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2012-06-15Add event notification for guest balloon changesDaniel P. Berrange1-0/+14
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: Daniel P. Berrange <berrange@redhat.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27qapi: fix qmp_balloon() conversionLuiz Capitulino1-1/+1
Commit d72f326431 forgot to convert a call from qerror_report() to error_set(). Fix it. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2011-12-06qapi: Convert balloonLuiz Capitulino1-20/+8
Note that the command being dropped uses the deprecated MONITOR_CMD_ASYNC API, but the new command is a regular synchronous command. There shouldn't be visible differences though, as MONITOR_CMD_ASYNC is internal only. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27qapi: Convert query-balloonLuiz Capitulino1-58/+14
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>
2011-09-09balloon: Disassociate handlers from balloon device on unplugAmit Shah1-0/+10
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>
2011-08-04balloon: Reject negative balloon valuesAmit Shah1-1/+7
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>
2011-08-04balloon: Don't allow multiple balloon handler registrationsAmit Shah1-2/+10
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>
2011-08-04balloon: Fix header comment; add CopyrightAmit Shah1-2/+3
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2011-08-04balloon: Separate out stat and balloon handlingAmit Shah1-7/+10
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>
2011-08-04balloon: Simplify code flowAmit Shah1-9/+7
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>
2011-08-04balloon: Add braces around if statementsAmit Shah1-3/+4
Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-08-04balloon: Make functions, local vars staticAmit Shah1-11/+11
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>
2011-04-15Remove unused sysemu.h include directivesBlue Swirl1-1/+0
Remove unused sysemu.h include directives to speed up build with the following patches. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-09-09trace: Trace entry point of balloon request handlerPrerna Saxena1-0/+2
Signed-off-by: Prerna Saxena <prerna@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-04-09move balloon handling to balloon.cPaolo Bonzini1-0/+146
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>