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John Snow 8b2e20f64f block/dirty-bitmap: change semantics of enabled predicate
Currently, the enabled predicate means something like:
"the QAPI status of the bitmap is ACTIVE."
After this patch, it should mean exclusively:
"This bitmap is recording guest writes, and is allowed to do so."

In many places, this is how this predicate was already used.
Internal usages of the bitmap QPI can call user_locked to find out if
the bitmap is in use by an operation.

To accommodate this, modify the create_successor routine to now
explicitly disable the parent bitmap at creation time.

Justifications:

1. bdrv_dirty_bitmap_status suffers no change from the lack of
   1:1 parity with the new predicates because of the order in which
   the predicates are checked. This is now only for compatibility.

2. bdrv_set_dirty() is unchanged: pre-patch, it was skipping bitmaps that were
   disabled or had a successor, while post-patch it is only skipping bitmaps
   that are disabled. To accommodate this, create_successor now ensures that
   any bitmap with a successor is explicitly disabled.

3. qcow2_store_persistent_dirty_bitmaps: No functional change. This function
   cares only about the literal enabled bit, and makes no effort to check if
   the bitmap is in-use or not. After this patch there are still no ways to
   produce an enabled bitmap with a successor.

4. block_dirty_bitmap_enable_prepare
   block_dirty_bitmap_disable_prepare
   init_dirty_bitmap_migration
   nbd_export_new

