[PATCH v11 0/3] Allow to enable multifd and postcopy migration together

[PATCH v11 0/3] Allow to enable multifd and postcopy migration together

[Prasad Pandit]

From: Prasad Pandit <pjp@fedoraproject.org>

 Hello,

* This series (v11) fixes spelling and capitalisations glitches and
  does some refactoring and reordering changes as suggested in the
  review of v10.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             196.69s   81 subtests passed
===


v10: https://lore.kernel.org/qemu-devel/20250508122849.207213-2-ppandit@redhat.com/T/#t
* This series (v10) fixes the migration hang issue caused by optimised
  writing of the zero pages during multifd phase. It also fixes the qtest
  failure caused by missing 'env->has_uffd' check before running a postcopy
  test.

  Some of the patches from v9 series were pulled upstream. This series
  has the remaining few patches.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             191.80s   81 subtests passed
===


v9: https://lore.kernel.org/qemu-devel/20250411114534.3370816-1-ppandit@redhat.com/T/#t
* This series (v9) does minor refactoring and reordering changes as
  suggested in the review of earlier series (v8). Also tried to
  reproduce/debug a qtest hang issue, but it could not be reproduced.
  From the shared stack traces it looked like Postcopy thread was
  preparing to finish before migrating all the pages.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             170.50s   81 subtests passed
===


v8: https://lore.kernel.org/qemu-devel/20250318123846.1370312-1-ppandit@redhat.com/T/#t
* This series (v8) splits earlier patch-2 which enabled multifd and
  postcopy options together into two separate patches. One modifies
  the channel discovery in migration_ioc_process_incoming() function,
  and second one enables the multifd and postcopy migration together.

  It also adds the 'save_postcopy_prepare' savevm_state handler to
  enable different sections to take an action just before the Postcopy
  phase starts. Thank you Peter for these patches.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             152.66s   81 subtests passed
===


v7: https://lore.kernel.org/qemu-devel/20250228121749.553184-1-ppandit@redhat.com/T/#t
* This series (v7) adds 'MULTIFD_RECV_SYNC' migration command. It is used
  to notify the destination migration thread to synchronise with the Multifd
  threads. This allows Multifd ('mig/dst/recv_x') threads on the destination
  to receive all their data, before they are shutdown.

  This series also updates the channel discovery function and qtests as
  suggested in the previous review comments.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             147.84s   81 subtests passed
===


v6: https://lore.kernel.org/qemu-devel/20250215123119.814345-1-ppandit@redhat.com/T/#t
* This series (v6) shuts down Multifd threads before starting Postcopy
  migration. It helps to avoid an issue of multifd pages arriving late
  at the destination during Postcopy phase and corrupting the vCPU
  state. It also reorders the qtest patches and does some refactoring
  changes as suggested in previous review.
===
67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             161.35s   73 subtests passed
===


v5: https://lore.kernel.org/qemu-devel/20250205122712.229151-1-ppandit@redhat.com/T/#t
* This series (v5) consolidates migration capabilities setting in one
  'set_migration_capabilities()' function, thus simplifying test sources.
  It passes all migration tests.
===
66/66 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             143.66s   71 subtests passed
===


v4: https://lore.kernel.org/qemu-devel/20250127120823.144949-1-ppandit@redhat.com/T/#t
* This series (v4) adds more 'multifd+postcopy' qtests which test
  Precopy migration with 'postcopy-ram' attribute set. And run
  Postcopy migrations with 'multifd' channels enabled.
===
$ ../qtest/migration-test --tap -k -r '/x86_64/migration/multifd+postcopy' | grep -i 'slow test'
# slow test /x86_64/migration/multifd+postcopy/plain executed in 1.29 secs
# slow test /x86_64/migration/multifd+postcopy/recovery/tls/psk executed in 2.48 secs
# slow test /x86_64/migration/multifd+postcopy/preempt/plain executed in 1.49 secs
# slow test /x86_64/migration/multifd+postcopy/preempt/recovery/tls/psk executed in 2.52 secs
# slow test /x86_64/migration/multifd+postcopy/tcp/tls/psk/match executed in 3.62 secs
# slow test /x86_64/migration/multifd+postcopy/tcp/plain/zstd executed in 1.34 secs
# slow test /x86_64/migration/multifd+postcopy/tcp/plain/cancel executed in 2.24 secs
...
66/66 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             148.41s   71 subtests passed
===


v3: https://lore.kernel.org/qemu-devel/20250121131032.1611245-1-ppandit@redhat.com/T/#t
* This series (v3) passes all existing 'tests/qtest/migration/*' tests
  and adds a new one to enable multifd channels with postcopy migration.


