From 17257b90be4f51dd3040ca2e472201407b2327c4 Mon Sep 17 00:00:00 2001 From: Hyman Huang Date: Wed, 1 Nov 2023 22:04:06 +0800 Subject: [PATCH] tests: Add migration dirty-limit capability test Add migration dirty-limit capability test if kernel support dirty ring. Migration dirty-limit capability introduce dirty limit capability, two parameters: x-vcpu-dirty-limit-period and vcpu-dirty-limit are introduced to implement the live migration with dirty limit. The test case does the following things: 1. start src, dst vm and enable dirty-limit capability 2. start migrate and set cancel it to check if dirty limit stop working. 3. restart dst vm 4. start migrate and enable dirty-limit capability 5. check if migration satisfy the convergence condition during pre-switchover phase. Note that this test case involves many passes, so it runs in slow mode only. Signed-off-by: Hyman Huang Acked-by: Peter Xu Reviewed-by: Fabiano Rosas Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela Message-ID: --- tests/qtest/migration-test.c | 164 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c index e803b46039..5752412b64 100644 --- a/tests/qtest/migration-test.c +++ b/tests/qtest/migration-test.c @@ -3091,6 +3091,166 @@ static void test_vcpu_dirty_limit(void) dirtylimit_stop_vm(vm); } +static void migrate_dirty_limit_wait_showup(QTestState *from, + const int64_t period, + const int64_t value) +{ + /* Enable dirty limit capability */ + migrate_set_capability(from, "dirty-limit", true); + + /* Set dirty limit parameters */ + migrate_set_parameter_int(from, "x-vcpu-dirty-limit-period", period); + migrate_set_parameter_int(from, "vcpu-dirty-limit", value); + + /* Make sure migrate can't converge */ + migrate_ensure_non_converge(from); + + /* To check limit rate after precopy */ + migrate_set_capability(from, "pause-before-switchover", true); + + /* Wait for the serial output from the source */ + wait_for_serial("src_serial"); +} + +/* + * This test does: + * source destination + * start vm + * start incoming vm + * migrate + * wait dirty limit to begin + * cancel migrate + * cancellation check + * restart incoming vm + * migrate + * wait dirty limit to begin + * wait pre-switchover event + * convergence condition check + * + * And see if dirty limit migration works correctly. + * This test case involves many passes, so it runs in slow mode only. + */ +static void test_migrate_dirty_limit(void) +{ + g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs); + QTestState *from, *to; + int64_t remaining; + uint64_t throttle_us_per_full; + /* + * We want the test to be stable and as fast as possible. + * E.g., with 1Gb/s bandwith migration may pass without dirty limit, + * so we need to decrease a bandwidth. + */ + const int64_t dirtylimit_period = 1000, dirtylimit_value = 50; + const int64_t max_bandwidth = 400000000; /* ~400Mb/s */ + const int64_t downtime_limit = 250; /* 250ms */ + /* + * We migrate through unix-socket (> 500Mb/s). + * Thus, expected migration speed ~= bandwidth limit (< 500Mb/s). + * So, we can predict expected_threshold + */ + const int64_t expected_threshold = max_bandwidth * downtime_limit / 1000; + int max_try_count = 10; + MigrateCommon args = { + .start = { + .hide_stderr = true, + .use_dirty_ring = true, + }, + .listen_uri = uri, + .connect_uri = uri, + }; + + /* Start src, dst vm */ + if (test_migrate_start(&from, &to, args.listen_uri, &args.start)) { + return; + } + + /* Prepare for dirty limit migration and wait src vm show up */ + migrate_dirty_limit_wait_showup(from, dirtylimit_period, dirtylimit_value); + + /* Start migrate */ + migrate_qmp(from, uri, "{}"); + + /* Wait for dirty limit throttle begin */ + throttle_us_per_full = 0; + while (throttle_us_per_full == 0) { + throttle_us_per_full = + read_migrate_property_int(from, "dirty-limit-throttle-time-per-round"); + usleep(100); + g_assert_false(got_src_stop); + } + + /* Now cancel migrate and wait for dirty limit throttle switch off */ + migrate_cancel(from); + wait_for_migration_status(from, "cancelled", NULL); + + /* Check if dirty limit throttle switched off, set timeout 1ms */ + do { + throttle_us_per_full = + read_migrate_property_int(from, "dirty-limit-throttle-time-per-round"); + usleep(100); + g_assert_false(got_src_stop); + } while (throttle_us_per_full != 0 && --max_try_count); + + /* Assert dirty limit is not in service */ + g_assert_cmpint(throttle_us_per_full, ==, 0); + + args = (MigrateCommon) { + .start = { + .only_target = true, + .use_dirty_ring = true, + }, + .listen_uri = uri, + .connect_uri = uri, + }; + + /* Restart dst vm, src vm already show up so we needn't wait anymore */ + if (test_migrate_start(&from, &to, args.listen_uri, &args.start)) { + return; + } + + /* Start migrate */ + migrate_qmp(from, uri, "{}"); + + /* Wait for dirty limit throttle begin */ + throttle_us_per_full = 0; + while (throttle_us_per_full == 0) { + throttle_us_per_full = + read_migrate_property_int(from, "dirty-limit-throttle-time-per-round"); + usleep(100); + g_assert_false(got_src_stop); + } + + /* + * The dirty limit rate should equals the return value of + * query-vcpu-dirty-limit if dirty limit cap set + */ + g_assert_cmpint(dirtylimit_value, ==, get_limit_rate(from)); + + /* Now, we have tested if dirty limit works, let it converge */ + migrate_set_parameter_int(from, "downtime-limit", downtime_limit); + migrate_set_parameter_int(from, "max-bandwidth", max_bandwidth); + + /* + * Wait for pre-switchover status to check if migration + * satisfy the convergence condition + */ + wait_for_migration_status(from, "pre-switchover", NULL); + + remaining = read_ram_property_int(from, "remaining"); + g_assert_cmpint(remaining, <, + (expected_threshold + expected_threshold / 100)); + + migrate_continue(from, "pre-switchover"); + + qtest_qmp_eventwait(to, "RESUME"); + + wait_for_serial("dest_serial"); + wait_for_migration_complete(from); + + test_migrate_end(from, to, true); +} + static bool kvm_dirty_ring_supported(void) { #if defined(__linux__) && defined(HOST_X86_64) @@ -3301,6 +3461,10 @@ int main(int argc, char **argv) */ if (g_test_slow()) { qtest_add_func("/migration/auto_converge", test_migrate_auto_converge); + if (g_str_equal(arch, "x86_64") && + has_kvm && kvm_dirty_ring_supported()) { + qtest_add_func("/migration/dirty_limit", test_migrate_dirty_limit); + } } qtest_add_func("/migration/multifd/tcp/plain/none", test_multifd_tcp_none); -- 2.11.0