migration/next for 20140308

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Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20140308-1' into staging

migration/next for 20140308

# gpg: Signature made Sat 08 Mar 2014 21:26:01 GMT using RSA key ID 5872D723
# gpg: Can't check signature: public key not found

* remotes/juanquintela/tags/migration/20140308-1:
  migration: extend section_start/end traces
  vl: add system_wakeup_request tracepoint
  qemu_file: Fix mismerge of "use fwrite() correctly"
  XBZRLE: Fix qemu crash when resize the xbzrle cache

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

arch_init.c

@@ -164,8 +164,9 @@ static struct {
     uint8_t *encoded_buf;
     /* buffer for storing page content */
     uint8_t *current_buf;
-    /* Cache for XBZRLE */
+    /* Cache for XBZRLE, Protected by lock. */
     PageCache *cache;
+    QemuMutex lock;
 } XBZRLE = {
     .encoded_buf = NULL,
     .current_buf = NULL,
@@ -174,16 +175,52 @@ static struct {
 /* buffer used for XBZRLE decoding */
 static uint8_t *xbzrle_decoded_buf;
 
+static void XBZRLE_cache_lock(void)
+{
+    if (migrate_use_xbzrle())
+        qemu_mutex_lock(&XBZRLE.lock);
+}
+
+static void XBZRLE_cache_unlock(void)
+{
+    if (migrate_use_xbzrle())
+        qemu_mutex_unlock(&XBZRLE.lock);
+}
+
 int64_t xbzrle_cache_resize(int64_t new_size)
 {
+    PageCache *new_cache, *cache_to_free;
+
     if (new_size < TARGET_PAGE_SIZE) {
         return -1;
     }
 
+    /* no need to lock, the current thread holds qemu big lock */
     if (XBZRLE.cache != NULL) {
-        return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
+        /* check XBZRLE.cache again later */
-            TARGET_PAGE_SIZE;
+        if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
+            return pow2floor(new_size);
         }
+        new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
+                                        TARGET_PAGE_SIZE);
+        if (!new_cache) {
+            DPRINTF("Error creating cache\n");
+            return -1;
+        }
+
+        XBZRLE_cache_lock();
+        /* the XBZRLE.cache may have be destroyed, check it again */
+        if (XBZRLE.cache != NULL) {
+            cache_to_free = XBZRLE.cache;
+            XBZRLE.cache = new_cache;
+        } else {
+            cache_to_free = new_cache;
+        }
+        XBZRLE_cache_unlock();
+
+        cache_fini(cache_to_free);
+    }
+
     return pow2floor(new_size);
 }
 
@@ -539,6 +576,8 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
             ret = ram_control_save_page(f, block->offset,
                                offset, TARGET_PAGE_SIZE, &bytes_sent);
 
+            XBZRLE_cache_lock();
+
             current_addr = block->offset + offset;
             if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
                 if (ret != RAM_SAVE_CONTROL_DELAYED) {
@@ -587,6 +626,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
                 acct_info.norm_pages++;
             }
 
+            XBZRLE_cache_unlock();
             /* if page is unmodified, continue to the next */
             if (bytes_sent > 0) {
                 last_sent_block = block;
@@ -654,6 +694,7 @@ static void migration_end(void)
         migration_bitmap = NULL;
     }
 
+    XBZRLE_cache_lock();
     if (XBZRLE.cache) {
         cache_fini(XBZRLE.cache);
         g_free(XBZRLE.cache);
@@ -663,6 +704,7 @@ static void migration_end(void)
         XBZRLE.encoded_buf = NULL;
         XBZRLE.current_buf = NULL;
     }
+    XBZRLE_cache_unlock();
 }
 
 static void ram_migration_cancel(void *opaque)
@@ -693,13 +735,17 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     dirty_rate_high_cnt = 0;
 
     if (migrate_use_xbzrle()) {
+        qemu_mutex_lock_iothread();
         XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
                                   TARGET_PAGE_SIZE,
                                   TARGET_PAGE_SIZE);
         if (!XBZRLE.cache) {
+            qemu_mutex_unlock_iothread();
             DPRINTF("Error creating cache\n");
             return -1;
         }
+        qemu_mutex_init(&XBZRLE.lock);
+        qemu_mutex_unlock_iothread();
 
