[Qemu-devel] [PATCH v3 0/5] Create setup/cleanup methods for migration incoming side

[Qemu-devel] [PATCH v3 0/5] Create setup/cleanup methods for migration incoming side

[Juan Quintela]

Hi

Changes from v2:
- rename htab_cleanup htab_save_cleanup (dave)
- loaded_data was needed because caller can need it (dave)
- improve error message (dave)

Please, review.

[v2]
- Kevin detected that I didn't  called load_cleanup(), fix it.
- Be consistent and change the naming of the functions so they are all:
  qemu_savevm_state_* or qemu_loadvm_state*
- the traces still used the all names of _begin, instead of _setup,
  fix that.

Please, review.

Later, Juan.

PD: Yes, now that the includes are internal, we coauld rename
    "qemu_savevm_state_" to something shorter, like `savevm_".  The
    same for the loadvm counterparts.  But I am not doing any such
    changes soon, too much churn for so little gain.

[v1]
This series make:
- use of cleanup/save methods generic, not only for save_live methods
- create the equivalent methods for the load side (load_setup/cleanup)
- Make ram use this methods to see how/when they are used.

Stefan, Kevin, this were the methods that you asked for the block.c
migration, right?  Please, comment if they are enough for you.

Juan Quintela (5):
  migration: Rename save_live_setup() to save_setup()
  migration: Rename cleanup() to save_cleanup()
  migration: Create load_setup()/cleanup() methods
  migration: Convert ram to use new load_setup()/load_cleanup()
  migration: Make compression_threads use save/load_setup/cleanup()

 hw/ppc/spapr.c               |  6 ++---
 include/migration/register.h |  6 +++--
 migration/block.c            |  4 +--
 migration/colo.c             |  2 +-
 migration/migration.c        | 10 +------
 migration/ram.c              | 63 +++++++++++++++++++++++++++++++-------------
 migration/ram.h              |  6 -----
 migration/savevm.c           | 60 +++++++++++++++++++++++++++++++++++------
 migration/savevm.h           |  2 +-
 migration/trace-events       |  4 ++-
 10 files changed, 112 insertions(+), 51 deletions(-)

-- 
2.9.4

[Qemu-devel] [PATCH v3 1/5] migration: Rename save_live_setup() to save_setup()

[Juan Quintela]

We are going to use it now for more than save live regions.
Once there rename qemu_savevm_state_begin() to qemu_savevm_state_setup().

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/ppc/spapr.c               |  2 +-
 include/migration/register.h |  2 +-
 migration/block.c            |  2 +-
 migration/colo.c             |  2 +-
 migration/migration.c        |  2 +-
 migration/ram.c              |  2 +-
 migration/savevm.c           | 12 ++++++------
 migration/savevm.h           |  2 +-
 migration/trace-events       |  2 +-
 9 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index e877d45..422109f 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1869,7 +1869,7 @@ static void htab_cleanup(void *opaque)
 }
 
 static SaveVMHandlers savevm_htab_handlers = {
-    .save_live_setup = htab_save_setup,
+    .save_setup = htab_save_setup,
     .save_live_iterate = htab_save_iterate,
     .save_live_complete_precopy = htab_save_complete,
     .cleanup = htab_cleanup,
diff --git a/include/migration/register.h b/include/migration/register.h
index d9498d9..f607769 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -33,7 +33,7 @@ typedef struct SaveVMHandlers {
     int (*save_live_iterate)(QEMUFile *f, void *opaque);
 
     /* This runs outside the iothread lock!  */
-    int (*save_live_setup)(QEMUFile *f, void *opaque);
+    int (*save_setup)(QEMUFile *f, void *opaque);
     void (*save_live_pending)(QEMUFile *f, void *opaque,
                               uint64_t threshold_size,
                               uint64_t *non_postcopiable_pending,
diff --git a/migration/block.c b/migration/block.c
index 7674ae1..7cb77e5 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -1004,7 +1004,7 @@ static bool block_is_active(void *opaque)
 }
 
