This reverts commit e76a92b869f17d7a3f554890fb89b7da595dd652.
---
tests/qtest/migration-test.c | 143 +++++------------------------------
1 file changed, 18 insertions(+), 125 deletions(-)
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index d2cd71e6cf..b0c355bbd9 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -46,20 +46,6 @@ static bool uffd_feature_thread_id;
static bool got_src_stop;
static bool got_dst_resume;
-/*
- * An initial 3 MB offset is used as that corresponds
- * to ~1 sec of data transfer with our bandwidth setting.
- */
-#define MAGIC_OFFSET_BASE (3 * 1024 * 1024)
-/*
- * A further 1k is added to ensure we're not a multiple
- * of TEST_MEM_PAGE_SIZE, thus avoid clash with writes
- * from the migration guest workload.
- */
-#define MAGIC_OFFSET_SHUFFLE 1024
-#define MAGIC_OFFSET (MAGIC_OFFSET_BASE + MAGIC_OFFSET_SHUFFLE)
-#define MAGIC_MARKER 0xFEED12345678CAFEULL
-
/*
* Dirtylimit stop working if dirty page rate error
* value less than DIRTYLIMIT_TOLERANCE_RANGE
@@ -459,91 +445,6 @@ static void migrate_ensure_converge(QTestState *who)
migrate_set_parameter_int(who, "downtime-limit", 30 * 1000);
}
-/*
- * Our goal is to ensure that we run a single full migration
- * iteration, and also dirty memory, ensuring that at least
- * one further iteration is required.
- *
- * We can't directly synchronize with the start of a migration
- * so we have to apply some tricks monitoring memory that is
- * transferred.
- *
- * Initially we set the migration bandwidth to an insanely
- * low value, with tiny max downtime too. This basically
- * guarantees migration will never complete.
- *
- * This will result in a test that is unacceptably slow though,
- * so we can't let the entire migration pass run at this speed.
- * Our intent is to let it run just long enough that we can
- * prove data prior to the marker has been transferred *AND*
- * also prove this transferred data is dirty again.
- *
- * Before migration starts, we write a 64-bit magic marker
- * into a fixed location in the src VM RAM.
- *
- * Then watch dst memory until the marker appears. This is
- * proof that start_address -> MAGIC_OFFSET_BASE has been
- * transferred.
- *
- * Finally we go back to the source and read a byte just
- * before the marker untill we see it flip in value. This
- * is proof that start_address -> MAGIC_OFFSET_BASE
- * is now dirty again.
- *
- * IOW, we're guaranteed at least a 2nd migration pass
- * at this point.
- *
- * We can now let migration run at full speed to finish
- * the test
- */
-static void migrate_prepare_for_dirty_mem(QTestState *from)
-{
- /*
- * The guest workflow iterates from start_address to
- * end_address, writing 1 byte every TEST_MEM_PAGE_SIZE
- * bytes.
- *
- * IOW, if we write to mem at a point which is NOT
- * a multiple of TEST_MEM_PAGE_SIZE, our write won't
- * conflict with the migration workflow.
- *
- * We put in a marker here, that we'll use to determine
- * when the data has been transferred to the dst.
- */
- qtest_writeq(from, start_address + MAGIC_OFFSET, MAGIC_MARKER);
-}
-
-static void migrate_wait_for_dirty_mem(QTestState *from,
- QTestState *to)
-{
- uint64_t watch_address = start_address + MAGIC_OFFSET_BASE;
- uint64_t marker_address = start_address + MAGIC_OFFSET;
- uint8_t watch_byte;
-
- /*
- * Wait for the MAGIC_MARKER to get transferred, as an
- * indicator that a migration pass has made some known
- * amount of progress.
