Commit Graph

12 Commits

Author SHA1 Message Date
Luiz Capitulino 96637bcdf9 qapi: Convert query-balloon
Please, note that some of the code supporting memory statistics is
still around (eg. virtio_balloon_receive_stats() and reset_stats()).

Also, the qmp_query_balloon() function is synchronous and thus doesn't
make any use of the (not fully working) monitor's asynchronous command
support (the old non-qapi implementation did).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Amit Shah 8a7d552cb3 balloon: Disassociate handlers from balloon device on unplug
When a balloon device gets unplugged, allow the balloon handlers to be
freed.

Reported-by: Shaolong Hu <shu@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-09-09 12:58:16 -05:00
Amit Shah 514e73eceb balloon: Reject negative balloon values
Negative balloon values don't make sense, reject them and throw a qerror
with QERR_INVALID_PARAMETER_VALUE.

Reported-by: Mike Cao <bcao@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2011-08-04 16:43:09 -05:00
Amit Shah 6c6ec1821a balloon: Don't allow multiple balloon handler registrations
Multiple balloon devices don't make sense; disallow more than one
registration attempt to register handlers.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2011-08-04 16:43:09 -05:00
Amit Shah 73428a8ed5 balloon: Fix header comment; add Copyright
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2011-08-04 16:43:09 -05:00
Amit Shah 30fb2ca603 balloon: Separate out stat and balloon handling
Passing on '0' as ballooning target to indicate retrieval of stats is
bad API.  It also makes 'balloon 0' in the monitor cause a segfault.
Have two different functions handle the different functionality instead.

Detailed explanation from Markus's review:

1. do_info_balloon() is an info_async() method.  It receives a callback
   with argument, to be called exactly once (callback frees the
   argument).  It passes the callback via qemu_balloon_status() and
   indirectly through qemu_balloon_event to virtio_balloon_to_target().

   virtio_balloon_to_target() executes its balloon stats half.  It
   stores the callback in the device state.

   If it can't send a stats request, it resets stats and calls the
   callback right away.

   Else, it sends a stats request.  The device model runs the callback
   when it receives the answer.

   Works.

2. do_balloon() is a cmd_async() method.  It receives a callback with
   argument, to be called when the command completes.  do_balloon()
   calls it right before it succeeds.  Odd, but should work.

   Nevertheless, it passes the callback on via qemu_ballon() and
   indirectly through qemu_balloon_event to virtio_balloon_to_target().

   a. If the argument is non-zero, virtio_balloon_to_target() executes
      its balloon half, which doesn't use the callback in any way.

      Odd, but works.

   b. If the argument is zero, virtio_balloon_to_target() executes its
      balloon stats half, just like in 1.  It either calls the callback
      right away, or arranges for it to be called later.

      Thus, the callback runs twice: use after free and double free.

Test case: start with -S -device virtio-balloon, execute "balloon 0" in
human monitor.  Runs the callback first from virtio_balloon_to_target(),
then again from do_balloon().

Reported-by: Mike Cao <bcao@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-08-04 16:43:09 -05:00
Amit Shah 182b9203f8 balloon: Simplify code flow
Replace:
  if (foo) {
    ...
  } else {
    return 0;
  }

by

  if (!foo) {
    return 0;
  }
  ...

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-08-04 16:43:09 -05:00
Amit Shah b80bc1ddb2 balloon: Add braces around if statements
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-08-04 16:43:08 -05:00
Amit Shah 0a2a30d5ad balloon: Make functions, local vars static
balloon.h had function declarations for a couple of functions that are
local to balloon.c.  Make them static.

Drop the 'qemu_' prefix for balloon.c-local variables, and make them
static.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-08-04 16:43:08 -05:00
Blue Swirl a08784dd11 Remove unused sysemu.h include directives
Remove unused sysemu.h include directives to speed up build
with the following patches.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-04-15 18:25:41 +00:00
Prerna Saxena 62dd89dea2 trace: Trace entry point of balloon request handler
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-09-09 16:22:45 -05:00
Paolo Bonzini 28c2897373 move balloon handling to balloon.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-04-09 18:55:56 +02:00