migration/next for 20170517

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Merge remote-tracking branch 'quintela/tags/migration/20170517' into staging

migration/next for 20170517

# gpg: Signature made Wed 17 May 2017 11:46:36 AM BST
# gpg:                using RSA key 0xF487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* quintela/tags/migration/20170517:
  migration: Move check_migratable() into qdev.c
  migration: Move postcopy stuff to postcopy-ram.c
  migration: Move page_cache.c to migration/
  migration: Create migration/blocker.h
  ram: Rename RAM_SAVE_FLAG_COMPRESS to RAM_SAVE_FLAG_ZERO
  migration: Pass Error ** argument to {save,load}_vmstate
  migration: Fix regression with compression threads

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Makefile.objs

@@ -49,7 +49,6 @@ common-obj-$(CONFIG_POSIX) += os-posix.o
 common-obj-$(CONFIG_LINUX) += fsdev/
 
 common-obj-y += migration/
-common-obj-y += page_cache.o #aio.o
 
 common-obj-$(CONFIG_SPICE) += spice-qemu-char.o
 

block/qcow.c

@@ -32,7 +32,7 @@
 #include <zlib.h>
 #include "qapi/qmp/qerror.h"
 #include "crypto/cipher.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 
 /**************************************************************/
 /* QEMU COW block driver with compression and encryption support */

block/vdi.c

@@ -55,7 +55,7 @@
 #include "sysemu/block-backend.h"
 #include "qemu/module.h"
 #include "qemu/bswap.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/coroutine.h"
 #include "qemu/cutils.h"
 #include "qemu/uuid.h"

block/vhdx.c

@@ -24,7 +24,7 @@
 #include "qemu/crc32c.h"
 #include "qemu/bswap.h"
 #include "block/vhdx.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/uuid.h"
 
 /* Options for VHDX creation */

block/vmdk.c

@@ -31,7 +31,7 @@
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "qemu/bswap.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/cutils.h"
 #include <zlib.h>
 

block/vpc.c

@@ -28,7 +28,7 @@
 #include "block/block_int.h"
 #include "sysemu/block-backend.h"
 #include "qemu/module.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/bswap.h"
 #include "qemu/uuid.h"
 

block/vvfat.c

@@ -28,7 +28,7 @@
 #include "block/block_int.h"
 #include "qemu/module.h"
 #include "qemu/bswap.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qapi/qmp/qint.h"
 #include "qapi/qmp/qbool.h"
 #include "qapi/qmp/qstring.h"

hmp.c

@@ -1274,17 +1274,22 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
 {
     int saved_vm_running  = runstate_is_running();
     const char *name = qdict_get_str(qdict, "name");
+    Error *err = NULL;
 
     vm_stop(RUN_STATE_RESTORE_VM);
 
-    if (load_vmstate(name) == 0 && saved_vm_running) {
+    if (load_vmstate(name, &err) == 0 && saved_vm_running) {
         vm_start();
     }
+    hmp_handle_error(mon, &err);
 }
 
 void hmp_savevm(Monitor *mon, const QDict *qdict)
 {
-    save_vmstate(qdict_get_try_str(qdict, "name"));
+    Error *err = NULL;
+
+    save_vmstate(qdict_get_try_str(qdict, "name"), &err);
+    hmp_handle_error(mon, &err);
 }
 
 void hmp_delvm(Monitor *mon, const QDict *qdict)

hw/9pfs/9p.c

@@ -23,7 +23,7 @@
 #include "9p-xattr.h"
 #include "coth.h"
 #include "trace.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 
 int open_fd_hw;
 int total_open_fd;

hw/core/qdev.c

@@ -37,7 +37,7 @@
 #include "hw/boards.h"
 #include "hw/sysbus.h"
 #include "qapi-event.h"
-#include "migration/migration.h"
+#include "migration/vmstate.h"
 
 bool qdev_hotplug = false;
 static bool qdev_hot_added = false;
@@ -861,6 +861,20 @@ static bool device_get_realized(Object *obj, Error **errp)
     return dev->realized;
 }
 
