diff --git a/migration/migration.c b/migration/migration.c
diff --git a/migration/migration.h b/migration/migration.h
@@ -447,8 +447,6 @@ bool migration_is_blocked(Error **errp);
 bool migration_in_postcopy(void);
 MigrationState *migrate_get_current(void);
 
-int migrate_use_tls(void);
-
 uint64_t ram_get_total_transferred_pages(void);
 
 /* Sending on the return path - generic and then for each message type */

diff --git a/migration/options.c b/migration/options.c
diff --git a/migration/options.h b/migration/options.h
@@ -14,6 +14,13 @@
 #ifndef QEMU_MIGRATION_OPTIONS_H
 #define QEMU_MIGRATION_OPTIONS_H
 
+/* constants */
+
+/* Amount of time to allocate to each "chunk" of bandwidth-throttled
+ * data. */
+#define BUFFER_DELAY     100
+#define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
+
 /* capabilities */
 
 bool migrate_auto_converge(void);
@@ -46,6 +53,7 @@ bool migrate_zero_copy_send(void);
  */
 
 bool migrate_postcopy(void);
+bool migrate_tls(void);
 
 /* capabilities helpers */
 
@@ -73,4 +81,8 @@ int migrate_multifd_zstd_level(void);
 uint8_t migrate_throttle_trigger_threshold(void);
 uint64_t migrate_xbzrle_cache_size(void);
 
+/* parameters helpers */
+
+bool migrate_params_check(MigrationParameters *params, Error **errp);
+
 #endif
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
@@ -283,19 +283,21 @@ static bool request_ufd_features(int ufd, uint64_t features)
     return true;
 }
 
-static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
+static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis,
+                                Error **errp)
 {
     uint64_t asked_features = 0;
     static uint64_t supported_features;
 
+    ERRP_GUARD();
     /*
      * it's not possible to
      * request UFFD_API twice per one fd
      * userfault fd features is persistent
      */
     if (!supported_features) {
         if (!receive_ufd_features(&supported_features)) {
-            error_report("%s failed", __func__);
+            error_setg(errp, "Userfault feature detection failed");
             return false;
         }
     }
@@ -317,8 +319,7 @@ static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
      * userfault file descriptor
      */
     if (!request_ufd_features(ufd, asked_features)) {
-        error_report("%s failed: features %" PRIu64, __func__,
-                     asked_features);
+        error_setg(errp, "Failed features %" PRIu64, asked_features);
         return false;
     }
 
@@ -329,7 +330,8 @@ static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
         have_hp = supported_features & UFFD_FEATURE_MISSING_HUGETLBFS;
 #endif
         if (!have_hp) {
-            error_report("Userfault on this host does not support huge pages");
+            error_setg(errp,
+                       "Userfault on this host does not support huge pages");
             return false;
         }
     }
@@ -338,24 +340,26 @@ static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
 
 /* Callback from postcopy_ram_supported_by_host block iterator.
  */
-static int test_ramblock_postcopiable(RAMBlock *rb)
+static int test_ramblock_postcopiable(RAMBlock *rb, Error **errp)
 {
     const char *block_name = qemu_ram_get_idstr(rb);
     ram_addr_t length = qemu_ram_get_used_length(rb);
     size_t pagesize = qemu_ram_pagesize(rb);
     QemuFsType fs;
 
     if (length % pagesize) {
-        error_report("Postcopy requires RAM blocks to be a page size multiple,"
-                     " block %s is 0x" RAM_ADDR_FMT " bytes with a "
-                     "page size of 0x%zx", block_name, length, pagesize);
+        error_setg(errp,
+                   "Postcopy requires RAM blocks to be a page size multiple,"
+                   " block %s is 0x" RAM_ADDR_FMT " bytes with a "
+                   "page size of 0x%zx", block_name, length, pagesize);
         return 1;
     }
 