         /* We prefer not to abort if there is no memory */
         XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);

qemu-file.c

@@ -105,7 +105,7 @@ static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
     res = fwrite(buf, 1, size, s->stdio_file);
 
     if (res != size) {
-        return -EIO;	/* fake errno value */
+        return -errno;
     }
     return res;
 }

savevm.c

@@ -527,13 +527,13 @@ int qemu_savevm_state_iterate(QEMUFile *f)
         if (qemu_file_rate_limit(f)) {
             return 0;
         }
-        trace_savevm_section_start();
+        trace_savevm_section_start(se->idstr, se->section_id);
         /* Section type */
         qemu_put_byte(f, QEMU_VM_SECTION_PART);
         qemu_put_be32(f, se->section_id);
 
         ret = se->ops->save_live_iterate(f, se->opaque);
-        trace_savevm_section_end(se->section_id);
+        trace_savevm_section_end(se->idstr, se->section_id);
 
         if (ret < 0) {
             qemu_file_set_error(f, ret);
@@ -565,13 +565,13 @@ void qemu_savevm_state_complete(QEMUFile *f)
                 continue;
             }
         }
-        trace_savevm_section_start();
+        trace_savevm_section_start(se->idstr, se->section_id);
         /* Section type */
         qemu_put_byte(f, QEMU_VM_SECTION_END);
         qemu_put_be32(f, se->section_id);
 
         ret = se->ops->save_live_complete(f, se->opaque);
-        trace_savevm_section_end(se->section_id);
+        trace_savevm_section_end(se->idstr, se->section_id);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
             return;
@@ -584,7 +584,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
         if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
             continue;
         }
-        trace_savevm_section_start();
+        trace_savevm_section_start(se->idstr, se->section_id);
         /* Section type */
         qemu_put_byte(f, QEMU_VM_SECTION_FULL);
         qemu_put_be32(f, se->section_id);
@@ -598,7 +598,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
         qemu_put_be32(f, se->version_id);
 
         vmstate_save(f, se);
-        trace_savevm_section_end(se->section_id);
+        trace_savevm_section_end(se->idstr, se->section_id);
     }
 
     qemu_put_byte(f, QEMU_VM_EOF);

trace-events

@@ -486,6 +486,7 @@ runstate_set(int new_state) "new state %d"
 g_malloc(size_t size, void *ptr) "size %zu ptr %p"
 g_realloc(void *ptr, size_t size, void *newptr) "ptr %p size %zu newptr %p"
 g_free(void *ptr) "ptr %p"
+system_wakeup_request(int reason) "reason=%d"
 
 # block/qcow2.c
 qcow2_writev_start_req(void *co, int64_t sector, int nb_sectors) "co %p sector %" PRIx64 " nb_sectors %d"
@@ -1039,8 +1040,8 @@ vmware_scratch_write(uint32_t index, uint32_t value) "index %d, value 0x%x"
 vmware_setmode(uint32_t w, uint32_t h, uint32_t bpp) "%dx%d @ %d bpp"
 
 # savevm.c
-savevm_section_start(void) ""
+savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
-savevm_section_end(unsigned int section_id) "section_id %u"
+savevm_section_end(const char *id, unsigned int section_id) "%s, section_id %u"
 
 # arch_init.c
 migration_bitmap_sync_start(void) ""

vl.c

@@ -1837,6 +1837,8 @@ void qemu_register_suspend_notifier(Notifier *notifier)
 
 void qemu_system_wakeup_request(WakeupReason reason)
 {
+    trace_system_wakeup_request(reason);
+
     if (!runstate_check(RUN_STATE_SUSPENDED)) {
         return;
     }