+static bool check_only_migratable(Object *obj, Error **err)
+{
+    DeviceClass *dc = DEVICE_GET_CLASS(obj);
+
+    if (!vmstate_check_only_migratable(dc->vmsd)) {
+        error_setg(err, "Device %s is not migratable, but "
+                   "--only-migratable was specified",
+                   object_get_typename(obj));
+        return false;
+    }
+
+    return true;
+}
+
 static void device_set_realized(Object *obj, bool value, Error **errp)
 {
     DeviceState *dev = DEVICE(obj);
@@ -870,7 +884,6 @@ static void device_set_realized(Object *obj, bool value, Error **errp)
     Error *local_err = NULL;
     bool unattached_parent = false;
     static int unattached_count;
-    int ret;
 
     if (dev->hotplugged && !dc->hotpluggable) {
         error_setg(errp, QERR_DEVICE_NO_HOTPLUG, object_get_typename(obj));
@@ -878,8 +891,7 @@ static void device_set_realized(Object *obj, bool value, Error **errp)
     }
 
     if (value && !dev->realized) {
-        ret = check_migratable(obj, &local_err);
+        if (!check_only_migratable(obj, &local_err)) {
-        if (ret < 0) {
             goto fail;
         }
 

hw/display/qxl.c

@@ -26,7 +26,7 @@
 #include "qemu/queue.h"
 #include "qemu/atomic.h"
 #include "sysemu/sysemu.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "trace.h"
 
 #include "qxl.h"

hw/display/virtio-gpu.c

@@ -19,7 +19,7 @@
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/virtio-gpu.h"
 #include "hw/virtio/virtio-bus.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
 

hw/intc/arm_gic_kvm.c

@@ -24,7 +24,7 @@
 #include "qemu-common.h"
 #include "cpu.h"
 #include "hw/sysbus.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
 #include "gic_internal.h"

hw/intc/arm_gicv3_its_kvm.c

@@ -24,7 +24,7 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 
 #define TYPE_KVM_ARM_ITS "arm-its-kvm"
 #define KVM_ARM_ITS(obj) OBJECT_CHECK(GICv3ITSState, (obj), TYPE_KVM_ARM_ITS)

hw/intc/arm_gicv3_kvm.c

@@ -28,7 +28,7 @@
 #include "kvm_arm.h"
 #include "gicv3_internal.h"
 #include "vgic_common.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 
 #ifdef DEBUG_GICV3_KVM
 #define DPRINTF(fmt, ...) \

hw/misc/ivshmem.c

@@ -25,7 +25,7 @@
 #include "hw/pci/msi.h"
 #include "hw/pci/msix.h"
 #include "sysemu/kvm.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "qemu/error-report.h"
 #include "qemu/event_notifier.h"
 #include "qom/object_interfaces.h"

hw/scsi/vhost-scsi.c

@@ -21,7 +21,7 @@
 #include "qemu/error-report.h"
 #include "qemu/queue.h"
 #include "monitor/monitor.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "hw/virtio/vhost-scsi.h"
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/virtio-scsi.h"

hw/virtio/vhost.c

@@ -25,7 +25,7 @@
 #include "exec/address-spaces.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-access.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "sysemu/dma.h"
 
 /* enabled until disconnected backend stabilizes */

include/migration/blocker.h

@@ -0,0 +1,35 @@
+/*
+ * QEMU migration blockers
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef MIGRATION_BLOCKER_H
+#define MIGRATION_BLOCKER_H
+
+/**
+ * @migrate_add_blocker - prevent migration from proceeding
+ *
+ * @reason - an error to be returned whenever migration is attempted
+ *
+ * @errp - [out] The reason (if any) we cannot block migration right now.
+ *
+ * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
+ */
+int migrate_add_blocker(Error *reason, Error **errp);
+
+/**
+ * @migrate_del_blocker - remove a blocking error from migration
+ *
+ * @reason - the error blocking migration
+ */
+void migrate_del_blocker(Error *reason);
+
+#endif

include/migration/migration.h

@@ -22,7 +22,6 @@
 #include "qapi-types.h"
 #include "exec/cpu-common.h"
 #include "qemu/coroutine_int.h"
-#include "qom/object.h"
 
