[PULL 00/21] migration queue

[PULL 00/21] migration queue

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

The following changes since commit 98b2e3c9ab3abfe476a2b02f8f51813edb90e72d:

  Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging (2019-10-08 16:08:35 +0100)

are available in the Git repository at:

  git://github.com/dagrh/qemu.git tags/pull-migration-20191011a

for you to fetch changes up to 9a85e4b8f672016adbf7b7d5beaab2a99b9b5615:

  migration: Support gtree migration (2019-10-11 17:52:31 +0100)

----------------------------------------------------------------
Migration pull 2019-10-11

Mostly cleanups and minor fixes

[Note I'm seeing a hang on the aarch64 hosted x86-64 tcg migration
test in xbzrle; but I'm seeing that on current head as well]

----------------------------------------------------------------
Dr. David Alan Gilbert (6):
      rcu: Add automatically released rcu_read_lock variants
      migration: Fix missing rcu_read_unlock
      migration: Use automatic rcu_read unlock in ram.c
      migration: Use automatic rcu_read unlock in rdma.c
      rcu: Use automatic rc_read unlock in core memory/exec code
      migration: Don't try and recover return path in non-postcopy

Eric Auger (1):
      migration: Support gtree migration

Wei Yang (14):
      migration: use migration_is_active to represent active state
      migration/postcopy: allocate tmp_page in setup stage
      migration/postcopy: map large zero page in postcopy_ram_incoming_setup()
      migration/postcopy: fix typo in mark_postcopy_blocktime_begin's comment
      migration: pass in_postcopy instead of check state again
      migration: report SaveStateEntry id and name on failure
      migration/postcopy: mis->have_listen_thread check will never be touched
      migration/postcopy: postpone setting PostcopyState to END
      migration/postcopy: rename postcopy_ram_enable_notify to postcopy_ram_incoming_setup
      migration/postcopy: check PostcopyState before setting to POSTCOPY_INCOMING_RUNNING
      migration/multifd: fix a typo in comment of multifd_recv_unfill_packet()
      migration/multifd: use pages->allocated instead of the static max
      migration/multifd: initialize packet->magic/version once at setup stage
      migration/multifd: pages->used would be cleared when attach to multifd_send_state

 docs/devel/rcu.txt          |  16 ++
 exec.c                      | 116 +++++-------
 include/exec/ram_addr.h     | 138 +++++++--------
 include/migration/misc.h    |   1 +
 include/migration/vmstate.h |  40 +++++
 include/qemu/rcu.h          |  25 +++
 memory.c                    |  15 +-
 migration/migration.c       |  17 +-
 migration/postcopy-ram.c    |  88 ++++-----
 migration/postcopy-ram.h    |   9 +-
 migration/ram.c             | 298 +++++++++++++++----------------
 migration/rdma.c            |  57 ++----
 migration/savevm.c          |  14 +-
 migration/trace-events      |   5 +
 migration/vmstate-types.c   | 152 ++++++++++++++++
 tests/test-vmstate.c        | 421 ++++++++++++++++++++++++++++++++++++++++++++
 16 files changed, 980 insertions(+), 432 deletions(-)

[PULL 01/21] migration: use migration_is_active to represent active state

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Wrap the check into a function to make it easy to read.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190717005341.14140-1-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 include/migration/misc.h |  1 +
 migration/migration.c    | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/migration/misc.h b/include/migration/misc.h
index b9d8e787af..d2762257aa 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -60,6 +60,7 @@ void migration_object_init(void);
 void migration_shutdown(void);
 void qemu_start_incoming_migration(const char *uri, Error **errp);
 bool migration_is_idle(void);
+bool migration_is_active(MigrationState *);
 void add_migration_state_change_notifier(Notifier *notify);
 void remove_migration_state_change_notifier(Notifier *notify);
 bool migration_in_setup(MigrationState *);
diff --git a/migration/migration.c b/migration/migration.c
index 5f7e4d15e9..0c51aa6ac7 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1533,8 +1533,7 @@ static void migrate_fd_cleanup(MigrationState *s)
         qemu_fclose(tmp);
     }
 
-    assert((s->state != MIGRATION_STATUS_ACTIVE) &&
-           (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
+    assert(!migration_is_active(s));
 
     if (s->state == MIGRATION_STATUS_CANCELLING) {
         migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
@@ -1703,6 +1702,12 @@ bool migration_is_idle(void)
     return false;
 }
 
+bool migration_is_active(MigrationState *s)
+{
+    return (s->state == MIGRATION_STATUS_ACTIVE ||
+            s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+}
+
 void migrate_init(MigrationState *s)
 {
     /*
@@ -3266,8 +3271,7 @@ static void *migration_thread(void *opaque)
 
     trace_migration_thread_setup_complete();
 
-    while (s->state == MIGRATION_STATUS_ACTIVE ||
-           s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
+    while (migration_is_active(s)) {
         int64_t current_time;
 
         if (urgent || !qemu_file_rate_limit(s->to_dst_file)) {
-- 
2.23.0

[PULL 02/21] rcu: Add automatically released rcu_read_lock variants

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

RCU_READ_LOCK_GUARD() takes the rcu_read_lock and then uses glib's
g_auto infrastructure (and thus whatever the compiler's hooks are) to
release it on all exits of the block.

WITH_RCU_READ_LOCK_GUARD() is similar but is used as a wrapper for the
lock, i.e.:

   WITH_RCU_READ_LOCK_GUARD() {
       stuff under lock
   }

Note the 'unused' attribute is needed to work around clang bug:
  https://bugs.llvm.org/show_bug.cgi?id=43482

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-2-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 docs/devel/rcu.txt | 16 ++++++++++++++++
 include/qemu/rcu.h | 25 +++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/docs/devel/rcu.txt b/docs/devel/rcu.txt
index c84e7f42b2..d83fed2f79 100644
--- a/docs/devel/rcu.txt
+++ b/docs/devel/rcu.txt
@@ -187,6 +187,22 @@ The following APIs must be used before RCU is used in a thread:
 Note that these APIs are relatively heavyweight, and should _not_ be
 nested.
 
+Convenience macros
+==================
+
+Two macros are provided that automatically release the read lock at the
+end of the scope.
+
+      RCU_READ_LOCK_GUARD()
+
+         Takes the lock and will release it at the end of the block it's
+         used in.
+
+      WITH_RCU_READ_LOCK_GUARD()  { code }
+
+         Is used at the head of a block to protect the code within the block.
+
+Note that 'goto'ing out of the guarded block will also drop the lock.
 
 DIFFERENCES WITH LINUX
 ======================
diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h
index 22876d1428..9c82683e37 100644
--- a/include/qemu/rcu.h
+++ b/include/qemu/rcu.h
@@ -154,6 +154,31 @@ extern void call_rcu1(struct rcu_head *head, RCUCBFunc *func);
       }),                                                                \
       (RCUCBFunc *)g_free);
 
+typedef void RCUReadAuto;
+static inline RCUReadAuto *rcu_read_auto_lock(void)
+{
+    rcu_read_lock();
+    /* Anything non-NULL causes the cleanup function to be called */
+    return (void *)(uintptr_t)0x1;
+}
+
+static inline void rcu_read_auto_unlock(RCUReadAuto *r)
+{
+    rcu_read_unlock();
+}
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(RCUReadAuto, rcu_read_auto_unlock)
+
+#define WITH_RCU_READ_LOCK_GUARD() \
+    WITH_RCU_READ_LOCK_GUARD_(_rcu_read_auto##__COUNTER__)
+
+#define WITH_RCU_READ_LOCK_GUARD_(var) \
+    for (g_autoptr(RCUReadAuto) var = rcu_read_auto_lock(); \
+        (var); rcu_read_auto_unlock(var), (var) = NULL)
+
+#define RCU_READ_LOCK_GUARD() \
+    g_autoptr(RCUReadAuto) _rcu_read_auto __attribute__((unused)) = rcu_read_auto_lock()
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.23.0

[PULL 03/21] migration: Fix missing rcu_read_unlock

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use the automatic rcu_read unlocker to fix a missing unlock.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-3-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 22423f08cd..484d66379a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3373,24 +3373,23 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     }
     (*rsp)->f = f;
 
-    rcu_read_lock();
-
-    qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
+    WITH_RCU_READ_LOCK_GUARD() {
+        qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
-        qemu_put_byte(f, strlen(block->idstr));
-        qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
-        qemu_put_be64(f, block->used_length);
-        if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) {
-            qemu_put_be64(f, block->page_size);
-        }
-        if (migrate_ignore_shared()) {
-            qemu_put_be64(f, block->mr->addr);
+        RAMBLOCK_FOREACH_MIGRATABLE(block) {
+            qemu_put_byte(f, strlen(block->idstr));
+            qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
+            qemu_put_be64(f, block->used_length);
+            if (migrate_postcopy_ram() && block->page_size !=
+                                          qemu_host_page_size) {
+                qemu_put_be64(f, block->page_size);
+            }
+            if (migrate_ignore_shared()) {
+                qemu_put_be64(f, block->mr->addr);
+            }
         }
     }
 
-    rcu_read_unlock();
-
     ram_control_before_iterate(f, RAM_CONTROL_SETUP);
     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
 
-- 
2.23.0

[PULL 04/21] migration: Use automatic rcu_read unlock in ram.c

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use the automatic read unlocker in migration/ram.c

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-4-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 259 ++++++++++++++++++++++--------------------------
 1 file changed, 121 insertions(+), 138 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 484d66379a..e29c8b3408 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -181,14 +181,14 @@ int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque)
     RAMBlock *block;
     int ret = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
+
     RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         ret = func(block, opaque);
         if (ret) {
             break;
         }
     }
-    rcu_read_unlock();
     return ret;
 }
 
@@ -1848,12 +1848,12 @@ static void migration_bitmap_sync(RAMState *rs)
     memory_global_dirty_log_sync();
 
     qemu_mutex_lock(&rs->bitmap_mutex);
-    rcu_read_lock();
-    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
-        ramblock_sync_dirty_bitmap(rs, block);
+    WITH_RCU_READ_LOCK_GUARD() {
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+            ramblock_sync_dirty_bitmap(rs, block);
+        }
+        ram_counters.remaining = ram_bytes_remaining();
     }
-    ram_counters.remaining = ram_bytes_remaining();
-    rcu_read_unlock();
     qemu_mutex_unlock(&rs->bitmap_mutex);
 
     memory_global_after_dirty_log_sync();
@@ -2397,13 +2397,12 @@ static void migration_page_queue_free(RAMState *rs)
     /* This queue generally should be empty - but in the case of a failed
      * migration might have some droppings in.
      */
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     QSIMPLEQ_FOREACH_SAFE(mspr, &rs->src_page_requests, next_req, next_mspr) {
         memory_region_unref(mspr->rb->mr);
         QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req);
         g_free(mspr);
     }
-    rcu_read_unlock();
 }
 
 /**
@@ -2424,7 +2423,8 @@ int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len)
     RAMState *rs = ram_state;
 
     ram_counters.postcopy_requests++;
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
+
     if (!rbname) {
         /* Reuse last RAMBlock */
         ramblock = rs->last_req_rb;
@@ -2466,12 +2466,10 @@ int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len)
     QSIMPLEQ_INSERT_TAIL(&rs->src_page_requests, new_entry, next_req);
     migration_make_urgent_request();
     qemu_mutex_unlock(&rs->src_page_req_mutex);
-    rcu_read_unlock();
 
     return 0;
 
 err:
-    rcu_read_unlock();
     return -1;
 }
 
@@ -2700,7 +2698,8 @@ static uint64_t ram_bytes_total_common(bool count_ignored)
     RAMBlock *block;
     uint64_t total = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
+
     if (count_ignored) {
         RAMBLOCK_FOREACH_MIGRATABLE(block) {
             total += block->used_length;
@@ -2710,7 +2709,6 @@ static uint64_t ram_bytes_total_common(bool count_ignored)
             total += block->used_length;
         }
     }
-    rcu_read_unlock();
     return total;
 }
 
