Block live migration

This patch introduces block migration called during live migration. Block
are being copied to the destination in an async way. First the code will
transfer the whole disk and then transfer all dirty blocks accumulted during
the migration.
Still need to improve transition from the iterative phase of migration to the
end phase. For now transition will take place when all blocks transfered once,
all the dirty blocks will be transfered during the end phase (guest is
suspended).

Changes from v4:
- Global variabels moved to a global state structure allocated dynamically.
- Minor coding style issues.
- Poll block.c for tracking of dirty blocks instead of manage it here.

Signed-off-by: Liran Schour <lirans@il.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 46 insertions, 16 deletions

diff --git a/savevm.c b/savevm.c
index 74f2c66d29..4668843c3f 100644
--- a/savevm.c
+++ b/savevm.c
@@ -169,6 +169,7 @@ struct QEMUFile {
     QEMUFileCloseFunc *close;
     QEMUFileRateLimit *rate_limit;
     QEMUFileSetRateLimit *set_rate_limit;
+    QEMUFileGetRateLimit *get_rate_limit;
     void *opaque;
     int is_write;
 
@@ -264,9 +265,11 @@ QEMUFile *qemu_popen(FILE *stdio_file, const char *mode)
     s->stdio_file = stdio_file;
 
     if(mode[0] == 'r') {
-        s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_pclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_pclose, 
+				 NULL, NULL, NULL);
     } else {
-        s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_pclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_pclose, 
+				 NULL, NULL, NULL);
     }
     return s->file;
 }
@@ -311,9 +314,11 @@ QEMUFile *qemu_fdopen(int fd, const char *mode)
         goto fail;
 
     if(mode[0] == 'r') {
-        s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_fclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, NULL, stdio_get_buffer, stdio_fclose, 
+				 NULL, NULL, NULL);
     } else {
-        s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_fclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, stdio_put_buffer, NULL, stdio_fclose, 
+				 NULL, NULL, NULL);
     }
     return s->file;
 
@@ -327,7 +332,8 @@ QEMUFile *qemu_fopen_socket(int fd)
     QEMUFileSocket *s = qemu_mallocz(sizeof(QEMUFileSocket));
 
     s->fd = fd;
-    s->file = qemu_fopen_ops(s, NULL, socket_get_buffer, socket_close, NULL, NULL);
+    s->file = qemu_fopen_ops(s, NULL, socket_get_buffer, socket_close, 
+			     NULL, NULL, NULL);
     return s->file;
 }
 
@@ -363,11 +369,13 @@ QEMUFile *qemu_fopen(const char *filename, const char *mode)
     s->stdio_file = fopen(filename, mode);
     if (!s->stdio_file)
         goto fail;
-
+    
     if(mode[0] == 'w') {
-        s->file = qemu_fopen_ops(s, file_put_buffer, NULL, stdio_fclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, file_put_buffer, NULL, stdio_fclose, 
+				 NULL, NULL, NULL);
     } else {
-        s->file = qemu_fopen_ops(s, NULL, file_get_buffer, stdio_fclose, NULL, NULL);
+        s->file = qemu_fopen_ops(s, NULL, file_get_buffer, stdio_fclose, 
+			       NULL, NULL, NULL);
     }
     return s->file;
 fail:
@@ -395,15 +403,17 @@ static int bdrv_fclose(void *opaque)
 static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
 {
     if (is_writable)
-        return qemu_fopen_ops(bs, block_put_buffer, NULL, bdrv_fclose, NULL, NULL);
-    return qemu_fopen_ops(bs, NULL, block_get_buffer, bdrv_fclose, NULL, NULL);
+        return qemu_fopen_ops(bs, block_put_buffer, NULL, bdrv_fclose, 
+			      NULL, NULL, NULL);
+    return qemu_fopen_ops(bs, NULL, block_get_buffer, bdrv_fclose, NULL, NULL, NULL);
 }
 
 QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
                          QEMUFileGetBufferFunc *get_buffer,
                          QEMUFileCloseFunc *close,
                          QEMUFileRateLimit *rate_limit,
-                         QEMUFileSetRateLimit *set_rate_limit)
+                         QEMUFileSetRateLimit *set_rate_limit,
+                         QEMUFileGetRateLimit *get_rate_limit)
 {
     QEMUFile *f;
 
