Merge remote-tracking branch 'quintela/migration-pull' into staging

1 files changed, 139 insertions, 83 deletions

diff --git a/savevm.c b/savevm.c
index abb4a60643..cf79a56871 100644
--- a/savevm.c
+++ b/savevm.c
@@ -173,7 +173,7 @@ struct QEMUFile {
     int buf_size; /* 0 when writing */
     uint8_t buf[IO_BUF_SIZE];
 
-    int has_error;
+    int last_error;
 };
 
 typedef struct QEMUFileStdio
@@ -425,14 +425,14 @@ QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
     return f;
 }
 
-int qemu_file_has_error(QEMUFile *f)
+int qemu_file_get_error(QEMUFile *f)
 {
-    return f->has_error;
+    return f->last_error;
 }
 
-void qemu_file_set_error(QEMUFile *f)
+void qemu_file_set_error(QEMUFile *f, int ret)
 {
-    f->has_error = 1;
+    f->last_error = ret;
 }
 
 void qemu_fflush(QEMUFile *f)
@@ -447,7 +447,7 @@ void qemu_fflush(QEMUFile *f)
         if (len > 0)
             f->buf_offset += f->buf_index;
         else
-            f->has_error = 1;
+            f->last_error = -EINVAL;
         f->buf_index = 0;
     }
 }
@@ -455,6 +455,7 @@ void qemu_fflush(QEMUFile *f)
 static void qemu_fill_buffer(QEMUFile *f)
 {
     int len;
+    int pending;
 
     if (!f->get_buffer)
         return;
@@ -462,13 +463,20 @@ static void qemu_fill_buffer(QEMUFile *f)
     if (f->is_write)
         abort();
 
-    len = f->get_buffer(f->opaque, f->buf, f->buf_offset, IO_BUF_SIZE);
+    pending = f->buf_size - f->buf_index;
+    if (pending > 0) {
+        memmove(f->buf, f->buf + f->buf_index, pending);
+    }
+    f->buf_index = 0;
+    f->buf_size = pending;
+
+    len = f->get_buffer(f->opaque, f->buf + pending, f->buf_offset,
+                        IO_BUF_SIZE - pending);
     if (len > 0) {
-        f->buf_index = 0;
-        f->buf_size = len;
+        f->buf_size += len;
         f->buf_offset += len;
     } else if (len != -EAGAIN)
-        f->has_error = 1;
+        f->last_error = len;
 }
 
 int qemu_fclose(QEMUFile *f)
@@ -490,13 +498,13 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
 {
     int l;
 
-    if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
+    if (!f->last_error && f->is_write == 0 && f->buf_index > 0) {
         fprintf(stderr,
                 "Attempted to write to buffer while read buffer is not empty\n");
         abort();
     }
 
-    while (!f->has_error && size > 0) {
+    while (!f->last_error && size > 0) {
         l = IO_BUF_SIZE - f->buf_index;
         if (l > size)
             l = size;
@@ -512,7 +520,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
 
 void qemu_put_byte(QEMUFile *f, int v)
 {
-    if (!f->has_error && f->is_write == 0 && f->buf_index > 0) {
+    if (!f->last_error && f->is_write == 0 && f->buf_index > 0) {
         fprintf(stderr,
                 "Attempted to write to buffer while read buffer is not empty\n");
         abort();
@@ -524,56 +532,86 @@ void qemu_put_byte(QEMUFile *f, int v)
         qemu_fflush(f);
 }
 
-int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size1)
+static void qemu_file_skip(QEMUFile *f, int size)
+{
+    if (f->buf_index + size <= f->buf_size) {
+        f->buf_index += size;
+    }
+}
+
+static int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
 {
-    int size, l;
+    int pending;
+    int index;
 
-    if (f->is_write)
+    if (f->is_write) {
         abort();
+    }
 
-    size = size1;
-    while (size > 0) {
-        l = f->buf_size - f->buf_index;
-        if (l == 0) {
-            qemu_fill_buffer(f);
-            l = f->buf_size - f->buf_index;
-            if (l == 0)
-                break;
+    index = f->buf_index + offset;
+    pending = f->buf_size - index;
+    if (pending < size) {
+        qemu_fill_buffer(f);
+        index = f->buf_index + offset;
+        pending = f->buf_size - index;
+    }
+
+    if (pending <= 0) {
+        return 0;
+    }
+    if (size > pending) {
+        size = pending;
+    }
+
+    memcpy(buf, f->buf + index, size);
+    return size;
+}
+
+int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size)
+{
+    int pending = size;
+    int done = 0;
+
+    while (pending > 0) {
+        int res;
+
+        res = qemu_peek_buffer(f, buf, pending, 0);
+        if (res == 0) {
+            return done;
         }
-        if (l > size)
-            l = size;
-        memcpy(buf, f->buf + f->buf_index, l);
-        f->buf_index += l;
-        buf += l;
-        size -= l;
+        qemu_file_skip(f, res);
+        buf += res;
+        pending -= res;
+        done += res;
     }
-    return size1 - size;
+    return done;
 }
 
-static int qemu_peek_byte(QEMUFile *f)
+static int qemu_peek_byte(QEMUFile *f, int offset)
 {
-    if (f->is_write)
+    int index = f->buf_index + offset;
+
+    if (f->is_write) {
         abort();
+    }
 
-    if (f->buf_index >= f->buf_size) {
+    if (index >= f->buf_size) {
         qemu_fill_buffer(f);
-        if (f->buf_index >= f->buf_size)
+        index = f->buf_index + offset;
+        if (index >= f->buf_size) {
             return 0;
+        }
     }
-    return f->buf[f->buf_index];
+    return f->buf[index];
 }
 
 int qemu_get_byte(QEMUFile *f)
 {
-    if (f->is_write)
-        abort();
+    int result;
 