v2: https://lore.kernel.org/qemu-devel/20241129122256.96778-1-ppandit@redhat.com/T/#u
* This series (v2) further refactors the 'ram_save_target_page'
  function to make it independent of the multifd & postcopy change.


v1: https://lore.kernel.org/qemu-devel/20241126115748.118683-1-ppandit@redhat.com/T/#u
* This series removes magic value (4-bytes) introduced in the
  previous series for the Postcopy channel.


v0: https://lore.kernel.org/qemu-devel/20241029150908.1136894-1-ppandit@redhat.com/T/#u
* Currently Multifd and Postcopy migration can not be used together.
  QEMU shows "Postcopy is not yet compatible with multifd" message.

  When migrating guests with large (100's GB) RAM, Multifd threads
  help to accelerate migration, but inability to use it with the
  Postcopy mode delays guest start up on the destination side.

* This patch series allows to enable both Multifd and Postcopy
  migration together. Precopy and Multifd threads work during
  the initial guest (RAM) transfer. When migration moves to the
  Postcopy phase, Multifd threads are restrained and the Postcopy
  threads start to request pages from the source side.

* This series introduces magic value (4-bytes) to be sent on the
  Postcopy channel. It helps to differentiate channels and properly
  setup incoming connections on the destination side.


Thank you.
---
Prasad Pandit (3):
  migration: write zero pages when postcopy enabled
  migration: enable multifd and postcopy together
  tests/qtest/migration: add postcopy tests with multifd

 migration/multifd-nocomp.c                |  3 +-
 migration/multifd-zero-page.c             | 22 +++++++++-
 migration/multifd.c                       |  7 ++++
 migration/options.c                       |  5 ---
 migration/ram.c                           |  5 +--
 tests/qtest/migration/compression-tests.c | 18 ++++++++
 tests/qtest/migration/postcopy-tests.c    | 27 ++++++++++++
 tests/qtest/migration/precopy-tests.c     | 28 ++++++++++++-
 tests/qtest/migration/tls-tests.c         | 50 +++++++++++++++++++++++
 9 files changed, 152 insertions(+), 13 deletions(-)

--
2.49.0

[PATCH v11 1/3] migration: write zero pages when postcopy enabled

[Prasad Pandit]

From: Prasad Pandit <pjp@fedoraproject.org>

During multifd migration, zero pages are written if
they are migrated more than once.

This may result in a migration thread hang issue when
multifd and postcopy are enabled together.

When postcopy is enabled, always write zero pages as and
when they are migrated.

Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
---
 migration/multifd-zero-page.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

v11:
- s/ones/once, remove capitalisations and call _test_byte_offset() once

v10:
- https://lore.kernel.org/qemu-devel/20250508122849.207213-2-ppandit@redhat.com/T/#t

diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c
index dbc1184921..4cde868159 100644
--- a/migration/multifd-zero-page.c
+++ b/migration/multifd-zero-page.c
@@ -85,9 +85,27 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p)
 {
     for (int i = 0; i < p->zero_num; i++) {
         void *page = p->host + p->zero[i];
-        if (ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i])) {
+        bool received =
+                ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i]);
+
+        /*
+         * During multifd migration zero page is written to the memory
+         * only if it is migrated more than once.
+         *
+         * It becomes a problem when both multifd & postcopy options are
+         * enabled. If the zero page which was skipped during multifd phase,
+         * is accessed during the postcopy phase of the migration, a page
+         * fault occurs. But this page fault is not served because the
+         * 'receivedmap' says the zero page is already received. Thus the
+         * thread accessing that page may hang.
+         *
+         * When postcopy is enabled, always write the zero page as and when
+         * it is migrated.
+         */
+        if (migrate_postcopy_ram() || received) {
             memset(page, 0, multifd_ram_page_size());
-        } else {
+        }
+        if (!received) {
             ramblock_recv_bitmap_set_offset(p->block, p->zero[i]);
         }
     }
--
2.49.0

[PATCH v11 2/3] migration: enable multifd and postcopy together

[Prasad Pandit]

From: Prasad Pandit <pjp@fedoraproject.org>

Enable Multifd and Postcopy migration together.
The migration_ioc_process_incoming() routine checks
magic value sent on each channel and helps to properly
setup multifd and postcopy channels.