 static SaveVMHandlers savevm_block_handlers = {
-    .save_live_setup = block_save_setup,
+    .save_setup = block_save_setup,
     .save_live_iterate = block_save_iterate,
     .save_live_complete_precopy = block_save_complete,
     .save_live_pending = block_save_pending,
diff --git a/migration/colo.c b/migration/colo.c
index c4ba4c3..ef35f00 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -350,7 +350,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     /* Disable block migration */
     migrate_set_block_enabled(false, &local_err);
     qemu_savevm_state_header(fb);
-    qemu_savevm_state_begin(fb);
+    qemu_savevm_state_setup(fb);
     qemu_mutex_lock_iothread();
     qemu_savevm_state_complete_precopy(fb, false, false);
     qemu_mutex_unlock_iothread();
diff --git a/migration/migration.c b/migration/migration.c
index f588329..520d9b9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1824,7 +1824,7 @@ static void *migration_thread(void *opaque)
         qemu_savevm_send_postcopy_advise(s->to_dst_file);
     }
 
-    qemu_savevm_state_begin(s->to_dst_file);
+    qemu_savevm_state_setup(s->to_dst_file);
 
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
     migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
diff --git a/migration/ram.c b/migration/ram.c
index 0baa1e0..480248a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2623,7 +2623,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 }
 
 static SaveVMHandlers savevm_ram_handlers = {
-    .save_live_setup = ram_save_setup,
+    .save_setup = ram_save_setup,
     .save_live_iterate = ram_save_iterate,
     .save_live_complete_postcopy = ram_save_complete,
     .save_live_complete_precopy = ram_save_complete,
diff --git a/migration/savevm.c b/migration/savevm.c
index 6bfd489..c699dc9 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -606,7 +606,7 @@ int register_savevm_live(DeviceState *dev,
     se->opaque = opaque;
     se->vmsd = NULL;
     /* if this is a live_savem then set is_ram */
-    if (ops->save_live_setup != NULL) {
+    if (ops->save_setup != NULL) {
         se->is_ram = 1;
     }
 
@@ -977,14 +977,14 @@ void qemu_savevm_state_header(QEMUFile *f)
 
 }
 
-void qemu_savevm_state_begin(QEMUFile *f)
+void qemu_savevm_state_setup(QEMUFile *f)
 {
     SaveStateEntry *se;
     int ret;
 
-    trace_savevm_state_begin();
+    trace_savevm_state_setup();
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
-        if (!se->ops || !se->ops->save_live_setup) {
+        if (!se->ops || !se->ops->save_setup) {
             continue;
         }
         if (se->ops && se->ops->is_active) {
@@ -994,7 +994,7 @@ void qemu_savevm_state_begin(QEMUFile *f)
         }
         save_section_header(f, se, QEMU_VM_SECTION_START);
 
-        ret = se->ops->save_live_setup(f, se->opaque);
+        ret = se->ops->save_setup(f, se->opaque);
         save_section_footer(f, se);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
@@ -1263,7 +1263,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
 
     qemu_mutex_unlock_iothread();
     qemu_savevm_state_header(f);
-    qemu_savevm_state_begin(f);
+    qemu_savevm_state_setup(f);
     qemu_mutex_lock_iothread();
 
     while (qemu_file_get_error(f) == 0) {
diff --git a/migration/savevm.h b/migration/savevm.h
index 5a2ed11..6babc62 100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -30,7 +30,7 @@
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
 bool qemu_savevm_state_blocked(Error **errp);
-void qemu_savevm_state_begin(QEMUFile *f);
+void qemu_savevm_state_setup(QEMUFile *f);
 void qemu_savevm_state_header(QEMUFile *f);
 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy);
 void qemu_savevm_state_cleanup(void);
diff --git a/migration/trace-events b/migration/trace-events
index 38345be..9669e94 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -32,7 +32,7 @@ savevm_send_open_return_path(void) ""
 savevm_send_ping(uint32_t val) "%x"
 savevm_send_postcopy_listen(void) ""
 savevm_send_postcopy_run(void) ""
-savevm_state_begin(void) ""
+savevm_state_setup(void) ""
 savevm_state_header(void) ""
 savevm_state_iterate(void) ""
 savevm_state_cleanup(void) ""
-- 
2.9.4

