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  1. 23 6月, 2014 1 次提交
  3. 19 12月, 2012 2 次提交
  5. 16 6月, 2012 1 次提交
    • D
      Add event notification for guest balloon changes · 973603a8
      由 Daniel P. Berrange 提交于 
      After setting a balloon target value, applications have to
continually poll 'query-balloon' to determine whether the
guest has reacted to this request. The virtio-balloon backend
knows exactly when the guest has reacted though, and thus it
is possible to emit a JSON event to tell the mgmt application
whenever the guest balloon changes.

This introduces a new 'qemu_balloon_changed()' API which is
to be called by balloon driver backends, whenever they have
a change in balloon value. This takes the 'actual' balloon
value, as would be found in the BalloonInfo struct.

The qemu_balloon_change API emits a JSON monitor event which
looks like:

  {"timestamp": {"seconds": 1337162462, "microseconds": 814521},
   "event": "BALLOON_CHANGE", "data": {"actual": 944766976}}

* balloon.c, balloon.h: Introduce qemu_balloon_changed() for
  emitting balloon change events on the monitor
* hw/virtio-balloon.c: Invoke qemu_balloon_changed() whenever
  the guest changes the balloon actual value
* monitor.c, monitor.h: Define QEVENT_BALLOON_CHANGE
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Acked-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
      973603a8
  7. 06 12月, 2011 1 次提交
  9. 27 10月, 2011 1 次提交
  11. 10 9月, 2011 1 次提交
  13. 05 8月, 2011 3 次提交
    • A
      balloon: Don't allow multiple balloon handler registrations · 6c6ec182
      由 Amit Shah 提交于 
      Multiple balloon devices don't make sense; disallow more than one
registration attempt to register handlers.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
      6c6ec182
    • A
      balloon: Separate out stat and balloon handling · 30fb2ca6
      由 Amit Shah 提交于 
      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: NMike Cao <bcao@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
      30fb2ca6
    • A
      balloon: Make functions, local vars static · 0a2a30d5
      由 Amit Shah 提交于 
      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: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
      0a2a30d5
  15. 10 4月, 2010 1 次提交
  17. 30 3月, 2010 1 次提交
  19. 27 1月, 2010 1 次提交
    • A
      virtio: Add memory statistics reporting to the balloon driver · 625a5bef
      由 Adam Litke 提交于 
      When using ballooning to manage overcommitted memory on a host, a system for
guests to communicate their memory usage to the host can provide information
that will minimize the impact of ballooning on the guests.  The current method
employs a daemon running in each guest that communicates memory statistics to a
host daemon at a specified time interval.  The host daemon aggregates this
information and inflates and/or deflates balloons according to the level of
host memory pressure.  This approach is effective but overly complex since a
daemon must be installed inside each guest and coordinated to communicate with
the host.  A simpler approach is to collect memory statistics in the virtio
balloon driver and communicate them directly to the hypervisor.
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
      625a5bef
  21. 02 10月, 2009 2 次提交
  23. 05 12月, 2008 1 次提交