@@ -3034,7 +3032,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
     RAMBlock *block;
     int ret;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     /* This should be our last sync, the src is now paused */
     migration_bitmap_sync(rs);
@@ -3048,7 +3046,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
         /* Deal with TPS != HPS and huge pages */
         ret = postcopy_chunk_hostpages(ms, block);
         if (ret) {
-            rcu_read_unlock();
             return ret;
         }
 
@@ -3060,7 +3057,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
     trace_ram_postcopy_send_discard_bitmap();
 
     ret = postcopy_each_ram_send_discard(ms);
-    rcu_read_unlock();
 
     return ret;
 }
@@ -3081,7 +3077,7 @@ int ram_discard_range(const char *rbname, uint64_t start, size_t length)
 
     trace_ram_discard_range(rbname, start, length);
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     RAMBlock *rb = qemu_ram_block_by_name(rbname);
 
     if (!rb) {
@@ -3101,8 +3097,6 @@ int ram_discard_range(const char *rbname, uint64_t start, size_t length)
     ret = ram_block_discard_range(rb, start, length);
 
 err:
-    rcu_read_unlock();
-
     return ret;
 }
 
@@ -3231,13 +3225,12 @@ static void ram_init_bitmaps(RAMState *rs)
     /* For memory_global_dirty_log_start below.  */
     qemu_mutex_lock_iothread();
     qemu_mutex_lock_ramlist();
-    rcu_read_lock();
 
-    ram_list_init_bitmaps();
-    memory_global_dirty_log_start();
-    migration_bitmap_sync_precopy(rs);
-
-    rcu_read_unlock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        ram_list_init_bitmaps();
+        memory_global_dirty_log_start();
+        migration_bitmap_sync_precopy(rs);
+    }
     qemu_mutex_unlock_ramlist();
     qemu_mutex_unlock_iothread();
 }
@@ -3424,55 +3417,57 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
         goto out;
     }
 
-    rcu_read_lock();
-    if (ram_list.version != rs->last_version) {
-        ram_state_reset(rs);
-    }
-
-    /* Read version before ram_list.blocks */
-    smp_rmb();
+    WITH_RCU_READ_LOCK_GUARD() {
+        if (ram_list.version != rs->last_version) {
+            ram_state_reset(rs);
+        }
 
-    ram_control_before_iterate(f, RAM_CONTROL_ROUND);
+        /* Read version before ram_list.blocks */
+        smp_rmb();
 
-    t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-    i = 0;
-    while ((ret = qemu_file_rate_limit(f)) == 0 ||
-            !QSIMPLEQ_EMPTY(&rs->src_page_requests)) {
-        int pages;
+        ram_control_before_iterate(f, RAM_CONTROL_ROUND);
 
-        if (qemu_file_get_error(f)) {
-            break;
-        }
+        t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+        i = 0;
+        while ((ret = qemu_file_rate_limit(f)) == 0 ||
+                !QSIMPLEQ_EMPTY(&rs->src_page_requests)) {
+            int pages;
 
-        pages = ram_find_and_save_block(rs, false);
-        /* no more pages to sent */
-        if (pages == 0) {
-            done = 1;
-            break;
-        }
+            if (qemu_file_get_error(f)) {
+                break;
+            }
 
-        if (pages < 0) {
-            qemu_file_set_error(f, pages);
-            break;
-        }
+            pages = ram_find_and_save_block(rs, false);
+            /* no more pages to sent */
+            if (pages == 0) {
+                done = 1;
+                break;
+            }
 
-        rs->target_page_count += pages;
-
-        /* we want to check in the 1st loop, just in case it was the 1st time
-           and we had to sync the dirty bitmap.
-           qemu_clock_get_ns() is a bit expensive, so we only check each some
-           iterations
-        */
-        if ((i & 63) == 0) {
-            uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
-            if (t1 > MAX_WAIT) {
-                trace_ram_save_iterate_big_wait(t1, i);
+            if (pages < 0) {
+                qemu_file_set_error(f, pages);
                 break;
             }
+
+            rs->target_page_count += pages;
+
+            /*
+             * we want to check in the 1st loop, just in case it was the 1st
+             * time and we had to sync the dirty bitmap.
+             * qemu_clock_get_ns() is a bit expensive, so we only check each
+             * some iterations
+             */
+            if ((i & 63) == 0) {
+                uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) /
+                              1000000;
+                if (t1 > MAX_WAIT) {
+                    trace_ram_save_iterate_big_wait(t1, i);
+                    break;
+                }
+            }
+            i++;
         }
-        i++;
     }
-    rcu_read_unlock();
 
     /*
      * Must occur before EOS (or any QEMUFile operation)
@@ -3510,35 +3505,33 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
     RAMState *rs = *temp;
     int ret = 0;
 
-    rcu_read_lock();
-
-    if (!migration_in_postcopy()) {
-        migration_bitmap_sync_precopy(rs);
-    }
+    WITH_RCU_READ_LOCK_GUARD() {
+        if (!migration_in_postcopy()) {
+            migration_bitmap_sync_precopy(rs);
+        }
 
-    ram_control_before_iterate(f, RAM_CONTROL_FINISH);
+        ram_control_before_iterate(f, RAM_CONTROL_FINISH);
 
-    /* try transferring iterative blocks of memory */
+        /* try transferring iterative blocks of memory */
 
-    /* flush all remaining blocks regardless of rate limiting */
-    while (true) {
-        int pages;
+        /* flush all remaining blocks regardless of rate limiting */
+        while (true) {
+            int pages;
 
-        pages = ram_find_and_save_block(rs, !migration_in_colo_state());
-        /* no more blocks to sent */
-        if (pages == 0) {
-            break;
-        }
-        if (pages < 0) {
-            ret = pages;
-            break;
+            pages = ram_find_and_save_block(rs, !migration_in_colo_state());
+            /* no more blocks to sent */
+            if (pages == 0) {
+                break;
+            }
+            if (pages < 0) {
+                ret = pages;
+                break;
+            }
         }
-    }
-
-    flush_compressed_data(rs);
-    ram_control_after_iterate(f, RAM_CONTROL_FINISH);
 
-    rcu_read_unlock();
+        flush_compressed_data(rs);
+        ram_control_after_iterate(f, RAM_CONTROL_FINISH);
+    }
 
     multifd_send_sync_main(rs);
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
@@ -3561,9 +3554,9 @@ static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
     if (!migration_in_postcopy() &&
         remaining_size < max_size) {
         qemu_mutex_lock_iothread();
-        rcu_read_lock();
-        migration_bitmap_sync_precopy(rs);
-        rcu_read_unlock();
+        WITH_RCU_READ_LOCK_GUARD() {
+            migration_bitmap_sync_precopy(rs);
+        }
         qemu_mutex_unlock_iothread();
         remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE;
     }
@@ -3907,7 +3900,13 @@ int colo_init_ram_cache(void)
             error_report("%s: Can't alloc memory for COLO cache of block %s,"
                          "size 0x" RAM_ADDR_FMT, __func__, block->idstr,
                          block->used_length);
-            goto out_locked;
+            RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+                if (block->colo_cache) {
+                    qemu_anon_ram_free(block->colo_cache, block->used_length);
+                    block->colo_cache = NULL;
+                }
+            }
+            return -errno;
         }
         memcpy(block->colo_cache, block->host, block->used_length);
     }
@@ -3933,18 +3932,6 @@ int colo_init_ram_cache(void)
     memory_global_dirty_log_start();
 
     return 0;
-
-out_locked:
-
-    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
-        if (block->colo_cache) {
-            qemu_anon_ram_free(block->colo_cache, block->used_length);
-            block->colo_cache = NULL;
-        }
-    }
-
-    rcu_read_unlock();
-    return -errno;
 }
 
 /* It is need to hold the global lock to call this helper */
@@ -3958,16 +3945,14 @@ void colo_release_ram_cache(void)
         block->bmap = NULL;
     }
 
-    rcu_read_lock();
-
-    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
-        if (block->colo_cache) {
-            qemu_anon_ram_free(block->colo_cache, block->used_length);
-            block->colo_cache = NULL;
+    WITH_RCU_READ_LOCK_GUARD() {
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+            if (block->colo_cache) {
+                qemu_anon_ram_free(block->colo_cache, block->used_length);
+                block->colo_cache = NULL;
+            }
         }
     }
-
-    rcu_read_unlock();
     qemu_mutex_destroy(&ram_state->bitmap_mutex);
     g_free(ram_state);
     ram_state = NULL;
@@ -4205,31 +4190,30 @@ static void colo_flush_ram_cache(void)
     unsigned long offset = 0;
 
     memory_global_dirty_log_sync();
-    rcu_read_lock();
-    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
-        ramblock_sync_dirty_bitmap(ram_state, block);
+    WITH_RCU_READ_LOCK_GUARD() {
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+            ramblock_sync_dirty_bitmap(ram_state, block);
+        }
     }
-    rcu_read_unlock();
 
     trace_colo_flush_ram_cache_begin(ram_state->migration_dirty_pages);
-    rcu_read_lock();
-    block = QLIST_FIRST_RCU(&ram_list.blocks);
+    WITH_RCU_READ_LOCK_GUARD() {
+        block = QLIST_FIRST_RCU(&ram_list.blocks);
 
-    while (block) {
-        offset = migration_bitmap_find_dirty(ram_state, block, offset);
+        while (block) {
+            offset = migration_bitmap_find_dirty(ram_state, block, offset);
 
-        if (offset << TARGET_PAGE_BITS >= block->used_length) {
-            offset = 0;
-            block = QLIST_NEXT_RCU(block, next);
-        } else {
-            migration_bitmap_clear_dirty(ram_state, block, offset);
-            dst_host = block->host + (offset << TARGET_PAGE_BITS);
-            src_host = block->colo_cache + (offset << TARGET_PAGE_BITS);
-            memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+            if (offset << TARGET_PAGE_BITS >= block->used_length) {
+                offset = 0;
+                block = QLIST_NEXT_RCU(block, next);
+            } else {
+                migration_bitmap_clear_dirty(ram_state, block, offset);
+                dst_host = block->host + (offset << TARGET_PAGE_BITS);
+                src_host = block->colo_cache + (offset << TARGET_PAGE_BITS);
+                memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+            }
         }
     }
-
-    rcu_read_unlock();
     trace_colo_flush_ram_cache_end();
 }
 
@@ -4428,16 +4412,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
      * it will be necessary to reduce the granularity of this
      * critical section.
      */
-    rcu_read_lock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        if (postcopy_running) {
+            ret = ram_load_postcopy(f);
+        } else {
+            ret = ram_load_precopy(f);
+        }
 
