Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20171029' into staging

migration/next for 20171029

# gpg: Signature made Sun 29 Oct 2017 13:07:43 GMT
# 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

* remotes/juanquintela/tags/migration/20171029:
  tests: check that migration parameters are really assigned
  tests: Don't abuse global_qtest
  tests: Factorize out migrate_test_start/end
  tests: Refactor setting of parameters/capabilities
  tests: rename postcopy-test to migration-test
  migration: Make xbzrle_cache_size a migration parameter
  migration: No need to return the size of the cache
  migration: Don't play games with the requested cache size
  migration: Make sure that we pass the right cache size

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

10 files changed, 244 insertions, 142 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 2650063242..1fd7a6273c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1563,6 +1563,7 @@ F: include/migration/
 F: migration/
 F: scripts/vmstate-static-checker.py
 F: tests/vmstate-static-checker-data/
+F: tests/migration-test.c
 F: docs/devel/migration.txt
 F: qapi/migration.json
 
diff --git a/hmp.c b/hmp.c
index 41fcce6f5a..a01be50daa 100644
--- a/hmp.c
+++ b/hmp.c
@@ -342,6 +342,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: %" PRId64 "\n",
             MigrationParameter_str(MIGRATION_PARAMETER_X_MULTIFD_PAGE_COUNT),
             params->x_multifd_page_count);
+        monitor_printf(mon, "%s: %" PRId64 "\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
+            params->xbzrle_cache_size);
     }
 
     qapi_free_MigrationParameters(params);
@@ -1578,6 +1581,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
     Visitor *v = string_input_visitor_new(valuestr);
     MigrateSetParameters *p = g_new0(MigrateSetParameters, 1);
     uint64_t valuebw = 0;
+    uint64_t cache_size;
     Error *err = NULL;
     int val, ret;
 
@@ -1653,6 +1657,16 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         p->has_x_multifd_page_count = true;
         visit_type_int(v, param, &p->x_multifd_page_count, &err);
         break;
+    case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
+        p->has_xbzrle_cache_size = true;
+        visit_type_size(v, param, &cache_size, &err);
+        if (err || cache_size > INT64_MAX
+            || (size_t)cache_size != cache_size) {
+            error_setg(&err, "Invalid size %s", valuestr);
+            break;
+        }
+        p->xbzrle_cache_size = cache_size;
+        break;
     default:
         assert(0);
     }
diff --git a/migration/migration.c b/migration/migration.c
index 62761d5705..4de3b551fe 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -71,7 +71,7 @@
 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10
 
 /* Migration XBZRLE default cache size */
-#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
+#define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024)
 
 /* The delay time (in ms) between two COLO checkpoints
  * Note: Please change this default value to 10000 when we support hybrid mode.
@@ -515,6 +515,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->x_multifd_channels = s->parameters.x_multifd_channels;
     params->has_x_multifd_page_count = true;
     params->x_multifd_page_count = s->parameters.x_multifd_page_count;
+    params->has_xbzrle_cache_size = true;
+    params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
 
     return params;
 }
@@ -817,6 +819,16 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
         return false;
     }
 
+    if (params->has_xbzrle_cache_size &&
+        (params->xbzrle_cache_size < qemu_target_page_size() ||
+         !is_power_of_2(params->xbzrle_cache_size))) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   "xbzrle_cache_size",
+                   "is invalid, it should be bigger than target page size"
+                   " and a power of two");
+        return false;
+    }
+
     return true;
 }
 
@@ -878,9 +890,12 @@ static void migrate_params_test_apply(MigrateSetParameters *params,
     if (params->has_x_multifd_page_count) {
         dest->x_multifd_page_count = params->x_multifd_page_count;
     }
+    if (params->has_xbzrle_cache_size) {
+        dest->xbzrle_cache_size = params->xbzrle_cache_size;
+    }
 }
 
-static void migrate_params_apply(MigrateSetParameters *params)
+static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
 {
     MigrationState *s = migrate_get_current();
 