   These functions care about the literal enabled bit,
   and already check user_locked separately.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:48 -04:00
accel qdev: Fix latent bug with compat_props and onboard devices 2019-03-11 22:53:44 +01:00
audio audio/sdlaudio: Simplify the sdl_callback function 2019-02-28 10:30:08 +01:00
authz authz: add QAuthZPAM object type for authorizing using PAM 2019-02-26 15:32:19 +00:00
backends hostmem: fix crash when querying empty host-nodes property via QMP 2019-03-06 11:51:08 -03:00
block block/dirty-bitmap: change semantics of enabled predicate 2019-03-12 12:05:48 -04:00
bsd-user avoid TABs in files that only contain a few 2019-01-11 15:46:56 +01:00
capstone@22ead3e0bf disas: Add capstone as submodule 2017-10-26 11:56:20 +02:00
chardev chardev: add support for authorization for TLS clients 2019-03-11 16:55:52 +01:00
contrib contrib/elf2dmp: add kernel start address checking 2019-03-11 16:33:49 +01:00
crypto authz: delete existing ACL implementation 2019-02-26 15:32:19 +00:00
default-configs PPC: E500: Add FSL I2C controller and integrate RTC with it 2019-03-12 14:33:04 +11:00
disas disas: nanoMIPS: Add graphical description of pool organization 2019-03-05 17:01:57 +01:00
docs docs/interop/firmware.json: Prefer -machine to if=pflash 2019-03-11 22:54:25 +01:00
dtc@88f18909db Update dtc/libfdt submodule to v1.4.7 2018-10-02 13:53:26 +10:00
fpu softfloat: Support float_round_to_odd more places 2019-02-26 14:08:03 +00:00
fsdev qemu/queue.h: leave head structs anonymous unless necessary 2019-01-11 15:46:55 +01:00
gdb-xml gdbstub: Fix i386/x86_64 machine description and add control registers 2019-02-05 16:50:18 +01:00
hw VFIO updates 2019-03-11 2019-03-12 13:37:29 +00:00
include block/dirty-bitmaps: rename frozen predicate helper 2019-03-12 12:05:48 -04:00
io io: Remove redundant read/write_coroutine assignments 2019-02-25 15:03:19 +01:00
libdecnumber build: remove CONFIG_LIBDECNUMBER 2017-10-16 18:03:52 +02:00
linux-headers include: update Linux headers to 4.21-rc1/5.0-rc1 2019-02-04 00:08:58 -05:00
linux-user linux-user: add new netlink types 2019-03-07 11:02:33 +01:00
migration block/dirty-bitmaps: rename frozen predicate helper 2019-03-12 12:05:48 -04:00
nbd qemu-nbd: add support for authorization of TLS clients 2019-03-06 11:05:27 -06:00
net build-sys: link with slirp as an external project 2019-03-07 12:46:31 +01:00
pc-bios PPC: E500: Update u-boot to v2019.01 2019-03-12 14:33:04 +11:00
po po/Makefile: Modern shell scripting (use $() instead of ``) 2018-10-24 07:39:10 +01:00
python/qemu Python queue, 2019-02-22 2019-03-07 16:16:02 +00:00
qapi block/dirty-bitmap: add recording and busy properties 2019-03-12 12:05:48 -04:00
qga qemu/queue.h: simplify reverse access to QTAILQ 2019-01-11 15:46:55 +01:00
qobject json: Fix % handling when not interpolating 2019-01-24 15:20:59 +01:00
qom qom: Move compat_props machinery from qdev to QOM 2019-03-11 22:53:44 +01:00
replay replay: Exit on errors reading from replay log 2018-11-08 13:24:35 +00:00
roms PPC: E500: Update u-boot to v2019.01 2019-03-12 14:33:04 +11:00
scripts qemugdb: fix licensing 2019-03-11 16:55:52 +01:00
scsi file-posix: Switch to .bdrv_co_ioctl 2018-12-14 11:52:41 +01:00
slirp slirp: remove QEMU Makefile.objs 2019-03-07 12:46:31 +01:00
stubs exec: Change RAMBlockIterFunc definition 2019-03-06 10:49:17 +00:00
target spapr: Use CamelCase properly 2019-03-12 14:33:05 +11:00
tcg tcg: Remove TODO file 2019-02-21 10:22:24 -08:00
tests block/dirty-bitmap: add recording and busy properties 2019-03-12 12:05:48 -04:00
trace build: get rid of target-obj-y 2019-03-11 16:33:49 +01:00
ui vnc: allow specifying a custom authorization object name 2019-03-11 08:39:02 +01:00
util oslib-posix: Ignore fcntl("/dev/null", F_SETFL, O_NONBLOCK) failure 2019-03-11 16:33:49 +01:00
.cirrus.yml cirrus.yml: Add macOS continuous integration task 2019-03-08 09:54:29 +01:00
.dir-locals.el Add .dir-locals.el file to configure emacs coding style 2015-10-08 19:46:01 +03:00
.editorconfig editorconfig: set emacs mode 2018-11-01 12:13:12 +04:00
.exrc qemu: add .exrc 2012-09-07 09:02:44 +03:00
.gdbinit .gdbinit: load QEMU sub-commands when gdb starts 2017-06-07 14:38:45 +01:00
.gitignore Makefile, configure: Support building rST documentation 2019-03-07 14:26:46 +00:00
.gitlab-ci.yml Add a gitlab-ci file for Continuous Integration testing on Gitlab 2019-02-22 09:32:32 +00:00