     if (rb->fd >= 0) {
         fs = qemu_fd_getfs(rb->fd);
         if (fs != QEMU_FS_TYPE_TMPFS && fs != QEMU_FS_TYPE_HUGETLBFS) {
-            error_report("Host backend files need to be TMPFS or HUGETLBFS only");
+            error_setg(errp,
+                       "Host backend files need to be TMPFS or HUGETLBFS only");
             return 1;
         }
     }
@@ -368,7 +372,8 @@ static int test_ramblock_postcopiable(RAMBlock *rb)
  * normally fine since if the postcopy succeeds it gets turned back on at the
  * end.
  */
-bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
+bool postcopy_ram_supported_by_host(MigrationIncomingState *mis,
+                                    Error **errp)
 {
     long pagesize = qemu_real_host_page_size();
     int ufd = -1;
@@ -377,29 +382,27 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
     struct uffdio_register reg_struct;
     struct uffdio_range range_struct;
     uint64_t feature_mask;
-    Error *local_err = NULL;
     RAMBlock *block;
 
+    ERRP_GUARD();
     if (qemu_target_page_size() > pagesize) {
-        error_report("Target page size bigger than host page size");
+        error_setg(errp, "Target page size bigger than host page size");
         goto out;
     }
 
     ufd = uffd_open(O_CLOEXEC);
     if (ufd == -1) {
-        error_report("%s: userfaultfd not available: %s", __func__,
-                     strerror(errno));
+        error_setg(errp, "Userfaultfd not available: %s", strerror(errno));
         goto out;
     }
 
     /* Give devices a chance to object */
-    if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, &local_err)) {
-        error_report_err(local_err);
+    if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, errp)) {
         goto out;
     }
 
     /* Version and features check */
-    if (!ufd_check_and_apply(ufd, mis)) {
+    if (!ufd_check_and_apply(ufd, mis, errp)) {
         goto out;
     }
 
@@ -417,7 +420,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
      * affect in reality, or we can revisit.
      */
     RAMBLOCK_FOREACH(block) {
-        if (test_ramblock_postcopiable(block)) {
+        if (test_ramblock_postcopiable(block, errp)) {
             goto out;
         }
     }
@@ -427,7 +430,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
      * it was enabled.
      */
     if (munlockall()) {
-        error_report("%s: munlockall: %s", __func__,  strerror(errno));
+        error_setg(errp, "munlockall() failed: %s", strerror(errno));
         goto out;
     }
 
@@ -439,8 +442,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
     testarea = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE |
                                     MAP_ANONYMOUS, -1, 0);
     if (testarea == MAP_FAILED) {
-        error_report("%s: Failed to map test area: %s", __func__,
-                     strerror(errno));
+        error_setg(errp, "Failed to map test area: %s", strerror(errno));
         goto out;
     }
     g_assert(QEMU_PTR_IS_ALIGNED(testarea, pagesize));
@@ -450,23 +452,23 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
     reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
 
     if (ioctl(ufd, UFFDIO_REGISTER, &reg_struct)) {
-        error_report("%s userfault register: %s", __func__, strerror(errno));
+        error_setg(errp, "UFFDIO_REGISTER failed: %s", strerror(errno));
         goto out;
     }
 
     range_struct.start = (uintptr_t)testarea;
     range_struct.len = pagesize;
     if (ioctl(ufd, UFFDIO_UNREGISTER, &range_struct)) {
-        error_report("%s userfault unregister: %s", __func__, strerror(errno));
+        error_setg(errp, "UFFDIO_UNREGISTER failed: %s", strerror(errno));
         goto out;
     }
 
     feature_mask = (__u64)1 << _UFFDIO_WAKE |
                    (__u64)1 << _UFFDIO_COPY |
                    (__u64)1 << _UFFDIO_ZEROPAGE;
     if ((reg_struct.ioctls & feature_mask) != feature_mask) {
-        error_report("Missing userfault map features: %" PRIx64,
-                     (uint64_t)(~reg_struct.ioctls & feature_mask));
+        error_setg(errp, "Missing userfault map features: %" PRIx64,
+                   (uint64_t)(~reg_struct.ioctls & feature_mask));
         goto out;
     }
 