The Precopy and Multifd threads work during the initial
guest RAM transfer. When migration moves to the Postcopy
phase, the multifd threads cease to send data on multifd
channels and Postcopy threads on the destination
request/pull data from the source side.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
---
 migration/multifd-nocomp.c | 3 ++-
 migration/multifd.c        | 7 +++++++
 migration/options.c        | 5 -----
 migration/ram.c            | 5 ++---
 4 files changed, 11 insertions(+), 9 deletions(-)

v11: no change

v10:
- https://lore.kernel.org/qemu-devel/20250508122849.207213-2-ppandit@redhat.com/T/#t

diff --git a/migration/multifd-nocomp.c b/migration/multifd-nocomp.c
index 88fe0f99f2..b48eae3d86 100644
--- a/migration/multifd-nocomp.c
+++ b/migration/multifd-nocomp.c
@@ -17,6 +17,7 @@
 #include "migration-stats.h"
 #include "multifd.h"
 #include "options.h"
+#include "migration.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
@@ -398,7 +399,7 @@ int multifd_ram_flush_and_sync(QEMUFile *f)
     MultiFDSyncReq req;
     int ret;
 
-    if (!migrate_multifd()) {
+    if (!migrate_multifd() || migration_in_postcopy()) {
         return 0;
     }
 
diff --git a/migration/multifd.c b/migration/multifd.c
index ec108af624..f18b166bcf 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -1379,6 +1379,13 @@ static void *multifd_recv_thread(void *opaque)
         }
 
         if (has_data) {
+            /*
+             * multifd thread should not be active and receive data
+             * when migration is in the Postcopy phase. Two threads
+             * writing the same memory area could easily corrupt
+             * the guest state.
+             */
+            assert(!migration_in_postcopy());
             if (is_device_state) {
                 assert(use_packets);
                 ret = multifd_device_state_recv(p, &local_err);
diff --git a/migration/options.c b/migration/options.c
index b6ae95358d..3fcd577cd7 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -509,11 +509,6 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp)
             error_setg(errp, "Postcopy is not compatible with ignore-shared");
             return false;
         }
-
-        if (new_caps[MIGRATION_CAPABILITY_MULTIFD]) {
-            error_setg(errp, "Postcopy is not yet compatible with multifd");
-            return false;
-        }
     }
 
     if (new_caps[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) {
diff --git a/migration/ram.c b/migration/ram.c
index e12913b43e..d26dbd37c4 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1993,9 +1993,8 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss)
         }
     }
 
-    if (migrate_multifd()) {
-        RAMBlock *block = pss->block;
-        return ram_save_multifd_page(block, offset);
+    if (migrate_multifd() && !migration_in_postcopy()) {
+        return ram_save_multifd_page(pss->block, offset);
     }
 
     return ram_save_page(rs, pss);
-- 
2.49.0

[PATCH v11 3/3] tests/qtest/migration: add postcopy tests with multifd

[Prasad Pandit]

From: Prasad Pandit <pjp@fedoraproject.org>

Add new qtests to run postcopy migration with multifd
channels enabled.

Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
---
 tests/qtest/migration/compression-tests.c | 18 ++++++++
 tests/qtest/migration/postcopy-tests.c    | 27 ++++++++++++
 tests/qtest/migration/precopy-tests.c     | 28 ++++++++++++-
 tests/qtest/migration/tls-tests.c         | 50 +++++++++++++++++++++++
 4 files changed, 121 insertions(+), 2 deletions(-)

v11:
- pass 'postcopy_ram' variable as a function argument

v10:
- https://lore.kernel.org/qemu-devel/20250508122849.207213-2-ppandit@redhat.com/T/#t

diff --git a/tests/qtest/migration/compression-tests.c b/tests/qtest/migration/compression-tests.c
index 41e79f031b..b827665b8e 100644
--- a/tests/qtest/migration/compression-tests.c
+++ b/tests/qtest/migration/compression-tests.c
@@ -42,6 +42,20 @@ static void test_multifd_tcp_zstd(void)
     };
     test_precopy_common(&args);
 }
+
+static void test_multifd_postcopy_tcp_zstd(void)
+{
+    MigrateCommon args = {
+        .listen_uri = "defer",
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+            .caps[MIGRATION_CAPABILITY_POSTCOPY_RAM] = true,
+        },
+        .start_hook = migrate_hook_start_precopy_tcp_multifd_zstd,
+    };
+
+    test_precopy_common(&args);
+}
 #endif /* CONFIG_ZSTD */
 
 #ifdef CONFIG_QATZIP
@@ -184,6 +198,10 @@ void migration_test_add_compression(MigrationTestEnv *env)
 #ifdef CONFIG_ZSTD
     migration_test_add("/migration/multifd/tcp/plain/zstd",
                        test_multifd_tcp_zstd);
+    if (env->has_uffd) {
+        migration_test_add("/migration/multifd+postcopy/tcp/plain/zstd",
+                           test_multifd_postcopy_tcp_zstd);
+    }
 #endif
 
