attach_child() doesn't need
the feature.
Look at bdrv_attach_child_noperm() callers:
- bdrv_attach_child() doesn't need the feature
- bdrv_set_file_or_backing_noperm() uses the feature to manage
bs->file and bs->backing, we don't want it anymore
- bdrv_append() uses the feature to manage bs->backing, again we
don't want it anymore
So, we should drop this stuff! Great!
We could probably keep BdrvChild** argument to keep the int return
value, but it seems not worth the complexity.
Finally, we now set .file / .backing automatically in generic code and
want to restring setting them by hand outside of .attach/.detach.
So, this patch cleanups all remaining places where they were set.
To find such places I use:
git grep '\->file ='
git grep '\->backing ='
git grep '&.*\<backing\>'
git grep '&.*\<file\>'
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220726201134.924743-14-vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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| .github/workflows | ||
| .gitlab/issue_templates | ||
| .gitlab-ci.d | ||
| accel | ||
| audio | ||
| authz | ||
| backends | ||
| block | ||
| bsd-user | ||
| chardev | ||
| common-user | ||
| configs | ||
| contrib | ||
| crypto | ||
| disas | ||
| docs | ||
| dtc@b6910bec11 | ||
| dump | ||
| ebpf | ||
| fpu | ||
| fsdev | ||
| gdb-xml | ||
| gdbstub | ||
| hw | ||
| include | ||
| io | ||
| libdecnumber | ||
| linux-headers | ||
| linux-user | ||
| meson@3a9b285a55 | ||
| migration | ||
| monitor | ||
| nbd | ||
| net | ||
| pc-bios | ||
| plugins | ||
| po | ||
| python | ||
| qapi | ||
| qga | ||
| qobject | ||
| qom | ||
| replay | ||
| roms | ||
| scripts | ||
| scsi | ||
| semihosting | ||
| softmmu | ||
| storage-daemon | ||
| stubs | ||
| subprojects | ||
| target | ||
| tcg | ||
| tests | ||
| tools | ||
| trace | ||
| ui | ||
| util | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .exrc | ||
| .gdbinit | ||
| .gitattributes | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .gitmodules | ||
| .gitpublish | ||
| .mailmap | ||
| .patchew.yml | ||
| .readthedocs.yml | ||
| .travis.yml | ||
| block.c | ||
| blockdev-nbd.c | ||
| blockdev.c | ||
| blockjob.c | ||
| configure | ||
| COPYING | ||
| COPYING.LIB | ||
| cpu.c | ||
| cpus-common.c | ||
| disas.c | ||
| event-loop-base.c | ||
| gitdm.config | ||
| hmp-commands-info.hx | ||
| hmp-commands.hx | ||
| iothread.c | ||
| job-qmp.c | ||
| job.c | ||
| Kconfig | ||
| Kconfig.host | ||
| LICENSE | ||
| MAINTAINERS | ||
| Makefile | ||
| memory_ldst.c.inc | ||
| meson_options.txt | ||
| meson.build | ||
| module-common.c | ||
| os-posix.c | ||
| os-win32.c | ||
| page-vary-common.c | ||
| page-vary.c | ||
| qemu-bridge-helper.c | ||
| qemu-edid.c | ||
| qemu-img-cmds.hx | ||
| qemu-img.c | ||
| qemu-io-cmds.c | ||
| qemu-io.c | ||
| qemu-keymap.c | ||
| qemu-nbd.c | ||
| qemu-options.hx | ||
| qemu.nsi | ||
| qemu.sasl | ||
| README.rst | ||
| replication.c | ||
| trace-events | ||
| VERSION | ||
| 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>`_