 #define QEMU_VM_FILE_MAGIC           0x5145564d
 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
@@ -39,9 +38,6 @@
 #define QEMU_VM_COMMAND              0x08
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
-/* for vl.c */
-extern int only_migratable;
-
 struct MigrationParams {
     bool blk;
     bool shared;
@@ -61,28 +57,6 @@ enum mig_rp_message_type {
 
 typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
 
-/* The current postcopy state is read/set by postcopy_state_get/set
- * which update it atomically.
- * The state is updated as postcopy messages are received, and
- * in general only one thread should be writing to the state at any one
- * time, initially the main thread and then the listen thread;
- * Corner cases are where either thread finishes early and/or errors.
- * The state is checked as messages are received to ensure that
- * the source is sending us messages in the correct order.
- * The state is also used by the RAM reception code to know if it
- * has to place pages atomically, and the cleanup code at the end of
- * the main thread to know if it has to delay cleanup until the end
- * of postcopy.
- */
-typedef enum {
-    POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
-    POSTCOPY_INCOMING_ADVISE,
-    POSTCOPY_INCOMING_DISCARD,
-    POSTCOPY_INCOMING_LISTENING,
-    POSTCOPY_INCOMING_RUNNING,
-    POSTCOPY_INCOMING_END
-} PostcopyState;
-
 /* State for the incoming migration */
 struct MigrationIncomingState {
     QEMUFile *from_src_file;
@@ -275,26 +249,6 @@ int ram_discard_range(const char *block_name, uint64_t start, size_t length);
 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 void ram_postcopy_migrated_memory_release(MigrationState *ms);
 
-/**
- * @migrate_add_blocker - prevent migration from proceeding
- *
- * @reason - an error to be returned whenever migration is attempted
- *
- * @errp - [out] The reason (if any) we cannot block migration right now.
- *
- * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
- */
-int migrate_add_blocker(Error *reason, Error **errp);
-
-/**
- * @migrate_del_blocker - remove a blocking error from migration
- *
- * @reason - the error blocking migration
- */
-void migrate_del_blocker(Error *reason);
-
-int check_migratable(Object *obj, Error **err);
-
 bool migrate_release_ram(void);
 bool migrate_postcopy_ram(void);
 bool migrate_zero_blocks(void);
@@ -357,8 +311,4 @@ void global_state_store_running(void);
 void migration_page_queue_free(void);
 int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
 uint64_t ram_pagesize_summary(void);
-
-PostcopyState postcopy_state_get(void);
-/* Set the state and return the old state */
-PostcopyState postcopy_state_set(PostcopyState new_state);
 #endif

include/migration/vmstate.h

@@ -1067,4 +1067,6 @@ int64_t self_announce_delay(int round)
 
 void dump_vmstate_json_to_file(FILE *out_fp);
 
+bool vmstate_check_only_migratable(const VMStateDescription *vmsd);
+
 #endif

include/sysemu/sysemu.h

@@ -15,7 +15,7 @@
 /* vl.c */
 
 extern const char *bios_name;
-
+extern int only_migratable;
 extern const char *qemu_name;
 extern QemuUUID qemu_uuid;
 extern bool qemu_uuid_set;
@@ -75,8 +75,8 @@ void qemu_remove_exit_notifier(Notifier *notify);
 void qemu_add_machine_init_done_notifier(Notifier *notify);
 void qemu_remove_machine_init_done_notifier(Notifier *notify);
 