 #ifdef CONFIG_QATZIP
diff --git a/tests/qtest/migration/postcopy-tests.c b/tests/qtest/migration/postcopy-tests.c
index 483e3ff99f..eb637f94f7 100644
--- a/tests/qtest/migration/postcopy-tests.c
+++ b/tests/qtest/migration/postcopy-tests.c
@@ -94,6 +94,29 @@ static void migration_test_add_postcopy_smoke(MigrationTestEnv *env)
     }
 }
 
+static void test_multifd_postcopy(void)
+{
+    MigrateCommon args = {
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+        },
+    };
+
+    test_postcopy_common(&args);
+}
+
+static void test_multifd_postcopy_preempt(void)
+{
+    MigrateCommon args = {
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+            .caps[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT] = true,
+        },
+    };
+
+    test_postcopy_common(&args);
+}
+
 void migration_test_add_postcopy(MigrationTestEnv *env)
 {
     migration_test_add_postcopy_smoke(env);
@@ -114,6 +137,10 @@ void migration_test_add_postcopy(MigrationTestEnv *env)
             "/migration/postcopy/recovery/double-failures/reconnect",
             test_postcopy_recovery_fail_reconnect);
 
+        migration_test_add("/migration/postcopy/multifd/plain",
+                           test_multifd_postcopy);
+        migration_test_add("/migration/postcopy/multifd/preempt/plain",
+                           test_multifd_postcopy_preempt);
         if (env->is_x86) {
             migration_test_add("/migration/postcopy/suspend",
                                test_postcopy_suspend);
diff --git a/tests/qtest/migration/precopy-tests.c b/tests/qtest/migration/precopy-tests.c
index 87b0a7e8ef..441a65bcf5 100644
--- a/tests/qtest/migration/precopy-tests.c
+++ b/tests/qtest/migration/precopy-tests.c
@@ -524,7 +524,7 @@ static void test_multifd_tcp_channels_none(void)
  *
  *  And see that it works
  */
-static void test_multifd_tcp_cancel(void)
+static void test_multifd_tcp_cancel(bool postcopy_ram)
 {
     MigrateStart args = {
         .hide_stderr = true,
@@ -538,6 +538,11 @@ static void test_multifd_tcp_cancel(void)
     migrate_ensure_non_converge(from);
     migrate_prepare_for_dirty_mem(from);
 
+    if (postcopy_ram) {
+        migrate_set_capability(from, "postcopy-ram", true);
+        migrate_set_capability(to, "postcopy-ram", true);
+    }
+
     migrate_set_parameter_int(from, "multifd-channels", 16);
     migrate_set_parameter_int(to, "multifd-channels", 16);
 
@@ -579,6 +584,10 @@ static void test_multifd_tcp_cancel(void)
         return;
     }
 
+    if (postcopy_ram) {
+        migrate_set_capability(to2, "postcopy-ram", true);
+    }
+
     migrate_set_parameter_int(to2, "multifd-channels", 16);
 
     migrate_set_capability(to2, "multifd", true);
@@ -602,6 +611,16 @@ static void test_multifd_tcp_cancel(void)
     migrate_end(from, to2, true);
 }
 
+static void test_multifd_precopy_tcp_cancel(void)
+{
+    test_multifd_tcp_cancel(false);
+}
+
+static void test_multifd_postcopy_tcp_cancel(void)
+{
+    test_multifd_tcp_cancel(true);
+}
+
 static void test_cancel_src_after_failed(QTestState *from, QTestState *to,
                                          const char *uri, const char *phase)
 {
@@ -1188,7 +1207,12 @@ static void migration_test_add_precopy_smoke(MigrationTestEnv *env)
     migration_test_add("/migration/multifd/tcp/uri/plain/none",
                        test_multifd_tcp_uri_none);
     migration_test_add("/migration/multifd/tcp/plain/cancel",
-                       test_multifd_tcp_cancel);
+                       test_multifd_precopy_tcp_cancel);
+    if (env->has_uffd) {
+        migration_test_add("/migration/multifd+postcopy/tcp/plain/cancel",
+                           test_multifd_postcopy_tcp_cancel);
+    }
+
 #ifdef CONFIG_RDMA
     migration_test_add("/migration/precopy/rdma/plain",
                        test_precopy_rdma_plain);
diff --git a/tests/qtest/migration/tls-tests.c b/tests/qtest/migration/tls-tests.c
index 72f44defbb..50a07a1c0f 100644
--- a/tests/qtest/migration/tls-tests.c
+++ b/tests/qtest/migration/tls-tests.c
@@ -395,6 +395,19 @@ static void test_postcopy_recovery_tls_psk(void)
     test_postcopy_recovery_common(&args);
 }
 
