[Qemu-devel] [RFC PATCH v1: 11/12] mc: register MC qemu-file functions and expose MC tunable capability

[mrhines]

From: "Michael R. Hines" <address@hidden>

The capability allows management software to throttle the MC frequency
during VM application transience.

The qemu-file savevm() functions inform the destination that the incoming
traffic is MC-specific traffic and not vanilla live-migration traffic.

Signed-off-by: Michael R. Hines <address@hidden>
---
 hmp-commands.hx  | 14 ++++++++++++++
 hmp.c            |  6 ++++++
 hmp.h            |  1 +
 qapi-schema.json | 13 +++++++++++++
 qmp-commands.hx  | 23 +++++++++++++++++++++++
 vl.c             |  3 +++
 6 files changed, 60 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index caae5ad..7db0597 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -960,6 +960,20 @@ Set maximum tolerated downtime (in seconds) for migration.
 ETEXI
 
     {
+        .name       = "migrate-set-mc-delay",
+        .args_type  = "value:i",
+        .params     = "value",
+        .help       = "set maximum delay (in milliseconds) between 
micro-checkpoints",
+        .mhandler.cmd = hmp_migrate_set_mc_delay,
+    },
+
+STEXI
address@hidden migrate_set_downtime @var{second}
address@hidden migrate_set_downtime
+Set maximum tolerated downtime (in seconds) for migration.
+ETEXI
+
+    {
         .name       = "migrate_set_capability",
         .args_type  = "capability:s,state:b",
         .params     = "capability state",
diff --git a/hmp.c b/hmp.c
index 43896e9..8e89ac7 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1026,6 +1026,12 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict 
*qdict)
     qmp_migrate_set_downtime(value, NULL);
 }
 
+void hmp_migrate_set_mc_delay(Monitor *mon, const QDict *qdict)
+{
+    int64_t value = qdict_get_int(qdict, "value");
+    qmp_migrate_set_mc_delay(value, NULL);
+}
+
 void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict)
 {
     int64_t value = qdict_get_int(qdict, "value");
diff --git a/hmp.h b/hmp.h
index 54cf71f..b6548a3 100644
--- a/hmp.h
+++ b/hmp.h
@@ -60,6 +60,7 @@ void hmp_drive_mirror(Monitor *mon, const QDict *qdict);
 void hmp_drive_backup(Monitor *mon, const QDict *qdict);
 void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_mc_delay(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
diff --git a/qapi-schema.json b/qapi-schema.json
index e0a430c..2ed8098 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2135,6 +2135,19 @@
 { 'command': 'migrate_set_downtime', 'data': {'value': 'number'} }
 
 ##
+# @migrate-set-mc-delay
+#
+# Set delay (in milliseconds) between micro checkpoints.
+#
+# @value: maximum delay in milliseconds 
+#
+# Returns: nothing on success
+#
+# Since: 1.6
+##
+{ 'command': 'migrate-set-mc-delay', 'data': {'value': 'int'} }
+
+##
 # @migrate_set_speed
 #
 # Set maximum speed for migration.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index fba15cd..6d7ef2f 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -754,6 +754,29 @@ Example:
 EQMP
 
     {
+        .name       = "migrate-set-mc-delay",
+        .args_type  = "value:i",
+        .mhandler.cmd_new = qmp_marshal_input_migrate_set_mc_delay,
+    },
+
+SQMP
+migrate-set-mc-delay
+--------------------
+
+Set maximum delay (in milliseconds) between micro-checkpoints.
+
+Arguments:
+
+- "value": maximum delay (json-int)
+
+Example:
+
+-> { "execute": "migrate-set-mc-delay", "arguments": { "value": 100 } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "client_migrate_info",
         .args_type  = 
"protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
         .params     = "protocol hostname port tls-port cert-subject",
diff --git a/vl.c b/vl.c
index 74d52ab..fa23d66 100644
--- a/vl.c
+++ b/vl.c
@@ -29,6 +29,7 @@
 #include <sys/time.h>
 #include <zlib.h>
 #include "qemu/bitmap.h"
+#include "migration/qemu-file.h"
 
 /* Needed early for CONFIG_BSD etc. */
 #include "config-host.h"
@@ -4192,6 +4193,8 @@ int main(int argc, char **argv, char **envp)
     default_drive(default_sdcard, snapshot, IF_SD, 0, SD_OPTS);
 
     register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
+    register_savevm(NULL, "mc", -1, MC_VERSION, mc_info_save, 
+                                mc_info_load, NULL); 
 
     if (nb_numa_nodes > 0) {
         int i;
-- 
1.8.1.2