-int save_vmstate(const char *name);
+int save_vmstate(const char *name, Error **errp);
-int load_vmstate(const char *name);
+int load_vmstate(const char *name, Error **errp);
 
 void qemu_announce_self(void);
 

migration/Makefile.objs

@@ -1,7 +1,7 @@
 common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += tls.o
 common-obj-y += colo-comm.o colo.o colo-failover.o
-common-obj-y += vmstate.o
+common-obj-y += vmstate.o page_cache.o
 common-obj-y += qemu-file.o
 common-obj-y += qemu-file-channel.o
 common-obj-y += xbzrle.o postcopy-ram.o

migration/migration.c

@@ -17,6 +17,7 @@
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
+#include "migration/blocker.h"
 #include "migration/migration.h"
 #include "migration/qemu-file.h"
 #include "sysemu/sysemu.h"
@@ -77,13 +78,6 @@ static NotifierList migration_state_notifiers =
 
 static bool deferred_incoming;
 
-/*
- * Current state of incoming postcopy; note this is not part of
- * MigrationIncomingState since it's state is used during cleanup
- * at the end as MIS is being freed.
- */
-static PostcopyState incoming_postcopy_state;
-
 /* When we add fault tolerance, we could have several
    migrations at once.  For now we don't need to add
    dynamic creation of migration */
@@ -1149,21 +1143,6 @@ void migrate_del_blocker(Error *reason)
     migration_blockers = g_slist_remove(migration_blockers, reason);
 }
 
-int check_migratable(Object *obj, Error **err)
-{
-    DeviceClass *dc = DEVICE_GET_CLASS(obj);
-    if (only_migratable && dc->vmsd) {
-        if (dc->vmsd->unmigratable) {
-            error_setg(err, "Device %s is not migratable, but "
-                       "--only-migratable was specified",
-                       object_get_typename(obj));
-            return -1;
-        }
-    }
-
-    return 0;
-}
-
 void qmp_migrate_incoming(const char *uri, Error **errp)
 {
     Error *local_err = NULL;
@@ -2097,14 +2076,3 @@ void migrate_fd_connect(MigrationState *s)
     s->migration_thread_running = true;
 }
 
-PostcopyState  postcopy_state_get(void)
-{
-    return atomic_mb_read(&incoming_postcopy_state);
-}
-
-/* Set the state and return the old state */
-PostcopyState postcopy_state_set(PostcopyState new_state)
-{
-    return atomic_xchg(&incoming_postcopy_state, new_state);
-}
-

migration/postcopy-ram.c

@@ -784,3 +784,21 @@ void postcopy_discard_send_finish(MigrationState *ms, PostcopyDiscardState *pds)
 
     g_free(pds);
 }
+
+/*
+ * Current state of incoming postcopy; note this is not part of
+ * MigrationIncomingState since it's state is used during cleanup
+ * at the end as MIS is being freed.
+ */
+static PostcopyState incoming_postcopy_state;
+
+PostcopyState  postcopy_state_get(void)
+{
+    return atomic_mb_read(&incoming_postcopy_state);
+}
+
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(PostcopyState new_state)
+{
+    return atomic_xchg(&incoming_postcopy_state, new_state);
+}

migration/postcopy-ram.h

@@ -81,6 +81,28 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
 int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
                              size_t pagesize);
 
+/* The current postcopy state is read/set by postcopy_state_get/set
+ * which update it atomically.
+ * The state is updated as postcopy messages are received, and
+ * in general only one thread should be writing to the state at any one
+ * time, initially the main thread and then the listen thread;
+ * Corner cases are where either thread finishes early and/or errors.
+ * The state is checked as messages are received to ensure that
+ * the source is sending us messages in the correct order.
+ * The state is also used by the RAM reception code to know if it
+ * has to place pages atomically, and the cleanup code at the end of
+ * the main thread to know if it has to delay cleanup until the end
+ * of postcopy.
+ */
+typedef enum {
+    POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
+    POSTCOPY_INCOMING_ADVISE,
+    POSTCOPY_INCOMING_DISCARD,
+    POSTCOPY_INCOMING_LISTENING,
+    POSTCOPY_INCOMING_RUNNING,
+    POSTCOPY_INCOMING_END
+} PostcopyState;
+
 /*
  * Allocate a page of memory that can be mapped at a later point in time
  * using postcopy_place_page
@@ -88,4 +110,8 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
  */
 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);
+
 #endif

migration/ram.c

@@ -48,8 +48,14 @@
 /***********************************************************/
 /* ram save/restore */
 