-    if (postcopy_running) {
-        ret = ram_load_postcopy(f);
-    } else {
-        ret = ram_load_precopy(f);
+        ret |= wait_for_decompress_done();
     }
-
-    ret |= wait_for_decompress_done();
-    rcu_read_unlock();
     trace_ram_load_complete(ret, seq_iter);
 
     if (!ret  && migration_incoming_in_colo_state()) {
-- 
2.23.0

[PULL 05/21] migration: Use automatic rcu_read unlock in rdma.c

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use the automatic read unlocker in migration/rdma.c.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-5-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/rdma.c | 57 ++++++++++--------------------------------------
 1 file changed, 11 insertions(+), 46 deletions(-)

diff --git a/migration/rdma.c b/migration/rdma.c
index 4c74e88a37..e241dcb992 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -88,7 +88,6 @@ static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL;
                                 " to abort!"); \
                 rdma->error_reported = 1; \
             } \
-            rcu_read_unlock(); \
             return rdma->error_state; \
         } \
     } while (0)
@@ -2678,11 +2677,10 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
     size_t i;
     size_t len = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmaout);
 
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
@@ -2695,7 +2693,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
     ret = qemu_rdma_write_flush(f, rdma);
     if (ret < 0) {
         rdma->error_state = ret;
-        rcu_read_unlock();
         return ret;
     }
 
@@ -2715,7 +2712,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
 
             if (ret < 0) {
                 rdma->error_state = ret;
-                rcu_read_unlock();
                 return ret;
             }
 
@@ -2724,7 +2720,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
         }
     }
 
-    rcu_read_unlock();
     return done;
 }
 
@@ -2764,11 +2759,10 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
     ssize_t i;
     size_t done = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmain);
 
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
@@ -2805,7 +2799,6 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
 
         if (ret < 0) {
             rdma->error_state = ret;
-            rcu_read_unlock();
             return ret;
         }
 
@@ -2819,14 +2812,12 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
         /* Still didn't get enough, so lets just return */
         if (want) {
             if (done == 0) {
-                rcu_read_unlock();
                 return QIO_CHANNEL_ERR_BLOCK;
             } else {
                 break;
             }
         }
     }
-    rcu_read_unlock();
     return done;
 }
 
@@ -2882,7 +2873,7 @@ qio_channel_rdma_source_prepare(GSource *source,
     GIOCondition cond = 0;
     *timeout = -1;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     if (rsource->condition == G_IO_IN) {
         rdma = atomic_rcu_read(&rsource->rioc->rdmain);
     } else {
@@ -2891,7 +2882,6 @@ qio_channel_rdma_source_prepare(GSource *source,
 
     if (!rdma) {
         error_report("RDMAContext is NULL when prepare Gsource");
-        rcu_read_unlock();
         return FALSE;
     }
 
@@ -2900,7 +2890,6 @@ qio_channel_rdma_source_prepare(GSource *source,
     }
     cond |= G_IO_OUT;
 
-    rcu_read_unlock();
     return cond & rsource->condition;
 }
 
@@ -2911,7 +2900,7 @@ qio_channel_rdma_source_check(GSource *source)
     RDMAContext *rdma;
     GIOCondition cond = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     if (rsource->condition == G_IO_IN) {
         rdma = atomic_rcu_read(&rsource->rioc->rdmain);
     } else {
@@ -2920,7 +2909,6 @@ qio_channel_rdma_source_check(GSource *source)
 
     if (!rdma) {
         error_report("RDMAContext is NULL when check Gsource");
-        rcu_read_unlock();
         return FALSE;
     }
 
@@ -2929,7 +2917,6 @@ qio_channel_rdma_source_check(GSource *source)
     }
     cond |= G_IO_OUT;
 
-    rcu_read_unlock();
     return cond & rsource->condition;
 }
 
@@ -2943,7 +2930,7 @@ qio_channel_rdma_source_dispatch(GSource *source,
     RDMAContext *rdma;
     GIOCondition cond = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     if (rsource->condition == G_IO_IN) {
         rdma = atomic_rcu_read(&rsource->rioc->rdmain);
     } else {
@@ -2952,7 +2939,6 @@ qio_channel_rdma_source_dispatch(GSource *source,
 
     if (!rdma) {
         error_report("RDMAContext is NULL when dispatch Gsource");
-        rcu_read_unlock();
         return FALSE;
     }
 
@@ -2961,7 +2947,6 @@ qio_channel_rdma_source_dispatch(GSource *source,
     }
     cond |= G_IO_OUT;
 
-    rcu_read_unlock();
     return (*func)(QIO_CHANNEL(rsource->rioc),
                    (cond & rsource->condition),
                    user_data);
@@ -3073,7 +3058,7 @@ qio_channel_rdma_shutdown(QIOChannel *ioc,
     QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc);
     RDMAContext *rdmain, *rdmaout;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     rdmain = atomic_rcu_read(&rioc->rdmain);
     rdmaout = atomic_rcu_read(&rioc->rdmain);
@@ -3100,7 +3085,6 @@ qio_channel_rdma_shutdown(QIOChannel *ioc,
         break;
     }
 
-    rcu_read_unlock();
     return 0;
 }
 
@@ -3146,18 +3130,16 @@ static size_t qemu_rdma_save_page(QEMUFile *f, void *opaque,
     RDMAContext *rdma;
     int ret;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmaout);
 
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
     CHECK_ERROR_STATE();
 
     if (migration_in_postcopy()) {
-        rcu_read_unlock();
         return RAM_SAVE_CONTROL_NOT_SUPP;
     }
 
@@ -3242,11 +3224,9 @@ static size_t qemu_rdma_save_page(QEMUFile *f, void *opaque,
         }
     }
 
-    rcu_read_unlock();
     return RAM_SAVE_CONTROL_DELAYED;
 err:
     rdma->error_state = ret;
-    rcu_read_unlock();
     return ret;
 }
 
@@ -3470,11 +3450,10 @@ static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque)
     int count = 0;
     int i = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmain);
 
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
@@ -3717,7 +3696,6 @@ out:
     if (ret < 0) {
         rdma->error_state = ret;
     }
-    rcu_read_unlock();
     return ret;
 }
 
@@ -3735,11 +3713,10 @@ rdma_block_notification_handle(QIOChannelRDMA *rioc, const char *name)
     int curr;
     int found = -1;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmain);
 
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
@@ -3753,7 +3730,6 @@ rdma_block_notification_handle(QIOChannelRDMA *rioc, const char *name)
 
     if (found == -1) {
         error_report("RAMBlock '%s' not found on destination", name);
-        rcu_read_unlock();
         return -ENOENT;
     }
 
@@ -3761,7 +3737,6 @@ rdma_block_notification_handle(QIOChannelRDMA *rioc, const char *name)
     trace_rdma_block_notification_handle(name, rdma->next_src_index);
     rdma->next_src_index++;
 
-    rcu_read_unlock();
     return 0;
 }
 
@@ -3786,17 +3761,15 @@ static int qemu_rdma_registration_start(QEMUFile *f, void *opaque,
     QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(opaque);
     RDMAContext *rdma;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmaout);
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
     CHECK_ERROR_STATE();
 
     if (migration_in_postcopy()) {
-        rcu_read_unlock();
         return 0;
     }
 
@@ -3804,7 +3777,6 @@ static int qemu_rdma_registration_start(QEMUFile *f, void *opaque,
     qemu_put_be64(f, RAM_SAVE_FLAG_HOOK);
     qemu_fflush(f);
 
-    rcu_read_unlock();
     return 0;
 }
 
@@ -3821,17 +3793,15 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
     RDMAControlHeader head = { .len = 0, .repeat = 1 };
     int ret = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     rdma = atomic_rcu_read(&rioc->rdmaout);
     if (!rdma) {
-        rcu_read_unlock();
         return -EIO;
     }
 
     CHECK_ERROR_STATE();
 
     if (migration_in_postcopy()) {
-        rcu_read_unlock();
         return 0;
     }
 
@@ -3863,7 +3833,6 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
                     qemu_rdma_reg_whole_ram_blocks : NULL);
         if (ret < 0) {
             ERROR(errp, "receiving remote info!");
-            rcu_read_unlock();
             return ret;
         }
 
@@ -3887,7 +3856,6 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
                         "not identical on both the source and destination.",
                         local->nb_blocks, nb_dest_blocks);
             rdma->error_state = -EINVAL;
-            rcu_read_unlock();
             return -EINVAL;
         }
 
@@ -3904,7 +3872,6 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
                             local->block[i].length,
                             rdma->dest_blocks[i].length);
                 rdma->error_state = -EINVAL;
-                rcu_read_unlock();
                 return -EINVAL;
             }
             local->block[i].remote_host_addr =
@@ -3922,11 +3889,9 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
         goto err;
     }
 
-    rcu_read_unlock();
     return 0;
 err:
     rdma->error_state = ret;
-    rcu_read_unlock();
     return ret;
 }
 
-- 
2.23.0

[PULL 06/21] rcu: Use automatic rc_read unlock in core memory/exec code

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-6-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 exec.c                  | 116 ++++++++++++++-------------------
 include/exec/ram_addr.h | 138 +++++++++++++++++++---------------------
 memory.c                |  15 ++---
 3 files changed, 118 insertions(+), 151 deletions(-)

diff --git a/exec.c b/exec.c
index bdcfcdff3f..fb0943cfed 100644
--- a/exec.c
+++ b/exec.c
@@ -1037,16 +1037,14 @@ void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs)
         return;
     }
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     mr = address_space_translate(as, addr, &addr, &l, false, attrs);
     if (!(memory_region_is_ram(mr)
           || memory_region_is_romd(mr))) {
-        rcu_read_unlock();
         return;
     }
     ram_addr = memory_region_get_ram_addr(mr) + addr;
     tb_invalidate_phys_page_range(ram_addr, ram_addr + 1);
-    rcu_read_unlock();
 }
 
 static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
@@ -1332,14 +1330,13 @@ static void tlb_reset_dirty_range_all(ram_addr_t start, ram_addr_t length)
     end = TARGET_PAGE_ALIGN(start + length);
     start &= TARGET_PAGE_MASK;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     block = qemu_get_ram_block(start);
     assert(block == qemu_get_ram_block(end - 1));
     start1 = (uintptr_t)ramblock_ptr(block, start - block->offset);
     CPU_FOREACH(cpu) {
         tlb_reset_dirty(cpu, start1, length);
     }
-    rcu_read_unlock();
 }
 
 /* Note: start and end must be within the same ram block.  */
@@ -1360,30 +1357,29 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+        ramblock = qemu_get_ram_block(start);
+        /* Range sanity check on the ramblock */
+        assert(start >= ramblock->offset &&
+               start + length <= ramblock->offset + ramblock->used_length);
 
-    blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
-    ramblock = qemu_get_ram_block(start);
-    /* Range sanity check on the ramblock */
-    assert(start >= ramblock->offset &&
-           start + length <= ramblock->offset + ramblock->used_length);
+        while (page < end) {
+            unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+            unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+            unsigned long num = MIN(end - page,
+                                    DIRTY_MEMORY_BLOCK_SIZE - offset);
 
-    while (page < end) {
-        unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long num = MIN(end - page, DIRTY_MEMORY_BLOCK_SIZE - offset);
+            dirty |= bitmap_test_and_clear_atomic(blocks->blocks[idx],
+                                                  offset, num);
+            page += num;
+        }
 
-        dirty |= bitmap_test_and_clear_atomic(blocks->blocks[idx],
-                                              offset, num);
-        page += num;
+        mr_offset = (ram_addr_t)(page << TARGET_PAGE_BITS) - ramblock->offset;
+        mr_size = (end - page) << TARGET_PAGE_BITS;
+        memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size);
     }
 