+static void test_multifd_postcopy_recovery_tls_psk(void)
+{
+    MigrateCommon args = {
+        .start_hook = migrate_hook_start_tls_psk_match,
+        .end_hook = migrate_hook_end_tls_psk,
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+        },
+    };
+
+    test_postcopy_recovery_common(&args);
+}
+
 /* This contains preempt+recovery+tls test altogether */
 static void test_postcopy_preempt_all(void)
 {
@@ -409,6 +422,20 @@ static void test_postcopy_preempt_all(void)
     test_postcopy_recovery_common(&args);
 }
 
+static void test_multifd_postcopy_preempt_recovery_tls_psk(void)
+{
+    MigrateCommon args = {
+        .start_hook = migrate_hook_start_tls_psk_match,
+        .end_hook = migrate_hook_end_tls_psk,
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+            .caps[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT] = true,
+        },
+    };
+
+    test_postcopy_recovery_common(&args);
+}
+
 static void test_precopy_unix_tls_psk(void)
 {
     g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
@@ -657,6 +684,21 @@ static void test_multifd_tcp_tls_psk_mismatch(void)
     test_precopy_common(&args);
 }
 
+static void test_multifd_postcopy_tcp_tls_psk_match(void)
+{
+    MigrateCommon args = {
+        .start = {
+            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
+            .caps[MIGRATION_CAPABILITY_POSTCOPY_RAM] = true,
+        },
+        .listen_uri = "defer",
+        .start_hook = migrate_hook_start_multifd_tcp_tls_psk_match,
+        .end_hook = migrate_hook_end_tls_psk,
+    };
+
+    test_precopy_common(&args);
+}
+
 #ifdef CONFIG_TASN1
 static void test_multifd_tcp_tls_x509_default_host(void)
 {
@@ -774,6 +816,10 @@ void migration_test_add_tls(MigrationTestEnv *env)
                            test_postcopy_preempt_tls_psk);
         migration_test_add("/migration/postcopy/preempt/recovery/tls/psk",
                            test_postcopy_preempt_all);
+        migration_test_add("/migration/postcopy/multifd/recovery/tls/psk",
+                           test_multifd_postcopy_recovery_tls_psk);
+        migration_test_add("/migration/postcopy/multifd/preempt/recovery/tls/psk",
+                           test_multifd_postcopy_preempt_recovery_tls_psk);
     }
 #ifdef CONFIG_TASN1
     migration_test_add("/migration/precopy/unix/tls/x509/default-host",
@@ -805,6 +851,10 @@ void migration_test_add_tls(MigrationTestEnv *env)
                        test_multifd_tcp_tls_psk_match);
     migration_test_add("/migration/multifd/tcp/tls/psk/mismatch",
                        test_multifd_tcp_tls_psk_mismatch);
+    if (env->has_uffd) {
+        migration_test_add("/migration/multifd+postcopy/tcp/tls/psk/match",
+                           test_multifd_postcopy_tcp_tls_psk_match);
+    }
 #ifdef CONFIG_TASN1
     migration_test_add("/migration/multifd/tcp/tls/x509/default-host",
                        test_multifd_tcp_tls_x509_default_host);
--
2.49.0

Re: [PATCH v11 1/3] migration: write zero pages when postcopy enabled

[Fabiano Rosas]

Prasad Pandit <ppandit@redhat.com> writes:

> From: Prasad Pandit <pjp@fedoraproject.org>
>
> During multifd migration, zero pages are written if
> they are migrated more than once.
>
> This may result in a migration thread hang issue when
> multifd and postcopy are enabled together.
>
> When postcopy is enabled, always write zero pages as and
> when they are migrated.
>
> Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>

Reviewed-by: Fabiano Rosas <farosas@suse.de>

Re: [PATCH v11 0/3] Allow to enable multifd and postcopy migration together

[Peter Xu]

On Mon, May 12, 2025 at 06:21:21PM +0530, Prasad Pandit wrote:
> From: Prasad Pandit <pjp@fedoraproject.org>
> 
>  Hello,
> 
> * This series (v11) fixes spelling and capitalisations glitches and
>   does some refactoring and reordering changes as suggested in the
>   review of v10.
> ===
> 67/67 qemu:qtest+qtest-x86_64 / qtest-x86_64/migration-test                 OK             196.69s   81 subtests passed
> ===

I queued it with some renames in the last test file, the fixup attached,
please let me know if anyone sees any issues.

