Commit Graph

23 Commits

Author SHA1 Message Date
Fabiano Rosas
87d67fadb9 monitor: Stop removing non-duplicated fds
monitor_fdsets_cleanup() currently has three responsibilities:

1- Remove the fds that have been marked for removal(->removed=true) by
   qmp_remove_fd(). This is overly complicated, but ok.

2- Remove any file descriptors that have been passed into QEMU and
   never duplicated[1,2]. A file descriptor without duplicates
   indicates that no part of QEMU has made use of it. This is
   problematic because the current implementation does it only if the
   guest is not running and the monitor is closed.

3- Remove/free fdsets that have become empty due to the above
   removals. This is ok.

The scenario described in (2) is starting to show some cracks now that
we're trying to consume fds from the migration code:

- Doing cleanup every time the last monitor connection closes works to
  reap unused fds, but also has the side effect of forcing the
  management layer to pass the file descriptors again in case of a
  disconnect/re-connect, if that happened to be the only monitor
  connection.

  Another side effect is that removing an fd with qmp_remove_fd() is
  effectively delayed until the last monitor connection closes.

  The usage of mon_refcount is also problematic because it's racy.

- Checking runstate_is_running() skips the cleanup unless the VM is
  running and avoids premature cleanup of the fds, but also has the
  side effect of blocking the legitimate removal of an fd via
  qmp_remove_fd() if the VM happens to be in another state.

  This affects qmp_remove_fd() and qmp_query_fdsets() in particular
  because requesting a removal at a bad time (guest stopped) might
  cause an fd to never be removed, or to be removed at a much later
  point in time, causing the query command to continue showing the
  supposedly removed fd/fdset.

Note that file descriptors that *have* been duplicated are owned by
the code that uses them and will be removed after qemu_close() is
called. Therefore we've decided that the best course of action to
avoid the undesired side-effects is to stop managing non-duplicated
file descriptors.

1- efb87c1697 ("monitor: Clean up fd sets on monitor disconnect")
2- ebe52b592d ("monitor: Prevent removing fd from set during init")

Reviewed-by: Peter Xu <peterx@redhat.com>
[fix logic mistake: s/fdset_free/fdset_free_if_empty]
Signed-off-by: Fabiano Rosas <farosas@suse.de>
2024-06-21 09:44:53 -03:00
Paolo Bonzini
9f2d58546e monitor: introduce qmp_dispatcher_co_wake
This makes it possible to turn qmp_dispatcher_co_busy into a static
variable.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-25 10:18:33 +02:00
Paolo Bonzini
6ee7c82d0d monitor: do not use mb_read/mb_set for suspend_cnt
Clean up monitor_event to just use monitor_suspend/monitor_resume,
using mon->mux_out to protect against incorrect nesting (especially
on startup).

The only remaining case of reading suspend_cnt is in the can_read
callback, which is just advisory and can use qatomic_read.

As an extra benefit, mux_out is now simply protected by mon_lock.
Also, moving the prompt to the beginning of the main loop removes
it from the output in some error cases where QEMU does not actually
start successfully.  It is not a full fix and it would be nice to
also remove the monitor heading, but this is already a small (though
unintentional) improvement.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-25 10:18:33 +02:00
Markus Armbruster
5ec92f2d92 hmp: Rename help_cmd() to hmp_help_cmd(), move declaration to hmp.h
The next commit will move a caller of help_cmd() to a new file.
Including monitor/monitor-internal.h there just for help_cmd() feels
silly.  Better to provide it in monitor/hmp.h suitably renamed.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-8-armbru@redhat.com>
2023-02-04 07:56:54 +01:00
Alex Bennée
bf0c50d4aa monitor: expose monitor_puts to rest of code
This helps us construct strings elsewhere before echoing to the
monitor. It avoids having to jump through hoops like:

  monitor_printf(mon, "%s", s->str);

It will be useful in following patches but for now convert all
existing plain "%s" printfs to use the _puts api.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220929114231.583801-33-alex.bennee@linaro.org>
2022-10-06 11:53:40 +01:00
Stefan Reiter
26fcd76617 monitor/hmp: add support for flag argument with value
Adds support for the "-xs" parameter type, where "-x" denotes a flag
name and the "s" suffix indicates that this flag is supposed to take
an arbitrary string parameter.

These parameters are always optional, the entry in the qdict will be
omitted if the flag is not given.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
[FE: fixed typo pointed out by Eric Blake
     use s instead of V to indicate string parameter]
Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Message-Id: <20220225084949.35746-2-f.ebner@proxmox.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:12:40 +00:00
Daniel P. Berrangé
f9429c6790 monitor: introduce HumanReadableText and HMP support
This provides a foundation on which to convert simple HMP commands to
use QMP. The QMP implementation will generate formatted text targeted
for human consumption, returning it in the HumanReadableText data type.