-    mr_offset = (ram_addr_t)(page << TARGET_PAGE_BITS) - ramblock->offset;
-    mr_size = (end - page) << TARGET_PAGE_BITS;
-    memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size);
-
-    rcu_read_unlock();
-
     if (dirty && tcg_enabled()) {
         tlb_reset_dirty_range_all(start, length);
     }
@@ -1411,28 +1407,27 @@ DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
     end  = last  >> TARGET_PAGE_BITS;
     dest = 0;
 
-    rcu_read_lock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
 
-    blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+        while (page < end) {
+            unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+            unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+            unsigned long num = MIN(end - page,
+                                    DIRTY_MEMORY_BLOCK_SIZE - offset);
 
-    while (page < end) {
-        unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long num = MIN(end - page, DIRTY_MEMORY_BLOCK_SIZE - offset);
-
-        assert(QEMU_IS_ALIGNED(offset, (1 << BITS_PER_LEVEL)));
-        assert(QEMU_IS_ALIGNED(num,    (1 << BITS_PER_LEVEL)));
-        offset >>= BITS_PER_LEVEL;
+            assert(QEMU_IS_ALIGNED(offset, (1 << BITS_PER_LEVEL)));
+            assert(QEMU_IS_ALIGNED(num,    (1 << BITS_PER_LEVEL)));
+            offset >>= BITS_PER_LEVEL;
 
-        bitmap_copy_and_clear_atomic(snap->dirty + dest,
-                                     blocks->blocks[idx] + offset,
-                                     num);
-        page += num;
-        dest += num >> BITS_PER_LEVEL;
+            bitmap_copy_and_clear_atomic(snap->dirty + dest,
+                                         blocks->blocks[idx] + offset,
+                                         num);
+            page += num;
+            dest += num >> BITS_PER_LEVEL;
+        }
     }
 
-    rcu_read_unlock();
-
     if (tcg_enabled()) {
         tlb_reset_dirty_range_all(start, length);
     }
@@ -1643,7 +1638,7 @@ void ram_block_dump(Monitor *mon)
     RAMBlock *block;
     char *psize;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     monitor_printf(mon, "%24s %8s  %18s %18s %18s\n",
                    "Block Name", "PSize", "Offset", "Used", "Total");
     RAMBLOCK_FOREACH(block) {
@@ -1655,7 +1650,6 @@ void ram_block_dump(Monitor *mon)
                        (uint64_t)block->max_length);
         g_free(psize);
     }
-    rcu_read_unlock();
 }
 
 #ifdef __linux__
@@ -2009,11 +2003,10 @@ static unsigned long last_ram_page(void)
     RAMBlock *block;
     ram_addr_t last = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     RAMBLOCK_FOREACH(block) {
         last = MAX(last, block->offset + block->max_length);
     }
-    rcu_read_unlock();
     return last >> TARGET_PAGE_BITS;
 }
 
@@ -2100,7 +2093,7 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
     }
     pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     RAMBLOCK_FOREACH(block) {
         if (block != new_block &&
             !strcmp(block->idstr, new_block->idstr)) {
@@ -2109,7 +2102,6 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
             abort();
         }
     }
-    rcu_read_unlock();
 }
 
 /* Called with iothread lock held.  */
@@ -2651,17 +2643,16 @@ RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
 
     if (xen_enabled()) {
         ram_addr_t ram_addr;
-        rcu_read_lock();
+        RCU_READ_LOCK_GUARD();
         ram_addr = xen_ram_addr_from_mapcache(ptr);
         block = qemu_get_ram_block(ram_addr);
         if (block) {
             *offset = ram_addr - block->offset;
         }
-        rcu_read_unlock();
         return block;
     }
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     block = atomic_rcu_read(&ram_list.mru_block);
     if (block && block->host && host - block->host < block->max_length) {
         goto found;
@@ -2677,7 +2668,6 @@ RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
         }
     }
 
-    rcu_read_unlock();
     return NULL;
 
 found:
@@ -2685,7 +2675,6 @@ found:
     if (round_offset) {
         *offset &= TARGET_PAGE_MASK;
     }
-    rcu_read_unlock();
     return block;
 }
 
@@ -3281,10 +3270,9 @@ MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
     FlatView *fv;
 
     if (len > 0) {
-        rcu_read_lock();
+        RCU_READ_LOCK_GUARD();
         fv = address_space_to_flatview(as);
         result = flatview_read(fv, addr, attrs, buf, len);
-        rcu_read_unlock();
     }
 
     return result;
@@ -3298,10 +3286,9 @@ MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
     FlatView *fv;
 
     if (len > 0) {
-        rcu_read_lock();
+        RCU_READ_LOCK_GUARD();
         fv = address_space_to_flatview(as);
         result = flatview_write(fv, addr, attrs, buf, len);
-        rcu_read_unlock();
     }
 
     return result;
@@ -3341,7 +3328,7 @@ static inline MemTxResult address_space_write_rom_internal(AddressSpace *as,
     hwaddr addr1;
     MemoryRegion *mr;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     while (len > 0) {
         l = len;
         mr = address_space_translate(as, addr, &addr1, &l, true, attrs);
@@ -3366,7 +3353,6 @@ static inline MemTxResult address_space_write_rom_internal(AddressSpace *as,
         buf += l;
         addr += l;
     }
-    rcu_read_unlock();
     return MEMTX_OK;
 }
 
@@ -3511,10 +3497,9 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr,
     FlatView *fv;
     bool result;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     fv = address_space_to_flatview(as);
     result = flatview_access_valid(fv, addr, len, is_write, attrs);
-    rcu_read_unlock();
     return result;
 }
 
@@ -3569,13 +3554,12 @@ void *address_space_map(AddressSpace *as,
     }
 
     l = len;
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     fv = address_space_to_flatview(as);
     mr = flatview_translate(fv, addr, &xlat, &l, is_write, attrs);
 
     if (!memory_access_is_direct(mr, is_write)) {
         if (atomic_xchg(&bounce.in_use, true)) {
-            rcu_read_unlock();
             return NULL;
         }
         /* Avoid unbounded allocations */
@@ -3591,7 +3575,6 @@ void *address_space_map(AddressSpace *as,
                                bounce.buffer, l);
         }
 
-        rcu_read_unlock();
         *plen = l;
         return bounce.buffer;
     }
@@ -3601,7 +3584,6 @@ void *address_space_map(AddressSpace *as,
     *plen = flatview_extend_translation(fv, addr, len, mr, xlat,
                                         l, is_write, attrs);
     ptr = qemu_ram_ptr_length(mr->ram_block, xlat, plen, true);
-    rcu_read_unlock();
 
     return ptr;
 }
@@ -3869,13 +3851,12 @@ bool cpu_physical_memory_is_io(hwaddr phys_addr)
     hwaddr l = 1;
     bool res;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     mr = address_space_translate(&address_space_memory,
                                  phys_addr, &phys_addr, &l, false,
                                  MEMTXATTRS_UNSPECIFIED);
 
     res = !(memory_region_is_ram(mr) || memory_region_is_romd(mr));
-    rcu_read_unlock();
     return res;
 }
 
@@ -3884,14 +3865,13 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
     RAMBlock *block;
     int ret = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     RAMBLOCK_FOREACH(block) {
         ret = func(block, opaque);
         if (ret) {
             break;
         }
     }
-    rcu_read_unlock();
     return ret;
 }
 
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index e96e621de5..ad158bb247 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -193,30 +193,29 @@ static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
-
-    blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+    WITH_RCU_READ_LOCK_GUARD() {
+        blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+
+        idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+        offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+        base = page - offset;
+        while (page < end) {
+            unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
+            unsigned long num = next - base;
+            unsigned long found = find_next_bit(blocks->blocks[idx],
+                                                num, offset);
+            if (found < num) {
+                dirty = true;
+                break;
+            }
 
-    idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-    offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-    base = page - offset;
-    while (page < end) {
-        unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
-        unsigned long num = next - base;
-        unsigned long found = find_next_bit(blocks->blocks[idx], num, offset);
-        if (found < num) {
-            dirty = true;
-            break;
+            page = next;
+            idx++;
+            offset = 0;
+            base += DIRTY_MEMORY_BLOCK_SIZE;
         }
-
-        page = next;
-        idx++;
-        offset = 0;
-        base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     return dirty;
 }
 
@@ -234,7 +233,7 @@ static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
 
@@ -256,8 +255,6 @@ static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
         base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     return dirty;
 }
 
@@ -309,13 +306,11 @@ static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
 
     set_bit_atomic(offset, blocks->blocks[idx]);
-
-    rcu_read_unlock();
 }
 
 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
@@ -334,39 +329,37 @@ static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+            blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i]);
+        }
 
-    for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
-        blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i]);
-    }
+        idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+        offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+        base = page - offset;
+        while (page < end) {
+            unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
 
-    idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-    offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-    base = page - offset;
-    while (page < end) {
-        unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
+            if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
+                                  offset, next - page);
+            }
+            if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
+                                  offset, next - page);
+            }
+            if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
+                                  offset, next - page);
+            }
 
-        if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
-                              offset, next - page);
+            page = next;
+            idx++;
+            offset = 0;
+            base += DIRTY_MEMORY_BLOCK_SIZE;
         }
-        if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
-                              offset, next - page);
-        }
-        if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
-                              offset, next - page);
-        }
-
-        page = next;
-        idx++;
-        offset = 0;
-        base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     xen_hvm_modified_memory(start, length);
 }
 
@@ -396,36 +389,35 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
                           DIRTY_MEMORY_BLOCK_SIZE);
 
-        rcu_read_lock();
+        WITH_RCU_READ_LOCK_GUARD() {
+            for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+                blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
+            }
 
-        for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
-            blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
-        }
+            for (k = 0; k < nr; k++) {
+                if (bitmap[k]) {
+                    unsigned long temp = leul_to_cpu(bitmap[k]);
 
-        for (k = 0; k < nr; k++) {
-            if (bitmap[k]) {
-                unsigned long temp = leul_to_cpu(bitmap[k]);
+                    atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
 
-                atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
+                    if (global_dirty_log) {
+                        atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
+                                  temp);
+                    }
 
-                if (global_dirty_log) {
-                    atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
-                              temp);
+                    if (tcg_enabled()) {
+                        atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
+                                  temp);
+                    }
                 }
 
-                if (tcg_enabled()) {
-                    atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset], temp);
+                if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
+                    offset = 0;
+                    idx++;
                 }
             }
-
-            if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
-                offset = 0;
-                idx++;
-            }
         }
 
-        rcu_read_unlock();
-
         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
     } else {
         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
diff --git a/memory.c b/memory.c
index 978da3d3df..c952eabb5d 100644
--- a/memory.c
+++ b/memory.c
@@ -779,14 +779,13 @@ FlatView *address_space_get_flatview(AddressSpace *as)
 {
     FlatView *view;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     do {
         view = address_space_to_flatview(as);
         /* If somebody has replaced as->current_map concurrently,
          * flatview_ref returns false.
          */
     } while (!flatview_ref(view));
-    rcu_read_unlock();
     return view;
 }
 
@@ -2166,12 +2165,11 @@ int memory_region_get_fd(MemoryRegion *mr)
 {
     int fd;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     while (mr->alias) {
         mr = mr->alias;
     }
     fd = mr->ram_block->fd;
-    rcu_read_unlock();
 
     return fd;
 }
@@ -2181,14 +2179,13 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr)
     void *ptr;
     uint64_t offset = 0;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     while (mr->alias) {
         offset += mr->alias_offset;
         mr = mr->alias;
     }
     assert(mr->ram_block);
     ptr = qemu_map_ram_ptr(mr->ram_block, offset);
-    rcu_read_unlock();
 
     return ptr;
 }
@@ -2578,12 +2575,11 @@ MemoryRegionSection memory_region_find(MemoryRegion *mr,
                                        hwaddr addr, uint64_t size)
 {
     MemoryRegionSection ret;
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     ret = memory_region_find_rcu(mr, addr, size);
     if (ret.mr) {
         memory_region_ref(ret.mr);
     }
-    rcu_read_unlock();
     return ret;
 }
 
@@ -2591,9 +2587,8 @@ bool memory_region_present(MemoryRegion *container, hwaddr addr)
 {
     MemoryRegion *mr;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
     mr = memory_region_find_rcu(container, addr, 1).mr;
-    rcu_read_unlock();
     return mr && mr != container;
 }
 
-- 
2.23.0

[PULL 07/21] migration: Don't try and recover return path in non-postcopy

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

In normal precopy we can't do reconnection recovery - but we also
don't need to, since you can just rerun migration.
At the moment if the 'return-path' capability is on, we use
the return path in precopy to give a positive 'OK' to the end
of migration; however if migration fails then we fall into
the postcopy recovery path and hang.  This fixes it by only
running the return path in the postcopy case.

