From 91c3d430c96ca365ae40bf922df3e4f83295e331 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Thu, 16 Mar 2017 14:37:56 +0100
Subject: [PATCH] qemu: stats: Display the block threshold size in bulk stats

Management tools may want to check whether the threshold is still set if
they missed an event. Add the data to the bulk stats API where they can
also query the current backing size at the same time.
---
 src/libvirt-domain.c   |  3 +++
 src/qemu/qemu_driver.c | 51 +++++++++++++++++++++++++++++++++++++++---
 tools/virsh.pod        |  3 +++
 3 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 0cd80a6095..26da0e7f32 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -11206,6 +11206,9 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
  *                              backing image as unsigned long long.
  *     "block.<num>.physical" - physical size in bytes of the container of the
  *                              backing image as unsigned long long.
+ *     "block.<num>.threshold" - current threshold for delivering the
+ *                               VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD
+ *                               event in bytes. See virDomainSetBlockThreshold.
  *
  * VIR_DOMAIN_STATS_PERF:
  *     Return perf event statistics.
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2c20419124..53c9090726 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -19206,6 +19206,32 @@ qemuDomainGetStatsOneBlockFallback(virQEMUDriverPtr driver,
 }
 
 
+static int
+qemuDomainGetStatsOneBlockNode(virDomainStatsRecordPtr record,
+                               int *maxparams,
+                               virStorageSourcePtr src,
+                               size_t block_idx,
+                               virHashTablePtr nodedata)
+{
+    virJSONValuePtr data;
+    unsigned long long tmp;
+    int ret = -1;
+
+    if (src->nodebacking &&
+        (data = virHashLookup(nodedata, src->nodebacking))) {
+        if (virJSONValueObjectGetNumberUlong(data, "write_threshold", &tmp) == 0 &&
+            tmp > 0)
+            QEMU_ADD_BLOCK_PARAM_ULL(record, maxparams, block_idx,
+                                     "threshold", tmp);
+    }
+
+    ret = 0;
+
+ cleanup:
+    return ret;
+}
+
+
 static int
 qemuDomainGetStatsOneBlock(virQEMUDriverPtr driver,
                            virQEMUDriverConfigPtr cfg,
@@ -19216,7 +19242,8 @@ qemuDomainGetStatsOneBlock(virQEMUDriverPtr driver,
                            virStorageSourcePtr src,
                            size_t block_idx,
                            unsigned int backing_idx,
-                           virHashTablePtr stats)
+                           virHashTablePtr stats,
+                           virHashTablePtr nodedata)
 {
     qemuBlockStats *entry;
     int ret = -1;
@@ -19285,6 +19312,10 @@ qemuDomainGetStatsOneBlock(virQEMUDriverPtr driver,
         }
     }
 
+    if (qemuDomainGetStatsOneBlockNode(record, maxparams, src, block_idx,
+                                       nodedata) < 0)
+        goto cleanup;
+
     ret = 0;
  cleanup:
     VIR_FREE(alias);
@@ -19303,8 +19334,12 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver,
     int ret = -1;
     int rc;
     virHashTablePtr stats = NULL;
+    virHashTablePtr nodestats = NULL;
+    virJSONValuePtr nodedata = NULL;
     qemuDomainObjPrivatePtr priv = dom->privateData;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+    bool fetchnodedata = virQEMUCapsGet(priv->qemuCaps,
+                                        QEMU_CAPS_QUERY_NAMED_BLOCK_NODES);
     int count_index = -1;
     size_t visited = 0;
     bool visitBacking = !!(privflags & QEMU_DOMAIN_STATS_BACKING);
@@ -19316,14 +19351,22 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver,
         if (rc >= 0)
             ignore_value(qemuMonitorBlockStatsUpdateCapacity(priv->mon, stats,
                                                              visitBacking));
+
+        if (fetchnodedata)
+            nodedata = qemuMonitorQueryNamedBlockNodes(priv->mon);
+
         if (qemuDomainObjExitMonitor(driver, dom) < 0)
             goto cleanup;
 
         /* failure to retrieve stats is fine at this point */
-        if (rc < 0)
+        if (rc < 0 || (fetchnodedata && !nodedata))
             virResetLastError();
     }
 
+    if (nodedata &&
+        !(nodestats = qemuBlockGetNodeData(nodedata)))
+        goto cleanup;
+
     /* When listing backing chains, it's easier to fix up the count
      * after the iteration than it is to iterate twice; but we still
      * want count listed first.  */
@@ -19338,7 +19381,7 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver,
         while (src && (backing_idx == 0 || visitBacking)) {
             if (qemuDomainGetStatsOneBlock(driver, cfg, dom, record, maxparams,
                                            disk, src, visited, backing_idx,
-                                           stats) < 0)
+                                           stats, nodestats) < 0)
                 goto cleanup;
             visited++;
             backing_idx++;
@@ -19351,6 +19394,8 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver,
 
  cleanup:
     virHashFree(stats);
+    virHashFree(nodestats);
+    virJSONValueFree(nodedata);
     virObjectUnref(cfg);
     return ret;
 }
diff --git a/tools/virsh.pod b/tools/virsh.pod
index 48be192346..7fa7985b83 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -1005,6 +1005,9 @@ Information listed includes:
  "block.<num>.allocation" - offset of highest written sector in bytes
  "block.<num>.capacity" - logical size of source file in bytes
  "block.<num>.physical" - physical size of source file in bytes
+ "block.<num>.threshold" - threshold (in bytes) for delivering the
+                           VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD event
+                           See domblkthreshold.
 
 Selecting a specific statistics groups doesn't guarantee that the
 daemon supports the selected group of stats. Flag I<--enforce>