diff mbox series

[6/9] tests/qtest/migration: Add tests for file migration with direct-io

Message ID 20240426142042.14573-7-farosas@suse.de (mailing list archive)
State New, archived
Headers show
Series migration/mapped-ram: Add direct-io support | expand

Commit Message

Fabiano Rosas April 26, 2024, 2:20 p.m. UTC
The tests are only allowed to run in systems that know about the
O_DIRECT flag and in filesystems which support it.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/migration-helpers.c | 42 +++++++++++++++++++++++++++++++++
 tests/qtest/migration-helpers.h |  1 +
 tests/qtest/migration-test.c    | 42 +++++++++++++++++++++++++++++++++
 3 files changed, 85 insertions(+)

Comments

Peter Xu May 3, 2024, 6:38 p.m. UTC | #1
On Fri, Apr 26, 2024 at 11:20:39AM -0300, Fabiano Rosas wrote:
> The tests are only allowed to run in systems that know about the
> O_DIRECT flag and in filesystems which support it.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Mostly:

Reviewed-by: Peter Xu <peterx@redhat.com>

Two trivial comments below.

> ---
>  tests/qtest/migration-helpers.c | 42 +++++++++++++++++++++++++++++++++
>  tests/qtest/migration-helpers.h |  1 +
>  tests/qtest/migration-test.c    | 42 +++++++++++++++++++++++++++++++++
>  3 files changed, 85 insertions(+)
> 
> diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
> index ce6d6615b5..356cd4fa8c 100644
> --- a/tests/qtest/migration-helpers.c
> +++ b/tests/qtest/migration-helpers.c
> @@ -473,3 +473,45 @@ void migration_test_add(const char *path, void (*fn)(void))
>      qtest_add_data_func_full(path, test, migration_test_wrapper,
>                               migration_test_destroy);
>  }
> +
> +#ifdef O_DIRECT
> +/*
> + * Probe for O_DIRECT support on the filesystem. Since this is used
> + * for tests, be conservative, if anything fails, assume it's
> + * unsupported.
> + */
> +bool probe_o_direct_support(const char *tmpfs)
> +{
> +    g_autofree char *filename = g_strdup_printf("%s/probe-o-direct", tmpfs);
> +    int fd, flags = O_CREAT | O_RDWR | O_TRUNC | O_DIRECT;
> +    void *buf;
> +    ssize_t ret, len;
> +    uint64_t offset;
> +
> +    fd = open(filename, flags, 0660);
> +    if (fd < 0) {
> +        unlink(filename);
> +        return false;
> +    }
> +
> +    /*
> +     * Assuming 4k should be enough to satisfy O_DIRECT alignment
> +     * requirements. The migration code uses 1M to be conservative.
> +     */
> +    len = 0x100000;
> +    offset = 0x100000;
> +
> +    buf = aligned_alloc(len, len);

This is the first usage of aligned_alloc() in qemu.  IIUC it's just a newer
posix_memalign(), which QEMU has one use of, and it's protected with:

#if defined(CONFIG_POSIX_MEMALIGN)
    int ret;
    ret = posix_memalign(&ptr, alignment, size);
    ...
#endif

Didn't check deeper.  Just keep this in mind if you see any compilation
issues in future CIs, or simply switch to similar pattern.

> +    g_assert(buf);
> +
> +    ret = pwrite(fd, buf, len, offset);
> +    unlink(filename);
> +    g_free(buf);
> +
> +    if (ret < 0) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +#endif
> diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
> index 1339835698..d827e16145 100644
> --- a/tests/qtest/migration-helpers.h
> +++ b/tests/qtest/migration-helpers.h
> @@ -54,5 +54,6 @@ char *find_common_machine_version(const char *mtype, const char *var1,
>                                    const char *var2);
>  char *resolve_machine_version(const char *alias, const char *var1,
>                                const char *var2);
> +bool probe_o_direct_support(const char *tmpfs);
>  void migration_test_add(const char *path, void (*fn)(void));
>  #endif /* MIGRATION_HELPERS_H */
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 7b177686b4..512b7ede8b 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -2295,6 +2295,43 @@ static void test_multifd_file_mapped_ram(void)
>      test_file_common(&args, true);
>  }
>  
> +#ifdef O_DIRECT
> +static void *migrate_mapped_ram_dio_start(QTestState *from,
> +                                                 QTestState *to)
> +{
> +    migrate_mapped_ram_start(from, to);

This line seems redundant, migrate_multifd_mapped_ram_start() should cover that.