- */
- do {
- usleep(1000 * 10);
- } while (qtest_readq(to, marker_address) != MAGIC_MARKER);
-
- /*
- * Now ensure that already transferred bytes are
- * dirty again from the guest workload. Note the
- * guest byte value will wrap around and by chance
- * match the original watch_byte. This is harmless
- * as we'll eventually see a different value if we
- * keep watching
- */
- watch_byte = qtest_readb(from, watch_address);
- do {
- usleep(1000 * 10);
- } while (qtest_readb(from, watch_address) == watch_byte);
-}
-
-
static void migrate_pause(QTestState *who)
{
qtest_qmp_assert_success(who, "{ 'execute': 'migrate-pause' }");
@@ -676,10 +577,7 @@ typedef struct {
MIG_TEST_FAIL_DEST_QUIT_ERR,
} result;
- /*
- * Optional: set number of migration passes to wait for, if live==true.
- * If zero, then merely wait for a few MB of dirty data
- */
+ /* Optional: set number of migration passes to wait for, if live==true */
unsigned int iterations;
/*
@@ -1267,14 +1165,12 @@ static int migrate_postcopy_prepare(QTestState
**from_ptr,
migrate_ensure_non_converge(from);
- migrate_prepare_for_dirty_mem(from);
-
/* Wait for the first serial output from the source */
wait_for_serial("src_serial");
migrate_qmp(from, uri, "{}");
- migrate_wait_for_dirty_mem(from, to);
+ wait_for_migration_pass(from);
*from_ptr = from;
*to_ptr = to;
@@ -1509,8 +1405,14 @@ static void test_precopy_common(MigrateCommon *args)
}
if (args->live) {
+ /*
+ * Testing live migration, we want to ensure that some
+ * memory is re-dirtied after being transferred, so that
+ * we exercise logic for dirty page handling. We achieve
+ * this with a ridiculosly low bandwidth that guarantees
+ * non-convergance.
+ */
migrate_ensure_non_converge(from);
- migrate_prepare_for_dirty_mem(from);
} else {
/*
* Testing non-live migration, we allow it to run at
@@ -1545,16 +1447,13 @@ static void test_precopy_common(MigrateCommon *args)
}
} else {
if (args->live) {
- /*
- * For initial iteration(s) we must do a full pass,
- * but for the final iteration, we need only wait
- * for some dirty mem before switching to converge
- */
- while (args->iterations > 1) {
+ if (args->iterations) {
+ while (args->iterations--) {
+ wait_for_migration_pass(from);
+ }
+ } else {
wait_for_migration_pass(from);
- args->iterations--;
}
- migrate_wait_for_dirty_mem(from, to);
migrate_ensure_converge(from);
@@ -1687,9 +1586,6 @@ static void test_ignore_shared(void)
return;
}
- migrate_ensure_non_converge(from);
- migrate_prepare_for_dirty_mem(from);
-
migrate_set_capability(from, "x-ignore-shared", true);
migrate_set_capability(to, "x-ignore-shared", true);
@@ -1698,7 +1594,7 @@ static void test_ignore_shared(void)
migrate_qmp(from, uri, "{}");
- migrate_wait_for_dirty_mem(from, to);
+ wait_for_migration_pass(from);
if (!got_src_stop) {
qtest_qmp_eventwait(from, "STOP");
@@ -2402,7 +2298,6 @@ static void test_multifd_tcp_cancel(void)
}
migrate_ensure_non_converge(from);
- migrate_prepare_for_dirty_mem(from);
migrate_set_parameter_int(from, "multifd-channels", 16);
migrate_set_parameter_int(to, "multifd-channels", 16);
@@ -2421,7 +2316,7 @@ static void test_multifd_tcp_cancel(void)
migrate_qmp(from, uri, "{}");
- migrate_wait_for_dirty_mem(from, to);
+ wait_for_migration_pass(from);
migrate_cancel(from);
@@ -2450,13 +2345,11 @@ static void test_multifd_tcp_cancel(void)
wait_for_migration_status(from, "cancelled", NULL);
- migrate_ensure_non_converge(from);
+ migrate_ensure_converge(from);
migrate_qmp(from, uri, "{}");
- migrate_wait_for_dirty_mem(from, to);
-
- migrate_ensure_converge(from);
+ wait_for_migration_pass(from);
if (!got_src_stop) {
qtest_qmp_eventwait(from, "STOP");
--
2.40.1
