Add XBZRLE statistics

Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

arch_init.c

@@ -206,6 +206,10 @@ typedef struct AccountingInfo {
     uint64_t dup_pages;
     uint64_t norm_pages;
     uint64_t iterations;
+    uint64_t xbzrle_bytes;
+    uint64_t xbzrle_pages;
+    uint64_t xbzrle_cache_miss;
+    uint64_t xbzrle_overflows;
 } AccountingInfo;
 
 static AccountingInfo acct_info;
@@ -235,6 +239,26 @@ uint64_t norm_mig_pages_transferred(void)
     return acct_info.norm_pages;
 }
 
+uint64_t xbzrle_mig_bytes_transferred(void)
+{
+    return acct_info.xbzrle_bytes;
+}
+
+uint64_t xbzrle_mig_pages_transferred(void)
+{
+    return acct_info.xbzrle_pages;
+}
+
+uint64_t xbzrle_mig_pages_cache_miss(void)
+{
+    return acct_info.xbzrle_cache_miss;
+}
+
+uint64_t xbzrle_mig_pages_overflow(void)
+{
+    return acct_info.xbzrle_overflows;
+}
+
 static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
         int cont, int flag)
 {
@@ -259,6 +283,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
     if (!cache_is_cached(XBZRLE.cache, current_addr)) {
         cache_insert(XBZRLE.cache, current_addr,
                      g_memdup(current_data, TARGET_PAGE_SIZE));
+        acct_info.xbzrle_cache_miss++;
         return -1;
     }
 
@@ -276,6 +301,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
         return 0;
     } else if (encoded_len == -1) {
         DPRINTF("Overflow\n");
+        acct_info.xbzrle_overflows++;
         /* update data in the cache */
         memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
         return -1;
@@ -290,6 +316,8 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
     qemu_put_be16(f, encoded_len);
     qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
     bytes_sent = encoded_len + 1 + 2;
+    acct_info.xbzrle_pages++;
+    acct_info.xbzrle_bytes += bytes_sent;
 
     return bytes_sent;
 }

hmp.c

@@ -177,6 +177,19 @@ void hmp_info_migrate(Monitor *mon)
                        info->disk->total >> 10);
     }
 
+    if (info->has_xbzrle_cache) {
+        monitor_printf(mon, "cache size: %" PRIu64 " bytes\n",
+                       info->xbzrle_cache->cache_size);
+        monitor_printf(mon, "xbzrle transferred: %" PRIu64 " kbytes\n",
+                       info->xbzrle_cache->bytes >> 10);
+        monitor_printf(mon, "xbzrle pages: %" PRIu64 " pages\n",
+                       info->xbzrle_cache->pages);
+        monitor_printf(mon, "xbzrle cache miss: %" PRIu64 "\n",
+                       info->xbzrle_cache->cache_miss);
+        monitor_printf(mon, "xbzrle overflow : %" PRIu64 "\n",
+                       info->xbzrle_cache->overflow);
+    }
+
     qapi_free_MigrationInfo(info);
     qapi_free_MigrationCapabilityStatusList(caps);
 }

migration.c

@@ -141,6 +141,19 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
     return head;
 }
 
+static void get_xbzrle_cache_stats(MigrationInfo *info)
+{
+    if (migrate_use_xbzrle()) {
+        info->has_xbzrle_cache = true;
+        info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
+        info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
+        info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
+        info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
+        info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
+        info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
+    }
+}
+
 MigrationInfo *qmp_query_migrate(Error **errp)
 {
     MigrationInfo *info = g_malloc0(sizeof(*info));
@@ -172,8 +185,12 @@ MigrationInfo *qmp_query_migrate(Error **errp)
             info->disk->remaining = blk_mig_bytes_remaining();
             info->disk->total = blk_mig_bytes_total();
         }
+
+        get_xbzrle_cache_stats(info);
         break;
     case MIG_STATE_COMPLETED:
+        get_xbzrle_cache_stats(info);
+
         info->has_status = true;
         info->status = g_strdup("completed");
 

migration.h

@@ -91,6 +91,10 @@ uint64_t dup_mig_bytes_transferred(void);
 uint64_t dup_mig_pages_transferred(void);
 uint64_t norm_mig_bytes_transferred(void);
 uint64_t norm_mig_pages_transferred(void);
+uint64_t xbzrle_mig_bytes_transferred(void);
+uint64_t xbzrle_mig_pages_transferred(void);
+uint64_t xbzrle_mig_pages_overflow(void);
+uint64_t xbzrle_mig_pages_cache_miss(void);
 
 /**
  * @migrate_add_blocker - prevent migration from proceeding

qapi-schema.json

@@ -277,6 +277,27 @@
            'total-time': 'int', 'duplicate': 'int', 'normal': 'int',
            'normal-bytes': 'int' } }
 
+##
+# @XBZRLECacheStats
+#
+# Detailed XBZRLE migration cache statistics
+#
+# @cache-size: XBZRLE cache size
+#
+# @bytes: amount of bytes already transferred to the target VM
+#
+# @pages: amount of pages transferred to the target VM
+#
+# @cache-miss: number of cache miss
+#
+# @overflow: number of overflows
+#
+# Since: 1.2
+##
+{ 'type': 'XBZRLECacheStats',
+  'data': {'cache-size': 'int', 'bytes': 'int', 'pages': 'int',
+           'cache-miss': 'int', 'overflow': 'int' } }
+
 ##
 # @MigrationInfo
 #
@@ -295,11 +316,16 @@
 #        status, only returned if status is 'active' and it is a block
 #        migration
 #
+# @xbzrle-cache: #optional @XBZRLECacheStats containing detailed XBZRLE
+#                migration statistics, only returned if XBZRLE feature is on and
+#                status is 'active' or 'completed' (since 1.2)
+#
 # Since: 0.14.0
 ##
 { 'type': 'MigrationInfo',
   'data': {'*status': 'str', '*ram': 'MigrationStats',
-           '*disk': 'MigrationStats'} }
+           '*disk': 'MigrationStats',
+           '*xbzrle-cache': 'XBZRLECacheStats'} }
 
 ##
 # @query-migrate

qmp-commands.hx

@@ -2133,7 +2133,13 @@ The main json-object contains the following:
          - "transferred": amount transferred (json-int)
          - "remaining": amount remaining (json-int)
          - "total": total (json-int)
-
+- "xbzrle-cache": only present if XBZRLE is active.
+  It is a json-object with the following XBZRLE information:
+         - "cache-size": XBZRLE cache size
+         - "bytes": total XBZRLE bytes transferred
+         - "pages": number of XBZRLE compressed pages
+         - "cache-miss": number of cache misses
+         - "overflow": number of XBZRLE overflows
 Examples:
 
 1. Before the first migration
@@ -2204,6 +2210,32 @@ Examples:
       }
    }
 
+6. Migration is being performed and XBZRLE is active:
+
+-> { "execute": "query-migrate" }
+<- {
+      "return":{
+         "status":"active",
+         "capabilities" : [ { "capability": "xbzrle", "state" : true } ],
+         "ram":{
+            "total":1057024,
+            "remaining":1053304,
+            "transferred":3720,
+            "total-time":12345,
+            "duplicate":10,
+            "normal":3333,
+            "normal-bytes":3412992
+         },
+         "xbzrle-cache":{
+            "cache-size":67108864,
+            "bytes":20971520,
+            "pages":2444343,
+            "cache-miss":2244,
+            "overflow":34434
+         }
+      }
+   }
+
 EQMP
 
     {