> +    migrate_set_parameter_bool(from, "direct-io", true);
> +    migrate_set_parameter_bool(to, "direct-io", true);
> +
> +    return NULL;
> +}
> +
> +static void *migrate_multifd_mapped_ram_dio_start(QTestState *from,
> +                                                 QTestState *to)
> +{
> +    migrate_multifd_mapped_ram_start(from, to);
> +    return migrate_mapped_ram_dio_start(from, to);
> +}
> +
> +static void test_multifd_file_mapped_ram_dio(void)
> +{
> +    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
> +                                           FILE_TEST_FILENAME);
> +    MigrateCommon args = {
> +        .connect_uri = uri,
> +        .listen_uri = "defer",
> +        .start_hook = migrate_multifd_mapped_ram_dio_start,
> +    };
> +
> +    if (!probe_o_direct_support(tmpfs)) {
> +        g_test_skip("Filesystem does not support O_DIRECT");
> +        return;
> +    }
> +
> +    test_file_common(&args, true);
> +}
> +
> +#endif /* O_DIRECT */
>  
>  static void test_precopy_tcp_plain(void)
>  {
> @@ -3719,6 +3756,11 @@ int main(int argc, char **argv)
>      migration_test_add("/migration/multifd/file/mapped-ram/live",
>                         test_multifd_file_mapped_ram_live);
>  
> +#ifdef O_DIRECT
> +    migration_test_add("/migration/multifd/file/mapped-ram/dio",
> +                       test_multifd_file_mapped_ram_dio);
> +#endif
> +
>  #ifdef CONFIG_GNUTLS
>      migration_test_add("/migration/precopy/unix/tls/psk",
>                         test_precopy_unix_tls_psk);
> -- 
> 2.35.3
>
Fabiano Rosas May 3, 2024, 9:05 p.m. UTC | #2
Peter Xu <peterx@redhat.com> writes:

> On Fri, Apr 26, 2024 at 11:20:39AM -0300, Fabiano Rosas wrote:
>> The tests are only allowed to run in systems that know about the
>> O_DIRECT flag and in filesystems which support it.
>> 
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>
> Mostly:
>
> Reviewed-by: Peter Xu <peterx@redhat.com>
>
> Two trivial comments below.
>
>> ---
>>  tests/qtest/migration-helpers.c | 42 +++++++++++++++++++++++++++++++++
>>  tests/qtest/migration-helpers.h |  1 +
>>  tests/qtest/migration-test.c    | 42 +++++++++++++++++++++++++++++++++
>>  3 files changed, 85 insertions(+)
>> 
>> diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
>> index ce6d6615b5..356cd4fa8c 100644
>> --- a/tests/qtest/migration-helpers.c
>> +++ b/tests/qtest/migration-helpers.c
>> @@ -473,3 +473,45 @@ void migration_test_add(const char *path, void (*fn)(void))
>>      qtest_add_data_func_full(path, test, migration_test_wrapper,
>>                               migration_test_destroy);
>>  }
>> +
>> +#ifdef O_DIRECT
>> +/*
>> + * Probe for O_DIRECT support on the filesystem. Since this is used
>> + * for tests, be conservative, if anything fails, assume it's
>> + * unsupported.
>> + */
>> +bool probe_o_direct_support(const char *tmpfs)
>> +{
>> +    g_autofree char *filename = g_strdup_printf("%s/probe-o-direct", tmpfs);
>> +    int fd, flags = O_CREAT | O_RDWR | O_TRUNC | O_DIRECT;
>> +    void *buf;
>> +    ssize_t ret, len;
>> +    uint64_t offset;
>> +
>> +    fd = open(filename, flags, 0660);
>> +    if (fd < 0) {
>> +        unlink(filename);
>> +        return false;
>> +    }
>> +
>> +    /*
>> +     * Assuming 4k should be enough to satisfy O_DIRECT alignment
>> +     * requirements. The migration code uses 1M to be conservative.
>> +     */
>> +    len = 0x100000;
>> +    offset = 0x100000;
>> +
>> +    buf = aligned_alloc(len, len);
>
> This is the first usage of aligned_alloc() in qemu.  IIUC it's just a newer
> posix_memalign(), which QEMU has one use of, and it's protected with:
>
> #if defined(CONFIG_POSIX_MEMALIGN)
>     int ret;
>     ret = posix_memalign(&ptr, alignment, size);
>     ...
> #endif
>
> Didn't check deeper.  Just keep this in mind if you see any compilation
> issues in future CIs, or simply switch to similar pattern.
>
>> +    g_assert(buf);
>> +
>> +    ret = pwrite(fd, buf, len, offset);
>> +    unlink(filename);
>> +    g_free(buf);
>> +
>> +    if (ret < 0) {
>> +        return false;
>> +    }
>> +
>> +    return true;
>> +}
>> +#endif
>> diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
>> index 1339835698..d827e16145 100644
>> --- a/tests/qtest/migration-helpers.h
>> +++ b/tests/qtest/migration-helpers.h
>> @@ -54,5 +54,6 @@ char *find_common_machine_version(const char *mtype, const char *var1,
>>                                    const char *var2);
>>  char *resolve_machine_version(const char *alias, const char *var1,
>>                                const char *var2);
>> +bool probe_o_direct_support(const char *tmpfs);
>>  void migration_test_add(const char *path, void (*fn)(void));
>>  #endif /* MIGRATION_HELPERS_H */
>> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
>> index 7b177686b4..512b7ede8b 100644
>> --- a/tests/qtest/migration-test.c
>> +++ b/tests/qtest/migration-test.c
>> @@ -2295,6 +2295,43 @@ static void test_multifd_file_mapped_ram(void)
>>      test_file_common(&args, true);
>>  }
>>  
>> +#ifdef O_DIRECT
>> +static void *migrate_mapped_ram_dio_start(QTestState *from,
>> +                                                 QTestState *to)
>> +{
>> +    migrate_mapped_ram_start(from, to);
>
> This line seems redundant, migrate_multifd_mapped_ram_start() should cover that.
>