[Qemu-devel] [PATCH v3 2/5] migration: Rename cleanup() to save_cleanup()

[Juan Quintela]

We need a cleanup for loads, so we rename here to be consistent.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

--

Rename htab_cleanup to htap_save_cleanup as dave suggestion
---
 hw/ppc/spapr.c               | 4 ++--
 include/migration/register.h | 2 +-
 migration/block.c            | 2 +-
 migration/ram.c              | 2 +-
 migration/savevm.c           | 4 ++--
 5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 422109f..5e28719 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1861,7 +1861,7 @@ static int htab_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static void htab_cleanup(void *opaque)
+static void htab_save_cleanup(void *opaque)
 {
     sPAPRMachineState *spapr = opaque;
 
@@ -1872,7 +1872,7 @@ static SaveVMHandlers savevm_htab_handlers = {
     .save_setup = htab_save_setup,
     .save_live_iterate = htab_save_iterate,
     .save_live_complete_precopy = htab_save_complete,
-    .cleanup = htab_cleanup,
+    .save_cleanup = htab_save_cleanup,
     .load_state = htab_load,
 };
 
diff --git a/include/migration/register.h b/include/migration/register.h
index f607769..938ea2b 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -18,7 +18,7 @@ typedef struct SaveVMHandlers {
     /* This runs inside the iothread lock.  */
     SaveStateHandler *save_state;
 
-    void (*cleanup)(void *opaque);
+    void (*save_cleanup)(void *opaque);
     int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
     int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
 
diff --git a/migration/block.c b/migration/block.c
index 7cb77e5..0c24a7f 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -1009,7 +1009,7 @@ static SaveVMHandlers savevm_block_handlers = {
     .save_live_complete_precopy = block_save_complete,
     .save_live_pending = block_save_pending,
     .load_state = block_load,
-    .cleanup = block_migration_cleanup,
+    .save_cleanup = block_migration_cleanup,
     .is_active = block_is_active,
 };
 
diff --git a/migration/ram.c b/migration/ram.c
index 480248a..649f76c 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2629,7 +2629,7 @@ static SaveVMHandlers savevm_ram_handlers = {
     .save_live_complete_precopy = ram_save_complete,
     .save_live_pending = ram_save_pending,
     .load_state = ram_load,
-    .cleanup = ram_migration_cleanup,
+    .save_cleanup = ram_migration_cleanup,
 };
 
 void ram_mig_init(void)
diff --git a/migration/savevm.c b/migration/savevm.c
index c699dc9..7d273f9 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1237,8 +1237,8 @@ void qemu_savevm_state_cleanup(void)
 
     trace_savevm_state_cleanup();
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
-        if (se->ops && se->ops->cleanup) {
-            se->ops->cleanup(se->opaque);
+        if (se->ops && se->ops->save_cleanup) {
+            se->ops->save_cleanup(se->opaque);
         }
     }
 }
-- 
2.9.4

[Qemu-devel] [PATCH v3 3/5] migration: Create load_setup()/cleanup() methods

[Juan Quintela]

We need to do things at load time and at cleanup time.

Signed-off-by: Juan Quintela <quintela@redhat.com>

--

Move the printing of the error message so we can print the device
giving the error.
---
 include/migration/register.h |  2 ++
 migration/savevm.c           | 44 ++++++++++++++++++++++++++++++++++++++++++++
 migration/trace-events       |  2 ++
 3 files changed, 48 insertions(+)

diff --git a/include/migration/register.h b/include/migration/register.h
index 938ea2b..a0f1edd 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -39,6 +39,8 @@ typedef struct SaveVMHandlers {
                               uint64_t *non_postcopiable_pending,
                               uint64_t *postcopiable_pending);
     LoadStateHandler *load_state;
+    int (*load_setup)(QEMUFile *f, void *opaque);
+    int (*load_cleanup)(void *opaque);
 } SaveVMHandlers;
 
 int register_savevm_live(DeviceState *dev,
diff --git a/migration/savevm.c b/migration/savevm.c
index 7d273f9..a0733f9 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1923,6 +1923,44 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
     return 0;
 }
 
