Merge "These changes are the raw update to qemu-2.6."

1 files changed, 81 insertions, 25 deletions

diff --git a/qemu/migration/block.c b/qemu/migration/block.c
index 85496fd80..174331728 100644
--- a/qemu/migration/block.c
+++ b/qemu/migration/block.c
@@ -13,18 +13,20 @@
  * GNU GPL, version 2 or (at your option) any later version.
  */
 
+#include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "qemu-common.h"
 #include "block/block.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "hw/hw.h"
+#include "qemu/cutils.h"
 #include "qemu/queue.h"
 #include "qemu/timer.h"
 #include "migration/block.h"
 #include "migration/migration.h"
 #include "sysemu/blockdev.h"
 #include "sysemu/block-backend.h"
-#include <assert.h>
 
 #define BLOCK_SIZE                       (1 << 20)
 #define BDRV_SECTORS_PER_DIRTY_CHUNK     (BLOCK_SIZE >> BDRV_SECTOR_BITS)
@@ -36,6 +38,8 @@
 
 #define MAX_IS_ALLOCATED_SEARCH 65536
 
+#define MAX_INFLIGHT_IO 512
+
 //#define DEBUG_BLK_MIGRATION
 
 #ifdef DEBUG_BLK_MIGRATION
@@ -52,17 +56,25 @@ typedef struct BlkMigDevState {
     int shared_base;
     int64_t total_sectors;
     QSIMPLEQ_ENTRY(BlkMigDevState) entry;
+    Error *blocker;
 
     /* Only used by migration thread.  Does not need a lock.  */
     int bulk_completed;
     int64_t cur_sector;
     int64_t cur_dirty;
 
-    /* Protected by block migration lock.  */
+    /* Data in the aio_bitmap is protected by block migration lock.
+     * Allocation and free happen during setup and cleanup respectively.
+     */
     unsigned long *aio_bitmap;
+
+    /* Protected by block migration lock.  */
     int64_t completed_sectors;
+
+    /* During migration this is protected by iothread lock / AioContext.
+     * Allocation and free happen during setup and cleanup respectively.
+     */
     BdrvDirtyBitmap *dirty_bitmap;
-    Error *blocker;
 } BlkMigDevState;
 
 typedef struct BlkMigBlock {
@@ -98,7 +110,7 @@ typedef struct BlkMigState {
     int prev_progress;
     int bulk_completed;
 
-    /* Lock must be taken _inside_ the iothread lock.  */
+    /* Lock must be taken _inside_ the iothread lock and any AioContexts.  */
     QemuMutex lock;
 } BlkMigState;
 
@@ -262,11 +274,13 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
 
     if (bmds->shared_base) {
         qemu_mutex_lock_iothread();
+        aio_context_acquire(bdrv_get_aio_context(bs));
         while (cur_sector < total_sectors &&
                !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
                                   &nr_sectors)) {
             cur_sector += nr_sectors;
         }
+        aio_context_release(bdrv_get_aio_context(bs));
         qemu_mutex_unlock_iothread();
     }
 
@@ -300,11 +314,21 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     block_mig_state.submitted++;
     blk_mig_unlock();
 
+    /* We do not know if bs is under the main thread (and thus does
+     * not acquire the AioContext when doing AIO) or rather under
+     * dataplane.  Thus acquire both the iothread mutex and the
+     * AioContext.
+     *
+     * This is ugly and will disappear when we make bdrv_* thread-safe,
+     * without the need to acquire the AioContext.
+     */
     qemu_mutex_lock_iothread();
+    aio_context_acquire(bdrv_get_aio_context(bmds->bs));
     blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
                                 nr_sectors, blk_mig_read_cb, blk);
 
     bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector, nr_sectors);
+    aio_context_release(bdrv_get_aio_context(bmds->bs));
     qemu_mutex_unlock_iothread();
 
     bmds->cur_sector = cur_sector + nr_sectors;
@@ -319,8 +343,10 @@ static int set_dirty_tracking(void)
     int ret;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
                                                       NULL, NULL);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
         if (!bmds->dirty_bitmap) {
             ret = -errno;
             goto fail;
@@ -331,18 +357,24 @@ static int set_dirty_tracking(void)
 fail:
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
         if (bmds->dirty_bitmap) {
+            aio_context_acquire(bdrv_get_aio_context(bmds->bs));
             bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+            aio_context_release(bdrv_get_aio_context(bmds->bs));
         }
     }
     return ret;
 }
 
+/* Called with iothread lock taken.  */
+
 static void unset_dirty_tracking(void)
 {
     BlkMigDevState *bmds;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
     }
 }
 
@@ -442,7 +474,7 @@ static void blk_mig_reset_dirty_cursor(void)
     }
 }
 
-/* Called with iothread lock taken.  */
+/* Called with iothread lock and AioContext taken.  */
 
 static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
                                  int is_async)
@@ -525,7 +557,9 @@ static int blk_mig_save_dirty_block(QEMUFile *f, int is_async)
     int ret = 1;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         ret = mig_save_device_dirty(f, bmds, is_async);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
         if (ret <= 0) {
             break;
         }
@@ -583,7 +617,9 @@ static int64_t get_remaining_dirty(void)
     int64_t dirty = 0;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         dirty += bdrv_get_dirty_count(bmds->dirty_bitmap);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
     }
 
     return dirty << BDRV_SECTOR_BITS;
@@ -591,25 +627,32 @@ static int64_t get_remaining_dirty(void)
 