In general, I put all the new tests under /migration/multifd+postcopy/,
rather than using different path.

Thanks,

===8<===

From 89c22f1c5fbb4afdf5bf3f3b0ef2dae162094488 Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx@redhat.com>
Date: Tue, 13 May 2025 17:46:24 -0400
Subject: [PATCH] fixup! tests/qtest/migration: add postcopy tests with multifd

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tests/qtest/migration/postcopy-tests.c | 4 ++--
 tests/qtest/migration/tls-tests.c      | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/qtest/migration/postcopy-tests.c b/tests/qtest/migration/postcopy-tests.c
index eb637f94f7..3773525843 100644
--- a/tests/qtest/migration/postcopy-tests.c
+++ b/tests/qtest/migration/postcopy-tests.c
@@ -137,9 +137,9 @@ void migration_test_add_postcopy(MigrationTestEnv *env)
             "/migration/postcopy/recovery/double-failures/reconnect",
             test_postcopy_recovery_fail_reconnect);
 
-        migration_test_add("/migration/postcopy/multifd/plain",
+        migration_test_add("/migration/multifd+postcopy/plain",
                            test_multifd_postcopy);
-        migration_test_add("/migration/postcopy/multifd/preempt/plain",
+        migration_test_add("/migration/multifd+postcopy/preempt/plain",
                            test_multifd_postcopy_preempt);
         if (env->is_x86) {
             migration_test_add("/migration/postcopy/suspend",
diff --git a/tests/qtest/migration/tls-tests.c b/tests/qtest/migration/tls-tests.c
index 50a07a1c0f..46b48ef78c 100644
--- a/tests/qtest/migration/tls-tests.c
+++ b/tests/qtest/migration/tls-tests.c
@@ -816,9 +816,9 @@ void migration_test_add_tls(MigrationTestEnv *env)
                            test_postcopy_preempt_tls_psk);
         migration_test_add("/migration/postcopy/preempt/recovery/tls/psk",
                            test_postcopy_preempt_all);
-        migration_test_add("/migration/postcopy/multifd/recovery/tls/psk",
+        migration_test_add("/migration/multifd+postcopy/recovery/tls/psk",
                            test_multifd_postcopy_recovery_tls_psk);
-        migration_test_add("/migration/postcopy/multifd/preempt/recovery/tls/psk",
+        migration_test_add("/migration/multifd+postcopy/preempt/recovery/tls/psk",
                            test_multifd_postcopy_preempt_recovery_tls_psk);
     }
 #ifdef CONFIG_TASN1
-- 
2.49.0


-- 
Peter Xu

Re: [PATCH v11 3/3] tests/qtest/migration: add postcopy tests with multifd

[Prasad Pandit]

