Commit Graph

125 Commits

Author SHA1 Message Date
Angel M. Villegas
b68d8b677e guest-agent: improve help for --allow-rpcs and --block-rpcs
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1757

Updates to qga help output and documentation for --allow-rpcs and --blocks-rpcs

Signed-off-by: "Angel M. Villegas" <anvilleg@cisco.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2024-01-30 12:10:37 +02:00
Michael Tokarev
01dc06511d qga/: spelling fixes
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
2023-09-08 13:08:52 +03:00
Konstantin Kostiuk
133789e1bf qga: Add new option --allow-rpcs
The allow-rpcs option accepts a comma-separated list of RPCs to
enable. This option is opposite to --block-rpcs. Using --block-rpcs
and --allow-rpcs at the same time is not allowed.

resolves: https://gitlab.com/qemu-project/qemu/-/issues/1505

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2023-07-10 15:54:40 +03:00
Konstantin Kostiuk
27076d0399 qga: Rename ga_disable_not_allowed -> ga_disable_not_allowed_freeze
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2023-07-10 15:54:40 +03:00
Markus Armbruster
6f1e91f716 error: Drop superfluous #include "qapi/qmp/qerror.h"
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2023-02-23 13:56:14 +01:00
Andrey Drobyshev
8e86851bd6 qga: map GLib log levels to system levels
This patch translates GLib-specific log levels to system ones, so that
they may be used by both *nix syslog() (as a "priority" argument) and
Windows ReportEvent() (as a "wType" argument).

Currently the only codepath to write to "syslog" domain is slog()
function.  However, this patch allows the interface to be extended.

Note that since slog() is using G_LOG_LEVEL_INFO level, its behaviour
doesn't change.

Originally-by: Yuri Pudgorodskiy <yur@virtuozzo.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Tested-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-12-20 15:54:42 +02:00
Andrey Drobyshev
f9f0e6173e qga-win: add logging to Windows event log
This commit allows QGA to write to Windows event log using Win32 API's
ReportEvent() [1], much like syslog() under *nix guests.

In order to generate log message definitions we use a very basic message
text file [2], so that every QGA's message gets ID 1.  The tools
"windmc" and "windres" respectively are used to generate ".rc" file and
COFF object file, and then the COFF file is linked into qemu-ga.exe.

[1] https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-reporteventa
[2] https://learn.microsoft.com/en-us/windows/win32/eventlog/message-text-files

Originally-by: Yuri Pudgorodskiy <yur@virtuozzo.com>
Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Tested-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-12-20 15:54:41 +02:00
Brad Smith
28236ad8d1 qga: Add initial OpenBSD and NetBSD support
qga: Add initial OpenBSD and NetBSD support

Signed-off-by: Brad Smith <brad@comstyle.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-12-20 15:54:41 +02:00
Alexander Ivanov
bad0001eeb qga: Add UFS freeze/thaw support for FreeBSD
UFS supports FS freezing through ioctl UFSSUSPEND on /dev/ufssuspend.
Frozen FS can be thawed by closing /dev/ufssuspend file descriptior.

Use getmntinfo to get a list of mounted FS.

Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-10-26 20:35:07 +03:00
Alexander Ivanov
c6cd588bb3 qga: Add initial FreeBSD support
- Fix device path.
- Fix virtio-serial channel initialization.
- Make the code buildable in FreeBSD.

Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-10-26 20:35:07 +03:00
Thomas Huth
0e4ef702e8 qga: Replace 'blacklist' and 'whitelist' in the guest agent sources
Let's use better, more inclusive wording here.

Message-Id: <20220727092135.302915-3-thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-09-20 12:37:00 +02:00
Thomas Huth
582a098e6c qga: Replace 'blacklist' command line and config file options by 'block-rpcs'
Let's use a more appropriate wording for this command line and config
file option. The old ones are still accepted for compatibility reasons,
but marked as deprecated now so that it could be removed in a future
version of QEMU.

This change is based on earlier patches from Philippe Mathieu-Daudé,
with the idea for the new option name suggested by BALATON Zoltan.

And while we're at it, replace the "?" in the help text with "help"
since that does not have the problem of conflicting with the wildcard
character of the shells.