@@ -946,6 +961,10 @@ static void migrate_params_apply(MigrateSetParameters *params)
     if (params->has_x_multifd_page_count) {
         s->parameters.x_multifd_page_count = params->x_multifd_page_count;
     }
+    if (params->has_xbzrle_cache_size) {
+        s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
+        xbzrle_cache_resize(params->xbzrle_cache_size, errp);
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
@@ -974,7 +993,7 @@ void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
         return;
     }
 
-    migrate_params_apply(params);
+    migrate_params_apply(params, errp);
 }
 
 
@@ -1405,15 +1424,12 @@ void qmp_migrate_continue(MigrationStatus state, Error **errp)
 
 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
 {
-    MigrationState *s = migrate_get_current();
-    int64_t new_size;
-
-    new_size = xbzrle_cache_resize(value, errp);
-    if (new_size < 0) {
-        return;
-    }
+    MigrateSetParameters p = {
+        .has_xbzrle_cache_size = true,
+        .xbzrle_cache_size = value,
+    };
 
-    s->xbzrle_cache_size = new_size;
+    qmp_migrate_set_parameters(&p, errp);
 }
 
 int64_t qmp_query_migrate_cache_size(Error **errp)
@@ -1589,7 +1605,7 @@ int64_t migrate_xbzrle_cache_size(void)
 
     s = migrate_get_current();
 
-    return s->xbzrle_cache_size;
+    return s->parameters.xbzrle_cache_size;
 }
 
 bool migrate_use_block(void)
@@ -2407,6 +2423,9 @@ static Property migration_properties[] = {
     DEFINE_PROP_INT64("x-multifd-page-count", MigrationState,
                       parameters.x_multifd_page_count,
                       DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT),
+    DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,
+                      parameters.xbzrle_cache_size,
+                      DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),
 
     /* Migration capabilities */
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -2450,7 +2469,6 @@ static void migration_instance_init(Object *obj)
     MigrationParameters *params = &ms->parameters;
 
     ms->state = MIGRATION_STATUS_NONE;
-    ms->xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE;
     ms->mbps = -1;
     qemu_sem_init(&ms->pause_sem, 0);
     qemu_mutex_init(&ms->error_mutex);
@@ -2470,6 +2488,7 @@ static void migration_instance_init(Object *obj)
     params->has_block_incremental = true;
     params->has_x_multifd_channels = true;
     params->has_x_multifd_page_count = true;
+    params->has_xbzrle_cache_size = true;
 }
 
 /*
diff --git a/migration/migration.h b/migration/migration.h
index 8ccdd7a577..663415fe48 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -107,7 +107,6 @@ struct MigrationState
     int64_t downtime;
     int64_t expected_downtime;
     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
-    int64_t xbzrle_cache_size;
     int64_t setup_time;
 
     /* Flag set once the migration has been asked to enter postcopy */
diff --git a/migration/page_cache.c b/migration/page_cache.c
index 9a9d13d6a2..96268c3aea 100644
--- a/migration/page_cache.c
+++ b/migration/page_cache.c
@@ -58,6 +58,13 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
         return NULL;
     }
 
+    /* round down to the nearest power of 2 */
+    if (!is_power_of_2(num_pages)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+                   "is not a power of two number of pages");
+        return NULL;
+    }
+
     /* We prefer not to abort if there is no memory */
     cache = g_try_malloc(sizeof(*cache));
     if (!cache) {
@@ -65,11 +72,6 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
                    "Failed to allocate cache");
         return NULL;
     }
-    /* round down to the nearest power of 2 */
-    if (!is_power_of_2(num_pages)) {
-        num_pages = pow2floor(num_pages);
-        DPRINTF("rounding down to %" PRId64 "\n", num_pages);
-    }
     cache->page_size = page_size;
     cache->num_items = 0;
     cache->max_num_items = num_pages;
diff --git a/migration/ram.c b/migration/ram.c
index 7f6327f708..8620aa400a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -112,15 +112,15 @@ static void XBZRLE_cache_unlock(void)
  * migration may be using the cache and might finish during this call,
  * hence changes to the cache are protected by XBZRLE.lock().
  *
- * Returns the new_size or negative in case of error.
+ * Returns 0 for success or -1 for error
  *
  * @new_size: new cache size
  * @errp: set *errp if the check failed, with reason
  */
-int64_t xbzrle_cache_resize(int64_t new_size, Error **errp)
+int xbzrle_cache_resize(int64_t new_size, Error **errp)
 {
     PageCache *new_cache;
-    int64_t ret;
+    int64_t ret = 0;
 