+static int qemu_loadvm_state_setup(QEMUFile *f)
+{
+    SaveStateEntry *se;
+    int ret;
+
+    trace_loadvm_state_setup();
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+        if (!se->ops || !se->ops->load_setup) {
+            continue;
+        }
+        if (se->ops && se->ops->is_active) {
+            if (!se->ops->is_active(se->opaque)) {
+                continue;
+            }
+        }
+
+        ret = se->ops->load_setup(f, se->opaque);
+        if (ret < 0) {
+            qemu_file_set_error(f, ret);
+            error_report("Load state of device %s failed", se->idstr);
+            return ret;
+        }
+    }
+    return 0;
+}
+
+static void qemu_loadvm_state_cleanup(void)
+{
+    SaveStateEntry *se;
+
+    trace_loadvm_state_cleanup();
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+        if (se->ops && se->ops->load_cleanup) {
+            se->ops->load_cleanup(se->opaque);
+        }
+    }
+}
+
 static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
 {
     uint8_t section_type;
@@ -1995,6 +2033,11 @@ int qemu_loadvm_state(QEMUFile *f)
         return -ENOTSUP;
     }
 
+
+    if (qemu_loadvm_state_setup(f) != 0) {
+        return -EINVAL;
+    }
+
     if (!savevm_state.skip_configuration || enforce_config_section()) {
         if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
             error_report("Configuration section missing");
@@ -2058,6 +2101,7 @@ int qemu_loadvm_state(QEMUFile *f)
         }
     }
 
+    qemu_loadvm_state_cleanup();
     cpu_synchronize_all_post_init();
 
     return ret;
diff --git a/migration/trace-events b/migration/trace-events
index 9669e94..cb2c4b5 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -7,6 +7,8 @@ qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
 qemu_loadvm_state_post_main(int ret) "%d"
 qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
 qemu_savevm_send_packaged(void) ""
+loadvm_state_setup(void) ""
+loadvm_state_cleanup(void) ""
 loadvm_handle_cmd_packaged(unsigned int length) "%u"
 loadvm_handle_cmd_packaged_main(int ret) "%d"
 loadvm_handle_cmd_packaged_received(int ret) "%d"
-- 
2.9.4

[Qemu-devel] [PATCH v3 4/5] migration: Convert ram to use new load_setup()/load_cleanup()

[Juan Quintela]

Once there, I rename ram_migration_cleanup() to ram_save_cleanup().
Notice that this is the first pass, and I only passed XBZRLE to the
new scheme.  Moved decoded_buf to inside XBZRLE struct.
As a bonus, I don't have to export xbzrle functions from ram.c.

Signed-off-by: Juan Quintela <quintela@redhat.com>

--

loaded_data pointer was needed because called can change it (dave)
---
 migration/migration.c |  3 ---
 migration/ram.c       | 49 ++++++++++++++++++++++++++++++++++++-------------
 migration/ram.h       |  1 -
 3 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index 520d9b9..aaaf7ff 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -350,9 +350,6 @@ static void process_incoming_migration_co(void *opaque)
         migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
     }
-
-    free_xbzrle_decoded_buf();
-
     mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
     qemu_bh_schedule(mis->bh);
 }
diff --git a/migration/ram.c b/migration/ram.c
index 649f76c..a619e0b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -85,11 +85,10 @@ static struct {
     QemuMutex lock;
     /* it will store a page full of zeros */
     uint8_t *zero_target_page;
+    /* buffer used for XBZRLE decoding */
+    uint8_t *decoded_buf;
 } XBZRLE;
 
-/* buffer used for XBZRLE decoding */
-static uint8_t *xbzrle_decoded_buf;
-
 static void XBZRLE_cache_lock(void)
 {
     if (migrate_use_xbzrle())
@@ -1350,13 +1349,18 @@ uint64_t ram_bytes_total(void)
     return total;
 }
 
-void free_xbzrle_decoded_buf(void)
+static void xbzrle_load_setup(void)
 {
-    g_free(xbzrle_decoded_buf);
-    xbzrle_decoded_buf = NULL;
+    XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
 }
 