Message-Id: <20220727092135.302915-2-thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-09-20 12:37:00 +02:00
Akihiko Odaki
a24827942a qga: Relocate a path emitted in the help text
Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20220624145455.50058-1-akihiko.odaki@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-08 11:03:36 +02:00
Konstantin Kostiuk
323f3a8f22 trivial: qga: Log version on start
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220523191644.823726-2-kkostiuk@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2022-05-25 12:12:02 +03:00
Marc-André Lureau
55fa017072 qga: use fixed-length and GDateTime for log timestamp
The old code is kind of wrong. Say it's 1649309843.000001 seconds past
the epoch. Prints "1649309843.1". 9us later, it prints "1649309843.10".
Should really use %06lu for the microseconds part.

Use GDateTime instead, as suggested by Daniel.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2022-04-21 17:37:16 +04:00
Marc-André Lureau
1fbf2665e6 util: replace qemu_get_local_state_pathname()
Simplify the function to only return the directory path. Callers are
adjusted to use the GLib function to build paths, g_build_filename().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-39-marcandre.lureau@redhat.com>
2022-04-21 17:09:09 +04:00
Marc-André Lureau
4e8c41947b qga: replace usleep() with g_usleep()
The latter simply requires glib.h, while the former is not in the
Windows API (but provided by mingw header & CRT)

Also simplify the expression for 1/10s.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-12-marcandre.lureau@redhat.com>
2022-04-21 17:03:51 +04:00
Marc-André Lureau
49f9522193 include: rename qemu-common.h qemu/help-texts.h
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220420132624.2439741-7-marcandre.lureau@redhat.com>
2022-04-21 16:58:24 +04:00
Marc-André Lureau
6e9396696f qga: replace deprecated g_get_current_time()
According to GLib API:
g_get_current_time has been deprecated since version 2.62 and should not
be used in newly-written code. GTimeVal is not year-2038-safe. Use
g_get_real_time() instead.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-13-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Marc-André Lureau
45297887dc qga: remove bswap.h include
Apparently not needed anymore.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2022-03-22 14:46:18 +04:00
Marc-André Lureau
c98939daec qga: return a more explicit error on why a command is disabled
qmp_disable_command() now takes an optional error string to return a
more explicit error message.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1928806

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
*fix up 80+ char line
Signed-off-by: Michael Roth <michael.roth@amd.com>
2021-03-16 20:21:47 -05:00
AlexChen
86dc17d4d0 qga: Switch and case should be at the same indent
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: AlexChen <alex.chen@huawei.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
2021-03-16 20:21:47 -05:00
AlexChen
aaaed19972 qga: Open brace '{' following struct go on the same
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: AlexChen <alex.chen@huawei.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
2021-03-16 20:21:47 -05:00
AlexChen
0697e9ed29 qga: Add spaces around operator
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: AlexChen <alex.chen@huawei.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
*fix 80+ char violation while we're here
*fix w32 build breakage from changing INVALID_SET_FILE_POINTER
 definition from a cast to a subtraction
Signed-off-by: Michael Roth <michael.roth@amd.com>
2021-03-16 20:20:37 -05:00
Markus Armbruster
eab3a4678b qobject: Change qobject_to_json()'s value to GString
qobject_to_json() and qobject_to_json_pretty() build a GString, then
covert it to QString.  Just one of the callers actually needs a
QString: qemu_rbd_parse_filename().  A few others need a string they
can modify: qmp_send_response(), qga's send_response(), to_json_str(),
and qmp_fd_vsend_fds().  The remainder just need a string.

Change qobject_to_json() and qobject_to_json_pretty() to return the
GString.

qemu_rbd_parse_filename() now has to convert to QString.  All others
save a QString temporary.  to_json_str() actually becomes a bit
simpler, because GString provides more convenient modification
functions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-6-armbru@redhat.com>
2020-12-19 10:38:43 +01:00
Kevin Wolf
41725fa7ed qmp: Call monitor_set_cur() only in qmp_dispatch()
The correct way to set the current monitor for a coroutine handler will
be different than for a blocking handler, so monitor_set_cur() needs to
be called in qmp_dispatch().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-7-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Paolo Bonzini
a9eacf8b4d qga: relocate path to default configuration and hook
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-30 19:11:36 +02:00
Marc-André Lureau
844bd70b56 qga: fix assert regression on guest-shutdown
Since commit 781f2b3d1e ("qga: process_event() simplification"),
send_response() is called unconditionally, but will assert when "rsp" is
NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
"guest-shutdown".