+/* RAM_SAVE_FLAG_ZERO used to be named RAM_SAVE_FLAG_COMPRESS, it
+ * worked for pages that where filled with the same char.  We switched
+ * it to only search for the zero value.  And to avoid confusion with
+ * RAM_SSAVE_FLAG_COMPRESS_PAGE just rename it.
+ */
+
 #define RAM_SAVE_FLAG_FULL     0x01 /* Obsolete, not used anymore */
-#define RAM_SAVE_FLAG_COMPRESS 0x02
+#define RAM_SAVE_FLAG_ZERO     0x02
 #define RAM_SAVE_FLAG_MEM_SIZE 0x04
 #define RAM_SAVE_FLAG_PAGE     0x08
 #define RAM_SAVE_FLAG_EOS      0x10
@@ -436,20 +442,21 @@ void migrate_compress_threads_create(void)
  * @offset: offset inside the block for the page
  *          in the lower bits, it contains flags
  */
-static size_t save_page_header(RAMState *rs, RAMBlock *block, ram_addr_t offset)
+static size_t save_page_header(RAMState *rs, QEMUFile *f,  RAMBlock *block,
+                               ram_addr_t offset)
 {
     size_t size, len;
 
     if (block == rs->last_sent_block) {
         offset |= RAM_SAVE_FLAG_CONTINUE;
     }
-    qemu_put_be64(rs->f, offset);
+    qemu_put_be64(f, offset);
     size = 8;
 
     if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
         len = strlen(block->idstr);
-        qemu_put_byte(rs->f, len);
+        qemu_put_byte(f, len);
-        qemu_put_buffer(rs->f, (uint8_t *)block->idstr, len);
+        qemu_put_buffer(f, (uint8_t *)block->idstr, len);
         size += 1 + len;
         rs->last_sent_block = block;
     }
@@ -571,7 +578,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
     }
 
     /* Send XBZRLE based compressed page */
-    bytes_xbzrle = save_page_header(rs, block,
+    bytes_xbzrle = save_page_header(rs, rs->f, block,
                                     offset | RAM_SAVE_FLAG_XBZRLE);
     qemu_put_byte(rs->f, ENCODING_FLAG_XBZRLE);
     qemu_put_be16(rs->f, encoded_len);
@@ -745,7 +752,7 @@ static int save_zero_page(RAMState *rs, RAMBlock *block, ram_addr_t offset,
     if (is_zero_range(p, TARGET_PAGE_SIZE)) {
         rs->zero_pages++;
         rs->bytes_transferred +=
-            save_page_header(rs, block, offset | RAM_SAVE_FLAG_COMPRESS);
+            save_page_header(rs, rs->f, block, offset | RAM_SAVE_FLAG_ZERO);
         qemu_put_byte(rs->f, 0);
         rs->bytes_transferred += 1;
         pages = 1;
@@ -834,7 +841,7 @@ static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage)
 
     /* XBZRLE overflow or normal page */
     if (pages == -1) {
-        rs->bytes_transferred += save_page_header(rs, block,
+        rs->bytes_transferred += save_page_header(rs, rs->f, block,
                                                   offset | RAM_SAVE_FLAG_PAGE);
         if (send_async) {
             qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE,
@@ -860,7 +867,7 @@ static int do_compress_ram_page(QEMUFile *f, RAMBlock *block,
     int bytes_sent, blen;
     uint8_t *p = block->host + (offset & TARGET_PAGE_MASK);
 