-static void ram_migration_cleanup(void *opaque)
+static void xbzrle_load_cleanup(void)
+{
+    g_free(XBZRLE.decoded_buf);
+    XBZRLE.decoded_buf = NULL;
+}
+
+static void ram_save_cleanup(void *opaque)
 {
     RAMState **rsp = opaque;
     RAMBlock *block;
@@ -2078,11 +2082,6 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
     int xh_flags;
     uint8_t *loaded_data;
 
-    if (!xbzrle_decoded_buf) {
-        xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
-    }
-    loaded_data = xbzrle_decoded_buf;
-
     /* extract RLE header */
     xh_flags = qemu_get_byte(f);
     xh_len = qemu_get_be16(f);
@@ -2096,7 +2095,9 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
         error_report("Failed to load XBZRLE page - len overflow!");
         return -1;
     }
+    loaded_data = XBZRLE.decoded_buf;
     /* load data and decode */
+    /* it can change laded_data to point to an internal buffer */
     qemu_get_buffer_in_place(f, &loaded_data, xh_len);
 
     /* decode RLE */
@@ -2310,6 +2311,26 @@ static void decompress_data_with_multi_threads(QEMUFile *f,
 }
 
 /**
+ * ram_load_setup: Setup RAM for migration incoming side
+ *
+ * Returns zero to indicate success and negative for error
+ *
+ * @f: QEMUFile where to receive the data
+ * @opaque: RAMState pointer
+ */
+static int ram_load_setup(QEMUFile *f, void *opaque)
+{
+    xbzrle_load_setup();
+    return 0;
+}
+
+static int ram_load_cleanup(void *opaque)
+{
+    xbzrle_load_cleanup();
+    return 0;
+}
+
+/**
  * ram_postcopy_incoming_init: allocate postcopy data structures
  *
  * Returns 0 for success and negative if there was one error
@@ -2629,7 +2650,9 @@ static SaveVMHandlers savevm_ram_handlers = {
     .save_live_complete_precopy = ram_save_complete,
     .save_live_pending = ram_save_pending,
     .load_state = ram_load,
-    .save_cleanup = ram_migration_cleanup,
+    .save_cleanup = ram_save_cleanup,
+    .load_setup = ram_load_setup,
+    .load_cleanup = ram_load_cleanup,
 };
 
 void ram_mig_init(void)
diff --git a/migration/ram.h b/migration/ram.h
index 6272eb0..a8b79a4 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -47,7 +47,6 @@ void migrate_decompress_threads_join(void);
 uint64_t ram_pagesize_summary(void);
 int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
 void acct_update_position(QEMUFile *f, size_t size, bool zero);
-void free_xbzrle_decoded_buf(void);
 void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
                            unsigned long pages);
 void ram_postcopy_migrated_memory_release(MigrationState *ms);
-- 
2.9.4

[Qemu-devel] [PATCH v3 5/5] migration: Make compression_threads use save/load_setup/cleanup()

[Juan Quintela]

Once there, be consistent and use
compress_thread_{save,load}_{setup,cleanup}.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/migration.c |  5 -----
 migration/ram.c       | 12 ++++++++----
 migration/ram.h       |  5 -----
 3 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index aaaf7ff..f6b7404 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -284,7 +284,6 @@ static void process_incoming_migration_bh(void *opaque)
     } else {
         runstate_set(global_state_get_runstate());
     }
-    migrate_decompress_threads_join();
     /*
      * This must happen after any state changes since as soon as an external
      * observer sees this event they might start to prod at the VM assuming
@@ -347,7 +346,6 @@ static void process_incoming_migration_co(void *opaque)
         migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                           MIGRATION_STATUS_FAILED);
         error_report("load of migration failed: %s", strerror(-ret));
-        migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
     }
     mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
@@ -358,7 +356,6 @@ void migration_fd_process_incoming(QEMUFile *f)
 {
     Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, f);
 
-    migrate_decompress_threads_create();
     qemu_file_set_blocking(f, false);
     qemu_coroutine_enter(co);
 }
@@ -825,7 +822,6 @@ static void migrate_fd_cleanup(void *opaque)
         }
         qemu_mutex_lock_iothread();
 