Reported-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/migration.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/migration.c b/migration/migration.c
index 0c51aa6ac7..d7f8b428e0 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2486,7 +2486,7 @@ retry:
 out:
     res = qemu_file_get_error(rp);
     if (res) {
-        if (res == -EIO) {
+        if (res == -EIO && migration_in_postcopy()) {
             /*
              * Maybe there is something we can do: it looks like a
              * network down issue, and we pause for a recovery.
-- 
2.23.0

[PULL 08/21] migration/postcopy: allocate tmp_page in setup stage

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

During migration, a tmp page is allocated so that we could place a whole
host page during postcopy.

Currently the page is allocated during load stage, this is a little bit
late. And more important, if we failed to allocate it, the error is not
checked properly. Even it is NULL, we would still use it.

This patch moves the allocation to setup stage and if failed error
message would be printed and caller would notice it.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/postcopy-ram.c | 40 ++++++++++------------------------------
 migration/postcopy-ram.h |  7 -------
 migration/ram.c          |  2 +-
 3 files changed, 11 insertions(+), 38 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 1f63e65ed7..9a16f52a79 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -1134,6 +1134,16 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
         return -1;
     }
 
+    mis->postcopy_tmp_page = mmap(NULL, mis->largest_page_size,
+                                  PROT_READ | PROT_WRITE, MAP_PRIVATE |
+                                  MAP_ANONYMOUS, -1, 0);
+    if (mis->postcopy_tmp_page == MAP_FAILED) {
+        mis->postcopy_tmp_page = NULL;
+        error_report("%s: Failed to map postcopy_tmp_page %s",
+                     __func__, strerror(errno));
+        return -1;
+    }
+
     /*
      * Ballooning can mark pages as absent while we're postcopying
      * that would cause false userfaults.
@@ -1260,30 +1270,6 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
     }
 }
 
-/*
- * Returns a target page of memory that can be mapped at a later point in time
- * using postcopy_place_page
- * The same address is used repeatedly, postcopy_place_page just takes the
- * backing page away.
- * Returns: Pointer to allocated page
- *
- */
-void *postcopy_get_tmp_page(MigrationIncomingState *mis)
-{
-    if (!mis->postcopy_tmp_page) {
-        mis->postcopy_tmp_page = mmap(NULL, mis->largest_page_size,
-                             PROT_READ | PROT_WRITE, MAP_PRIVATE |
-                             MAP_ANONYMOUS, -1, 0);
-        if (mis->postcopy_tmp_page == MAP_FAILED) {
-            mis->postcopy_tmp_page = NULL;
-            error_report("%s: %s", __func__, strerror(errno));
-            return NULL;
-        }
-    }
-
-    return mis->postcopy_tmp_page;
-}
-
 #else
 /* No target OS support, stubs just fail */
 void fill_destination_postcopy_migration_info(MigrationInfo *info)
@@ -1341,12 +1327,6 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
     return -1;
 }
 
-void *postcopy_get_tmp_page(MigrationIncomingState *mis)
-{
-    assert(0);
-    return NULL;
-}
-
 int postcopy_wake_shared(struct PostCopyFD *pcfd,
                          uint64_t client_addr,
                          RAMBlock *rb)
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 9c8bd2bae0..fb4cd11d28 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -100,13 +100,6 @@ typedef enum {
     POSTCOPY_INCOMING_END
 } PostcopyState;
 
-/*
- * Allocate a page of memory that can be mapped at a later point in time
- * using postcopy_place_page
- * Returns: Pointer to allocated page
- */
-void *postcopy_get_tmp_page(MigrationIncomingState *mis);
-
 PostcopyState postcopy_state_get(void);
 /* Set the state and return the old state */
 PostcopyState postcopy_state_set(PostcopyState new_state);
diff --git a/migration/ram.c b/migration/ram.c
index e29c8b3408..071687ef37 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4032,7 +4032,7 @@ static int ram_load_postcopy(QEMUFile *f)
     bool matches_target_page_size = false;
     MigrationIncomingState *mis = migration_incoming_get_current();
     /* Temporary page that is later 'placed' */
-    void *postcopy_host_page = postcopy_get_tmp_page(mis);
+    void *postcopy_host_page = mis->postcopy_tmp_page;
     void *last_host = NULL;
     bool all_zero = false;
 
-- 
2.23.0

[PULL 09/21] migration/postcopy: map large zero page in postcopy_ram_incoming_setup()

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

postcopy_ram_incoming_setup() and postcopy_ram_incoming_cleanup() are
counterpart. It is reasonable to map/unmap large zero page in these two
functions respectively.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005135021.21721-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/postcopy-ram.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 9a16f52a79..08a3ed516e 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -1144,6 +1144,22 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
         return -1;
     }
 
+    /*
+     * Map large zero page when kernel can't use UFFDIO_ZEROPAGE for hugepages
+     */
+    mis->postcopy_tmp_zero_page = mmap(NULL, mis->largest_page_size,
+                                       PROT_READ | PROT_WRITE,
+                                       MAP_PRIVATE | MAP_ANONYMOUS,
+                                       -1, 0);
+    if (mis->postcopy_tmp_zero_page == MAP_FAILED) {
+        int e = errno;
+        mis->postcopy_tmp_zero_page = NULL;
+        error_report("%s: Failed to map large zero page %s",
+                     __func__, strerror(e));
+        return -e;
+    }
+    memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size);
+
     /*
      * Ballooning can mark pages as absent while we're postcopying
      * that would cause false userfaults.
@@ -1250,23 +1266,7 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
                                            qemu_ram_block_host_offset(rb,
                                                                       host));
     } else {
-        /* The kernel can't use UFFDIO_ZEROPAGE for hugepages */
-        if (!mis->postcopy_tmp_zero_page) {
-            mis->postcopy_tmp_zero_page = mmap(NULL, mis->largest_page_size,
-                                               PROT_READ | PROT_WRITE,
-                                               MAP_PRIVATE | MAP_ANONYMOUS,
-                                               -1, 0);
-            if (mis->postcopy_tmp_zero_page == MAP_FAILED) {
-                int e = errno;
-                mis->postcopy_tmp_zero_page = NULL;
-                error_report("%s: %s mapping large zero page",
-                             __func__, strerror(e));
-                return -e;
-            }
-            memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size);
-        }
-        return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page,
-                                   rb);
+        return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, rb);
     }
 }
 
-- 
2.23.0

[PULL 10/21] migration/postcopy: fix typo in mark_postcopy_blocktime_begin's comment

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-3-richardw.yang@linux.intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/postcopy-ram.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 08a3ed516e..3a72f7b4fe 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -768,9 +768,11 @@ static void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid,
     atomic_xchg(&dc->page_fault_vcpu_time[cpu], low_time_offset);
     atomic_xchg(&dc->vcpu_addr[cpu], addr);
 
-    /* check it here, not at the begining of the function,
-     * due to, check could accur early than bitmap_set in
-     * qemu_ufd_copy_ioctl */
+    /*
+     * check it here, not at the beginning of the function,
+     * due to, check could occur early than bitmap_set in
+     * qemu_ufd_copy_ioctl
+     */
     already_received = ramblock_recv_bitmap_test(rb, (void *)addr);
     if (already_received) {
         atomic_xchg(&dc->vcpu_addr[cpu], 0);
-- 
2.23.0

[PULL 11/21] migration: pass in_postcopy instead of check state again

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Not necessary to do the check again.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-4-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/migration.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index d7f8b428e0..3febd0f8f3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3149,8 +3149,7 @@ static MigIterateState migration_iteration_run(MigrationState *s)
             return MIG_ITERATE_SKIP;
         }
         /* Just another iteration step */
-        qemu_savevm_state_iterate(s->to_dst_file,
-            s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
     } else {
         trace_migration_thread_low_pending(pending_size);
         migration_completion(s);
-- 
2.23.0

[PULL 12/21] migration: report SaveStateEntry id and name on failure

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

This provides helpful information on which entry failed.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-5-richardw.yang@linux.intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/savevm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/migration/savevm.c b/migration/savevm.c
index bb9462a54d..241c5dd097 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1215,6 +1215,8 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
         save_section_footer(f, se);
 
         if (ret < 0) {
+            error_report("failed to save SaveStateEntry with id(name): %d(%s)",
+                         se->section_id, se->idstr);
             qemu_file_set_error(f, ret);
         }
         if (ret <= 0) {
-- 
2.23.0

[PULL 13/21] migration/postcopy: mis->have_listen_thread check will never be touched

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

If mis->have_listen_thread is true, this means current PostcopyState
must be LISTENING or RUNNING. While the check at the beginning of the
function makes sure the state transaction happens when its previous
PostcopyState is ADVISE or DISCARD.

This means we would never touch this check.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191006000249.29926-2-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/savevm.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 241c5dd097..c62687afef 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1878,11 +1878,6 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
         return -1;
     }
 
-    if (mis->have_listen_thread) {
-        error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
-        return -1;
-    }
-
     mis->have_listen_thread = true;
     /* Start up the listening thread and wait for it to signal ready */
     qemu_sem_init(&mis->listen_thread_sem, 0);
-- 
2.23.0

[PULL 14/21] migration/postcopy: postpone setting PostcopyState to END

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

There are two places to call function postcopy_ram_incoming_cleanup()

    postcopy_ram_listen_thread on migration success
    loadvm_postcopy_handle_listen one setup failure

On success, the vm will never accept another migration. On failure,
PostcopyState is transited from LISTENING to END and would be checked in
qemu_loadvm_state_main(). If PostcopyState is RUNNING, migration would
be paused and retried.

Currently PostcopyState is set to END in function
postcopy_ram_incoming_cleanup(). With above analysis, we can take this
step out and postpone this till the end of listen thread to indicate the
listen thread is done.