Fixes: 781f2b3d1e
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2020-07-13 17:17:08 -05:00
Stefan Hajnoczi
7b46aadbbf qemu-ga: document vsock-listen in the man page
Although qemu-ga has supported vsock since 2016 it was not documented on
the man page.

Also add the socket address representation to the qga --help output.

Fixes: 586ef5dee7
       ("qga: add vsock-listen method")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2020-03-24 11:32:19 -05:00
Marc-André Lureau
f0ccc00be1 qmp: constify QmpCommand and list
Since 0b69f6f72c "qapi: remove
qmp_unregister_command()", the command list can be declared const.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Message-Id: <20200316171824.2319695-1-marcandre.lureau@redhat.com>
[Rebased]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-03-17 21:43:12 +01:00
Markus Armbruster
00ca24ff9e qapi: Generate command registration stuff into separate files
Having to include qapi-commands.h just for qmp_init_marshal() is
suboptimal.  Generate it into separate files.  This lets
monitor/misc.c, qga/main.c, and the generated qapi-commands-FOO.h
include less.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191120182551.23795-4-armbru@redhat.com>
[Typos in docs/devel/qapi-code-gen.txt fixed]
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-14 11:01:58 +01:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Marc-André Lureau
781f2b3d1e qga: process_event() simplification
Simplify the code around qmp_dispatch():
- rely on qmp_dispatch/check_obj() for message checking
- have a single send_response() point
- constify send_response() argument

It changes a couple of error messages:

* When @req isn't a dictionary, from
    Invalid JSON syntax
  to
    QMP input must be a JSON object

* When @req lacks member "execute", from
    this feature or command is not currently supported
  to
    QMP input lacks member 'execute'

CC: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-18 10:48:06 -05:00
Bishara AbuHattoum
b70d6afe4d qga-win: changing --retry-path option behavior
Currently whenever the qemu-ga's service doesn't find the virtio-serial
the run_agent() loops in a QGA_RETRY_INTERVAL (default 5 seconds)
intervals and try to restart the qemu-ga which causes a synchronous loop.
Changed to wait and listen for the serial events by registering for
notifications a proper serial event handler that deals with events:
  DBT_DEVICEARRIVAL        indicates that the device has been inserted and
                           is available
  DBT_DEVICEREMOVECOMPLETE indicates that the devive has been removed
Which allow us to determine when the channel path is available for the
qemu-ga to restart.

Signed-off-by: Bishara AbuHattoum <bishara@daynix.com>
Signed-off-by: Sameeh Jubran <sameeh@daynix.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-31 09:04:20 -05:00
Michael Roth
d951fadad6 qga: add --retry-path option for re-initializing channel on failure
This adds an option to instruct the agent to periodically attempt
re-opening the communication channel after a channel error has
occurred. The main use-case for this is providing an OS-independent
way of allowing the agent to survive situations like hotplug/unplug of
the communication channel, or initial guest set up where the agent may
be installed/started prior to the installation of the channel device's
driver.

There are nicer ways of implementing this functionality via things
like systemd services, but this option is useful for platforms like
*BSD/w32.

Currently a channel error will result in the GSource for that channel
being removed from the GMainLoop, but the main loop continuing to run.
That behavior results in a dead loop when --retry-path isn't set, and
prevents us from knowing when to attempt re-opening the channel when
it is set, so we also force the loop to exit as part of this patch.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-31 09:04:20 -05:00
Michael Roth
d88495a864 qga: move w32 service handling out of run_agent()
Eventually we want a w32 service to be able to restart the qga main
loop from within service_main(). To allow for this we move service
handling out of run_agent() such that service_main() calls
run_agent() instead of the reverse.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Bishara AbuHattoum <bishara@daynix.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-31 09:04:20 -05:00
Michael Roth
0f4d3a4912 qga: hang GAConfig/socket_activation off of GAState global
For w32 services we rely on the global GAState to access resources
associated with the agent within service_main(). Currently this is
sufficient for starting the agent since we open the channel once prior
to calling service_main(), and simply start the GMainLoop to start the
agent from within service_main().