Hi,

On Mon, 12 May 2025 at 18:22, Prasad Pandit <ppandit@redhat.com> wrote:
> From: Prasad Pandit <pjp@fedoraproject.org>
>
> Add new qtests to run postcopy migration with multifd
> channels enabled.
>
> Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
> ---
>  tests/qtest/migration/compression-tests.c | 18 ++++++++
>  tests/qtest/migration/postcopy-tests.c    | 27 ++++++++++++
>  tests/qtest/migration/precopy-tests.c     | 28 ++++++++++++-
>  tests/qtest/migration/tls-tests.c         | 50 +++++++++++++++++++++++
>  4 files changed, 121 insertions(+), 2 deletions(-)
>
> v11:
> - pass 'postcopy_ram' variable as a function argument
>
> v10:
> - https://lore.kernel.org/qemu-devel/20250508122849.207213-2-ppandit@redhat.com/T/#t
>
> diff --git a/tests/qtest/migration/compression-tests.c b/tests/qtest/migration/compression-tests.c
> index 41e79f031b..b827665b8e 100644
> --- a/tests/qtest/migration/compression-tests.c
> +++ b/tests/qtest/migration/compression-tests.c
> @@ -42,6 +42,20 @@ static void test_multifd_tcp_zstd(void)
>      };
>      test_precopy_common(&args);
>  }
> +
> +static void test_multifd_postcopy_tcp_zstd(void)
> +{
> +    MigrateCommon args = {
> +        .listen_uri = "defer",
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +            .caps[MIGRATION_CAPABILITY_POSTCOPY_RAM] = true,
> +        },
> +        .start_hook = migrate_hook_start_precopy_tcp_multifd_zstd,
> +    };
> +
> +    test_precopy_common(&args);
> +}
>  #endif /* CONFIG_ZSTD */
>
>  #ifdef CONFIG_QATZIP
> @@ -184,6 +198,10 @@ void migration_test_add_compression(MigrationTestEnv *env)
>  #ifdef CONFIG_ZSTD
>      migration_test_add("/migration/multifd/tcp/plain/zstd",
>                         test_multifd_tcp_zstd);
> +    if (env->has_uffd) {
> +        migration_test_add("/migration/multifd+postcopy/tcp/plain/zstd",
> +                           test_multifd_postcopy_tcp_zstd);
> +    }
>  #endif
>
>  #ifdef CONFIG_QATZIP
> diff --git a/tests/qtest/migration/postcopy-tests.c b/tests/qtest/migration/postcopy-tests.c
> index 483e3ff99f..eb637f94f7 100644
> --- a/tests/qtest/migration/postcopy-tests.c
> +++ b/tests/qtest/migration/postcopy-tests.c
> @@ -94,6 +94,29 @@ static void migration_test_add_postcopy_smoke(MigrationTestEnv *env)
>      }
>  }
>
> +static void test_multifd_postcopy(void)
> +{
> +    MigrateCommon args = {
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +        },
> +    };
> +
> +    test_postcopy_common(&args);
> +}
> +
> +static void test_multifd_postcopy_preempt(void)
> +{
> +    MigrateCommon args = {
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +            .caps[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT] = true,
> +        },
> +    };
> +
> +    test_postcopy_common(&args);
> +}
> +
>  void migration_test_add_postcopy(MigrationTestEnv *env)
>  {
>      migration_test_add_postcopy_smoke(env);
> @@ -114,6 +137,10 @@ void migration_test_add_postcopy(MigrationTestEnv *env)
>              "/migration/postcopy/recovery/double-failures/reconnect",
>              test_postcopy_recovery_fail_reconnect);
>
> +        migration_test_add("/migration/postcopy/multifd/plain",
> +                           test_multifd_postcopy);
> +        migration_test_add("/migration/postcopy/multifd/preempt/plain",
> +                           test_multifd_postcopy_preempt);
>          if (env->is_x86) {
>              migration_test_add("/migration/postcopy/suspend",
>                                 test_postcopy_suspend);
> diff --git a/tests/qtest/migration/precopy-tests.c b/tests/qtest/migration/precopy-tests.c
> index 87b0a7e8ef..441a65bcf5 100644
> --- a/tests/qtest/migration/precopy-tests.c
> +++ b/tests/qtest/migration/precopy-tests.c
> @@ -524,7 +524,7 @@ static void test_multifd_tcp_channels_none(void)
>   *
>   *  And see that it works
>   */
> -static void test_multifd_tcp_cancel(void)
> +static void test_multifd_tcp_cancel(bool postcopy_ram)
>  {
>      MigrateStart args = {
>          .hide_stderr = true,
> @@ -538,6 +538,11 @@ static void test_multifd_tcp_cancel(void)
>      migrate_ensure_non_converge(from);
>      migrate_prepare_for_dirty_mem(from);
>
> +    if (postcopy_ram) {
> +        migrate_set_capability(from, "postcopy-ram", true);
> +        migrate_set_capability(to, "postcopy-ram", true);
> +    }
> +
>      migrate_set_parameter_int(from, "multifd-channels", 16);
>      migrate_set_parameter_int(to, "multifd-channels", 16);
>
> @@ -579,6 +584,10 @@ static void test_multifd_tcp_cancel(void)
>          return;
>      }
>
> +    if (postcopy_ram) {
> +        migrate_set_capability(to2, "postcopy-ram", true);
> +    }
> +
>      migrate_set_parameter_int(to2, "multifd-channels", 16);
>