This is a preparation patch for later cleanup.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191006000249.29926-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Fixed up in merge to the 1 parameter postcopy_state_set
---
 migration/postcopy-ram.c | 2 --
 migration/savevm.c       | 2 ++
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 3a72f7b4fe..a793bad477 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -577,8 +577,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
         }
     }
 
-    postcopy_state_set(POSTCOPY_INCOMING_END);
-
     if (mis->postcopy_tmp_page) {
         munmap(mis->postcopy_tmp_page, mis->largest_page_size);
         mis->postcopy_tmp_page = NULL;
diff --git a/migration/savevm.c b/migration/savevm.c
index c62687afef..bf3da58ecc 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1837,6 +1837,8 @@ static void *postcopy_ram_listen_thread(void *opaque)
 
     rcu_unregister_thread();
     mis->have_listen_thread = false;
+    postcopy_state_set(POSTCOPY_INCOMING_END);
+
     return NULL;
 }
 
-- 
2.23.0

[PULL 15/21] migration/postcopy: rename postcopy_ram_enable_notify to postcopy_ram_incoming_setup

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Function postcopy_ram_incoming_setup and postcopy_ram_incoming_cleanup
is a pair. Rename to make it clear for audience.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20191010011316.31363-2-richardw.yang@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/postcopy-ram.c | 4 ++--
 migration/postcopy-ram.h | 2 +-
 migration/savevm.c       | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index a793bad477..abccafc8c8 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -1094,7 +1094,7 @@ retry:
     return NULL;
 }
 
-int postcopy_ram_enable_notify(MigrationIncomingState *mis)
+int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
 {
     /* Open the fd for the kernel to give us userfaults */
     mis->userfault_fd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
@@ -1307,7 +1307,7 @@ int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
     return -1;
 }
 
-int postcopy_ram_enable_notify(MigrationIncomingState *mis)
+int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
 {
     assert(0);
     return -1;
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index fb4cd11d28..9941feb63a 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -20,7 +20,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis);
  * Make all of RAM sensitive to accesses to areas that haven't yet been written
  * and wire up anything necessary to deal with it.
  */
-int postcopy_ram_enable_notify(MigrationIncomingState *mis);
+int postcopy_ram_incoming_setup(MigrationIncomingState *mis);
 
 /*
  * Initialise postcopy-ram, setting the RAM to a state where we can go into
diff --git a/migration/savevm.c b/migration/savevm.c
index bf3da58ecc..95574c4e9d 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1869,7 +1869,7 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
      * shouldn't be doing anything yet so don't actually expect requests
      */
     if (migrate_postcopy_ram()) {
-        if (postcopy_ram_enable_notify(mis)) {
+        if (postcopy_ram_incoming_setup(mis)) {
             postcopy_ram_incoming_cleanup(mis);
             return -1;
         }
-- 
2.23.0

[PULL 16/21] migration/postcopy: check PostcopyState before setting to POSTCOPY_INCOMING_RUNNING

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Currently, we set PostcopyState blindly to RUNNING, even we found the
previous state is not LISTENING. This will lead to a corner case.

First let's look at the code flow:

qemu_loadvm_state_main()
    ret = loadvm_process_command()
        loadvm_postcopy_handle_run()
            return -1;
    if (ret < 0) {
        if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING)
            ...
    }

>From above snippet, the corner case is loadvm_postcopy_handle_run()
always sets state to RUNNING. And then it checks the previous state. If
the previous state is not LISTENING, it will return -1. But at this
moment, PostcopyState is already been set to RUNNING.

Then ret is checked in qemu_loadvm_state_main(), when it is -1
PostcopyState is checked. Current logic would pause postcopy and retry
if PostcopyState is RUNNING. This is not what we expect, because
postcopy is not active yet.

This patch makes sure state is set to RUNNING only previous state is
LISTENING by checking the state first.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Suggested by: Peter Xu <peterx@redhat.com>
Message-Id: <20191010011316.31363-3-richardw.yang@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/savevm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 95574c4e9d..8d95e261f6 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1933,7 +1933,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
 /* After all discards we can start running and asking for pages */
 static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
 {
-    PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
+    PostcopyState ps = postcopy_state_get();
 
     trace_loadvm_postcopy_handle_run();
     if (ps != POSTCOPY_INCOMING_LISTENING) {
@@ -1941,6 +1941,7 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
         return -1;
     }
 
+    postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
     mis->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, mis);
     qemu_bh_schedule(mis->bh);
 
-- 
2.23.0

[PULL 17/21] migration/multifd: fix a typo in comment of multifd_recv_unfill_packet()

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-2-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index 071687ef37..698ba4d669 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -838,7 +838,7 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
 
     packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
     /*
-     * If we recevied a packet that is 100 times bigger than expected
+     * If we received a packet that is 100 times bigger than expected
      * just stop migration.  It is a magic number.
      */
     if (packet->pages_alloc > pages_max * 100) {
-- 
2.23.0

[PULL 18/21] migration/multifd: use pages->allocated instead of the static max

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

multifd_send_fill_packet() prepares meta data for following pages to
transfer. It would be more proper to fill pages->allocated instead of
static max value, especially we want to support flexible packet size.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-3-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 698ba4d669..84c5953a84 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -791,13 +791,12 @@ static void multifd_pages_clear(MultiFDPages_t *pages)
 static void multifd_send_fill_packet(MultiFDSendParams *p)
 {
     MultiFDPacket_t *packet = p->packet;
-    uint32_t page_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
     int i;
 
     packet->magic = cpu_to_be32(MULTIFD_MAGIC);
     packet->version = cpu_to_be32(MULTIFD_VERSION);
     packet->flags = cpu_to_be32(p->flags);
-    packet->pages_alloc = cpu_to_be32(page_max);
+    packet->pages_alloc = cpu_to_be32(p->pages->allocated);
     packet->pages_used = cpu_to_be32(p->pages->used);
     packet->next_packet_size = cpu_to_be32(p->next_packet_size);
     packet->packet_num = cpu_to_be64(p->packet_num);
-- 
2.23.0

[PULL 19/21] migration/multifd: initialize packet->magic/version once at setup stage

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

MultiFDPacket_t's magic and version field never changes during
migration, so move these two fields in setup stage.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-4-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 84c5953a84..963e795ed0 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -793,8 +793,6 @@ static void multifd_send_fill_packet(MultiFDSendParams *p)
     MultiFDPacket_t *packet = p->packet;
     int i;
 
-    packet->magic = cpu_to_be32(MULTIFD_MAGIC);
-    packet->version = cpu_to_be32(MULTIFD_VERSION);
     packet->flags = cpu_to_be32(p->flags);
     packet->pages_alloc = cpu_to_be32(p->pages->allocated);
     packet->pages_used = cpu_to_be32(p->pages->used);
@@ -1240,6 +1238,8 @@ int multifd_save_setup(void)
         p->packet_len = sizeof(MultiFDPacket_t)
                       + sizeof(ram_addr_t) * page_count;
         p->packet = g_malloc0(p->packet_len);
+        p->packet->magic = cpu_to_be32(MULTIFD_MAGIC);
+        p->packet->version = cpu_to_be32(MULTIFD_VERSION);
         p->name = g_strdup_printf("multifdsend_%d", i);
         socket_send_channel_create(multifd_new_send_channel_async, p);
     }
-- 
2.23.0

[PULL 20/21] migration/multifd: pages->used would be cleared when attach to multifd_send_state

[Dr. David Alan Gilbert (git)]

From: Wei Yang <richardw.yang@linux.intel.com>

When we found an available channel in multifd_send_pages(), its
pages->used is cleared and then attached to multifd_send_state.

It is not necessary to do this twice.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-5-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index 963e795ed0..5078f94490 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1129,7 +1129,6 @@ static void *multifd_send_thread(void *opaque)
             p->flags = 0;
             p->num_packets++;
             p->num_pages += used;
-            p->pages->used = 0;
             qemu_mutex_unlock(&p->mutex);
 
             trace_multifd_send(p->id, packet_num, used, flags,
-- 
2.23.0

[PULL 21/21] migration: Support gtree migration

[Dr. David Alan Gilbert (git)]

From: Eric Auger <eric.auger@redhat.com>

Introduce support for GTree migration. A custom save/restore
is implemented. Each item is made of a key and a data.

If the key is a pointer to an object, 2 VMSDs are passed into
the GTree VMStateField.

When putting the items, the tree is traversed in sorted order by
g_tree_foreach.

On the get() path, gtrees must be allocated using the proper
key compare, key destroy and value destroy. This must be handled
beforehand, for example in a pre_load method.

Tests are added to test save/dump of structs containing gtrees
including the virtio-iommu domain/mappings scenario.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

Message-Id: <20191011121724.433-1-eric.auger@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  uintptr_t fixup for test on 32bit
---
 include/migration/vmstate.h |  40 ++++
 migration/trace-events      |   5 +
 migration/vmstate-types.c   | 152 +++++++++++++
 tests/test-vmstate.c        | 421 ++++++++++++++++++++++++++++++++++++
 4 files changed, 618 insertions(+)

diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 1fbfd099dd..b9ee563aa4 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -224,6 +224,7 @@ extern const VMStateInfo vmstate_info_unused_buffer;
 extern const VMStateInfo vmstate_info_tmp;
 extern const VMStateInfo vmstate_info_bitmap;
 extern const VMStateInfo vmstate_info_qtailq;
+extern const VMStateInfo vmstate_info_gtree;
 
 #define type_check_2darray(t1,t2,n,m) ((t1(*)[n][m])0 - (t2*)0)
 /*
@@ -754,6 +755,45 @@ extern const VMStateInfo vmstate_info_qtailq;
     .start        = offsetof(_type, _next),                              \
 }
 
+/*
+ * For migrating a GTree whose key is a pointer to _key_type and the
+ * value, a pointer to _val_type
+ * The target tree must have been properly initialized
+ * _vmsd: Start address of the 2 element array containing the data vmsd
+ *        and the key vmsd, in that order
+ * _key_type: type of the key
+ * _val_type: type of the value
+ */
+#define VMSTATE_GTREE_V(_field, _state, _version, _vmsd,                       \
+                        _key_type, _val_type)                                  \
+{                                                                              \
+    .name         = (stringify(_field)),                                       \
+    .version_id   = (_version),                                                \
+    .vmsd         = (_vmsd),                                                   \
+    .info         = &vmstate_info_gtree,                                       \
+    .start        = sizeof(_key_type),                                         \
+    .size         = sizeof(_val_type),                                         \
+    .offset       = offsetof(_state, _field),                                  \
+}
+
+/*
+ * For migrating a GTree with direct key and the value a pointer
+ * to _val_type
+ * The target tree must have been properly initialized
+ * _vmsd: data vmsd
+ * _val_type: type of the value
+ */
+#define VMSTATE_GTREE_DIRECT_KEY_V(_field, _state, _version, _vmsd, _val_type) \
+{                                                                              \
+    .name         = (stringify(_field)),                                       \
+    .version_id   = (_version),                                                \
+    .vmsd         = (_vmsd),                                                   \
+    .info         = &vmstate_info_gtree,                                       \
+    .start        = 0,                                                         \
+    .size         = sizeof(_val_type),                                         \
+    .offset       = offsetof(_state, _field),                                  \
+}
+
 /* _f : field name
    _f_n : num of elements field_name
    _n : num of elements
diff --git a/migration/trace-events b/migration/trace-events
index 858d415d56..6dee7b5389 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -71,6 +71,11 @@ get_qtailq_end(const char *name, const char *reason, int val) "%s %s/%d"
 put_qtailq(const char *name, int version_id) "%s v%d"
 put_qtailq_end(const char *name, const char *reason) "%s %s"
 