Eventually we want to be able to also [re-]open the communication
channel from within service_main(), which requires access to
config/socket_activation variables, so we hang them off GAState in
preparation for that.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Sameeh Jubran <sameeh@daynix.com>
*dont move GAConfig struct, just the typedef
*fix build bisect for w32
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-31 09:04:20 -05:00
Michael Roth
50d5b3c465 qga: group agent init/cleanup init separate routines
This patch better separates the init/cleanup routines out into
separate functions to make the start-up procedure a bit easier to
follow. This will be useful when we eventually break out the actual
start/stop of the agent's main loop into separates routines that
can be called multiple times after the init phase.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-31 09:04:20 -05:00
Chen Hanxiao
0692b03ee1 qga-win: add support for qmp_guest_fsfreeze_freeze_list
This patch add support for freeze specified fs.

The valid mountpoints list member are [1]:

  The path of a mounted folder, for example, Y:\MountX\
  A drive letter, for example, D:\
  A volume GUID path of the form \\?\Volume{GUID}\,
      where GUID identifies the volume
  A UNC path that specifies a remote file share,
      for example, \\Clusterx\Share1\

[1] https://docs.microsoft.com/en-us/windows/desktop/api/vsbackup/nf-vsbackup-ivssbackupcomponents-addtosnapshotset

Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-10-30 16:48:49 -05:00
Marc-André Lureau
9e6bdef224 util: add qemu_write_pidfile()
There are variants of qemu_create_pidfile() in qemu-pr-helper and
qemu-ga. Let's have a common implementation in libqemuutil.

The code is initially based from pr-helper write_pidfile(), with
various improvements and suggestions from Daniel Berrangé:

  QEMU will leave the pidfile existing on disk when it exits which
  initially made me think it avoids the deletion race. The app
  managing QEMU, however, may well delete the pidfile after it has
  seen QEMU exit, and even if the app locks the pidfile before
  deleting it, there is still a race.

  eg consider the following sequence

        QEMU 1        libvirtd        QEMU 2

  1.    lock(pidfile)

  2.    exit()

  3.                 open(pidfile)

  4.                 lock(pidfile)

  5.                                  open(pidfile)

  6.                 unlink(pidfile)

  7.                 close(pidfile)

  8.                                  lock(pidfile)

  IOW, at step 8 the new QEMU has successfully acquired the lock, but
  the pidfile no longer exists on disk because it was deleted after
  the original QEMU exited.

  While we could just say no external app should ever delete the
  pidfile, I don't think that is satisfactory as people don't read
  docs, and admins don't like stale pidfiles being left around on
  disk.

  To make this robust, I think we might want to copy libvirt's
  approach to pidfile acquisition which runs in a loop and checks that
  the file on disk /after/ acquiring the lock matches the file that
  was locked. Then we could in fact safely let QEMU delete its own
  pidfiles on clean exit..

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180831145314.14736-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02 18:47:55 +02:00
Markus Armbruster
86cdf9ec8d json: Clean up headers
The JSON parser has three public headers, json-lexer.h, json-parser.h,
json-streamer.h.  They all contain stuff that is of no interest
outside qobject/json-*.c.

Collect the public interface in include/qapi/qmp/json-parser.h, and
everything else in qobject/json-parser-int.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-54-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
84a56f38b2 json: Pass lexical errors and limit violations to callback
The callback to consume JSON values takes QObject *json, Error *err.
If both are null, the callback is supposed to make up an error by
itself.  This sucks.

qjson.c's consume_json() neglects to do so, which makes
qobject_from_json() null instead of failing.  I consider that a bug.

The culprit is json_message_process_token(): it passes two null
pointers when it runs into a lexical error or a limit violation.  Fix
it to pass a proper Error object then.  Update the callbacks:

* monitor.c's handle_qmp_command(): the code to make up an error is
  now dead, drop it.

* qga/main.c's process_event(): lumps the "both null" case together
  with the "not a JSON object" case.  The former is now gone.  The
  error message "Invalid JSON syntax" is misleading for the latter.
  Improve it to "Input must be a JSON object".

* qobject/qjson.c's consume_json(): no update; check-qjson
  demonstrates qobject_from_json() now sets an error on lexical
  errors, but still doesn't on some other errors.

* tests/libqtest.c's qmp_response(): the Error object is now reliable,
  so use it to improve the error message.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-40-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
62815d85ae json: Redesign the callback to consume JSON values
The classical way to structure parser and lexer is to have the client
call the parser to get an abstract syntax tree, the parser call the
lexer to get the next token, and the lexer call some function to get
input characters.