-    bytes_sent = save_page_header(rs, block, offset |
+    bytes_sent = save_page_header(rs, f, block, offset |
                                   RAM_SAVE_FLAG_COMPRESS_PAGE);
     blen = qemu_put_compression_data(f, p, TARGET_PAGE_SIZE,
                                      migrate_compress_level());
@@ -991,7 +998,7 @@ static int ram_save_compressed_page(RAMState *rs, PageSearchStatus *pss,
             pages = save_zero_page(rs, block, offset, p);
             if (pages == -1) {
                 /* Make sure the first page is sent out before other pages */
-                bytes_xmit = save_page_header(rs, block, offset |
+                bytes_xmit = save_page_header(rs, rs->f, block, offset |
                                               RAM_SAVE_FLAG_COMPRESS_PAGE);
                 blen = qemu_put_compression_data(rs->f, p, TARGET_PAGE_SIZE,
                                                  migrate_compress_level());
@@ -2405,7 +2412,7 @@ static int ram_load_postcopy(QEMUFile *f)
 
         trace_ram_load_postcopy_loop((uint64_t)addr, flags);
         place_needed = false;
-        if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE)) {
+        if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE)) {
             block = ram_block_from_stream(f, flags);
 
             host = host_from_ram_block_offset(block, addr);
@@ -2452,7 +2459,7 @@ static int ram_load_postcopy(QEMUFile *f)
         last_host = host;
 
         switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
-        case RAM_SAVE_FLAG_COMPRESS:
+        case RAM_SAVE_FLAG_ZERO:
             ch = qemu_get_byte(f);
             memset(page_buffer, ch, TARGET_PAGE_SIZE);
             if (ch) {
@@ -2541,7 +2548,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
         flags = addr & ~TARGET_PAGE_MASK;
         addr &= TARGET_PAGE_MASK;
 
-        if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
+        if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE |
                      RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
             RAMBlock *block = ram_block_from_stream(f, flags);
 
@@ -2603,7 +2610,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
             }
             break;
 
-        case RAM_SAVE_FLAG_COMPRESS:
+        case RAM_SAVE_FLAG_ZERO:
             ch = qemu_get_byte(f);
             ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
             break;

migration/savevm.c

@@ -2069,7 +2069,7 @@ int qemu_loadvm_state(QEMUFile *f)
     return ret;
 }
 
-int save_vmstate(const char *name)
+int save_vmstate(const char *name, Error **errp)
 {
     BlockDriverState *bs, *bs1;
     QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
@@ -2079,29 +2079,27 @@ int save_vmstate(const char *name)
     uint64_t vm_state_size;
     qemu_timeval tv;
     struct tm tm;
-    Error *local_err = NULL;
     AioContext *aio_context;
 
     if (!bdrv_all_can_snapshot(&bs)) {
-        error_report("Device '%s' is writable but does not support snapshots",
+        error_setg(errp, "Device '%s' is writable but does not support "
-                     bdrv_get_device_name(bs));
+                   "snapshots", bdrv_get_device_name(bs));
         return ret;
     }
 
     /* Delete old snapshots of the same name */
     if (name) {
-        ret = bdrv_all_delete_snapshot(name, &bs1, &local_err);
+        ret = bdrv_all_delete_snapshot(name, &bs1, errp);
         if (ret < 0) {
-            error_reportf_err(local_err,
+            error_prepend(errp, "Error while deleting snapshot on device "
-                              "Error while deleting snapshot on device '%s': ",
+                          "'%s': ", bdrv_get_device_name(bs1));
-                              bdrv_get_device_name(bs1));
             return ret;
         }
     }
 
     bs = bdrv_all_find_vmstate_bs();
     if (bs == NULL) {
-        error_report("No block device can accept snapshots");
+        error_setg(errp, "No block device can accept snapshots");
         return ret;
     }
     aio_context = bdrv_get_aio_context(bs);
@@ -2110,7 +2108,7 @@ int save_vmstate(const char *name)
 