-        migrate_compress_threads_join();
         qemu_fclose(s->to_dst_file);
         s->to_dst_file = NULL;
     }
@@ -1978,7 +1974,6 @@ void migrate_fd_connect(MigrationState *s)
         }
     }
 
-    migrate_compress_threads_create();
     qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
                        QEMU_THREAD_JOINABLE);
     s->migration_thread_running = true;
diff --git a/migration/ram.c b/migration/ram.c
index a619e0b..26393df 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -306,7 +306,7 @@ static inline void terminate_compression_threads(void)
     }
 }
 
-void migrate_compress_threads_join(void)
+static void compress_threads_save_cleanup(void)
 {
     int i, thread_count;
 
@@ -329,7 +329,7 @@ void migrate_compress_threads_join(void)
     comp_param = NULL;
 }
 
-void migrate_compress_threads_create(void)
+static void compress_threads_save_setup(void)
 {
     int i, thread_count;
 
@@ -1390,6 +1390,7 @@ static void ram_save_cleanup(void *opaque)
     }
     XBZRLE_cache_unlock();
     migration_page_queue_free(*rsp);
+    compress_threads_save_cleanup();
     g_free(*rsp);
     *rsp = NULL;
 }
@@ -1923,6 +1924,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     }
 
     rcu_read_unlock();
+    compress_threads_save_setup();
 
     ram_control_before_iterate(f, RAM_CONTROL_SETUP);
     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
@@ -2231,7 +2233,7 @@ static void wait_for_decompress_done(void)
     qemu_mutex_unlock(&decomp_done_lock);
 }
 
-void migrate_decompress_threads_create(void)
+static void compress_threads_load_setup(void)
 {
     int i, thread_count;
 
@@ -2255,7 +2257,7 @@ void migrate_decompress_threads_create(void)
     }
 }
 
-void migrate_decompress_threads_join(void)
+static void compress_threads_load_cleanup(void)
 {
     int i, thread_count;
 
@@ -2321,12 +2323,14 @@ static void decompress_data_with_multi_threads(QEMUFile *f,
 static int ram_load_setup(QEMUFile *f, void *opaque)
 {
     xbzrle_load_setup();
+    compress_threads_load_setup();
     return 0;
 }
 
 static int ram_load_cleanup(void *opaque)
 {
     xbzrle_load_cleanup();
+    compress_threads_load_cleanup();
     return 0;
 }
 
diff --git a/migration/ram.h b/migration/ram.h
index a8b79a4..c081fde 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -39,11 +39,6 @@ int64_t xbzrle_cache_resize(int64_t new_size);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_total(void);
 
-void migrate_compress_threads_create(void);
-void migrate_compress_threads_join(void);
-void migrate_decompress_threads_create(void);
-void migrate_decompress_threads_join(void);
-
 uint64_t ram_pagesize_summary(void);
 int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
 void acct_update_position(QEMUFile *f, size_t size, bool zero);
-- 
2.9.4

Re: [Qemu-devel] [PATCH v3 4/5] migration: Convert ram to use new load_setup()/load_cleanup()

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> Once there, I rename ram_migration_cleanup() to ram_save_cleanup().
> Notice that this is the first pass, and I only passed XBZRLE to the
> new scheme.  Moved decoded_buf to inside XBZRLE struct.
> As a bonus, I don't have to export xbzrle functions from ram.c.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>


Note a tiny comment typo below, but other than that:

