Add a multifd test for mapped-ram with passing of fds into QEMU. This
is how libvirt will consume the feature.
There are a couple of details to the fdset mechanism:
- multifd needs two distinct file descriptors (not duplicated with
dup()) on the outgoing side so it can enable O_DIRECT only on the
channels that write with alignment. The dup() system call creates
file descriptors that share status flags, of which O_DIRECT is one.
the incoming side doesn't set O_DIRECT, so it can dup() fds and
therefore can receive only one in the fdset.
- the open() access mode flags used for the fds passed into QEMU need
to match the flags QEMU uses to open the file. Currently O_WRONLY
for src and O_RDONLY for dst.
O_DIRECT is not supported on all systems/filesystems, so run the fdset
test without O_DIRECT if that's the case. The migration code should
still work in that scenario.
Signed-off-by: Fabiano Rosas <faro...@suse.de>
---
tests/qtest/migration-test.c | 90 ++++++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 512b7ede8b..d83f1bdd4f 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -2331,8 +2331,93 @@ static void test_multifd_file_mapped_ram_dio(void)
test_file_common(&args, true);
}
+static void migrate_multifd_mapped_ram_fdset_dio_end(QTestState *from,
+ QTestState *to,
+ void *opaque)
+{
+ QDict *resp;
+ QList *fdsets;
+
+ file_offset_finish_hook(from, to, opaque);
+
+ /*
+ * Check that we removed the fdsets after migration, otherwise a
+ * second migration would fail due to too many fdsets.
+ */
+
+ resp = qtest_qmp(from, "{'execute': 'query-fdsets', "
+ "'arguments': {}}");
+ g_assert(qdict_haskey(resp, "return"));
+ fdsets = qdict_get_qlist(resp, "return");
+ g_assert(fdsets && qlist_empty(fdsets));
+}
#endif /* O_DIRECT */
+#ifndef _WIN32
+static void *migrate_multifd_mapped_ram_fdset(QTestState *from, QTestState *to)
+{
+ g_autofree char *file = g_strdup_printf("%s/%s", tmpfs,
FILE_TEST_FILENAME);
+ int fds[3];
+ int src_flags = O_WRONLY;
+
+ file_dirty_offset_region();
+
+ /* main outgoing channel: no O_DIRECT */
+ fds[0] = open(file, src_flags, 0660);
+ assert(fds[0] != -1);
+
+ qtest_qmp_fds_assert_success(from, &fds[0], 1, "{'execute': 'add-fd', "
+ "'arguments': {'fdset-id': 1}}");
+
+#ifdef O_DIRECT
+ src_flags |= O_DIRECT;
+
+ /* secondary outgoing channels */
+ fds[1] = open(file, src_flags, 0660);
+ assert(fds[1] != -1);
+
+ qtest_qmp_fds_assert_success(from, &fds[1], 1, "{'execute': 'add-fd', "
+ "'arguments': {'fdset-id': 1}}");
+
+ /* incoming channel */
+ fds[2] = open(file, O_CREAT | O_RDONLY, 0660);
+ assert(fds[2] != -1);
+
+ qtest_qmp_fds_assert_success(to, &fds[2], 1, "{'execute': 'add-fd', "
+ "'arguments': {'fdset-id': 1}}");
+
+ migrate_multifd_mapped_ram_dio_start(from, to);
+#else
+ migrate_multifd_mapped_ram_start(from, to);
+#endif
+
+ return NULL;
+}
+
+static void test_multifd_file_mapped_ram_fdset(void)
+{
+ g_autofree char *uri = g_strdup_printf("file:/dev/fdset/1,offset=%d",
+ FILE_TEST_OFFSET);
+ MigrateCommon args = {
+ .connect_uri = uri,
+ .listen_uri = "defer",
+ .start_hook = migrate_multifd_mapped_ram_fdset,
+#ifdef O_DIRECT
+ .finish_hook = migrate_multifd_mapped_ram_fdset_dio_end,
+#endif
+ };
+
+#ifdef O_DIRECT
+ if (!probe_o_direct_support(tmpfs)) {
+ g_test_skip("Filesystem does not support O_DIRECT");
+ return;
+ }
+#endif
+
+ test_file_common(&args, true);
+}
+#endif /* _WIN32 */
+
static void test_precopy_tcp_plain(void)
{
MigrateCommon args = {
@@ -3761,6 +3846,11 @@ int main(int argc, char **argv)
test_multifd_file_mapped_ram_dio);
#endif
+#ifndef _WIN32
+ qtest_add_func("/migration/multifd/file/mapped-ram/fdset",
+ test_multifd_file_mapped_ram_fdset);
+#endif
+
#ifdef CONFIG_GNUTLS
migration_test_add("/migration/precopy/unix/tls/psk",
test_precopy_unix_tls_psk);
--
2.35.3