This is an artifact of another patch that adds direct-io + mapped-ram
without multifd. I'm bringing that back on v2. We were having a
discussion[1] about it in the libvirt mailing list. Having direct-io
even without multifd might still be useful for libvirt.

1- https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/K4BDDJDMJ22XMJEFAUE323H5S5E47VQX/

>> +    migrate_set_parameter_bool(from, "direct-io", true);
>> +    migrate_set_parameter_bool(to, "direct-io", true);
>> +
>> +    return NULL;
>> +}
>> +
>> +static void *migrate_multifd_mapped_ram_dio_start(QTestState *from,
>> +                                                 QTestState *to)
>> +{
>> +    migrate_multifd_mapped_ram_start(from, to);
>> +    return migrate_mapped_ram_dio_start(from, to);
>> +}
>> +
>> +static void test_multifd_file_mapped_ram_dio(void)
>> +{
>> +    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
>> +                                           FILE_TEST_FILENAME);
>> +    MigrateCommon args = {
>> +        .connect_uri = uri,
>> +        .listen_uri = "defer",
>> +        .start_hook = migrate_multifd_mapped_ram_dio_start,
>> +    };
>> +
>> +    if (!probe_o_direct_support(tmpfs)) {
>> +        g_test_skip("Filesystem does not support O_DIRECT");
>> +        return;
>> +    }
>> +
>> +    test_file_common(&args, true);
>> +}
>> +
>> +#endif /* O_DIRECT */
>>  
>>  static void test_precopy_tcp_plain(void)
>>  {
>> @@ -3719,6 +3756,11 @@ int main(int argc, char **argv)
>>      migration_test_add("/migration/multifd/file/mapped-ram/live",
>>                         test_multifd_file_mapped_ram_live);
>>  
>> +#ifdef O_DIRECT
>> +    migration_test_add("/migration/multifd/file/mapped-ram/dio",
>> +                       test_multifd_file_mapped_ram_dio);
>> +#endif
>> +
>>  #ifdef CONFIG_GNUTLS
>>      migration_test_add("/migration/precopy/unix/tls/psk",
>>                         test_precopy_unix_tls_psk);
>> -- 
>> 2.35.3
>>
Peter Xu May 3, 2024, 9:25 p.m. UTC | #3
On Fri, May 03, 2024 at 06:05:19PM -0300, Fabiano Rosas wrote:
> >> +#ifdef O_DIRECT
> >> +static void *migrate_mapped_ram_dio_start(QTestState *from,
> >> +                                                 QTestState *to)
> >> +{
> >> +    migrate_mapped_ram_start(from, to);
> >
> > This line seems redundant, migrate_multifd_mapped_ram_start() should cover that.
> >
> 
> This is an artifact of another patch that adds direct-io + mapped-ram
> without multifd. I'm bringing that back on v2. We were having a
> discussion[1] about it in the libvirt mailing list. Having direct-io
> even without multifd might still be useful for libvirt.
> 
> 1- https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/K4BDDJDMJ22XMJEFAUE323H5S5E47VQX/