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> --
> 
> loaded_data pointer was needed because called can change it (dave)
> ---
>  migration/migration.c |  3 ---
>  migration/ram.c       | 49 ++++++++++++++++++++++++++++++++++++-------------
>  migration/ram.h       |  1 -
>  3 files changed, 36 insertions(+), 17 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 520d9b9..aaaf7ff 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -350,9 +350,6 @@ static void process_incoming_migration_co(void *opaque)
>          migrate_decompress_threads_join();
>          exit(EXIT_FAILURE);
>      }
> -
> -    free_xbzrle_decoded_buf();
> -
>      mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
>      qemu_bh_schedule(mis->bh);
>  }
> diff --git a/migration/ram.c b/migration/ram.c
> index 649f76c..a619e0b 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -85,11 +85,10 @@ static struct {
>      QemuMutex lock;
>      /* it will store a page full of zeros */
>      uint8_t *zero_target_page;
> +    /* buffer used for XBZRLE decoding */
> +    uint8_t *decoded_buf;
>  } XBZRLE;
>  
> -/* buffer used for XBZRLE decoding */
> -static uint8_t *xbzrle_decoded_buf;
> -
>  static void XBZRLE_cache_lock(void)
>  {
>      if (migrate_use_xbzrle())
> @@ -1350,13 +1349,18 @@ uint64_t ram_bytes_total(void)
>      return total;
>  }
>  
> -void free_xbzrle_decoded_buf(void)
> +static void xbzrle_load_setup(void)
>  {
> -    g_free(xbzrle_decoded_buf);
> -    xbzrle_decoded_buf = NULL;
> +    XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
>  }
>  
> -static void ram_migration_cleanup(void *opaque)
> +static void xbzrle_load_cleanup(void)
> +{
> +    g_free(XBZRLE.decoded_buf);
> +    XBZRLE.decoded_buf = NULL;
> +}
> +
> +static void ram_save_cleanup(void *opaque)
>  {
>      RAMState **rsp = opaque;
>      RAMBlock *block;
> @@ -2078,11 +2082,6 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
>      int xh_flags;
>      uint8_t *loaded_data;
>  
> -    if (!xbzrle_decoded_buf) {
> -        xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
> -    }
> -    loaded_data = xbzrle_decoded_buf;
> -
>      /* extract RLE header */
>      xh_flags = qemu_get_byte(f);
>      xh_len = qemu_get_be16(f);
> @@ -2096,7 +2095,9 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
>          error_report("Failed to load XBZRLE page - len overflow!");
>          return -1;
>      }
> +    loaded_data = XBZRLE.decoded_buf;
>      /* load data and decode */
> +    /* it can change laded_data to point to an internal buffer */
                         ^--- o

>      qemu_get_buffer_in_place(f, &loaded_data, xh_len);
>  
>      /* decode RLE */
> @@ -2310,6 +2311,26 @@ static void decompress_data_with_multi_threads(QEMUFile *f,
>  }
>  
>  /**
> + * ram_load_setup: Setup RAM for migration incoming side
> + *
> + * Returns zero to indicate success and negative for error
> + *
> + * @f: QEMUFile where to receive the data
> + * @opaque: RAMState pointer
> + */
> +static int ram_load_setup(QEMUFile *f, void *opaque)
> +{
> +    xbzrle_load_setup();
> +    return 0;
> +}
> +
> +static int ram_load_cleanup(void *opaque)
> +{
> +    xbzrle_load_cleanup();
> +    return 0;
> +}
> +
> +/**
>   * ram_postcopy_incoming_init: allocate postcopy data structures
>   *
>   * Returns 0 for success and negative if there was one error
> @@ -2629,7 +2650,9 @@ static SaveVMHandlers savevm_ram_handlers = {
>      .save_live_complete_precopy = ram_save_complete,
>      .save_live_pending = ram_save_pending,
>      .load_state = ram_load,
> -    .save_cleanup = ram_migration_cleanup,
> +    .save_cleanup = ram_save_cleanup,
> +    .load_setup = ram_load_setup,
> +    .load_cleanup = ram_load_cleanup,
>  };
>  
>  void ram_mig_init(void)
> diff --git a/migration/ram.h b/migration/ram.h
> index 6272eb0..a8b79a4 100644
> --- a/migration/ram.h
> +++ b/migration/ram.h
> @@ -47,7 +47,6 @@ void migrate_decompress_threads_join(void);
>  uint64_t ram_pagesize_summary(void);
>  int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
>  void acct_update_position(QEMUFile *f, size_t size, bool zero);
> -void free_xbzrle_decoded_buf(void);
>  void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
>                             unsigned long pages);
>  void ram_postcopy_migrated_memory_release(MigrationState *ms);
> -- 
> 2.9.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH v3 3/5] migration: Create load_setup()/cleanup() methods