The HMP command handler will simply print out the formatted string
within the HumanReadableText data type. Since this will be an entirely
formulaic action in the case of HMP commands taking no arguments, a
custom command handler is provided.

Thus instead of registering a 'cmd' callback for the HMP command, a
'cmd_info_hrt' callback is provided, which will simply be a pointer
to the QMP implementation.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-11-02 15:55:13 +00:00
Markus Armbruster
624fa80c8c monitor: Drop query-qmp-schema 'gen': false hack
QMP commands return their response as a generated QAPI type, which the
monitor core converts to JSON via QObject.

query-qmp-schema's response is the generated introspection data.  This
is a QLitObject since commit 7d0f982bfb "qapi: generate a literal
qobject for introspection", v2.12).  Before, it was a string.  Instead
of converting QLitObject / string -> QObject -> QAPI type
SchemaInfoList -> QObject -> JSON, we take a shortcut: the command is
'gen': false, so it can return the QObject instead of the QAPI type.
Slightly simpler and more efficient.

The next commit will filter the response for output policy, and this
is easier in the SchemaInfoList representation.  Drop the shortcut.

This replaces the manual command registration by a generated one.  The
manual registration makes the command available before the machine is
built by passing flag QCO_ALLOW_PRECONFIG.  To keep it available
there, we need need to add 'allow-preconfig': true to its definition
in the schema.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-7-armbru@redhat.com>
2021-03-19 16:05:09 +01:00
Markus Armbruster
20076f4a8c monitor: Use GString instead of QString for output buffer
GString has a richer set of string operations than QString.  It should
be preferred to QString except where we need a QObject or reference
counting.  We don't here.  Switch to GString, and put its richer
interface to use.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-3-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-12-19 10:38:35 +01:00
Kevin Wolf
2fc5d01bb4 hmp: Pass monitor to mon_get_cpu()
mon_get_cpu() is indirectly called monitor_parse_arguments() where
the current monitor isn't set yet. Instead of using monitor_cur(),
explicitly pass the Monitor pointer to the function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201113114326.97663-2-kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-11-13 12:45:35 +00:00
Kevin Wolf
bb4b9ead95 hmp: Add support for coroutine command handlers
Often, QMP command handlers are not only called to handle QMP commands,
but also from a corresponding HMP command handler. In order to give them
a consistent environment, optionally run HMP command handlers in a
coroutine, too.

The implementation is a lot simpler than in QMP because for HMP, we
still block the VM while the coroutine is running.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20201005155855.256490-11-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 07:08:20 +02:00
Kevin Wolf
9ce44e2ce2 qmp: Move dispatcher to a coroutine
This moves the QMP dispatcher to a coroutine and runs all QMP command
handlers that declare 'coroutine': true in coroutine context so they
can avoid blocking the main loop while doing I/O or waiting for other
events.

For commands that are not declared safe to run in a coroutine, the
dispatcher drops out of coroutine context by calling the QMP command
handler from a bottom half.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201005155855.256490-10-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 07:08:20 +02:00
Markus Armbruster
ddfb0baaf2 qom: Clean up inconsistent use of gchar * vs. char *
Uses of gchar * in qom/object.h:

* ObjectProperty member @name

  Functions that take a property name argument all use char *.  Change
  the member to match.

* ObjectProperty member @type

  Functions that take a property type argument or return it all use
  char *.  Change the member to match.

* ObjectProperty member @description

  Functions that take a property description argument all use char *.
  Change the member to match.

* object_resolve_path_component() parameter @part

  Path components are property names.  Most callers pass char *
  arguments.  Change the parameter to match.  Adjust the few callers
  that pass gchar * to pass char *.

* Return value of object_get_canonical_path_component(),
  object_get_canonical_path()

  Most callers convert their return values right back to char *.
  Change the return value to match.  Adjust the few callers where that
  would add a conversion to gchar * to use char * instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-3-armbru@redhat.com>
2020-05-15 06:26:02 +02:00
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
Kevin Wolf
7d3f505359 monitor: Move qmp_query_qmp_schema to qmp-cmds-control.c
monitor/misc.c contains code that works only in the system emulator, so
it can't be linked to tools like a storage daemon. In order to make
schema introspection available for tools, move the function to
monitor/qmp-cmds-control.c, which can be linked into the storage daemon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200129102239.31435-5-kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-02-17 13:53:47 +01:00
Kevin Wolf
fa4dcf577e qapi: Split control.json off misc.json
misc.json contains definitions that are related to the system emulator,
so it can't be used for other tools like the storage daemon. This patch
moves basic functionality that is shared between all tools (and mostly
related to the monitor itself) into a new control.json, which could be
used in tools as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200129102239.31435-3-kwolf@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-02-17 13:53:47 +01:00
Markus Armbruster
2ae16a6aa4 Include generated QAPI headers less
Some of the generated qapi-types-MODULE.h are included all over the
place.  Changing a QAPI type can trigger massive recompiling.  Top
scorers recompile more than 1000 out of some 6600 objects (not
counting tests and objects that don't depend on qemu/osdep.h):