     /* Check for truncation */
     if (new_size != (size_t)new_size) {
@@ -129,19 +129,14 @@ int64_t xbzrle_cache_resize(int64_t new_size, Error **errp)
         return -1;
     }
 
-    /* Cache should not be larger than guest ram size */
-    if (new_size > ram_bytes_total()) {
-        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
-                   "exceeds guest ram size");
-        return -1;
+    if (new_size == migrate_xbzrle_cache_size()) {
+        /* nothing to do */
+        return 0;
     }
 
     XBZRLE_cache_lock();
 
     if (XBZRLE.cache != NULL) {
-        if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
-            goto out_new_size;
-        }
         new_cache = cache_init(new_size, TARGET_PAGE_SIZE, errp);
         if (!new_cache) {
             ret = -1;
@@ -151,9 +146,6 @@ int64_t xbzrle_cache_resize(int64_t new_size, Error **errp)
         cache_fini(XBZRLE.cache);
         XBZRLE.cache = new_cache;
     }
-
-out_new_size:
-    ret = pow2floor(new_size);
 out:
     XBZRLE_cache_unlock();
     return ret;
diff --git a/migration/ram.h b/migration/ram.h
index f9f7eef894..64d81e9f1d 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -35,7 +35,7 @@
 extern MigrationStats ram_counters;
 extern XBZRLECacheStats xbzrle_counters;
 
-int64_t xbzrle_cache_resize(int64_t new_size, Error **errp);
+int xbzrle_cache_resize(int64_t new_size, Error **errp);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_total(void);
 
diff --git a/qapi/migration.json b/qapi/migration.json
index 6ae866e1aa..bbc4671ded 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -483,6 +483,11 @@
 # @x-multifd-page-count: Number of pages sent together to a thread.
 #                        The default value is 16 (since 2.11)
 #
+# @xbzrle-cache-size: cache size to be used by XBZRLE migration.  It
+#                     needs to be a multiple of the target page size
+#                     and a power of 2
+#                     (Since 2.11)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
@@ -490,7 +495,8 @@
            'cpu-throttle-initial', 'cpu-throttle-increment',
            'tls-creds', 'tls-hostname', 'max-bandwidth',
            'downtime-limit', 'x-checkpoint-delay', 'block-incremental',
-           'x-multifd-channels', 'x-multifd-page-count' ] }
+           'x-multifd-channels', 'x-multifd-page-count',
+           'xbzrle-cache-size' ] }
 
 ##
 # @MigrateSetParameters:
@@ -554,6 +560,10 @@
 # @x-multifd-page-count: Number of pages sent together to a thread.
 #                        The default value is 16 (since 2.11)
 #
+# @xbzrle-cache-size: cache size to be used by XBZRLE migration.  It
+#                     needs to be a multiple of the target page size
+#                     and a power of 2
+#                     (Since 2.11)
 # Since: 2.4
 ##
 # TODO either fuse back into MigrationParameters, or make
@@ -571,7 +581,8 @@
             '*x-checkpoint-delay': 'int',
             '*block-incremental': 'bool',
             '*x-multifd-channels': 'int',
-            '*x-multifd-page-count': 'int' } }
+            '*x-multifd-page-count': 'int',
+            '*xbzrle-cache-size': 'size' } }
 
 ##
 # @migrate-set-parameters:
@@ -650,6 +661,10 @@
 # @x-multifd-page-count: Number of pages sent together to a thread.
 #                        The default value is 16 (since 2.11)
 #
+# @xbzrle-cache-size: cache size to be used by XBZRLE migration.  It
+#                     needs to be a multiple of the target page size
+#                     and a power of 2
+#                     (Since 2.11)
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -665,7 +680,8 @@
             '*x-checkpoint-delay': 'int',
             '*block-incremental': 'bool' ,
             '*x-multifd-channels': 'int',
-            '*x-multifd-page-count': 'int' } }
+            '*x-multifd-page-count': 'int',
+            '*xbzrle-cache-size': 'size' } }
 
