[Qemu-devel] [PATCH v4] hmp, qmp: introduce memory-size-summary commands

[Vadim Galitsyn <vadim.galitsyn@profitbricks.com>]

Commands above provide the following memory information in bytes:

  * base-memory - amount of unremovable memory specified
    with '-m' option at the start of the QEMU process.

  * hotpluggable-memory - amount of memory that was hot-plugged.
    If target does not have CONFIG_MEM_HOTPLUG enabled, no
    value is reported.

  * balloon-actual-memory - size of the memory that remains
    available to the guest after ballooning, as reported by the
    guest. If the guest has not reported its memory, this value
    equals to @base-memory + @hot-plug-memory. If ballooning
    is not enabled, no value is reported.

NOTE:

    Parameter @balloon-actual-memory reports the same as
    "info balloon" command when ballooning is enabled. The idea
    to have it in scope of this command(s) comes from
    https://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01472.html.

Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Signed-off-by: Mohammed Gamal <mohammed.gamal@profitbricks.com>
Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com>
Signed-off-by: Vadim Galitsyn <vadim.galitsyn@profitbricks.com>
Reviewed-by: Eugene Crosser <evgenii.cherkashin@profitbricks.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: qemu-devel@nongnu.org
---

v4:
 * Commands "info memory" and "query-memory" were renamed
   to "info memory-size-summary" and "query-memory-size-summary"
   correspondingly.
 * Descriptions for both commands as well as MemoryInfo structure
   fields were updated/renamed according to
   http://lists.nongnu.org/archive/html/qemu-devel/2017-06/msg05972.html.
 * In MemoryInfo structure following fields are now optional:
   hotpluggable-memory and balloon-actual-memory.
 * Field "hotpluggable-memory" now not displayed in HMP if target
   has no CONFIG_MEM_HOTPLUG enabled.
 * Field "balloon-actual-memory" now not displayed in HMP if
   ballooning not enabled.
 * qapi_free_MemoryInfo() used in order to free corresponding memory
   instead of g_free().
 * #ifdef CONFIG_MEM_HOTPLUG was removed and replaced with stubs/ approach.
   get_exiting_hotpluggable_memory_size() function was introduced in
   hw/mem/pc-dimm.c (available for all targets which have CONFIG_MEM_HOTPLUG
   enabled). For other targets, there is a stub in stubs/qmp_pc_dimm.c.
   In addition, stubs/qmp_pc_dimm_device_list.c was renamed to
   stubs/qmp_pc_dimm.c in order to reflect actual source file content.
 * Commit message was updated in order to reflect what was changed.

v3:
 * Use PRIu64 instead of 'lu' when printing results via HMP.
 * Report zero hot-plugged memory instead of reporting error
   when target architecture has no CONFIG_MEM_HOTPLUG enabled.

v2:
 * Fixed build for targets which do not have CONFIG_MEM_HOTPLUG
   enabled.

 hmp-commands-info.hx                               | 17 ++++++++++++
 hmp.c                                              | 23 ++++++++++++++++
 hmp.h                                              |  1 +
 hw/mem/pc-dimm.c                                   |  6 +++++
 include/hw/mem/pc-dimm.h                           |  1 +
 qapi-schema.json                                   | 28 +++++++++++++++++++
 qmp.c                                              | 31 ++++++++++++++++++++++
 stubs/Makefile.objs                                |  2 +-
 stubs/{qmp_pc_dimm_device_list.c => qmp_pc_dimm.c} |  5 ++++
 9 files changed, 113 insertions(+), 1 deletion(-)
 rename stubs/{qmp_pc_dimm_device_list.c => qmp_pc_dimm.c} (60%)

diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index ba98e581ab..a535960157 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -829,6 +829,23 @@ ETEXI
         .cmd = hmp_info_vm_generation_id,
     },
 
+STEXI
+@item info memory-size-summary
+@findex memory-size-summary
+Display the amount of initially allocated, hot-plugged (if enabled)
+and ballooned (if enabled) memory in bytes.
+ETEXI
+
+    {
+        .name       = "memory-size-summary",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show the amount of initially allocated, "
+                      "hot-plugged (if enabled) and ballooned (if enabled) "
+                      "memory in bytes.",
+        .cmd        = hmp_info_memory_size_summary,
+    },
+
 STEXI
 @end table
 ETEXI
diff --git a/hmp.c b/hmp.c
index dee40284c1..15f632481c 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2828,3 +2828,26 @@ void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict)
     hmp_handle_error(mon, &err);
     qapi_free_GuidInfo(info);
 }
+
+void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+    MemoryInfo *info = qmp_query_memory_size_summary(&err);
+    if (info) {
+        monitor_printf(mon, "base-memory: %" PRIu64 "\n",
+                       info->base_memory);
+
+        if (info->has_hotpluggable_memory) {
+            monitor_printf(mon, "hotpluggable-memory: %" PRIu64 "\n",
+                           info->hotpluggable_memory);
+        }
+
+        if (info->has_balloon_actual_memory) {
+            monitor_printf(mon, "balloon-actual-memory: %" PRIu64 "\n",
+                           info->balloon_actual_memory);
+        }
+
+        qapi_free_MemoryInfo(info);
+    }
+    hmp_handle_error(mon, &err);
+}
diff --git a/hmp.h b/hmp.h
index 214b2617e7..8c5398ea7a 100644
--- a/hmp.h
+++ b/hmp.h
@@ -144,5 +144,6 @@ void hmp_info_dump(Monitor *mon, const QDict *qdict);
 void hmp_info_ramblock(Monitor *mon, const QDict *qdict);
 void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict);
 void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
+void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index b72258e28f..ea81b1384a 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -159,6 +159,12 @@ uint64_t pc_existing_dimms_capacity(Error **errp)
     return cap.size;
 }
 
