qemu: Add support for xbzrle-cache-size migration parameter

Originally QEMU provided query-migrate-cache-size and
migrate-set-cache-size QMP commands for querying/setting XBZRLE cache
size. In version 2.11 QEMU added support for XBZRLE cache size to the
general migration paramaters commands.

This patch adds support for this parameter to libvirt to make sure it is
properly restored to its original value after a failed or aborted
migration.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_monitor.c

@@ -2639,7 +2639,7 @@ qemuMonitorSetMigrationParams(qemuMonitorPtr mon,
               "decompressThreads=%d:%d cpuThrottleInitial=%d:%d "
               "cpuThrottleIncrement=%d:%d tlsCreds=%s tlsHostname=%s "
               "maxBandwidth=%d:%llu downtimeLimit=%d:%llu "
-              "blockIncremental=%d:%d",
+              "blockIncremental=%d:%d xbzrleCacheSize=%d:%llu",
               params->compressLevel_set, params->compressLevel,
               params->compressThreads_set, params->compressThreads,
               params->decompressThreads_set, params->decompressThreads,
@@ -2648,7 +2648,8 @@ qemuMonitorSetMigrationParams(qemuMonitorPtr mon,
               NULLSTR(params->tlsCreds), NULLSTR(params->tlsHostname),
               params->maxBandwidth_set, params->maxBandwidth,
               params->downtimeLimit_set, params->downtimeLimit,
-              params->blockIncremental_set, params->blockIncremental);
+              params->blockIncremental_set, params->blockIncremental,
+              params->xbzrleCacheSize_set, params->xbzrleCacheSize);
 
     QEMU_CHECK_MONITOR_JSON(mon);
 

src/qemu/qemu_monitor.h

@@ -673,6 +673,9 @@ struct _qemuMonitorMigrationParams {
 
     bool blockIncremental_set;
     bool blockIncremental;
+
+    bool xbzrleCacheSize_set;
+    unsigned long long xbzrleCacheSize;
 };
 
 int qemuMonitorGetMigrationParams(qemuMonitorPtr mon,

src/qemu/qemu_monitor_json.c

@@ -2833,6 +2833,7 @@ qemuMonitorJSONGetMigrationParams(qemuMonitorPtr mon,
     PARSE_ULONG(maxBandwidth, "max-bandwidth");
     PARSE_ULONG(downtimeLimit, "downtime-limit");
     PARSE_BOOL(blockIncremental, "block-incremental");
+    PARSE_ULONG(xbzrleCacheSize, "xbzrle-cache-size");
 
 #undef PARSE_SET
 #undef PARSE_INT
@@ -2898,6 +2899,7 @@ qemuMonitorJSONSetMigrationParams(qemuMonitorPtr mon,
     APPEND_ULONG(maxBandwidth, "max-bandwidth");
     APPEND_ULONG(downtimeLimit, "downtime-limit");
     APPEND_BOOL(blockIncremental, "block-incremental");
+    APPEND_ULONG(xbzrleCacheSize, "xbzrle-cache-size");
 
 #undef APPEND
 #undef APPEND_INT

tests/qemumonitorjsontest.c

@@ -1810,7 +1810,8 @@ testQemuMonitorJSONqemuMonitorJSONGetMigrationParams(const void *data)
                                "        \"tls-hostname\": \"\","
                                "        \"max-bandwidth\": 1234567890,"
                                "        \"downtime-limit\": 500,"
-                               "        \"block-incremental\": true"
+                               "        \"block-incremental\": true,"
+                               "        \"xbzrle-cache-size\": 67108864"
                                "    }"
                                "}") < 0) {
         goto cleanup;
@@ -1867,6 +1868,7 @@ testQemuMonitorJSONqemuMonitorJSONGetMigrationParams(const void *data)
     CHECK_ULONG(maxBandwidth, "max-bandwidth", 1234567890ULL);
     CHECK_ULONG(downtimeLimit, "downtime-limit", 500ULL);
     CHECK_BOOL(blockIncremental, "block-incremental", true);
+    CHECK_ULONG(xbzrleCacheSize, "xbzrle-cache-size", 67108864ULL);
 
 #undef CHECK_NUM
 #undef CHECK_INT