Ah that's fine then.  Maybe add a comment somewhere for future readers?  Or
a sentence in the commit log would work too.
Daniel P. Berrangé May 8, 2024, 8:34 a.m. UTC | #4
On Fri, Apr 26, 2024 at 11:20:39AM -0300, Fabiano Rosas wrote:
> The tests are only allowed to run in systems that know about the
> O_DIRECT flag and in filesystems which support it.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>  tests/qtest/migration-helpers.c | 42 +++++++++++++++++++++++++++++++++
>  tests/qtest/migration-helpers.h |  1 +
>  tests/qtest/migration-test.c    | 42 +++++++++++++++++++++++++++++++++
>  3 files changed, 85 insertions(+)
> 
> diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
> index ce6d6615b5..356cd4fa8c 100644
> --- a/tests/qtest/migration-helpers.c
> +++ b/tests/qtest/migration-helpers.c
> @@ -473,3 +473,45 @@ void migration_test_add(const char *path, void (*fn)(void))
>      qtest_add_data_func_full(path, test, migration_test_wrapper,
>                               migration_test_destroy);
>  }
> +
> +#ifdef O_DIRECT
> +/*
> + * Probe for O_DIRECT support on the filesystem. Since this is used
> + * for tests, be conservative, if anything fails, assume it's
> + * unsupported.
> + */
> +bool probe_o_direct_support(const char *tmpfs)
> +{
> +    g_autofree char *filename = g_strdup_printf("%s/probe-o-direct", tmpfs);
> +    int fd, flags = O_CREAT | O_RDWR | O_TRUNC | O_DIRECT;
> +    void *buf;
> +    ssize_t ret, len;
> +    uint64_t offset;
> +
> +    fd = open(filename, flags, 0660);
> +    if (fd < 0) {
> +        unlink(filename);
> +        return false;
> +    }
> +
> +    /*
> +     * Assuming 4k should be enough to satisfy O_DIRECT alignment
> +     * requirements. The migration code uses 1M to be conservative.
> +     */
> +    len = 0x100000;
> +    offset = 0x100000;

4k is unlikely insufficient for architectures with a 64k small
page size, and filesystem constraints also play a part. Suggest
rewording to

  /*
   * Using 1MB alignment as conservative choice to satisfy
   * any plausible architecture default page size, and/or
   * filesystem alignment restrictions.
   */

> +
> +    buf = aligned_alloc(len, len);
> +    g_assert(buf);
> +
> +    ret = pwrite(fd, buf, len, offset);
> +    unlink(filename);
> +    g_free(buf);
> +
> +    if (ret < 0) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +#endif
> diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
> index 1339835698..d827e16145 100644
> --- a/tests/qtest/migration-helpers.h
> +++ b/tests/qtest/migration-helpers.h
> @@ -54,5 +54,6 @@ char *find_common_machine_version(const char *mtype, const char *var1,
>                                    const char *var2);
>  char *resolve_machine_version(const char *alias, const char *var1,
>                                const char *var2);
> +bool probe_o_direct_support(const char *tmpfs);
>  void migration_test_add(const char *path, void (*fn)(void));
>  #endif /* MIGRATION_HELPERS_H */
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 7b177686b4..512b7ede8b 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -2295,6 +2295,43 @@ static void test_multifd_file_mapped_ram(void)
>      test_file_common(&args, true);
>  }
>  
> +#ifdef O_DIRECT
> +static void *migrate_mapped_ram_dio_start(QTestState *from,
> +                                                 QTestState *to)
> +{
> +    migrate_mapped_ram_start(from, to);
> +    migrate_set_parameter_bool(from, "direct-io", true);
> +    migrate_set_parameter_bool(to, "direct-io", true);
> +
> +    return NULL;
> +}
> +
> +static void *migrate_multifd_mapped_ram_dio_start(QTestState *from,
> +                                                 QTestState *to)
> +{
> +    migrate_multifd_mapped_ram_start(from, to);
> +    return migrate_mapped_ram_dio_start(from, to);
> +}
> +
> +static void test_multifd_file_mapped_ram_dio(void)
> +{
> +    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
> +                                           FILE_TEST_FILENAME);
> +    MigrateCommon args = {
> +        .connect_uri = uri,
> +        .listen_uri = "defer",
> +        .start_hook = migrate_multifd_mapped_ram_dio_start,
> +    };
> +
> +    if (!probe_o_direct_support(tmpfs)) {
> +        g_test_skip("Filesystem does not support O_DIRECT");
> +        return;
> +    }
> +
> +    test_file_common(&args, true);
> +}
> +
> +#endif /* O_DIRECT */
>  
>  static void test_precopy_tcp_plain(void)
>  {
> @@ -3719,6 +3756,11 @@ int main(int argc, char **argv)
>      migration_test_add("/migration/multifd/file/mapped-ram/live",
>                         test_multifd_file_mapped_ram_live);
>  
> +#ifdef O_DIRECT
> +    migration_test_add("/migration/multifd/file/mapped-ram/dio",
> +                       test_multifd_file_mapped_ram_dio);
> +#endif
> +
>  #ifdef CONFIG_GNUTLS
>      migration_test_add("/migration/precopy/unix/tls/psk",
>                         test_precopy_unix_tls_psk);
> -- 
> 2.35.3
> 