+get_gtree(const char *field_name, const char *key_vmsd_name, const char *val_vmsd_name, uint32_t nnodes) "%s(%s/%s) nnodes=%d"
+get_gtree_end(const char *field_name, const char *key_vmsd_name, const char *val_vmsd_name, int ret) "%s(%s/%s) %d"
+put_gtree(const char *field_name, const char *key_vmsd_name, const char *val_vmsd_name, uint32_t nnodes) "%s(%s/%s) nnodes=%d"
+put_gtree_end(const char *field_name, const char *key_vmsd_name, const char *val_vmsd_name, int ret) "%s(%s/%s) %d"
+
 # qemu-file.c
 qemu_file_fclose(void) ""
 
diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c
index bee658a1b2..7236cf92bc 100644
--- a/migration/vmstate-types.c
+++ b/migration/vmstate-types.c
@@ -691,3 +691,155 @@ const VMStateInfo vmstate_info_qtailq = {
     .get  = get_qtailq,
     .put  = put_qtailq,
 };
+
+struct put_gtree_data {
+    QEMUFile *f;
+    const VMStateDescription *key_vmsd;
+    const VMStateDescription *val_vmsd;
+    QJSON *vmdesc;
+    int ret;
+};
+
+static gboolean put_gtree_elem(gpointer key, gpointer value, gpointer data)
+{
+    struct put_gtree_data *capsule = (struct put_gtree_data *)data;
+    QEMUFile *f = capsule->f;
+    int ret;
+
+    qemu_put_byte(f, true);
+
+    /* put the key */
+    if (!capsule->key_vmsd) {
+        qemu_put_be64(f, (uint64_t)(uintptr_t)(key)); /* direct key */
+    } else {
+        ret = vmstate_save_state(f, capsule->key_vmsd, key, capsule->vmdesc);
+        if (ret) {
+            capsule->ret = ret;
+            return true;
+        }
+    }
+
+    /* put the data */
+    ret = vmstate_save_state(f, capsule->val_vmsd, value, capsule->vmdesc);
+    if (ret) {
+        capsule->ret = ret;
+        return true;
+    }
+    return false;
+}
+
+static int put_gtree(QEMUFile *f, void *pv, size_t unused_size,
+                     const VMStateField *field, QJSON *vmdesc)
+{
+    bool direct_key = (!field->start);
+    const VMStateDescription *key_vmsd = direct_key ? NULL : &field->vmsd[1];
+    const VMStateDescription *val_vmsd = &field->vmsd[0];
+    const char *key_vmsd_name = direct_key ? "direct" : key_vmsd->name;
+    struct put_gtree_data capsule = {
+        .f = f,
+        .key_vmsd = key_vmsd,
+        .val_vmsd = val_vmsd,
+        .vmdesc = vmdesc,
+        .ret = 0};
+    GTree **pval = pv;
+    GTree *tree = *pval;
+    uint32_t nnodes = g_tree_nnodes(tree);
+    int ret;
+
+    trace_put_gtree(field->name, key_vmsd_name, val_vmsd->name, nnodes);
+    qemu_put_be32(f, nnodes);
+    g_tree_foreach(tree, put_gtree_elem, (gpointer)&capsule);
+    qemu_put_byte(f, false);
+    ret = capsule.ret;
+    if (ret) {
+        error_report("%s : failed to save gtree (%d)", field->name, ret);
+    }
+    trace_put_gtree_end(field->name, key_vmsd_name, val_vmsd->name, ret);
+    return ret;
+}
+
+static int get_gtree(QEMUFile *f, void *pv, size_t unused_size,
+                     const VMStateField *field)
+{
+    bool direct_key = (!field->start);
+    const VMStateDescription *key_vmsd = direct_key ? NULL : &field->vmsd[1];
+    const VMStateDescription *val_vmsd = &field->vmsd[0];
+    const char *key_vmsd_name = direct_key ? "direct" : key_vmsd->name;
+    int version_id = field->version_id;
+    size_t key_size = field->start;
+    size_t val_size = field->size;
+    int nnodes, count = 0;
+    GTree **pval = pv;
+    GTree *tree = *pval;
+    void *key, *val;
+    int ret = 0;
+
+    /* in case of direct key, the key vmsd can be {}, ie. check fields */
+    if (!direct_key && version_id > key_vmsd->version_id) {
+        error_report("%s %s",  key_vmsd->name, "too new");
+        return -EINVAL;
+    }
+    if (!direct_key && version_id < key_vmsd->minimum_version_id) {
+        error_report("%s %s",  key_vmsd->name, "too old");
+        return -EINVAL;
+    }
+    if (version_id > val_vmsd->version_id) {
+        error_report("%s %s",  val_vmsd->name, "too new");
+        return -EINVAL;
+    }
+    if (version_id < val_vmsd->minimum_version_id) {
+        error_report("%s %s",  val_vmsd->name, "too old");
+        return -EINVAL;
+    }
+
+    nnodes = qemu_get_be32(f);
+    trace_get_gtree(field->name, key_vmsd_name, val_vmsd->name, nnodes);
+
+    while (qemu_get_byte(f)) {
+        if ((++count) > nnodes) {
+            ret = -EINVAL;
+            break;
+        }
+        if (direct_key) {
+            key = (void *)(uintptr_t)qemu_get_be64(f);
+        } else {
+            key = g_malloc0(key_size);
+            ret = vmstate_load_state(f, key_vmsd, key, version_id);
+            if (ret) {
+                error_report("%s : failed to load %s (%d)",
+                             field->name, key_vmsd->name, ret);
+                goto key_error;
+            }
+        }
+        val = g_malloc0(val_size);
+        ret = vmstate_load_state(f, val_vmsd, val, version_id);
+        if (ret) {
+            error_report("%s : failed to load %s (%d)",
+                         field->name, val_vmsd->name, ret);
+            goto val_error;
+        }
+        g_tree_insert(tree, key, val);
+    }
+    if (count != nnodes) {
+        error_report("%s inconsistent stream when loading the gtree",
+                     field->name);
+        return -EINVAL;
+    }
+    trace_get_gtree_end(field->name, key_vmsd_name, val_vmsd->name, ret);
+    return ret;
+val_error:
+    g_free(val);
+key_error:
+    if (!direct_key) {
+        g_free(key);
+    }
+    trace_get_gtree_end(field->name, key_vmsd_name, val_vmsd->name, ret);
+    return ret;
+}
+
+
+const VMStateInfo vmstate_info_gtree = {
+    .name = "gtree",
+    .get  = get_gtree,
+    .put  = put_gtree,
+};
diff --git a/tests/test-vmstate.c b/tests/test-vmstate.c
index e80c4c6143..1e5be1d4ff 100644
--- a/tests/test-vmstate.c
+++ b/tests/test-vmstate.c
@@ -812,6 +812,423 @@ static void test_load_q(void)
     qemu_fclose(fload);
 }
 