    6300 qapi/qapi-builtin-types.h
    5700 qapi/qapi-types-run-state.h
    3900 qapi/qapi-types-common.h
    3300 qapi/qapi-types-sockets.h
    3000 qapi/qapi-types-misc.h
    3000 qapi/qapi-types-crypto.h
    3000 qapi/qapi-types-job.h
    3000 qapi/qapi-types-block-core.h
    2800 qapi/qapi-types-block.h
    1300 qapi/qapi-types-net.h

Clean up headers to include generated QAPI headers only where needed.
Impact is negligible except for hw/qdev-properties.h.

This header includes qapi/qapi-types-block.h and
qapi/qapi-types-misc.h.  They are used only in expansions of property
definition macros such as DEFINE_PROP_BLOCKDEV_ON_ERROR() and
DEFINE_PROP_OFF_AUTO().  Moving their inclusion from
hw/qdev-properties.h to the users of these macros avoids pointless
recompiles.  This is how other property definition macros, such as
DEFINE_PROP_NETDEV(), already work.

Improves things for some of the top scorers:

    3600 qapi/qapi-types-common.h
    2800 qapi/qapi-types-sockets.h
     900 qapi/qapi-types-misc.h
    2200 qapi/qapi-types-crypto.h
    2100 qapi/qapi-types-job.h
    2100 qapi/qapi-types-block-core.h
     270 qapi/qapi-types-block.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-3-armbru@redhat.com>
2019-08-16 13:31:51 +02:00
Kevin Wolf
fbfc29e3bf monitor: Replace monitor_init() with monitor_init_{hmp, qmp}()
Most callers know which monitor type they want to have. Instead of
calling monitor_init() with flags that can describe both types of
monitors, make monitor_init_{hmp,qmp}() public interfaces that take
specific bools instead of flags and call these functions directly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-15-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00
Kevin Wolf
920824165c monitor: Split Monitor.flags into separate bools
Monitor.flags contains three different flags: One to distinguish HMP
from QMP; one specific to HMP (MONITOR_USE_READLINE) that is ignored
with QMP; and another one specific to QMP (MONITOR_USE_PRETTY) that is
ignored with HMP.

Split the flags field into three bools and move them to the right
subclass. Flags are still in use for the monitor_init() interface.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-14-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00
Kevin Wolf
1d95db745b monitor: Split out monitor/monitor.c
Move the monitor core infrastructure from monitor/misc.c to
monitor/monitor.c. This is code that can be shared for all targets, so
compile it only once.

What remains in monitor/misc.c after this patch is mostly monitor
command implementations (which could move to hmp-cmds.c or qmp-cmds.c
later) and code that requires a system emulator or is even
target-dependent (including HMP command completion code).

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between all
monitor parts can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-13-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:14:17 +02:00
Kevin Wolf
ed7bda5d07 monitor: Split out monitor/hmp.c
Move HMP infrastructure from monitor/misc.c to monitor/hmp.c. This is
code that can be shared for all targets, so compile it only once.

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between HMP
and the monitor core can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-12-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Comment reformatted to make checkpatch.pl happy, #include <dirent.h>
moved to fix Windows build, superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-18 08:13:13 +02:00
Kevin Wolf
7e3c0deab1 monitor: Split out monitor/qmp.c
Move QMP infrastructure from monitor/misc.c to monitor/qmp.c. This is
code that can be shared for all targets, so compile it only once.

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between QMP
and the monitor core can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190613153405.24769-11-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[monitor_is_qmp() tidied up to make checkpatch.pl happy,
superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-17 20:36:56 +02:00
Kevin Wolf
5bce308aaa monitor: Create monitor-internal.h with common definitions
Before we can split monitor/misc.c, we need to create a header file that
contains the common definitions that will be used by multiple source
files.

For a start, add the type definitions for Monitor, MonitorHMP and
MonitorQMP and their dependencies. We'll add functions as needed when
splitting monitor/misc.c.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190613153405.24769-10-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Header guard symbol tidied up, superfluous #include dropped, FIXME in
hmp_change() resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-17 20:36:56 +02:00