 ##
 # @query-migrate-parameters:
@@ -947,6 +963,8 @@
 #
 # Returns: nothing on success
 #
+# Notes: This command is deprecated in favor of 'migrate-set-parameters'
+#
 # Since: 1.2
 #
 # Example:
@@ -965,6 +983,8 @@
 #
 # Returns: XBZRLE cache size in bytes
 #
+# Notes: This command is deprecated in favor of 'query-migrate-parameters'
+#
 # Since: 1.2
 #
 # Example:
diff --git a/tests/Makefile.include b/tests/Makefile.include
index 70dc711bca..434a2ce868 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -287,7 +287,7 @@ endif
 check-qtest-i386-$(CONFIG_SLIRP) += tests/test-netfilter$(EXESUF)
 check-qtest-i386-$(CONFIG_POSIX) += tests/test-filter-mirror$(EXESUF)
 check-qtest-i386-$(CONFIG_POSIX) += tests/test-filter-redirector$(EXESUF)
-check-qtest-i386-y += tests/postcopy-test$(EXESUF)
+check-qtest-i386-y += tests/migration-test$(EXESUF)
 check-qtest-i386-y += tests/test-x86-cpuid-compat$(EXESUF)
 check-qtest-i386-y += tests/numa-test$(EXESUF)
 check-qtest-x86_64-y += $(check-qtest-i386-y)
@@ -315,7 +315,7 @@ check-qtest-ppc64-y += tests/boot-order-test$(EXESUF)
 check-qtest-ppc64-y += tests/prom-env-test$(EXESUF)
 check-qtest-ppc64-y += tests/pnv-xscom-test$(EXESUF)
 check-qtest-ppc64-y += tests/drive_del-test$(EXESUF)
-check-qtest-ppc64-y += tests/postcopy-test$(EXESUF)
+check-qtest-ppc64-y += tests/migration-test$(EXESUF)
 check-qtest-ppc64-y += tests/boot-serial-test$(EXESUF)
 check-qtest-ppc64-y += tests/rtas-test$(EXESUF)
 check-qtest-ppc64-$(CONFIG_SLIRP) += tests/pxe-test$(EXESUF)
@@ -784,7 +784,7 @@ tests/usb-hcd-uhci-test$(EXESUF): tests/usb-hcd-uhci-test.o $(libqos-usb-obj-y)
 tests/usb-hcd-ehci-test$(EXESUF): tests/usb-hcd-ehci-test.o $(libqos-usb-obj-y)
 tests/usb-hcd-xhci-test$(EXESUF): tests/usb-hcd-xhci-test.o $(libqos-usb-obj-y)
 tests/pc-cpu-test$(EXESUF): tests/pc-cpu-test.o
-tests/postcopy-test$(EXESUF): tests/postcopy-test.o
+tests/migration-test$(EXESUF): tests/migration-test.o
 tests/vhost-user-test$(EXESUF): tests/vhost-user-test.o $(test-util-obj-y) \
 	$(qtest-obj-y) $(test-io-obj-y) $(libqos-virtio-obj-y) $(libqos-pc-obj-y) \
 	$(chardev-obj-y)
diff --git a/tests/postcopy-test.c b/tests/migration-test.c
index 8142f2ab90..be598d3257 100644
--- a/tests/postcopy-test.c
+++ b/tests/migration-test.c
@@ -1,5 +1,5 @@
 /*
- * QTest testcase for postcopy
+ * QTest testcase for migration
  *
  * Copyright (c) 2016 Red Hat, Inc. and/or its affiliates
  *   based on the vhost-user-test.c that is:
@@ -223,36 +223,37 @@ static void wait_for_serial(const char *side)
 /*
  * Events can get in the way of responses we are actually waiting for.
  */
-static QDict *return_or_event(QDict *response)
+static QDict *wait_command(QTestState *who, const char *command)
 {
     const char *event_string;
-    if (!qdict_haskey(response, "event")) {
-        return response;
-    }
+    QDict *response;
+
+    response = qtest_qmp(who, command);
 