-    if (f->buf_index >= f->buf_size) {
-        qemu_fill_buffer(f);
-        if (f->buf_index >= f->buf_size)
-            return 0;
-    }
-    return f->buf[f->buf_index++];
+    result = qemu_peek_byte(f, 0);
+    qemu_file_skip(f, 1);
+    return result;
 }
 
 int64_t qemu_ftell(QEMUFile *f)
@@ -1466,6 +1504,7 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
                             int shared)
 {
     SaveStateEntry *se;
+    int ret;
 
     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
         if(se->set_params == NULL) {
@@ -1495,17 +1534,27 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
         qemu_put_be32(f, se->instance_id);
         qemu_put_be32(f, se->version_id);
 
-        se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
+        ret = se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
+        if (ret < 0) {
+            qemu_savevm_state_cancel(mon, f);
+            return ret;
+        }
     }
-
-    if (qemu_file_has_error(f)) {
+    ret = qemu_file_get_error(f);
+    if (ret != 0) {
         qemu_savevm_state_cancel(mon, f);
-        return -EIO;
     }
 
-    return 0;
+    return ret;
+
 }
 
+/*
+ * this funtion has three return values:
+ *   negative: there was one error, and we have -errno.
+ *   0 : We haven't finished, caller have to go again
+ *   1 : We have finished, we can go to complete phase
+ */
 int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
 {
     SaveStateEntry *se;
@@ -1520,7 +1569,7 @@ int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
         qemu_put_be32(f, se->section_id);
 
         ret = se->save_live_state(mon, f, QEMU_VM_SECTION_PART, se->opaque);
-        if (!ret) {
+        if (ret <= 0) {
             /* Do not proceed to the next vmstate before this one reported
                completion of the current stage. This serializes the migration
                and reduces the probability that a faster changing state is
@@ -1528,21 +1577,20 @@ int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
             break;
         }
     }
-
-    if (ret)
-        return 1;
-
-    if (qemu_file_has_error(f)) {
+    if (ret != 0) {
+        return ret;
+    }
+    ret = qemu_file_get_error(f);
+    if (ret != 0) {
         qemu_savevm_state_cancel(mon, f);
-        return -EIO;
     }
-
-    return 0;
+    return ret;
 }
 
 int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
 {
     SaveStateEntry *se;
+    int ret;
 
     cpu_synchronize_all_states();
 
@@ -1554,7 +1602,10 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
         qemu_put_byte(f, QEMU_VM_SECTION_END);
         qemu_put_be32(f, se->section_id);
 
-        se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
+        ret = se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
+        if (ret < 0) {
+            return ret;
+        }
     }
 
     QTAILQ_FOREACH(se, &savevm_handlers, entry) {
@@ -1580,10 +1631,7 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
 
     qemu_put_byte(f, QEMU_VM_EOF);
 
-    if (qemu_file_has_error(f))
-        return -EIO;
-
-    return 0;
+    return qemu_file_get_error(f);
 }
 
 void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
@@ -1619,8 +1667,9 @@ static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
     ret = qemu_savevm_state_complete(mon, f);
 
 out:
-    if (qemu_file_has_error(f))
-        ret = -EIO;
+    if (ret == 0) {
+        ret = qemu_file_get_error(f);
+    }
 
     return ret;
 }
@@ -1659,29 +1708,36 @@ static const VMStateDescription *vmstate_get_subsection(const VMStateSubsection
 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
                                    void *opaque)
 {
-    const VMStateSubsection *sub = vmsd->subsections;
-
-    if (!sub || !sub->needed) {
-        return 0;
-    }
-
-    while (qemu_peek_byte(f) == QEMU_VM_SUBSECTION) {
+    while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {
         char idstr[256];
         int ret;
-        uint8_t version_id, len;
+        uint8_t version_id, len, size;
         const VMStateDescription *sub_vmsd;
 
-        qemu_get_byte(f); /* subsection */
-        len = qemu_get_byte(f);
-        qemu_get_buffer(f, (uint8_t *)idstr, len);
-        idstr[len] = 0;
-        version_id = qemu_get_be32(f);
+        len = qemu_peek_byte(f, 1);
+        if (len < strlen(vmsd->name) + 1) {
+            /* subsection name has be be "section_name/a" */
+            return 0;
+        }
+        size = qemu_peek_buffer(f, (uint8_t *)idstr, len, 2);
+        if (size != len) {
+            return 0;
+        }
+        idstr[size] = 0;
 
-        sub_vmsd = vmstate_get_subsection(sub, idstr);
+        if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) {
+            /* it don't have a valid subsection name */
+            return 0;
+        }
+        sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
         if (sub_vmsd == NULL) {
             return -ENOENT;
         }
-        assert(!sub_vmsd->subsections);
+        qemu_file_skip(f, 1); /* subsection */
+        qemu_file_skip(f, 1); /* len */
+        qemu_file_skip(f, len); /* idstr */
+        version_id = qemu_get_be32(f);
+
         ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
         if (ret) {
             return ret;
@@ -1705,7 +1761,6 @@ static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
             qemu_put_byte(f, len);
             qemu_put_buffer(f, (uint8_t *)vmsd->name, len);
             qemu_put_be32(f, vmsd->version_id);
-            assert(!vmsd->subsections);
             vmstate_save_state(f, vmsd, opaque);
         }
         sub++;
@@ -1831,8 +1886,9 @@ out:
         g_free(le);
     }
 
-    if (qemu_file_has_error(f))
-        ret = -EIO;
+    if (ret == 0) {
+        ret = qemu_file_get_error(f);
+    }
 
     return ret;
 }