     ret = global_state_store();
     if (ret) {
-        error_report("Error saving global state");
+        error_setg(errp, "Error saving global state");
         return ret;
     }
     vm_stop(RUN_STATE_SAVE_VM);
@@ -2142,21 +2140,20 @@ int save_vmstate(const char *name)
     /* save the VM state */
     f = qemu_fopen_bdrv(bs, 1);
     if (!f) {
-        error_report("Could not open VM state file");
+        error_setg(errp, "Could not open VM state file");
         goto the_end;
     }
-    ret = qemu_savevm_state(f, &local_err);
+    ret = qemu_savevm_state(f, errp);
     vm_state_size = qemu_ftell(f);
     qemu_fclose(f);
     if (ret < 0) {
-        error_report_err(local_err);
         goto the_end;
     }
 
     ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs);
     if (ret < 0) {
-        error_report("Error while creating snapshot on '%s'",
+        error_setg(errp, "Error while creating snapshot on '%s'",
-                     bdrv_get_device_name(bs));
+                   bdrv_get_device_name(bs));
         goto the_end;
     }
 
@@ -2229,7 +2226,7 @@ void qmp_xen_load_devices_state(const char *filename, Error **errp)
     migration_incoming_state_destroy();
 }
 
-int load_vmstate(const char *name)
+int load_vmstate(const char *name, Error **errp)
 {
     BlockDriverState *bs, *bs_vm_state;
     QEMUSnapshotInfo sn;
@@ -2239,20 +2236,22 @@ int load_vmstate(const char *name)
     MigrationIncomingState *mis = migration_incoming_get_current();
 
     if (!bdrv_all_can_snapshot(&bs)) {
-        error_report("Device '%s' is writable but does not support snapshots",
+        error_setg(errp,
-                     bdrv_get_device_name(bs));
+                   "Device '%s' is writable but does not support snapshots",
+                   bdrv_get_device_name(bs));
         return -ENOTSUP;
     }
     ret = bdrv_all_find_snapshot(name, &bs);
     if (ret < 0) {
-        error_report("Device '%s' does not have the requested snapshot '%s'",
+        error_setg(errp,
-                     bdrv_get_device_name(bs), name);
+                   "Device '%s' does not have the requested snapshot '%s'",
+                   bdrv_get_device_name(bs), name);
         return ret;
     }
 
     bs_vm_state = bdrv_all_find_vmstate_bs();
     if (!bs_vm_state) {
-        error_report("No block device supports snapshots");
+        error_setg(errp, "No block device supports snapshots");
         return -ENOTSUP;
     }
     aio_context = bdrv_get_aio_context(bs_vm_state);
@@ -2264,8 +2263,8 @@ int load_vmstate(const char *name)
     if (ret < 0) {
         return ret;
     } else if (sn.vm_state_size == 0) {
-        error_report("This is a disk-only snapshot. Revert to it offline "
+        error_setg(errp, "This is a disk-only snapshot. Revert to it "
-            "using qemu-img.");
+                   " offline using qemu-img");
         return -EINVAL;
     }
 
@@ -2274,7 +2273,7 @@ int load_vmstate(const char *name)
 
     ret = bdrv_all_goto_snapshot(name, &bs);
     if (ret < 0) {
-        error_report("Error %d while activating snapshot '%s' on '%s'",
+        error_setg(errp, "Error %d while activating snapshot '%s' on '%s'",
                      ret, name, bdrv_get_device_name(bs));
         return ret;
     }
@@ -2282,7 +2281,7 @@ int load_vmstate(const char *name)
     /* restore the VM state */
     f = qemu_fopen_bdrv(bs_vm_state, 0);
     if (!f) {
-        error_report("Could not open VM state file");
+        error_setg(errp, "Could not open VM state file");
         return -EINVAL;
     }
 