Another way to structure them would be to have the client feed
characters to the lexer, the lexer feed tokens to the parser, and the
parser feed abstract syntax trees to some callback provided by the
client.  This way is more easily integrated into an event loop that
dispatches input characters as they arrive.

Our JSON parser is kind of between the two.  The lexer feeds tokens to
a "streamer" instead of a real parser.  The streamer accumulates
tokens until it got the sequence of tokens that comprise a single JSON
value (it counts curly braces and square brackets to decide).  It
feeds those token sequences to a callback provided by the client.  The
callback passes each token sequence to the parser, and gets back an
abstract syntax tree.

I figure it was done that way to make a straightforward recursive
descent parser possible.  "Get next token" becomes "pop the first
token off the token sequence".  Drawback: we need to store a complete
token sequence.  Each token eats 13 + input characters + malloc
overhead bytes.

Observations:

1. This is not the only way to use recursive descent.  If we replaced
   "get next token" by a coroutine yield, we could do without a
   streamer.

2. The lexer reports errors by passing a JSON_ERROR token to the
   streamer.  This communicates the offending input characters and
   their location, but no more.

3. The streamer reports errors by passing a null token sequence to the
   callback.  The (already poor) lexical error information is thrown
   away.

4. Having the callback receive a token sequence duplicates the code to
   convert token sequence to abstract syntax tree in every callback.

5. Known bug: the streamer silently drops incomplete token sequences.

This commit rectifies 4. by lifting the call of the parser from the
callbacks into the streamer.  Later commits will address 3. and 5.

The lifting removes a bug from qjson.c's parse_json(): it passed a
pointer to a non-null Error * in certain cases, as demonstrated by
check-qjson.c.

json_parser_parse() is now unused.  It's a stupid wrapper around
json_parser_parse_err().  Drop it, and rename json_parser_parse_err()
to json_parser_parse().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-35-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Marc-André Lureau
ae7da1e5f6 qga: process_event() simplification and leak fix
json_parser_parse_err() may return something else than a QDict, in
which case we loose the object. Let's keep track of the original
object to avoid leaks.

When an error occurs, "qdict" contains the response, but we still
check the "execute" key there. Untangle a bit this code, by having a
clear error path.

CC: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2018-07-23 18:54:26 -05:00
Markus Armbruster
d43b16945a qmp: Use QDict * instead of QObject * for response objects
By using the more specific type, we get fewer downcasts.  The
downcasts are safe, but not obviously so, at least not locally.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-24-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
cee32796ca qmp: De-duplicate error response building
All callers of qmp_build_error_object() duplicate the code to wrap it
in a response object.  Replace it by qmp_error_response() that
captures the duplicated code, including error_free().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-23-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
674ed7228f qmp qemu-ga: Fix qemu-ga not to accept "control"
Commit cf869d5317 "qmp: support out-of-band (oob) execution"
accidentally made qemu-ga accept and ignore "control".  Fix that.

Out-of-band execution in a monitor that doesn't support it now fails
with

    {"error": {"class": "GenericError", "desc": "QMP input member 'control' is unexpected"}}

instead of

    {"error": {"class": "GenericError", "desc": "Please enable out-of-band first for the session during capabilities negotiation"}}

The old description is suboptimal when out-of-band cannot not be
enabled, or the command doesn't support out-of-band execution.

The new description is a bit unspecific, but it'll do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-12-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Michael S. Tsirkin
dc03272da6 qga: use local path for local headers
When pulling in headers that are in the same directory as the C file (as
opposed to one in include/), we should use its relative path, without a
directory.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-01 19:20:38 +03:00
Marc-André Lureau
cb3e7f08ae qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF
Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that work
everywhere instead of having to use QINCREF() / QDECREF() for QObject
and qobject_incref() / qobject_decref() for its subtypes.

The replacement is mechanical, except I broke a long line, and added a
cast in monitor_qmp_cleanup_req_queue_locked().  Unlike
qobject_decref(), qobject_unref() doesn't accept void *.

Note that the new macros evaluate their argument exactly once, thus no
need to shout them.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, semantic conflict resolved, commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-05-04 08:27:53 +02:00