.gitmodules roms: add the edk2 project as a git submodule 2019-02-21 12:28:41 -05:00
.gitpublish Add a git-publish configuration file 2018-03-05 09:03:17 +00:00
.mailmap maint: Grammar fix to mailmap 2018-12-11 18:35:54 +01:00
.shippable.yml .shippable.yml: disable the win cross tests 2018-12-17 13:02:12 +00:00
.travis.yml .travis.yml: test that no-default-device builds do not regress 2019-03-07 21:46:19 +01:00
arch_init.c arch_init: sort architectures 2018-06-01 19:20:38 +03:00
balloon.c balloon: Allow multiple inhibit users 2018-08-17 09:27:15 -06:00
block.c block: iterate_format with account of whitelisting 2019-03-08 12:26:45 +01:00
blockdev-nbd.c nbd: allow authorization with nbd-server-start QMP command 2019-03-06 11:05:27 -06:00
blockdev.c block: iterate_format with account of whitelisting 2019-03-08 12:26:45 +01:00
blockjob.c block: Use a single global AioWait 2018-09-25 15:50:15 +02:00
bootdevice.c fw_cfg: ignore suffixes in the bootdevice list dependent on machine class 2018-08-16 22:27:43 -03:00
bt-host.c all: Clean up includes 2016-02-04 17:41:30 +00:00
bt-vhci.c all: Clean up includes 2016-02-04 17:41:30 +00:00
Changelog Use HTTPS for qemu.org and other domains 2017-11-21 13:34:13 +00:00
CODING_STYLE CODING_STYLE: Define our preferred form for multiline comments 2018-06-15 15:23:34 +01:00
configure configure: Disable W^X on OpenBSD 2019-03-11 16:33:49 +01:00
COPYING
COPYING.LIB COPYING.LIB: Synchronize the LGPL 2.1 with the version from gnu.org 2019-01-30 11:01:22 +01:00
cpus-common.c qemu/queue.h: simplify reverse access to QTAILQ 2019-01-11 15:46:55 +01:00
cpus.c cpus: Properly release the iothread lock when killing a dummy VCPU 2019-02-26 09:21:25 +11:00
device_tree.c device_tree.c: Don't use load_image() 2018-12-14 13:30:52 +00:00
device-hotplug.c blockdev: Convert drive_new() to Error 2018-10-19 14:51:34 +02:00
disas.c disas: Add RISC-V support 2018-12-26 06:40:02 +11:00
dma-helpers.c block: explicitly acquire aiocontext in bottom halves that need it 2017-02-21 11:39:39 +00:00
dump.c dump: Set correct vaddr for ELF dump 2019-02-06 15:51:12 +01:00
exec.c exec.c: refactor function flatview_add_to_dispatch() 2019-03-11 16:51:42 +01:00
gdbstub.c gdbstub: Send a reply to the vKill packet. 2019-02-15 09:56:41 +00:00
gitdm.config contrib: add a basic gitdm config 2018-12-17 08:25:10 +00:00
HACKING HACKING: document preference for g_new instead of g_malloc 2018-05-20 08:32:09 +03:00
hmp-commands-info.hx hmp-commands-info: add sync-profile 2018-08-23 18:46:25 +02:00
hmp-commands.hx hmp: Add hmp_announce_self 2019-03-05 11:27:41 +08:00
hmp.c nbd: allow authorization with nbd-server-start QMP command 2019-03-06 11:05:27 -06:00
hmp.h hmp: Add hmp_announce_self 2019-03-05 11:27:41 +08:00
ioport.c trace: switch to modular code generation for sub-directories 2017-01-31 17:11:18 +00:00
iothread.c iothread: document about why we need explicit aio_poll() 2019-03-08 10:20:57 +00:00
job-qmp.c jobs: canonize Error object 2018-08-31 16:28:33 +02:00
job.c job: Fix off-by-one assert checks for JobSTT and JobVerbTable 2018-11-12 17:49:21 +01:00
Kconfig.host build: switch to Kconfig 2019-03-07 21:45:53 +01:00
LICENSE vfio: move hw/misc/vfio.c to hw/vfio/pci.c Move vfio.h into include/hw/vfio 2014-12-19 15:24:06 -07:00
MAINTAINERS PPC: E500: Add FSL I2C controller and integrate RTC with it 2019-03-12 14:33:04 +11:00
Makefile Makefile: Don't install non-sphinx files in sphinx docs install 2019-03-11 11:10:44 +00:00
Makefile.objs build: remove unnecessary assignments from Makefile.target 2019-03-11 16:33:49 +01:00
Makefile.target build: clean trace/generated-helpers.c 2019-03-11 16:33:49 +01:00
memory_ldst.inc.c exec: Fix MAP_RAM for cached access 2018-06-28 19:05:30 +02:00
memory_mapping.c qemu/queue.h: simplify reverse access to QTAILQ 2019-01-11 15:46:55 +01:00
memory.c memory: Do not update coalesced IO range in the case of NOP 2019-03-11 14:45:10 +01:00
module-common.c all: Clean up includes 2016-02-04 17:41:30 +00:00
monitor.c monitor: deprecate acl_show, acl_reset, acl_policy, acl_add, acl_remove 2019-03-11 08:39:02 +01:00
numa.c numa: Fixed the memory leak of numa error message 2019-01-28 15:52:05 -02:00
os-posix.c util: add qemu_write_pidfile() 2018-10-02 18:47:55 +02:00
os-win32.c util: add qemu_write_pidfile() 2018-10-02 18:47:55 +02:00
qdev-monitor.c qdev: Let the hotplug_handler_unplug() caller delete the device 2019-03-06 11:51:08 -03:00