-    /* OK, it was an event */
-    event_string = qdict_get_str(response, "event");
-    if (!strcmp(event_string, "STOP")) {
-        got_stop = true;
+    while (qdict_haskey(response, "event")) {
+        /* OK, it was an event */
+        event_string = qdict_get_str(response, "event");
+        if (!strcmp(event_string, "STOP")) {
+            got_stop = true;
+        }
+        QDECREF(response);
+        response = qtest_qmp_receive(who);
     }
-    QDECREF(response);
-    return return_or_event(qtest_qmp_receive(global_qtest));
+    return response;
 }
 
 
 /*
  * It's tricky to use qemu's migration event capability with qtest,
  * events suddenly appearing confuse the qmp()/hmp() responses.
- * so wait for a couple of passes to have happened before
- * going postcopy.
  */
 
-static uint64_t get_migration_pass(void)
+static uint64_t get_migration_pass(QTestState *who)
 {
     QDict *rsp, *rsp_return, *rsp_ram;
     uint64_t result;
 
-    rsp = return_or_event(qmp("{ 'execute': 'query-migrate' }"));
+    rsp = wait_command(who, "{ 'execute': 'query-migrate' }");
     rsp_return = qdict_get_qdict(rsp, "return");
     if (!qdict_haskey(rsp_return, "ram")) {
         /* Still in setup */
@@ -265,7 +266,7 @@ static uint64_t get_migration_pass(void)
     return result;
 }
 
-static void wait_for_migration_complete(void)
+static void wait_for_migration_complete(QTestState *who)
 {
     QDict *rsp, *rsp_return;
     bool completed;
@@ -273,7 +274,7 @@ static void wait_for_migration_complete(void)
     do {
         const char *status;
 
-        rsp = return_or_event(qmp("{ 'execute': 'query-migrate' }"));
+        rsp = wait_command(who, "{ 'execute': 'query-migrate' }");
         rsp_return = qdict_get_qdict(rsp, "return");
         status = qdict_get_str(rsp_return, "status");
         completed = strcmp(status, "completed") == 0;
@@ -283,14 +284,14 @@ static void wait_for_migration_complete(void)
     } while (!completed);
 }
 
-static void wait_for_migration_pass(void)
+static void wait_for_migration_pass(QTestState *who)
 {
-    uint64_t initial_pass = get_migration_pass();
+    uint64_t initial_pass = get_migration_pass(who);
     uint64_t pass;
 
     /* Wait for the 1st sync */
     do {
-        initial_pass = get_migration_pass();
+        initial_pass = get_migration_pass(who);
         if (got_stop || initial_pass) {
             break;
         }
@@ -299,11 +300,11 @@ static void wait_for_migration_pass(void)
 
     do {
         usleep(1000 * 100);
-        pass = get_migration_pass();
+        pass = get_migration_pass(who);
     } while (pass == initial_pass && !got_stop);
 }
 
-static void check_guests_ram(void)
+static void check_guests_ram(QTestState *who)
 {
     /* Our ASM test will have been incrementing one byte from each page from
      * 1MB to <100MB in order.
@@ -318,13 +319,13 @@ static void check_guests_ram(void)
     bool hit_edge = false;
     bool bad = false;
 
-    qtest_memread(global_qtest, start_address, &first_byte, 1);
+    qtest_memread(who, start_address, &first_byte, 1);
     last_byte = first_byte;
 
     for (address = start_address + 4096; address < end_address; address += 4096)
     {
         uint8_t b;
-        qtest_memread(global_qtest, address, &b, 1);
+        qtest_memread(who, address, &b, 1);
         if (b != last_byte) {
             if (((b + 1) % 256) == last_byte && !hit_edge) {
                 /* This is OK, the guest stopped at the point of
@@ -353,14 +354,88 @@ static void cleanup(const char *filename)
     g_free(path);
 }
 