+bool get_exiting_hotpluggable_memory_size(uint64_t *mem_size, Error **errp)
+{
+    *mem_size = pc_existing_dimms_capacity(errp);
+    return true;
+}
+
 int qmp_pc_dimm_device_list(Object *obj, void *opaque)
 {
     MemoryDeviceInfoList ***prev = opaque;
diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
index 1e483f2670..738343df32 100644
--- a/include/hw/mem/pc-dimm.h
+++ b/include/hw/mem/pc-dimm.h
@@ -95,6 +95,7 @@ int pc_dimm_get_free_slot(const int *hint, int max_slots, Error **errp);
 
 int qmp_pc_dimm_device_list(Object *obj, void *opaque);
 uint64_t pc_existing_dimms_capacity(Error **errp);
+bool get_exiting_hotpluggable_memory_size(uint64_t *mem_size, Error **errp);
 void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
                          MemoryRegion *mr, uint64_t align, Error **errp);
 void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
diff --git a/qapi-schema.json b/qapi-schema.json
index 37c4b95aad..683da8a711 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4327,6 +4327,34 @@
   'data': { 'name': 'str', '*migration-safe': 'bool', 'static': 'bool',
             '*unavailable-features': [ 'str' ], 'typename': 'str' } }
 
+##
+# @MemoryInfo:
+#
+# Actual memory information in bytes.
+#
+# @base-memory: size of unremovable memory which is specified
+#               with '-m size' CLI option.
+#
+# @hotpluggable-memory: size of hot-plugged memory.
+#
+# @balloon-actual-memory: amount of guest memory available after ballooning.
+#
+# Since: 2.10.0
+##
+{ 'struct': 'MemoryInfo',
+  'data'  : { 'base-memory': 'int', '*hotpluggable-memory': 'int',
+              '*balloon-actual-memory': 'int' } }
+
+##
+# @query-memory-size-summary:
+#
+# Return the amount of initially allocated, hot-plugged (if enabled)
+# and ballooned (if enabled) memory in bytes.
+#
+# Since: 2.10.0
+##
+{ 'command': 'query-memory-size-summary', 'returns': 'MemoryInfo' }
+
 ##
 # @query-cpu-definitions:
 #
diff --git a/qmp.c b/qmp.c
index 7ee9bcfdcf..a863726ad6 100644
--- a/qmp.c
+++ b/qmp.c
@@ -712,3 +712,34 @@ ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error **errp)
 
     return head;
 }
+
+MemoryInfo *qmp_query_memory_size_summary(Error **errp)
+{
+    MemoryInfo *mem_info = g_malloc0(sizeof(MemoryInfo));
+    BalloonInfo *balloon_info;
+    uint64_t hotpluggable_memory = 0;
+    Error *local_err = NULL;
+
+    mem_info->base_memory = ram_size;
+
+    mem_info->has_hotpluggable_memory =
+        get_exiting_hotpluggable_memory_size(&hotpluggable_memory,
+                                             &error_abort);
+    if (mem_info->has_hotpluggable_memory) {
+        mem_info->hotpluggable_memory = hotpluggable_memory;
+    }
+
+    /* In case if it is not possible to get balloon info, just ignore it. */
+    balloon_info = qmp_query_balloon(&local_err);
+    if (local_err) {
+        mem_info->has_balloon_actual_memory = false;
+        error_free(local_err);
+    } else {
+        mem_info->has_balloon_actual_memory = true;
+        mem_info->balloon_actual_memory = balloon_info->actual;
+    }
+
+    qapi_free_BalloonInfo(balloon_info);
+
+    return mem_info;
+}
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index f5b47bfd74..f7cab5b11c 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -32,7 +32,7 @@ stub-obj-y += uuid.o
 stub-obj-y += vm-stop.o
 stub-obj-y += vmstate.o
 stub-obj-$(CONFIG_WIN32) += fd-register.o
-stub-obj-y += qmp_pc_dimm_device_list.o
+stub-obj-y += qmp_pc_dimm.o
 stub-obj-y += target-monitor-defs.o
 stub-obj-y += target-get-monitor-def.o
 stub-obj-y += pc_madt_cpu_entry.o
diff --git a/stubs/qmp_pc_dimm_device_list.c b/stubs/qmp_pc_dimm.c
similarity index 60%
rename from stubs/qmp_pc_dimm_device_list.c
rename to stubs/qmp_pc_dimm.c
index def211564d..f50029326e 100644
--- a/stubs/qmp_pc_dimm_device_list.c
+++ b/stubs/qmp_pc_dimm.c
@@ -6,3 +6,8 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
 {
    return 0;
 }
+
+bool get_exiting_hotpluggable_memory_size(uint64_t *mem_size, Error **errp)
+{
+    return false;
+}
-- 
2.13.1.394.g41dd433