>      migrate_set_capability(to2, "multifd", true);
> @@ -602,6 +611,16 @@ static void test_multifd_tcp_cancel(void)
>      migrate_end(from, to2, true);
>  }
>
> +static void test_multifd_precopy_tcp_cancel(void)
> +{
> +    test_multifd_tcp_cancel(false);
> +}
> +
> +static void test_multifd_postcopy_tcp_cancel(void)
> +{
> +    test_multifd_tcp_cancel(true);
> +}
> +
>  static void test_cancel_src_after_failed(QTestState *from, QTestState *to,
>                                           const char *uri, const char *phase)
>  {
> @@ -1188,7 +1207,12 @@ static void migration_test_add_precopy_smoke(MigrationTestEnv *env)
>      migration_test_add("/migration/multifd/tcp/uri/plain/none",
>                         test_multifd_tcp_uri_none);
>      migration_test_add("/migration/multifd/tcp/plain/cancel",
> -                       test_multifd_tcp_cancel);
> +                       test_multifd_precopy_tcp_cancel);
> +    if (env->has_uffd) {
> +        migration_test_add("/migration/multifd+postcopy/tcp/plain/cancel",
> +                           test_multifd_postcopy_tcp_cancel);
> +    }
> +
>  #ifdef CONFIG_RDMA
>      migration_test_add("/migration/precopy/rdma/plain",
>                         test_precopy_rdma_plain);
> diff --git a/tests/qtest/migration/tls-tests.c b/tests/qtest/migration/tls-tests.c
> index 72f44defbb..50a07a1c0f 100644
> --- a/tests/qtest/migration/tls-tests.c
> +++ b/tests/qtest/migration/tls-tests.c
> @@ -395,6 +395,19 @@ static void test_postcopy_recovery_tls_psk(void)
>      test_postcopy_recovery_common(&args);
>  }
>
> +static void test_multifd_postcopy_recovery_tls_psk(void)
> +{
> +    MigrateCommon args = {
> +        .start_hook = migrate_hook_start_tls_psk_match,
> +        .end_hook = migrate_hook_end_tls_psk,
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +        },
> +    };
> +
> +    test_postcopy_recovery_common(&args);
> +}
> +
>  /* This contains preempt+recovery+tls test altogether */
>  static void test_postcopy_preempt_all(void)
>  {
> @@ -409,6 +422,20 @@ static void test_postcopy_preempt_all(void)
>      test_postcopy_recovery_common(&args);
>  }
>
> +static void test_multifd_postcopy_preempt_recovery_tls_psk(void)
> +{
> +    MigrateCommon args = {
> +        .start_hook = migrate_hook_start_tls_psk_match,
> +        .end_hook = migrate_hook_end_tls_psk,
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +            .caps[MIGRATION_CAPABILITY_POSTCOPY_PREEMPT] = true,
> +        },
> +    };
> +
> +    test_postcopy_recovery_common(&args);
> +}
> +
>  static void test_precopy_unix_tls_psk(void)
>  {
>      g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
> @@ -657,6 +684,21 @@ static void test_multifd_tcp_tls_psk_mismatch(void)
>      test_precopy_common(&args);
>  }
>
> +static void test_multifd_postcopy_tcp_tls_psk_match(void)
> +{
> +    MigrateCommon args = {
> +        .start = {
> +            .caps[MIGRATION_CAPABILITY_MULTIFD] = true,
> +            .caps[MIGRATION_CAPABILITY_POSTCOPY_RAM] = true,
> +        },
> +        .listen_uri = "defer",
> +        .start_hook = migrate_hook_start_multifd_tcp_tls_psk_match,
> +        .end_hook = migrate_hook_end_tls_psk,
> +    };
> +
> +    test_precopy_common(&args);
> +}
> +
>  #ifdef CONFIG_TASN1
>  static void test_multifd_tcp_tls_x509_default_host(void)
>  {
> @@ -774,6 +816,10 @@ void migration_test_add_tls(MigrationTestEnv *env)
>                             test_postcopy_preempt_tls_psk);
>          migration_test_add("/migration/postcopy/preempt/recovery/tls/psk",
>                             test_postcopy_preempt_all);
> +        migration_test_add("/migration/postcopy/multifd/recovery/tls/psk",
> +                           test_multifd_postcopy_recovery_tls_psk);
> +        migration_test_add("/migration/postcopy/multifd/preempt/recovery/tls/psk",
> +                           test_multifd_postcopy_preempt_recovery_tls_psk);
>      }
>  #ifdef CONFIG_TASN1
>      migration_test_add("/migration/precopy/unix/tls/x509/default-host",
> @@ -805,6 +851,10 @@ void migration_test_add_tls(MigrationTestEnv *env)
>                         test_multifd_tcp_tls_psk_match);
>      migration_test_add("/migration/multifd/tcp/tls/psk/mismatch",
>                         test_multifd_tcp_tls_psk_mismatch);
> +    if (env->has_uffd) {
> +        migration_test_add("/migration/multifd+postcopy/tcp/tls/psk/match",
> +                           test_multifd_postcopy_tcp_tls_psk_match);
> +    }
>  #ifdef CONFIG_TASN1
>      migration_test_add("/migration/multifd/tcp/tls/x509/default-host",
>                         test_multifd_tcp_tls_x509_default_host);
> --
> 2.49.0


* Ping...(this one needs an ack if all okay)

Thank you.
---
  - Prasad