Commit Graph

9 Commits

Author SHA1 Message Date
Kevin Wolf f27a9bb3e9 qmp: Fail gracefully if chardev is already in use
Trying to attach a QMP monitor to a chardev that is already in use
results in a crash because monitor_init_qmp() passes &error_abort to
qemu_chr_fe_init():

$ ./x86_64-softmmu/qemu-system-x86_64 --chardev stdio,id=foo --mon foo,mode=control --mon foo,mode=control
Unexpected error in qemu_chr_fe_init() at chardev/char-fe.c:220:
qemu-system-x86_64: --mon foo,mode=control: Device 'foo' is in use
Abgebrochen (Speicherabzug geschrieben)

Fix this by allowing monitor_init_qmp() to return an error and passing
any error in qemu_chr_fe_init() to its caller instead of aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-18-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-06 17:21:28 +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
Philippe Mathieu-Daudé 083b266f69 chardev: Use QEMUChrEvent enum in IOEventHandler typedef
The Chardev events are listed in the QEMUChrEvent enum.

By using the enum in the IOEventHandler typedef we:

- make the IOEventHandler type more explicit (this handler
  process out-of-band information, while the IOReadHandler
  is in-band),
- help static code analyzers.

This patch was produced with the following spatch script:

  @match@
  expression backend, opaque, context, set_open;
  identifier fd_can_read, fd_read, fd_event, be_change;
  @@
  qemu_chr_fe_set_handlers(backend, fd_can_read, fd_read, fd_event,
                           be_change, opaque, context, set_open);

  @depends on match@
  identifier opaque, event;
  identifier match.fd_event;
  @@
   static
  -void fd_event(void *opaque, int event)
  +void fd_event(void *opaque, QEMUChrEvent event)
   {
   ...
   }

Then the typedef was modified manually in
include/chardev/char-fe.h.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20191218172009.8868-15-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08 11:15:35 +01:00
Philippe Mathieu-Daudé ed7c5bb7ad monitor/qmp: Explicit we ignore few QEMUChrEvent in IOEventHandler
The Chardev events are listed in the QEMUChrEvent enum. To be
able to use this enum in the IOEventHandler typedef, we need to
explicit all the events ignored by this frontend, to silent the
following GCC warning:

    CC      monitor/qmp.o
  monitor/qmp.c: In function ‘monitor_qmp_event’:
  monitor/qmp.c:345:5: error: enumeration value ‘CHR_EVENT_BREAK’ not handled in switch [-Werror=switch]
    345 |     switch (event) {
        |     ^~~~~~
  monitor/qmp.c:345:5: error: enumeration value ‘CHR_EVENT_MUX_IN’ not handled in switch [-Werror=switch]
  monitor/qmp.c:345:5: error: enumeration value ‘CHR_EVENT_MUX_OUT’ not handled in switch [-Werror=switch]
  cc1: all warnings being treated as errors

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191218172009.8868-12-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-07 16:22:56 +01:00
Wolfgang Bumiller 2895aaa139 monitor/qmp: resume monitor when clearing its queue
When a monitor's queue is filled up in handle_qmp_command()
it gets suspended. It's the dispatcher bh's job currently to
resume the monitor, which it does after processing an event
from the queue. However, it is possible for a
CHR_EVENT_CLOSED event to be processed before before the bh
is scheduled, which will clear the queue without resuming
the monitor, thereby preventing the dispatcher from reaching
the resume() call.
Any new connections to the qmp socket will be accept()ed and
show the greeting, but will not respond to any messages sent
afterwards (as they will not be read from the
still-suspended socket).
Fix this by resuming the monitor when clearing a queue which
was filled up.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Message-Id: <20191115085914.21287-1-w.bumiller@proxmox.com>
2019-11-19 08:21:47 +01:00
Markus Armbruster eb707eac58 monitor/qmp: Update comment for commit 4eaca8de26
Commit 4eaca8de26 dropped monitor_qmp_respond()'s parameter @id
without updating its function comment.  Fix that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190816193305.12090-1-armbru@redhat.com>
2019-08-21 17:33:38 +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 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