+/* interval (key) */
+typedef struct TestGTreeInterval {
+    uint64_t low;
+    uint64_t high;
+} TestGTreeInterval;
+
+#define VMSTATE_INTERVAL                               \
+{                                                      \
+    .name = "interval",                                \
+    .version_id = 1,                                   \
+    .minimum_version_id = 1,                           \
+    .fields = (VMStateField[]) {                       \
+        VMSTATE_UINT64(low, TestGTreeInterval),        \
+        VMSTATE_UINT64(high, TestGTreeInterval),       \
+        VMSTATE_END_OF_LIST()                          \
+    }                                                  \
+}
+
+/* mapping (value) */
+typedef struct TestGTreeMapping {
+    uint64_t phys_addr;
+    uint32_t flags;
+} TestGTreeMapping;
+
+#define VMSTATE_MAPPING                               \
+{                                                     \
+    .name = "mapping",                                \
+    .version_id = 1,                                  \
+    .minimum_version_id = 1,                          \
+    .fields = (VMStateField[]) {                      \
+        VMSTATE_UINT64(phys_addr, TestGTreeMapping),  \
+        VMSTATE_UINT32(flags, TestGTreeMapping),      \
+        VMSTATE_END_OF_LIST()                         \
+    },                                                \
+}
+
+static const VMStateDescription vmstate_interval_mapping[2] = {
+    VMSTATE_MAPPING,   /* value */
+    VMSTATE_INTERVAL   /* key   */
+};
+
+typedef struct TestGTreeDomain {
+    int32_t  id;
+    GTree    *mappings;
+} TestGTreeDomain;
+
+typedef struct TestGTreeIOMMU {
+    int32_t  id;
+    GTree    *domains;
+} TestGTreeIOMMU;
+
+/* Interval comparison function */
+static gint interval_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
+{
+    TestGTreeInterval *inta = (TestGTreeInterval *)a;
+    TestGTreeInterval *intb = (TestGTreeInterval *)b;
+
+    if (inta->high < intb->low) {
+        return -1;
+    } else if (intb->high < inta->low) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/* ID comparison function */
+static gint int_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
+{
+    uint ua = GPOINTER_TO_UINT(a);
+    uint ub = GPOINTER_TO_UINT(b);
+    return (ua > ub) - (ua < ub);
+}
+
+static void destroy_domain(gpointer data)
+{
+    TestGTreeDomain *domain = (TestGTreeDomain *)data;
+
+    g_tree_destroy(domain->mappings);
+    g_free(domain);
+}
+
+static int domain_preload(void *opaque)
+{
+    TestGTreeDomain *domain = opaque;
+
+    domain->mappings = g_tree_new_full((GCompareDataFunc)interval_cmp,
+                                       NULL, g_free, g_free);
+    return 0;
+}
+
+static int iommu_preload(void *opaque)
+{
+    TestGTreeIOMMU *iommu = opaque;
+
+    iommu->domains = g_tree_new_full((GCompareDataFunc)int_cmp,
+                                     NULL, NULL, destroy_domain);
+    return 0;
+}
+
+static const VMStateDescription vmstate_domain = {
+    .name = "domain",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .pre_load = domain_preload,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(id, TestGTreeDomain),
+        VMSTATE_GTREE_V(mappings, TestGTreeDomain, 1,
+                        vmstate_interval_mapping,
+                        TestGTreeInterval, TestGTreeMapping),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_iommu = {
+    .name = "iommu",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .pre_load = iommu_preload,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(id, TestGTreeIOMMU),
+        VMSTATE_GTREE_DIRECT_KEY_V(domains, TestGTreeIOMMU, 1,
+                                   &vmstate_domain, TestGTreeDomain),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+uint8_t first_domain_dump[] = {
+    /* id */
+    0x00, 0x0, 0x0, 0x6,
+    0x00, 0x0, 0x0, 0x2, /* 2 mappings */
+    0x1, /* start of a */
+    /* a */
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF,
+    /* map_a */
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xa0, 0x00,
+    0x00, 0x00, 0x00, 0x01,
+    0x1, /* start of b */
+    /* b */
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4F, 0xFF,
+    /* map_b */
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x02,
+    0x0, /* end of gtree */
+    QEMU_VM_EOF, /* just to ensure we won't get EOF reported prematurely */
+};
+
+static TestGTreeDomain *create_first_domain(void)
+{
+    TestGTreeDomain *domain;
+    TestGTreeMapping *map_a, *map_b;
+    TestGTreeInterval *a, *b;
+
+    domain = g_malloc0(sizeof(TestGTreeDomain));
+    domain->id = 6;
+
+    a = g_malloc0(sizeof(TestGTreeInterval));
+    a->low = 0x1000;
+    a->high = 0x1FFF;
+
+    b = g_malloc0(sizeof(TestGTreeInterval));
+    b->low = 0x4000;
+    b->high = 0x4FFF;
+
+    map_a = g_malloc0(sizeof(TestGTreeMapping));
+    map_a->phys_addr = 0xa000;
+    map_a->flags = 1;
+
+    map_b = g_malloc0(sizeof(TestGTreeMapping));
+    map_b->phys_addr = 0xe0000;
+    map_b->flags = 2;
+
+    domain->mappings = g_tree_new_full((GCompareDataFunc)interval_cmp, NULL,
+                                        (GDestroyNotify)g_free,
+                                        (GDestroyNotify)g_free);
+    g_tree_insert(domain->mappings, a, map_a);
+    g_tree_insert(domain->mappings, b, map_b);
+    return domain;
+}
+
+static void test_gtree_save_domain(void)
+{
+    TestGTreeDomain *first_domain = create_first_domain();
+
+    save_vmstate(&vmstate_domain, first_domain);
+    compare_vmstate(first_domain_dump, sizeof(first_domain_dump));
+    destroy_domain(first_domain);
+}
+
+struct match_node_data {
+    GTree *tree;
+    gpointer key;
+    gpointer value;
+};
+
+struct tree_cmp_data {
+    GTree *tree1;
+    GTree *tree2;
+    GTraverseFunc match_node;
+};
+
+static gboolean match_interval_mapping_node(gpointer key,
+                                            gpointer value, gpointer data)
+{
+    TestGTreeMapping *map_a, *map_b;
+    TestGTreeInterval *a, *b;
+    struct match_node_data *d = (struct match_node_data *)data;
+    char *str = g_strdup_printf("dest");
+
+    g_free(str);
+    a = (TestGTreeInterval *)key;
+    b = (TestGTreeInterval *)d->key;
+
+    map_a = (TestGTreeMapping *)value;
+    map_b = (TestGTreeMapping *)d->value;
+
+    assert(a->low == b->low);
+    assert(a->high == b->high);
+    assert(map_a->phys_addr == map_b->phys_addr);
+    assert(map_a->flags == map_b->flags);
+    g_tree_remove(d->tree, key);
+    return true;
+}
+
+static gboolean diff_tree(gpointer key, gpointer value, gpointer data)
+{
+    struct tree_cmp_data *tp = (struct tree_cmp_data *)data;
+    struct match_node_data d = {tp->tree2, key, value};
+
+    g_tree_foreach(tp->tree2, tp->match_node, &d);
+    g_tree_remove(tp->tree1, key);
+    return false;
+}
+
+static void compare_trees(GTree *tree1, GTree *tree2,
+                          GTraverseFunc function)
+{
+    struct tree_cmp_data tp = {tree1, tree2, function};
+
+    g_tree_foreach(tree1, diff_tree, &tp);
+    assert(g_tree_nnodes(tree1) == 0);
+    assert(g_tree_nnodes(tree2) == 0);
+}
+
+static void diff_domain(TestGTreeDomain *d1, TestGTreeDomain *d2)
+{
+    assert(d1->id == d2->id);
+    compare_trees(d1->mappings, d2->mappings, match_interval_mapping_node);
+}
+
+static gboolean match_domain_node(gpointer key, gpointer value, gpointer data)
+{
+    uint64_t id1, id2;
+    TestGTreeDomain *d1, *d2;
+    struct match_node_data *d = (struct match_node_data *)data;
+
+    id1 = (uint64_t)(uintptr_t)key;
+    id2 = (uint64_t)(uintptr_t)d->key;
+    d1 = (TestGTreeDomain *)value;
+    d2 = (TestGTreeDomain *)d->value;
+    assert(id1 == id2);
+    diff_domain(d1, d2);
+    g_tree_remove(d->tree, key);
+    return true;
+}
+
+static void diff_iommu(TestGTreeIOMMU *iommu1, TestGTreeIOMMU *iommu2)
+{
+    assert(iommu1->id == iommu2->id);
+    compare_trees(iommu1->domains, iommu2->domains, match_domain_node);
+}
+
+static void test_gtree_load_domain(void)
+{
+    TestGTreeDomain *dest_domain = g_malloc0(sizeof(TestGTreeDomain));
+    TestGTreeDomain *orig_domain = create_first_domain();
+    QEMUFile *fload, *fsave;
+    char eof;
+
+    fsave = open_test_file(true);
+    qemu_put_buffer(fsave, first_domain_dump, sizeof(first_domain_dump));
+    g_assert(!qemu_file_get_error(fsave));
+    qemu_fclose(fsave);
+
+    fload = open_test_file(false);
+
+    vmstate_load_state(fload, &vmstate_domain, dest_domain, 1);
+    eof = qemu_get_byte(fload);
+    g_assert(!qemu_file_get_error(fload));
+    g_assert_cmpint(orig_domain->id, ==, dest_domain->id);
+    g_assert_cmpint(eof, ==, QEMU_VM_EOF);
+
+    diff_domain(orig_domain, dest_domain);
+    destroy_domain(orig_domain);
+    destroy_domain(dest_domain);
+    qemu_fclose(fload);
+}
+
+uint8_t iommu_dump[] = {
+    /* iommu id */
+    0x00, 0x0, 0x0, 0x7,
+    0x00, 0x0, 0x0, 0x2, /* 2 domains */
+    0x1,/* start of domain 5 */
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x0, 0x0, 0x5, /* key = 5 */
+        0x00, 0x0, 0x0, 0x5, /* domain1 id */
+        0x00, 0x0, 0x0, 0x1, /* 1 mapping */
+        0x1, /* start of mappings */
+            /* c */
+            0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00, 0x01, 0xFF, 0xFF, 0xFF,
+            /* map_c */
+            0x00, 0x00, 0x00, 0x00, 0x0F, 0x00, 0x00, 0x00,
+            0x00, 0x0, 0x0, 0x3,
+            0x0, /* end of domain1 mappings*/
+    0x1,/* start of domain 6 */
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x0, 0x0, 0x6, /* key = 6 */
+        0x00, 0x0, 0x0, 0x6, /* domain6 id */
+            0x00, 0x0, 0x0, 0x2, /* 2 mappings */
+            0x1, /* start of a */
+            /* a */
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF,
+            /* map_a */
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xa0, 0x00,
+            0x00, 0x00, 0x00, 0x01,
+            0x1, /* start of b */
+            /* b */
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00,
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4F, 0xFF,
+            /* map_b */
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x02,
+            0x0, /* end of domain6 mappings*/
+    0x0, /* end of domains */
+    QEMU_VM_EOF, /* just to ensure we won't get EOF reported prematurely */
+};
+
+static TestGTreeIOMMU *create_iommu(void)
+{
+    TestGTreeIOMMU *iommu = g_malloc0(sizeof(TestGTreeIOMMU));
+    TestGTreeDomain *first_domain = create_first_domain();
+    TestGTreeDomain *second_domain;
+    TestGTreeMapping *map_c;
+    TestGTreeInterval *c;
+
+    iommu->id = 7;
+    iommu->domains = g_tree_new_full((GCompareDataFunc)int_cmp, NULL,
+                                     NULL,
+                                     destroy_domain);
+
+    second_domain = g_malloc0(sizeof(TestGTreeDomain));
+    second_domain->id = 5;
+    second_domain->mappings = g_tree_new_full((GCompareDataFunc)interval_cmp,
+                                              NULL,
+                                              (GDestroyNotify)g_free,
+                                              (GDestroyNotify)g_free);
+
+    g_tree_insert(iommu->domains, GUINT_TO_POINTER(6), first_domain);
+    g_tree_insert(iommu->domains, (gpointer)0x0000000000000005, second_domain);
+
+    c = g_malloc0(sizeof(TestGTreeInterval));
+    c->low = 0x1000000;
+    c->high = 0x1FFFFFF;
+
+    map_c = g_malloc0(sizeof(TestGTreeMapping));
+    map_c->phys_addr = 0xF000000;
+    map_c->flags = 0x3;
+
+    g_tree_insert(second_domain->mappings, c, map_c);
+    return iommu;
+}
+
+static void destroy_iommu(TestGTreeIOMMU *iommu)
+{
+    g_tree_destroy(iommu->domains);
+    g_free(iommu);
+}
+
+static void test_gtree_save_iommu(void)
+{
+    TestGTreeIOMMU *iommu = create_iommu();
+
+    save_vmstate(&vmstate_iommu, iommu);
+    compare_vmstate(iommu_dump, sizeof(iommu_dump));
+    destroy_iommu(iommu);
+}
+
+static void test_gtree_load_iommu(void)
+{
+    TestGTreeIOMMU *dest_iommu = g_malloc0(sizeof(TestGTreeIOMMU));
+    TestGTreeIOMMU *orig_iommu = create_iommu();
+    QEMUFile *fsave, *fload;
+    char eof;
+    int ret;
+
+    fsave = open_test_file(true);
+    qemu_put_buffer(fsave, iommu_dump, sizeof(iommu_dump));
+    g_assert(!qemu_file_get_error(fsave));
+    qemu_fclose(fsave);
+
+    fload = open_test_file(false);
+    vmstate_load_state(fload, &vmstate_iommu, dest_iommu, 1);
+    ret = qemu_file_get_error(fload);
+    eof = qemu_get_byte(fload);
+    ret = qemu_file_get_error(fload);
+    g_assert(!ret);
+    g_assert_cmpint(orig_iommu->id, ==, dest_iommu->id);
+    g_assert_cmpint(eof, ==, QEMU_VM_EOF);
+
+    diff_iommu(orig_iommu, dest_iommu);
+    destroy_iommu(orig_iommu);
+    destroy_iommu(dest_iommu);
+    qemu_fclose(fload);
+}
+
 typedef struct TmpTestStruct {
     TestStruct *parent;
     int64_t diff;
@@ -932,6 +1349,10 @@ int main(int argc, char **argv)
                     test_arr_ptr_prim_0_load);
     g_test_add_func("/vmstate/qtailq/save/saveq", test_save_q);
     g_test_add_func("/vmstate/qtailq/load/loadq", test_load_q);
+    g_test_add_func("/vmstate/gtree/save/savedomain", test_gtree_save_domain);
+    g_test_add_func("/vmstate/gtree/load/loaddomain", test_gtree_load_domain);
+    g_test_add_func("/vmstate/gtree/save/saveiommu", test_gtree_save_iommu);
+    g_test_add_func("/vmstate/gtree/load/loadiommu", test_gtree_load_iommu);
     g_test_add_func("/vmstate/tmp_struct", test_tmp_struct);
     g_test_run();
 
-- 
2.23.0

Re: [PULL 00/21] migration queue

[Peter Maydell]

On Fri, 11 Oct 2019 at 20:19, Dr. David Alan Gilbert (git)
<dgilbert@redhat.com> wrote:
>
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The following changes since commit 98b2e3c9ab3abfe476a2b02f8f51813edb90e72d:
>
>   Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging (2019-10-08 16:08:35 +0100)
>
> are available in the Git repository at:
>
>   git://github.com/dagrh/qemu.git tags/pull-migration-20191011a
>
> for you to fetch changes up to 9a85e4b8f672016adbf7b7d5beaab2a99b9b5615:
>
>   migration: Support gtree migration (2019-10-11 17:52:31 +0100)
>
> ----------------------------------------------------------------
> Migration pull 2019-10-11
>
> Mostly cleanups and minor fixes
>
> [Note I'm seeing a hang on the aarch64 hosted x86-64 tcg migration
> test in xbzrle; but I'm seeing that on current head as well]
>


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/4.2
for any user-visible changes.

-- PMM