@@ -2296,7 +2295,7 @@ int load_vmstate(const char *name)
 
     migration_incoming_state_destroy();
     if (ret < 0) {
-        error_report("Error %d while loading VM state", ret);
+        error_setg(errp, "Error %d while loading VM state", ret);
         return ret;
     }
 
@@ -2318,3 +2317,13 @@ void vmstate_register_ram_global(MemoryRegion *mr)
 {
     vmstate_register_ram(mr, NULL);
 }
+
+bool vmstate_check_only_migratable(const VMStateDescription *vmsd)
+{
+    /* check needed if --only-migratable is specified */
+    if (!only_migratable) {
+        return true;
+    }
+
+    return !(vmsd && vmsd->unmigratable);
+}

replay/replay-snapshot.c

@@ -62,14 +62,18 @@ void replay_vmstate_register(void)
 
 void replay_vmstate_init(void)
 {
+    Error *err = NULL;
+
     if (replay_snapshot) {
         if (replay_mode == REPLAY_MODE_RECORD) {
-            if (save_vmstate(replay_snapshot) != 0) {
+            if (save_vmstate(replay_snapshot, &err) != 0) {
+                error_report_err(err);
                 error_report("Could not create snapshot for icount record");
                 exit(1);
             }
         } else if (replay_mode == REPLAY_MODE_PLAY) {
-            if (load_vmstate(replay_snapshot) != 0) {
+            if (load_vmstate(replay_snapshot, &err) != 0) {
+                error_report_err(err);
                 error_report("Could not load snapshot for icount replay");
                 exit(1);
             }

stubs/migr-blocker.c

@@ -1,6 +1,6 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 
 int migrate_add_blocker(Error *reason, Error **errp)
 {

stubs/vmstate.c

@@ -1,7 +1,6 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "migration/vmstate.h"
-#include "migration/migration.h"
 
 const VMStateDescription vmstate_dummy = {};
 
@@ -21,7 +20,7 @@ void vmstate_unregister(DeviceState *dev,
 {
 }
 
-int check_migratable(Object *obj, Error **err)
+bool vmstate_check_only_migratable(const VMStateDescription *vmsd)
 {
-    return 0;
+    return true;
 }

target/i386/kvm.c

@@ -43,7 +43,7 @@
 #include "standard-headers/asm-x86/hyperv.h"
 #include "hw/pci/pci.h"
 #include "hw/pci/msi.h"
-#include "migration/migration.h"
+#include "migration/blocker.h"
 #include "exec/memattrs.h"
 #include "trace.h"
 

tests/Makefile.include

@@ -554,7 +554,7 @@ tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(test-block-obj-y)
 tests/test-iov$(EXESUF): tests/test-iov.o $(test-util-obj-y)
 tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o $(test-util-obj-y)
 tests/test-x86-cpuid$(EXESUF): tests/test-x86-cpuid.o
-tests/test-xbzrle$(EXESUF): tests/test-xbzrle.o migration/xbzrle.o page_cache.o $(test-util-obj-y)
+tests/test-xbzrle$(EXESUF): tests/test-xbzrle.o migration/xbzrle.o migration/page_cache.o $(test-util-obj-y)
 tests/test-cutils$(EXESUF): tests/test-cutils.o util/cutils.o
 tests/test-int128$(EXESUF): tests/test-int128.o
 tests/rcutorture$(EXESUF): tests/rcutorture.o $(test-util-obj-y)

vl.c

@@ -4701,7 +4701,9 @@ int main(int argc, char **argv, char **envp)
     if (replay_mode != REPLAY_MODE_NONE) {
         replay_vmstate_init();
     } else if (loadvm) {
-        if (load_vmstate(loadvm) < 0) {
+        Error *local_err = NULL;
+        if (load_vmstate(loadvm, &local_err) < 0) {
+            error_report_err(local_err);
             autostart = 0;
         }
     }