From ae461b84dc527df2571aba77483b7030aded3bb6 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Luiz Capitulino Date: Tue, 11 Dec 2012 15:26:26 +0100 Subject: [PATCH 4/5] Add event notification for guest balloon changes RH-Author: Luiz Capitulino Message-id: <1355239587-12473-4-git-send-email-lcapitulino@redhat.com> Patchwork-id: 44911 O-Subject: [RHEL6.4 qemu-kvm PATCH 3/4] Add event notification for guest balloon changes Bugzilla: 881732 RH-Acked-by: Paolo Bonzini RH-Acked-by: Kevin Wolf RH-Acked-by: Markus Armbruster From: "Daniel P. Berrange" 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 Acked-by: Amit Shah Signed-off-by: Luiz Capitulino (cherry picked from commit 973603a813c5d60534b4fa0313f83be40e2b9c47) Conflicts: balloon.c balloon.h hw/virtio-balloon.c monitor.c monitor.h Signed-off-by: Luiz Capitulino --- QMP/qmp-events.txt | 18 ++++++++++++++++++ balloon.c | 13 +++++++++++++ balloon.h | 2 ++ hw/virtio-balloon.c | 5 +++++ monitor.c | 1 + monitor.h | 1 + 6 files changed, 40 insertions(+) Signed-off-by: Michal Novotny --- QMP/qmp-events.txt | 18 ++++++++++++++++++ balloon.c | 13 +++++++++++++ balloon.h | 2 ++ hw/virtio-balloon.c | 5 +++++ monitor.c | 1 + monitor.h | 1 + 6 files changed, 40 insertions(+) diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt index 8e805a7..8eec12a 100644 --- a/QMP/qmp-events.txt +++ b/QMP/qmp-events.txt @@ -388,3 +388,21 @@ Example: "len": 10737418240, "offset": 134217728, "speed": 0 }, "timestamp": { "seconds": 1267061043, "microseconds": 959568 } } + + +BALLOON_CHANGE +---------- + +Emitted when the guest changes the actual BALLOON level. This +value is equivalent to the 'actual' field return by the +'query-balloon' command + +Data: + +- "actual": actual level of the guest memory balloon in bytes (json-number) + +Example: + +{ "event": "BALLOON_CHANGE", + "data": { "actual": 944766976 }, + "timestamp": { "seconds": 1267020223, "microseconds": 435656 } } diff --git a/balloon.c b/balloon.c index a06a00b..7f7f886 100644 --- a/balloon.c +++ b/balloon.c @@ -32,6 +32,7 @@ #include "kvm.h" #include "balloon.h" #include "trace.h" +#include "qjson.h" static QEMUBalloonEvent *balloon_event_fn; static QEMUBalloonStatus *balloon_stat_fn; @@ -82,6 +83,18 @@ static int qemu_balloon_status(MonitorCompletion cb, void *opaque) return 1; } +void qemu_balloon_changed(int64_t actual) +{ + QObject *data; + + data = qobject_from_jsonf("{ 'actual': %" PRId64 " }", + actual); + + monitor_protocol_event(QEVENT_BALLOON_CHANGE, data); + + qobject_decref(data); +} + static void print_balloon_stat(const char *key, QObject *obj, void *opaque) { Monitor *mon = opaque; diff --git a/balloon.h b/balloon.h index 7fc1dde..d0fe3b4 100644 --- a/balloon.h +++ b/balloon.h @@ -30,4 +30,6 @@ int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque); int do_balloon(Monitor *mon, const QDict *params, MonitorCompletion cb, void *opaque); +void qemu_balloon_changed(int64_t actual); + #endif diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c index 15b0611..695ade4 100644 --- a/hw/virtio-balloon.c +++ b/hw/virtio-balloon.c @@ -194,8 +194,13 @@ static void virtio_balloon_set_config(VirtIODevice *vdev, { VirtIOBalloon *dev = to_virtio_balloon(vdev); struct virtio_balloon_config config; + uint32_t oldactual = dev->actual; memcpy(&config, config_data, 8); dev->actual = config.actual; + if (dev->actual != oldactual) { + qemu_balloon_changed(ram_size - + (dev->actual << VIRTIO_BALLOON_PFN_SHIFT)); + } } static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f) diff --git a/monitor.c b/monitor.c index 1c903b8..6e3c8d8 100644 --- a/monitor.c +++ b/monitor.c @@ -452,6 +452,7 @@ static const char *monitor_event_names[] = { [QEVENT_SUSPEND] = "SUSPEND", [QEVENT_SUSPEND_DISK] = "SUSPEND_DISK", [QEVENT_WAKEUP] = "WAKEUP", + [QEVENT_BALLOON_CHANGE] = "BALLOON_CHANGE", [QEVENT_SPICE_MIGRATE_COMPLETED] = "SPICE_MIGRATE_COMPLETED", }; QEMU_BUILD_BUG_ON(ARRAY_SIZE(monitor_event_names) != QEVENT_MAX) diff --git a/monitor.h b/monitor.h index ff3ff3e..f538274 100644 --- a/monitor.h +++ b/monitor.h @@ -47,6 +47,7 @@ typedef enum MonitorEvent { QEVENT_SUSPEND, QEVENT_SUSPEND_DISK, QEVENT_WAKEUP, + QEVENT_BALLOON_CHANGE, QEVENT_SPICE_MIGRATE_COMPLETED, /* Add to 'monitor_event_names' array in monitor.c when -- 1.7.11.7