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> We need to do things at load time and at cleanup time.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> --
> 
> Move the printing of the error message so we can print the device
> giving the error.
> ---
>  include/migration/register.h |  2 ++
>  migration/savevm.c           | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  migration/trace-events       |  2 ++
>  3 files changed, 48 insertions(+)
> 
> diff --git a/include/migration/register.h b/include/migration/register.h
> index 938ea2b..a0f1edd 100644
> --- a/include/migration/register.h
> +++ b/include/migration/register.h
> @@ -39,6 +39,8 @@ typedef struct SaveVMHandlers {
>                                uint64_t *non_postcopiable_pending,
>                                uint64_t *postcopiable_pending);
>      LoadStateHandler *load_state;
> +    int (*load_setup)(QEMUFile *f, void *opaque);
> +    int (*load_cleanup)(void *opaque);
>  } SaveVMHandlers;
>  
>  int register_savevm_live(DeviceState *dev,
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 7d273f9..a0733f9 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1923,6 +1923,44 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
>      return 0;
>  }
>  
> +static int qemu_loadvm_state_setup(QEMUFile *f)
> +{
> +    SaveStateEntry *se;
> +    int ret;
> +
> +    trace_loadvm_state_setup();
> +    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
> +        if (!se->ops || !se->ops->load_setup) {
> +            continue;
> +        }
> +        if (se->ops && se->ops->is_active) {
> +            if (!se->ops->is_active(se->opaque)) {
> +                continue;
> +            }
> +        }
> +
> +        ret = se->ops->load_setup(f, se->opaque);
> +        if (ret < 0) {
> +            qemu_file_set_error(f, ret);
> +            error_report("Load state of device %s failed", se->idstr);
> +            return ret;
> +        }
> +    }
> +    return 0;
> +}
> +
> +static void qemu_loadvm_state_cleanup(void)
> +{
> +    SaveStateEntry *se;
> +
> +    trace_loadvm_state_cleanup();
> +    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
> +        if (se->ops && se->ops->load_cleanup) {
> +            se->ops->load_cleanup(se->opaque);
> +        }
> +    }
> +}
> +
>  static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
>  {
>      uint8_t section_type;
> @@ -1995,6 +2033,11 @@ int qemu_loadvm_state(QEMUFile *f)
>          return -ENOTSUP;
>      }
>  
> +
> +    if (qemu_loadvm_state_setup(f) != 0) {
> +        return -EINVAL;
> +    }
> +
>      if (!savevm_state.skip_configuration || enforce_config_section()) {
>          if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
>              error_report("Configuration section missing");
> @@ -2058,6 +2101,7 @@ int qemu_loadvm_state(QEMUFile *f)
>          }
>      }
>  
> +    qemu_loadvm_state_cleanup();

Where does the equivalent happen for postcopy?
Do you need to add a call at the bottom of postcopy_ram_listen_thread?

Dave

>      cpu_synchronize_all_post_init();
>  
>      return ret;
> diff --git a/migration/trace-events b/migration/trace-events
> index 9669e94..cb2c4b5 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -7,6 +7,8 @@ qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
>  qemu_loadvm_state_post_main(int ret) "%d"
>  qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
>  qemu_savevm_send_packaged(void) ""
> +loadvm_state_setup(void) ""
> +loadvm_state_cleanup(void) ""
>  loadvm_handle_cmd_packaged(unsigned int length) "%u"
>  loadvm_handle_cmd_packaged_main(int ret) "%d"
>  loadvm_handle_cmd_packaged_received(int ret) "%d"
> -- 
> 2.9.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH v3 3/5] migration: Create load_setup()/cleanup() methods

[Juan Quintela]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> We need to do things at load time and at cleanup time.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> 

>>  
>> +    qemu_loadvm_state_cleanup();
>
> Where does the equivalent happen for postcopy?
> Do you need to add a call at the bottom of postcopy_ram_listen_thread?
>

I think yes, but it is not completely clear how we can arrive there that
way.

It appears that I still should put more things into load_cleanup() hooks
:p

Later, Juan.