| Message ID | 20240426142042.14573-10-farosas@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | migration/mapped-ram: Add direct-io support | expand |
On Fri, Apr 26, 2024 at 11:20:42AM -0300, Fabiano Rosas wrote: > 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. If O_DIRECT is not supported, then we're not setting 'direct-io', and thus isn't this test just duplicating coverage of existing tests ? If this test is specifically to cover O_DIRECT, then I'd just #ifdef the entire thing with O_DIRECT. > > Signed-off-by: Fabiano Rosas <farosas@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 > With regards, Daniel
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);
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 <farosas@suse.de> --- tests/qtest/migration-test.c | 90 ++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+)