[libvirt] [PATCHv4 3/8] qemu: bulk stats: implement balloon group

[Francesco Romani]

This patch implements the VIR_DOMAIN_STATS_BALLOON
group of statistics.

Signed-off-by: Francesco Romani <fromani at redhat.com>
---
 include/libvirt/libvirt.h.in |  1 +
 src/libvirt.c                |  6 ++++
 src/qemu/qemu_driver.c       | 73 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 8665c6c..c005442 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -2512,6 +2512,7 @@ struct _virDomainStatsRecord {
 typedef enum {
     VIR_DOMAIN_STATS_STATE = (1 << 0), /* return domain state */
     VIR_DOMAIN_STATS_CPU_TOTAL = (1 << 1), /* return domain CPU info */
+    VIR_DOMAIN_STATS_BALLOON = (1 << 2), /* return domain balloon info */
 } virDomainStatsTypes;
 
 typedef enum {
diff --git a/src/libvirt.c b/src/libvirt.c
index b22f9aa..3fa86ab 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -21569,6 +21569,12 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
  * "cpu.user" - user cpu time spent as unsigned long long.
  * "cpu.system" - system cpu time spent as unsigned long long.
  *
+ * VIR_DOMAIN_STATS_BALLOON: Return memory balloon device information.
+ * The typed parameter keys are in this format:
+ * "balloon.current" - the memory in kiB currently used
+ *                     as unsigned long long.
+ * "balloon.maximum" - the maximum memory in kiB allowed
+ *                     as unsigned long long.
  *
  * Using 0 for @stats returns all stats groups supported by the given
  * hypervisor.
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 9014976..f677884 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2525,6 +2525,48 @@ static int qemuDomainSendKey(virDomainPtr domain,
     return ret;
 }
 
+
+/*
+ * FIXME: this code is a stripped down version of what is done into
+ * qemuDomainGetInfo. Due to the different handling of jobs, it is not
+ * trivial to extract a common helper function.
+ */
+static int
+qemuDomainGetBalloonMemory(virQEMUDriverPtr driver, virDomainObjPtr vm,
+                           unsigned long long *memory)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+
+    if (vm->def->memballoon &&
+        vm->def->memballoon->model == VIR_DOMAIN_MEMBALLOON_MODEL_NONE) {
+        *memory = vm->def->mem.max_balloon;
+    } else if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BALLOON_EVENT)) {
+        *memory = vm->def->mem.cur_balloon;
+    } else {
+        int rv;
+        unsigned long long balloon;
+
+        qemuDomainObjEnterMonitor(driver, vm);
+        rv = qemuMonitorGetBalloonInfo(priv->mon, &balloon);
+        qemuDomainObjExitMonitor(driver, vm);
+
+        if (rv < 0) {
+            /* We couldn't get current memory allocation but that's not
+             * a show stopper; we wouldn't get it if there was a job
+             * active either
+             */
+            *memory = vm->def->mem.cur_balloon;
+        } else if (rv > 0) {
+            *memory = balloon;
+        } else {
+            /* Balloon not supported, so maxmem is always the allocation */
+            return -1;
+        }
+    }
+    return 0;
+}
+
+
 static int qemuDomainGetInfo(virDomainPtr dom,
                              virDomainInfoPtr info)
 {
@@ -17315,6 +17357,36 @@ qemuDomainGetStatsCpu(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
     return 0;
 }
 
+static int
+qemuDomainGetStatsBalloon(virQEMUDriverPtr driver,
+                          virDomainObjPtr dom,
+                          virDomainStatsRecordPtr record,
+                          int *maxparams,
+                          unsigned int privflags)
+{
+    if (HAVE_MONITOR(privflags) && virDomainObjIsActive(dom)) {
+        unsigned long long cur_balloon = 0;
+        int err = 0;
+
+        err = qemuDomainGetBalloonMemory(driver, dom, &cur_balloon);
+
+        if (!err && virTypedParamsAddULLong(&record->params,
+                                            &record->nparams,
+                                            maxparams,
+                                            "balloon.current",
+                                            cur_balloon) < 0)
+            return -1;
+    }
+
+    if (virTypedParamsAddULLong(&record->params,
+                                &record->nparams,
+                                maxparams,
+                                "balloon.maximum",
+                                dom->def->mem.max_balloon) < 0)
+        return -1;
+
+    return 0;
+}
 
 typedef int
 (*qemuDomainGetStatsFunc)(virQEMUDriverPtr driver,
@@ -17332,6 +17404,7 @@ struct qemuDomainGetStatsWorker {
 static struct qemuDomainGetStatsWorker qemuDomainGetStatsWorkers[] = {
     { qemuDomainGetStatsState, VIR_DOMAIN_STATS_STATE, false },
     { qemuDomainGetStatsCpu, VIR_DOMAIN_STATS_CPU_TOTAL, false },
+    { qemuDomainGetStatsBalloon, VIR_DOMAIN_STATS_BALLOON, true },
     { NULL, 0, false }
 };
 
-- 
1.9.3