 /* Called with iothread lock taken.  */
 
-static void blk_mig_cleanup(void)
+static void block_migration_cleanup(void *opaque)
 {
     BlkMigDevState *bmds;
     BlkMigBlock *blk;
+    AioContext *ctx;
 
     bdrv_drain_all();
 
     unset_dirty_tracking();
 
-    blk_mig_lock();
     while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
         bdrv_op_unblock_all(bmds->bs, bmds->blocker);
         error_free(bmds->blocker);
+
+        /* Save ctx, because bmds->bs can disappear during bdrv_unref.  */
+        ctx = bdrv_get_aio_context(bmds->bs);
+        aio_context_acquire(ctx);
         bdrv_unref(bmds->bs);
+        aio_context_release(ctx);
+
         g_free(bmds->aio_bitmap);
         g_free(bmds);
     }
 
+    blk_mig_lock();
     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
         g_free(blk->buf);
@@ -618,11 +661,6 @@ static void blk_mig_cleanup(void)
     blk_mig_unlock();
 }
 
-static void block_migration_cancel(void *opaque)
-{
-    blk_mig_cleanup();
-}
-
 static int block_save_setup(QEMUFile *f, void *opaque)
 {
     int ret;
@@ -636,13 +674,12 @@ static int block_save_setup(QEMUFile *f, void *opaque)
     /* start track dirty blocks */
     ret = set_dirty_tracking();
 
+    qemu_mutex_unlock_iothread();
+
     if (ret) {
-        qemu_mutex_unlock_iothread();
         return ret;
     }
 
-    qemu_mutex_unlock_iothread();
-
     ret = flush_blks(f);
     blk_mig_reset_dirty_cursor();
     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
@@ -670,7 +707,10 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
     blk_mig_lock();
     while ((block_mig_state.submitted +
             block_mig_state.read_done) * BLOCK_SIZE <
-           qemu_file_get_rate_limit(f)) {
+           qemu_file_get_rate_limit(f) &&
+           (block_mig_state.submitted +
+            block_mig_state.read_done) <
+           MAX_INFLIGHT_IO) {
         blk_mig_unlock();
         if (block_mig_state.bulk_completed == 0) {
             /* first finish the bulk phase */
@@ -753,26 +793,30 @@ static int block_save_complete(QEMUFile *f, void *opaque)
     return 0;
 }
 
-static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
+                               uint64_t *non_postcopiable_pending,
+                               uint64_t *postcopiable_pending)
 {
     /* Estimate pending number of bytes to send */
     uint64_t pending;
 
     qemu_mutex_lock_iothread();
+    pending = get_remaining_dirty();
+    qemu_mutex_unlock_iothread();
+
     blk_mig_lock();
-    pending = get_remaining_dirty() +
-                       block_mig_state.submitted * BLOCK_SIZE +
-                       block_mig_state.read_done * BLOCK_SIZE;
+    pending += block_mig_state.submitted * BLOCK_SIZE +
+               block_mig_state.read_done * BLOCK_SIZE;
+    blk_mig_unlock();
 
     /* Report at least one block pending during bulk phase */
     if (pending <= max_size && !block_mig_state.bulk_completed) {
         pending = max_size + BLOCK_SIZE;
     }
-    blk_mig_unlock();
-    qemu_mutex_unlock_iothread();
 
     DPRINTF("Enter save live pending  %" PRIu64 "\n", pending);
-    return pending;
+    /* We don't do postcopy */
+    *non_postcopiable_pending += pending;
 }
 
 static int block_load(QEMUFile *f, void *opaque, int version_id)
@@ -783,6 +827,7 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
     int64_t addr;
     BlockDriverState *bs, *bs_prev = NULL;
     BlockBackend *blk;
+    Error *local_err = NULL;
     uint8_t *buf;
     int64_t total_sectors = 0;
     int nr_sectors;
@@ -807,6 +852,11 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
                 return -EINVAL;
             }
             bs = blk_bs(blk);
+            if (!bs) {
+                fprintf(stderr, "Block device %s has no medium\n",
+                        device_name);
+                return -EINVAL;
+            }
 
             if (bs != bs_prev) {
                 bs_prev = bs;
@@ -816,6 +866,12 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
                                  device_name);
                     return -EINVAL;
                 }
+
+                bdrv_invalidate_cache(bs, &local_err);
+                if (local_err) {
+                    error_report_err(local_err);
+                    return -EINVAL;
+                }
             }
 
             if (total_sectors - addr < BDRV_SECTORS_PER_DIRTY_CHUNK) {
@@ -876,10 +932,10 @@ static SaveVMHandlers savevm_block_handlers = {
     .set_params = block_set_params,
     .save_live_setup = block_save_setup,
     .save_live_iterate = block_save_iterate,
-    .save_live_complete = block_save_complete,
+    .save_live_complete_precopy = block_save_complete,
     .save_live_pending = block_save_pending,
     .load_state = block_load,
-    .cancel = block_migration_cancel,
+    .cleanup = block_migration_cleanup,
     .is_active = block_is_active,
 };