-static void test_migrate(void)
+static void migrate_check_parameter(QTestState *who, const char *parameter,
+                                    const char *value)
+{
+    QDict *rsp, *rsp_return;
+    const char *result;
+
+    rsp = wait_command(who, "{ 'execute': 'query-migrate-parameters' }");
+    rsp_return = qdict_get_qdict(rsp, "return");
+    result = g_strdup_printf("%" PRId64,
+                             qdict_get_try_int(rsp_return,  parameter, -1));
+    g_assert_cmpstr(result, ==, value);
+    QDECREF(rsp);
+}
+
+static void migrate_set_downtime(QTestState *who, const double value)
+{
+    QDict *rsp;
+    gchar *cmd;
+    char *expected;
+    int64_t result_int;
+
+    cmd = g_strdup_printf("{ 'execute': 'migrate_set_downtime',"
+                          "'arguments': { 'value': %g } }", value);
+    rsp = qtest_qmp(who, cmd);
+    g_free(cmd);
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+    result_int = value * 1000L;
+    expected = g_strdup_printf("%" PRId64, result_int);
+    migrate_check_parameter(who, "downtime-limit", expected);
+    g_free(expected);
+}
+
+static void migrate_set_speed(QTestState *who, const char *value)
 {
-    char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
-    QTestState *global = global_qtest, *from, *to;
-    unsigned char dest_byte_a, dest_byte_b, dest_byte_c, dest_byte_d;
-    gchar *cmd, *cmd_src, *cmd_dst;
     QDict *rsp;
+    gchar *cmd;
 
+    cmd = g_strdup_printf("{ 'execute': 'migrate_set_speed',"
+                          "'arguments': { 'value': %s } }", value);
+    rsp = qtest_qmp(who, cmd);
+    g_free(cmd);
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+    migrate_check_parameter(who, "max-bandwidth", value);
+}
+
+static void migrate_set_capability(QTestState *who, const char *capability,
+                                   const char *value)
+{
+    QDict *rsp;
+    gchar *cmd;
+
+    cmd = g_strdup_printf("{ 'execute': 'migrate-set-capabilities',"
+                          "'arguments': { "
+                          "'capabilities': [ { "
+                          "'capability': '%s', 'state': %s } ] } }",
+                          capability, value);
+    rsp = qtest_qmp(who, cmd);
+    g_free(cmd);
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+}
+
+static void migrate(QTestState *who, const char *uri)
+{
+    QDict *rsp;
+    gchar *cmd;
+
+    cmd = g_strdup_printf("{ 'execute': 'migrate',"
+                          "'arguments': { 'uri': '%s' } }",
+                          uri);
+    rsp = qtest_qmp(who, cmd);
+    g_free(cmd);
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+}
+
+static void test_migrate_start(QTestState **from, QTestState **to,
+                               const char *uri)
+{
+    gchar *cmd_src, *cmd_dst;
     char *bootpath = g_strdup_printf("%s/bootsect", tmpfs);
     const char *arch = qtest_get_arch();
 
@@ -401,79 +476,19 @@ static void test_migrate(void)
 
     g_free(bootpath);
 
-    from = qtest_start(cmd_src);
+    *from = qtest_start(cmd_src);
     g_free(cmd_src);
 
-    to = qtest_init(cmd_dst);
+    *to = qtest_init(cmd_dst);
     g_free(cmd_dst);
+}
 