qemu-bridge-helper.c all: Remove unnecessary glib.h includes 2016-06-07 18:19:24 +03:00
qemu-deprecated.texi block/dirty-bitmap: add recording and busy properties 2019-03-12 12:05:48 -04:00
qemu-doc.texi qemu-doc: Add section on MIPS' Boston board 2019-02-27 14:26:14 +01:00
qemu-edid.c display/edid: add edid generator to qemu. 2018-09-27 08:07:51 +02:00
qemu-ga.texi qemu-ga: Remove stray 'q' in documentation 2016-10-28 18:17:23 +03:00
qemu-img-cmds.hx qemu-img: Add -C option for convert with copy offloading 2018-07-30 15:35:37 +02:00
qemu-img.c block: iterate_format with account of whitelisting 2019-03-08 12:26:45 +01:00
qemu-img.texi qemu-img: Add -C option for convert with copy offloading 2018-07-30 15:35:37 +02:00
qemu-io-cmds.c bdrv_query_image_info Error parameter added 2019-02-11 14:35:43 -06:00
qemu-io.c qom: Clean up error reporting in user_creatable_add_opts_foreach() 2018-10-19 14:51:34 +02:00
qemu-keymap.c ui: use enum to string helpers 2018-08-24 08:40:10 +02:00
qemu-nbd.c qemu-nbd: add support for authorization of TLS clients 2019-03-06 11:05:27 -06:00
qemu-nbd.texi qemu-nbd: add support for authorization of TLS clients 2019-03-06 11:05:27 -06:00
qemu-option-trace.texi qemu-option-trace: -trace enable= is a pattern, not a file 2018-05-20 08:29:01 +03:00
qemu-options-wrapper.h qemu-img: remove references to GEN_DOCS 2018-05-20 08:35:54 +03:00
qemu-options.h Clean up ill-advised or unusual header guards 2016-07-12 16:20:46 +02:00
qemu-options.hx chardev: add support for authorization for TLS clients 2019-03-11 16:55:52 +01:00
qemu-seccomp.c seccomp: Work-around GCC 4.x bug in gnu99 mode 2019-01-22 06:26:32 +01:00
qemu-tech.texi cli qmp: Mark --preconfig, exit-preconfig experimental 2018-07-16 15:38:19 +02:00
qemu.nsi Use HTTPS for qemu.org and other domains 2017-11-21 13:34:13 +00:00
qemu.sasl Default to GSSAPI (Kerberos) instead of DIGEST-MD5 for SASL 2017-05-09 14:41:47 +01:00
qmp.c qapi: make query-cpu-definitions depend on specific targets 2019-02-18 14:44:05 +01:00
qtest.c char: allow specifying a GMainContext at opening time 2019-02-13 14:23:39 +01:00
README README: use 'https://' instead of 'git://' 2018-11-12 11:26:02 +00:00
replication.c replication: Introduce new APIs to do replication operation 2016-09-13 11:00:56 +01:00
replication.h block/replication: Remove protocol_name field 2018-03-26 12:16:00 +02:00
rules.mak build: switch to Kconfig 2019-03-07 21:45:53 +01:00
thunk.c thunk: improve readability of allocation loop 2019-03-11 18:48:20 +01:00
tpm.c tpm: Clean up error reporting in tpm_init_tpmdev() 2018-10-19 14:51:34 +02:00
trace-events trace: improve runstate tracing 2019-01-25 10:21:27 +00:00
VERSION Open 4.0 development tree 2018-12-11 17:27:58 +00:00
version.rc Use HTTPS for qemu.org and other domains 2017-11-21 13:34:13 +00:00
vl.c fw_cfg and thunk code clean up 2019-03-12 12:29:53 +00:00
win_dump.c dump: fix Windows dump memory run mapping 2018-10-02 18:47:55 +02:00
win_dump.h dump: move Windows dump structures definitions 2018-10-02 19:09:12 +02:00

         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.


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:

  mkdir build
  cd build
  ../configure
  make

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

  https://qemu.org/Hosts/Linux
  https://qemu.org/Hosts/Mac
  https://qemu.org/Hosts/W32


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

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

   git clone https://git.qemu.org/git/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 HACKING and CODING_STYLE files.

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

  https://qemu.org/Contribute/SubmitAPatch
  https://qemu.org/Contribute/TrivialPatches

The QEMU website is also maintained under source control.

  git clone https://git.qemu.org/git/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:

  $ 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:

  $ 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 Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:

  https://bugs.launchpad.net/qemu/

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 launchpad.

For additional information on bug reporting consult:

  https://qemu.org/Contribute/ReportABug


Contact
=======

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

 - 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://qemu.org/Contribute/StartHere

-- End