[10/11] Add XBZRLE statistics

diff --git a/arch_init.c b/arch_init.c
index e50cdf2..f484bd5 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -209,7 +209,11 @@  int64_t xbzrle_cache_resize(int64_t new_size)
 typedef struct AccountingInfo {
     uint64_t dup_pages;
     uint64_t norm_pages;
+    uint64_t xbzrle_bytes;
+    uint64_t xbzrle_pages;
+    uint64_t xbzrle_cache_miss;
     uint64_t iterations;
+    uint64_t xbzrle_overflows;
 } AccountingInfo;
 
 static AccountingInfo acct_info;
@@ -239,6 +243,26 @@  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)
 {
@@ -267,6 +291,7 @@  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;
     }
 
@@ -284,6 +309,7 @@  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;
@@ -301,7 +327,9 @@  static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
     qemu_put_byte(f, hdr.xh_flags);
     qemu_put_be16(f, hdr.xh_len);
     qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
+    acct_info.xbzrle_pages++;
     bytes_sent = encoded_len + sizeof(hdr);
+    acct_info.xbzrle_bytes += bytes_sent;
 
     return bytes_sent;
 }
diff --git a/hmp.c b/hmp.c
index 9770d7b..383d5b1 100644
--- a/hmp.c
+++ b/hmp.c
@@ -172,6 +172,27 @@  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);
+        if (info->xbzrle_cache->has_xbzrle_bytes) {
+            monitor_printf(mon, "xbzrle transferred: %" PRIu64 " kbytes\n",
+                           info->xbzrle_cache->xbzrle_bytes >> 10);
+        }
+        if (info->xbzrle_cache->has_xbzrle_pages) {
+            monitor_printf(mon, "xbzrle pages: %" PRIu64 " pages\n",
+                           info->xbzrle_cache->xbzrle_pages);
+        }
+        if (info->xbzrle_cache->has_xbzrle_cache_miss) {
+            monitor_printf(mon, "xbzrle cache miss: %" PRIu64 "\n",
+                           info->xbzrle_cache->xbzrle_cache_miss);
+        }
+        if (info->xbzrle_cache->has_xbzrle_overflow) {
+            monitor_printf(mon, "xbzrle overflow : %" PRIu64 "\n",
+                           info->xbzrle_cache->xbzrle_overflow);
+        }
+    }
+
     qapi_free_MigrationInfo(info);
     qapi_free_MigrationParameters(params);
 }
diff --git a/migration.c b/migration.c
index 4dc99ba..fb802bc 100644
--- a/migration.c
+++ b/migration.c
@@ -136,6 +136,23 @@  MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     return params;
 }
 
+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->has_xbzrle_bytes = true;
+        info->xbzrle_cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
+        info->xbzrle_cache->has_xbzrle_pages = true;
+        info->xbzrle_cache->xbzrle_pages = xbzrle_mig_pages_transferred();
+        info->xbzrle_cache->has_xbzrle_cache_miss = true;
+        info->xbzrle_cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
+        info->xbzrle_cache->has_xbzrle_overflow = true;
+        info->xbzrle_cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
+    }
+}
+
 MigrationInfo *qmp_query_migrate(Error **errp)
 {
     MigrationInfo *info = g_malloc0(sizeof(*info));
@@ -144,6 +161,13 @@  MigrationInfo *qmp_query_migrate(Error **errp)
     switch (s->state) {
     case MIG_STATE_SETUP:
         /* no migration has happened ever */
+
+        /* display xbzrle cache size */
+        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();
+        }
         break;
     case MIG_STATE_ACTIVE:
         info->has_status = true;
@@ -166,8 +190,12 @@  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");
 
diff --git a/migration.h b/migration.h
index e4a7cd7..a9852fc 100644
--- a/migration.h
+++ b/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
diff --git a/qapi-schema.json b/qapi-schema.json
index 88b7b56..9418f23 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -273,6 +273,26 @@ 
 { 'type': 'MigrationStats',
   'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
            'total_time': 'int', '*duplicate': 'int', '*normal': 'int' } }
+##
+# @XBZRLECacheStats
+#
+# Detailed XBZRLE migration cache statistics
+#
+# @cache_size: XBZRLE cache size
+#
+# @xbzrle_bytes: amount of bytes already transferred to the target VM
+#
+# @xbzrle_pages: amount of pages transferred to the target VM
+#
+# @xbzrle_cache_miss: number of cache miss
+#
+# @xbzrle_overflow: number of overflows
+#
+# Since: 1.2
+##
+{ 'type': 'XBZRLECacheStats',
+  'data': {'cache-size': 'int', '*xbzrle-bytes': 'int', '*xbzrle-pages': 'int',
+           '*xbzrle-cache-miss': 'int', '*xbzrle-overflow': 'int' } }
 
 ##
 # @MigrationInfo
@@ -292,11 +312,15 @@ 
 #        status, only returned if status is 'active' and it is a block
 #        migration
 #
+# @xbzrle-cache: #optional @XBZRLECacheStats containing detailed XBZRLE
+#                migration statistics (since 1.2)
+#
 # Since: 0.14.0
 ##
 { 'type': 'MigrationInfo',
   'data': {'*status': 'str', '*ram': 'MigrationStats',
-           '*disk': 'MigrationStats'} }
+           '*disk': 'MigrationStats',
+           '*xbzrle-cache': 'XBZRLECacheStats'} }
 
 ##
 # @query-migrate
diff --git a/qmp-commands.hx b/qmp-commands.hx
index d0e8878..946d921 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2106,10 +2106,16 @@  The main json-object contains the following:
          - "transferred": amount transferred (json-int)
          - "remaining": amount remaining (json-int)
          - "total": total (json-int)
+- "cache": only present if "status" and XBZRLE is active.
+  It is a json-object with the following XBZRLE information:
+         - "cache-size": XBZRLE cache size
+         - "xbzrle-bytes": total XBZRLE bytes transferred
+         - "xbzrle-pages": number of XBZRLE compressed pages
+         - "cache-miss": number of cache misses
+         - "overflow": number of XBZRLE overflows
 Examples:
 
 1. Before the first migration
-
 -> { "execute": "query-migrate" }
 <- { "return": {} }
 
@@ -2164,6 +2170,30 @@  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,
+            "duplicate": 10,
+            "normal" : 3333
+         },
+         "cache":{
+            "cache-size": 1024
+            "xbzrle-transferred":20971520,
+            "xbzrle-pages":2444343,
+            "xbzrle-cache-miss":2244,
+            "xbzrle-overflow":34434
+         }
+      }
+   }
+
 EQMP
 
     {