@@ -1188,6 +1190,8 @@ static int postcopy_temp_pages_setup(MigrationIncomingState *mis)
 
 int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
 {
+    Error *local_err = NULL;
+
     /* Open the fd for the kernel to give us userfaults */
     mis->userfault_fd = uffd_open(O_CLOEXEC | O_NONBLOCK);
     if (mis->userfault_fd == -1) {
@@ -1200,7 +1204,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
      * Although the host check already tested the API, we need to
      * do the check again as an ABI handshake on the new fd.
      */
-    if (!ufd_check_and_apply(mis->userfault_fd, mis)) {
+    if (!ufd_check_and_apply(mis->userfault_fd, mis, &local_err)) {
+        error_report_err(local_err);
         return -1;
     }
 

diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
@@ -14,7 +14,8 @@
 #define QEMU_POSTCOPY_RAM_H
 
 /* Return true if the host supports everything we need to do postcopy-ram */
-bool postcopy_ram_supported_by_host(MigrationIncomingState *mis);
+bool postcopy_ram_supported_by_host(MigrationIncomingState *mis,
+                                    Error **errp);
 
 /*
  * Make all of RAM sensitive to accesses to areas that haven't yet been written

diff --git a/migration/savevm.c b/migration/savevm.c
@@ -536,6 +536,9 @@ static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
             field->version_id);
     fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "",
             field->field_exists ? "true" : "false");
+    if (field->flags & VMS_ARRAY) {
+        fprintf(out_file, "%*s\"num\": %d,\n", indent, "", field->num);
+    }
     fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size);
     if (field->vmsd != NULL) {
         fprintf(out_file, ",\n");
@@ -1753,7 +1756,8 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
         return -EINVAL;
     }
 
-    if (!postcopy_ram_supported_by_host(mis)) {
+    if (!postcopy_ram_supported_by_host(mis, &local_err)) {
+        error_report_err(local_err);
         postcopy_state_set(POSTCOPY_INCOMING_NONE);
         return -1;
     }

diff --git a/migration/tls.c b/migration/tls.c
@@ -22,6 +22,7 @@
 #include "channel.h"
 #include "migration.h"
 #include "tls.h"
+#include "options.h"
 #include "crypto/tlscreds.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
@@ -165,7 +166,7 @@ void migration_tls_channel_connect(MigrationState *s,
 
 bool migrate_channel_requires_tls_upgrade(QIOChannel *ioc)
 {
-    if (!migrate_use_tls()) {
+    if (!migrate_tls()) {
         return false;
     }
 

diff --git a/scripts/vmstate-static-checker.py b/scripts/vmstate-static-checker.py
@@ -134,6 +134,11 @@ def exists_in_substruct(fields, item):
     return check_fields_match(fields["Description"]["name"],
                               substruct_fields[0]["field"], item)
 
+def size_total(entry):
+    size = entry["size"]
+    if "num" not in entry:
+        return size
+    return size * entry["num"]
 
 def check_fields(src_fields, dest_fields, desc, sec):
     # This function checks for all the fields in a section.  If some
@@ -249,17 +254,19 @@ def check_fields(src_fields, dest_fields, desc, sec):
                 continue
 
             if s_item["field"] == "unused" or d_item["field"] == "unused":
-                if s_item["size"] == d_item["size"]:
+                s_size = size_total(s_item)
+                d_size = size_total(d_item)
+                if s_size == d_size:
                     continue
 
                 if d_item["field"] == "unused":
                     advance_dest = False
-                    unused_count = d_item["size"] - s_item["size"]
+                    unused_count = d_size - s_size;
                     continue
 
                 if s_item["field"] == "unused":
                     advance_src = False
-                    unused_count = s_item["size"] - d_item["size"]
+                    unused_count = s_size - d_size
                     continue
 
             print("Section \"" + sec + "\",", end=' ')