With regards,
Daniel
diff mbox series

Patch

diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
index ce6d6615b5..356cd4fa8c 100644
--- a/tests/qtest/migration-helpers.c
+++ b/tests/qtest/migration-helpers.c
@@ -473,3 +473,45 @@  void migration_test_add(const char *path, void (*fn)(void))
     qtest_add_data_func_full(path, test, migration_test_wrapper,
                              migration_test_destroy);
 }
+
+#ifdef O_DIRECT
+/*
+ * Probe for O_DIRECT support on the filesystem. Since this is used
+ * for tests, be conservative, if anything fails, assume it's
+ * unsupported.
+ */
+bool probe_o_direct_support(const char *tmpfs)
+{
+    g_autofree char *filename = g_strdup_printf("%s/probe-o-direct", tmpfs);
+    int fd, flags = O_CREAT | O_RDWR | O_TRUNC | O_DIRECT;
+    void *buf;
+    ssize_t ret, len;
+    uint64_t offset;
+
+    fd = open(filename, flags, 0660);
+    if (fd < 0) {
+        unlink(filename);
+        return false;
+    }
+
+    /*
+     * Assuming 4k should be enough to satisfy O_DIRECT alignment
+     * requirements. The migration code uses 1M to be conservative.
+     */
+    len = 0x100000;
+    offset = 0x100000;
+
+    buf = aligned_alloc(len, len);
+    g_assert(buf);
+
+    ret = pwrite(fd, buf, len, offset);
+    unlink(filename);
+    g_free(buf);
+
+    if (ret < 0) {
+        return false;
+    }
+
+    return true;
+}
+#endif
diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
index 1339835698..d827e16145 100644
--- a/tests/qtest/migration-helpers.h
+++ b/tests/qtest/migration-helpers.h
@@ -54,5 +54,6 @@  char *find_common_machine_version(const char *mtype, const char *var1,
                                   const char *var2);
 char *resolve_machine_version(const char *alias, const char *var1,
                               const char *var2);
+bool probe_o_direct_support(const char *tmpfs);
 void migration_test_add(const char *path, void (*fn)(void));
 #endif /* MIGRATION_HELPERS_H */
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 7b177686b4..512b7ede8b 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -2295,6 +2295,43 @@  static void test_multifd_file_mapped_ram(void)
     test_file_common(&args, true);
 }
 
+#ifdef O_DIRECT
+static void *migrate_mapped_ram_dio_start(QTestState *from,
+                                                 QTestState *to)
+{
+    migrate_mapped_ram_start(from, to);
+    migrate_set_parameter_bool(from, "direct-io", true);
+    migrate_set_parameter_bool(to, "direct-io", true);
+
+    return NULL;
+}
+
+static void *migrate_multifd_mapped_ram_dio_start(QTestState *from,
+                                                 QTestState *to)
+{
+    migrate_multifd_mapped_ram_start(from, to);
+    return migrate_mapped_ram_dio_start(from, to);
+}
+
+static void test_multifd_file_mapped_ram_dio(void)
+{
+    g_autofree char *uri = g_strdup_printf("file:%s/%s", tmpfs,
+                                           FILE_TEST_FILENAME);
+    MigrateCommon args = {
+        .connect_uri = uri,
+        .listen_uri = "defer",
+        .start_hook = migrate_multifd_mapped_ram_dio_start,
+    };
+
+    if (!probe_o_direct_support(tmpfs)) {
+        g_test_skip("Filesystem does not support O_DIRECT");
+        return;
+    }
+
+    test_file_common(&args, true);
+}
+
+#endif /* O_DIRECT */
 
 static void test_precopy_tcp_plain(void)
 {
@@ -3719,6 +3756,11 @@  int main(int argc, char **argv)
     migration_test_add("/migration/multifd/file/mapped-ram/live",
                        test_multifd_file_mapped_ram_live);
 
+#ifdef O_DIRECT
+    migration_test_add("/migration/multifd/file/mapped-ram/dio",
+                       test_multifd_file_mapped_ram_dio);
+#endif
+
 #ifdef CONFIG_GNUTLS
     migration_test_add("/migration/precopy/unix/tls/psk",
                        test_precopy_unix_tls_psk);