-    global_qtest = from;
-    rsp = qmp("{ 'execute': 'migrate-set-capabilities',"
-                  "'arguments': { "
-                      "'capabilities': [ {"
-                          "'capability': 'postcopy-ram',"
-                          "'state': true } ] } }");
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-    global_qtest = to;
-    rsp = qmp("{ 'execute': 'migrate-set-capabilities',"
-                  "'arguments': { "
-                      "'capabilities': [ {"
-                          "'capability': 'postcopy-ram',"
-                          "'state': true } ] } }");
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-    /* We want to pick a speed slow enough that the test completes
-     * quickly, but that it doesn't complete precopy even on a slow
-     * machine, so also set the downtime.
-     */
-    global_qtest = from;
-    rsp = qmp("{ 'execute': 'migrate_set_speed',"
-              "'arguments': { 'value': 100000000 } }");
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-    /* 1ms downtime - it should never finish precopy */
-    rsp = qmp("{ 'execute': 'migrate_set_downtime',"
-              "'arguments': { 'value': 0.001 } }");
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-
-    /* Wait for the first serial output from the source */
-    wait_for_serial("src_serial");
-
-    cmd = g_strdup_printf("{ 'execute': 'migrate',"
-                          "'arguments': { 'uri': '%s' } }",
-                          uri);
-    rsp = qmp(cmd);
-    g_free(cmd);
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-    wait_for_migration_pass();
-
-    rsp = return_or_event(qmp("{ 'execute': 'migrate-start-postcopy' }"));
-    g_assert(qdict_haskey(rsp, "return"));
-    QDECREF(rsp);
-
-    if (!got_stop) {
-        qmp_eventwait("STOP");
-    }
-
-    global_qtest = to;
-    qmp_eventwait("RESUME");
-
-    wait_for_serial("dest_serial");
-    global_qtest = from;
-    wait_for_migration_complete();
+static void test_migrate_end(QTestState *from, QTestState *to)
+{
+    unsigned char dest_byte_a, dest_byte_b, dest_byte_c, dest_byte_d;
 
     qtest_quit(from);
 
-    global_qtest = to;
-
     qtest_memread(to, start_address, &dest_byte_a, 1);
 
     /* Destination still running, wait for a byte to change */
@@ -482,19 +497,16 @@ static void test_migrate(void)
         usleep(10 * 1000);
     } while (dest_byte_a == dest_byte_b);
 
-    qmp_discard_response("{ 'execute' : 'stop'}");
+    qtest_qmp_discard_response(to, "{ 'execute' : 'stop'}");
     /* With it stopped, check nothing changes */
     qtest_memread(to, start_address, &dest_byte_c, 1);
     sleep(1);
     qtest_memread(to, start_address, &dest_byte_d, 1);
     g_assert_cmpint(dest_byte_c, ==, dest_byte_d);
 
-    check_guests_ram();
+    check_guests_ram(to);
 
     qtest_quit(to);
-    g_free(uri);
-
-    global_qtest = global;
 
     cleanup("bootsect");
     cleanup("migsocket");
@@ -502,9 +514,52 @@ static void test_migrate(void)
     cleanup("dest_serial");
 }
 
+static void test_migrate(void)
+{
+    char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
+    QTestState *from, *to;
+    QDict *rsp;
+
+    test_migrate_start(&from, &to, uri);
+
+    migrate_set_capability(from, "postcopy-ram", "true");
+    migrate_set_capability(to, "postcopy-ram", "true");
+
+    /* We want to pick a speed slow enough that the test completes
+     * quickly, but that it doesn't complete precopy even on a slow
+     * machine, so also set the downtime.
+     */
+    migrate_set_speed(from, "100000000");
+    migrate_set_downtime(from, 0.001);
+
+    /* Wait for the first serial output from the source */
+    wait_for_serial("src_serial");
+
+    migrate(from, uri);
+
+    wait_for_migration_pass(from);
+
+    rsp = wait_command(from, "{ 'execute': 'migrate-start-postcopy' }");
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+
+    if (!got_stop) {
+        qtest_qmp_eventwait(from, "STOP");
+    }
+
+    qtest_qmp_eventwait(to, "RESUME");
+
+    wait_for_serial("dest_serial");
+    wait_for_migration_complete(from);
+
+    g_free(uri);
+
+    test_migrate_end(from, to);
+}
+
 int main(int argc, char **argv)
 {
-    char template[] = "/tmp/postcopy-test-XXXXXX";
+    char template[] = "/tmp/migration-test-XXXXXX";
     int ret;
 
     g_test_init(&argc, &argv, NULL);
@@ -521,7 +576,7 @@ int main(int argc, char **argv)
 
     module_call_init(MODULE_INIT_QOM);
 
-    qtest_add_func("/postcopy", test_migrate);
+    qtest_add_func("/migration/postcopy/unix", test_migrate);
 
     ret = g_test_run();