@@ -415,6 +425,7 @@ QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
     f->close = close;
     f->rate_limit = rate_limit;
     f->set_rate_limit = set_rate_limit;
+    f->get_rate_limit = get_rate_limit;
     f->is_write = 0;
 
     return f;
@@ -592,6 +603,14 @@ int qemu_file_rate_limit(QEMUFile *f)
     return 0;
 }
 
+size_t qemu_file_get_rate_limit(QEMUFile *f)
+{
+    if (f->get_rate_limit)
+        return f->get_rate_limit(f->opaque);
+
+    return 0;
+}
+
 size_t qemu_file_set_rate_limit(QEMUFile *f, size_t new_rate)
 {
     /* any failed or completed migration keeps its state to allow probing of
@@ -964,6 +983,7 @@ typedef struct SaveStateEntry {
     int instance_id;
     int version_id;
     int section_id;
+    SaveSetParamsHandler *set_params;
     SaveLiveStateHandler *save_live_state;
     SaveStateHandler *save_state;
     LoadStateHandler *load_state;
@@ -971,6 +991,7 @@ typedef struct SaveStateEntry {
     void *opaque;
 } SaveStateEntry;
 
+
 static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
     QTAILQ_HEAD_INITIALIZER(savevm_handlers);
 static int global_section_id;
@@ -996,6 +1017,7 @@ static int calculate_new_instance_id(const char *idstr)
 int register_savevm_live(const char *idstr,
                          int instance_id,
                          int version_id,
+                         SaveSetParamsHandler *set_params,
                          SaveLiveStateHandler *save_live_state,
                          SaveStateHandler *save_state,
                          LoadStateHandler *load_state,
@@ -1003,10 +1025,11 @@ int register_savevm_live(const char *idstr,
 {
     SaveStateEntry *se;
 
-    se = qemu_malloc(sizeof(SaveStateEntry));
+    se = qemu_mallocz(sizeof(SaveStateEntry));
     pstrcpy(se->idstr, sizeof(se->idstr), idstr);
     se->version_id = version_id;
     se->section_id = global_section_id++;
+    se->set_params = set_params;
     se->save_live_state = save_live_state;
     se->save_state = save_state;
     se->load_state = load_state;
@@ -1031,7 +1054,7 @@ int register_savevm(const char *idstr,
                     void *opaque)
 {
     return register_savevm_live(idstr, instance_id, version_id,
-                                NULL, save_state, load_state, opaque);
+                                NULL, NULL, save_state, load_state, opaque);
 }
 
 void unregister_savevm(const char *idstr, void *opaque)
@@ -1051,7 +1074,7 @@ int vmstate_register(int instance_id, const VMStateDescription *vmsd,
 {
     SaveStateEntry *se;
 
-    se = qemu_malloc(sizeof(SaveStateEntry));
+    se = qemu_mallocz(sizeof(SaveStateEntry));
     pstrcpy(se->idstr, sizeof(se->idstr), vmsd->name);
     se->version_id = vmsd->version_id;
     se->section_id = global_section_id++;
@@ -1213,10 +1236,17 @@ static void vmstate_save(QEMUFile *f, SaveStateEntry *se)
 #define QEMU_VM_SECTION_END          0x03
 #define QEMU_VM_SECTION_FULL         0x04
 
-int qemu_savevm_state_begin(QEMUFile *f)
+int qemu_savevm_state_begin(QEMUFile *f, int blk_enable, int shared)
 {
     SaveStateEntry *se;
 
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if(se->set_params == NULL) {
+            continue;
+	}
+	se->set_params(blk_enable, shared, se->opaque);
+    }
+    
     qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
     qemu_put_be32(f, QEMU_VM_FILE_VERSION);
 
@@ -1326,7 +1356,7 @@ int qemu_savevm_state(QEMUFile *f)
 
     bdrv_flush_all();
 
-    ret = qemu_savevm_state_begin(f);
+    ret = qemu_savevm_state_begin(f, 0, 0);
     if (ret < 0)
         goto out;