diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 543384dc1c9b34596d0ae07b82bbce4bce60ded8..c9929c310779263fcd1920eea9b01b47dd59f91f 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -1776,6 +1776,23 @@ qemuMonitorGetAllBlockStatsInfo(qemuMonitorPtr mon,
     return qemuMonitorJSONGetAllBlockStatsInfo(mon, ret_stats);
 }
 
+
+/* Updates "stats" to fill virtual and physical size of the image */
+int qemuMonitorBlockStatsUpdateCapacity(qemuMonitorPtr mon,
+                                        virHashTablePtr stats)
+{
+    VIR_DEBUG("mon=%p, stats=%p", mon, stats);
+
+    if (!mon->json) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("block capacity/size info requires JSON monitor"));
+        return -1;
+    }
+
+    return qemuMonitorJSONBlockStatsUpdateCapacity(mon, stats);
+}
+
+
 /* Return 0 and update @nparams with the number of block stats
  * QEMU supports if success. Return -1 if failure.
  */
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index adf18ab5e0b44c462401981a3c4f96ca770ad912..616d960b8fa409e257a9af57da45a516e7d28de0 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -358,12 +358,18 @@ struct _qemuBlockStats {
     long long wr_total_times;
     long long flush_req;
     long long flush_total_times;
+    unsigned long long capacity;
+    unsigned long long physical;
 };
 
 int qemuMonitorGetAllBlockStatsInfo(qemuMonitorPtr mon,
                                     virHashTablePtr *ret_stats)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
+int qemuMonitorBlockStatsUpdateCapacity(qemuMonitorPtr mon,
+                                        virHashTablePtr stats)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
 int qemuMonitorGetBlockStatsParamsNumber(qemuMonitorPtr mon,
                                          int *nparams);
 
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index b3b64510124001aad5ecdefd0f5777928f8bac93..40446734d29fd4e9b909c96629cf03b493ab3c28 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -1925,6 +1925,84 @@ int qemuMonitorJSONGetAllBlockStatsInfo(qemuMonitorPtr mon,
 }
 
 
+int qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon,
+                                            virHashTablePtr stats)
+{
+    int ret = -1;
+    int rc;
+    size_t i;
+    virJSONValuePtr cmd;
+    virJSONValuePtr reply = NULL;
+    virJSONValuePtr devices;
+
+    if (!(cmd = qemuMonitorJSONMakeCommand("query-block", NULL)))
+        return -1;
+
+    if ((rc = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
+        goto cleanup;
+
+    if (qemuMonitorJSONCheckError(cmd, reply) < 0)
+        goto cleanup;
+
+    devices = virJSONValueObjectGet(reply, "return");
+    if (!devices || devices->type != VIR_JSON_TYPE_ARRAY) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-block reply was missing device list"));
+        goto cleanup;
+    }
+
+    for (i = 0; i < virJSONValueArraySize(devices); i++) {
+        virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
+        virJSONValuePtr inserted;
+        virJSONValuePtr image;
+        qemuBlockStatsPtr bstats;
+        const char *devname;
+
+        if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("query-block device entry was not "
+                             "in expected format"));
+            goto cleanup;
+        }
+
+        if (!(devname = virJSONValueObjectGetString(dev, "device"))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("query-block device entry was not "
+                             "in expected format"));
+            goto cleanup;
+        }
+
+        if (STRPREFIX(devname, QEMU_DRIVE_HOST_PREFIX))
+            devname += strlen(QEMU_DRIVE_HOST_PREFIX);
+
+        /* ignore missing info */
+        if (!(bstats = virHashLookup(stats, devname)))
+            continue;
+
+        /* drive may be empty */
+        if (!(inserted = virJSONValueObjectGet(dev, "inserted")) ||
+            !(image = virJSONValueObjectGet(inserted, "image")))
+            continue;
+
+        if (virJSONValueObjectGetNumberUlong(image, "virtual-size",
+                                             &bstats->capacity) < 0)
+            continue;
+
+        /* if actual-size is missing, image is not thin provisioned */
+        if (virJSONValueObjectGetNumberUlong(image, "actual-size",
+                                             &bstats->physical) < 0)
+            bstats->physical = bstats->capacity;
+    }
+
+    ret = 0;
+
+ cleanup:
+    virJSONValueFree(cmd);
+    virJSONValueFree(reply);
+    return ret;
+}
+
+
 int qemuMonitorJSONGetBlockStatsParamsNumber(qemuMonitorPtr mon,
                                              int *nparams)
 {
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index ef9b552565a5d0325d972c15a61e3fa4b683f2a1..c7dd4162d9ed6d7868bfb5f481c44c987d5f9654 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -81,6 +81,8 @@ int qemuMonitorJSONGetBlockStatsInfo(qemuMonitorPtr mon,
                                      long long *errs);
 int qemuMonitorJSONGetAllBlockStatsInfo(qemuMonitorPtr mon,
                                         virHashTablePtr *ret_stats);
+int qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon,
+                                            virHashTablePtr stats);
 int qemuMonitorJSONGetBlockStatsParamsNumber(qemuMonitorPtr mon,
                                              int *nparams);
 int qemuMonitorJSONGetBlockExtent(qemuMonitorPtr mon,