Merge tag 'migration-20240116-pull-request' of https://gitlab.com/peterx/qemu into staging

Migration pull request 2nd batch for 9.0

- Het's cleanup on migration qmp command paths
- Fabiano's migration cleanups and test improvements
- Fabiano's patch to re-enable multifd-cancel test
- Peter's migration doc reorganizations
- Nick Briggs's fix for Solaries build on rdma

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* tag 'migration-20240116-pull-request' of https://gitlab.com/peterx/qemu:
  migration/rdma: define htonll/ntohll only if not predefined
  docs/migration: Further move virtio to be feature of migration
  docs/migration: Further move vfio to be feature of migration
  docs/migration: Organize "Postcopy" page
  docs/migration: Split "dirty limit"
  docs/migration: Split "Postcopy"
  docs/migration: Split "Debugging" and "Firmware"
  docs/migration: Split "Backwards compatibility" separately
  docs/migration: Convert virtio.txt into rST
  docs/migration: Create index page
  docs/migration: Create migration/ directory
  tests/qtest: Re-enable multifd cancel test
  tests/qtest/migration: Use the new migration_test_add
  tests/qtest/migration: Add a wrapper to print test names
  tests/qtest/migration: Print migration incoming errors
  migration: Report error in incoming migration
  migration/multifd: Change multifd_pages_init argument
  migration/multifd: Remove QEMUFile from where it is not needed
  migration/multifd: Remove MultiFDPages_t::packet_num
  migration: Simplify initial conditionals in migration for better readability

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 45 insertions, 42 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 98c5c3e..219447d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -523,28 +523,26 @@ static void qemu_start_incoming_migration(const char *uri, bool has_channels,
     /*
      * Having preliminary checks for uri and channel
      */
-    if (uri && has_channels) {
-        error_setg(errp, "'uri' and 'channels' arguments are mutually "
-                   "exclusive; exactly one of the two should be present in "
-                   "'migrate-incoming' qmp command ");
+    if (!uri == !channels) {
+        error_setg(errp, "need either 'uri' or 'channels' argument");
         return;
-    } else if (channels) {
+    }
+
+    if (channels) {
         /* To verify that Migrate channel list has only item */
         if (channels->next) {
             error_setg(errp, "Channel list has more than one entries");
             return;
         }
         addr = channels->value->addr;
-    } else if (uri) {
+    }
+
+    if (uri) {
         /* caller uses the old URI syntax */
         if (!migrate_uri_parse(uri, &channel, errp)) {
             return;
         }
         addr = channel->addr;
-    } else {
-        error_setg(errp, "neither 'uri' or 'channels' argument are "
-                   "specified in 'migrate-incoming' qmp command ");
-        return;
     }
 
     /* transport mechanism not suitable for migration? */
@@ -699,6 +697,13 @@ process_incoming_migration_co(void *opaque)
     }
 
     if (ret < 0) {
+        MigrationState *s = migrate_get_current();
+
+        if (migrate_has_error(s)) {
+            WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
+                error_report_err(s->error);
+            }
+        }
         error_report("load of migration failed: %s", strerror(-ret));
         goto fail;
     }
@@ -1924,28 +1929,26 @@ void qmp_migrate(const char *uri, bool has_channels,
     /*
      * Having preliminary checks for uri and channel
      */
-    if (uri && has_channels) {
-        error_setg(errp, "'uri' and 'channels' arguments are mutually "
-                   "exclusive; exactly one of the two should be present in "
-                   "'migrate' qmp command ");
+    if (!uri == !channels) {
+        error_setg(errp, "need either 'uri' or 'channels' argument");
         return;
-    } else if (channels) {
+    }
+
+    if (channels) {
         /* To verify that Migrate channel list has only item */
         if (channels->next) {
             error_setg(errp, "Channel list has more than one entries");
             return;
         }
         addr = channels->value->addr;
-    } else if (uri) {
+    }
+
+    if (uri) {
         /* caller uses the old URI syntax */
         if (!migrate_uri_parse(uri, &channel, errp)) {
             return;
         }
         addr = channel->addr;
-    } else {
-        error_setg(errp, "neither 'uri' or 'channels' argument are "
-                   "specified in 'migrate' qmp command ");
-        return;
     }
 
     /* transport mechanism not suitable for migration? */
diff --git a/migration/multifd.c b/migration/multifd.c
index 9f353ae..25cbc6d 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -236,12 +236,12 @@ static int multifd_recv_initial_packet(QIOChannel *c, Error **errp)
     return msg.id;
 }
 
-static MultiFDPages_t *multifd_pages_init(size_t size)
+static MultiFDPages_t *multifd_pages_init(uint32_t n)
 {
     MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1);
 
-    pages->allocated = size;
-    pages->offset = g_new0(ram_addr_t, size);
+    pages->allocated = n;
+    pages->offset = g_new0(ram_addr_t, n);
 
     return pages;
 }
@@ -250,7 +250,6 @@ static void multifd_pages_clear(MultiFDPages_t *pages)
 {
     pages->num = 0;
     pages->allocated = 0;
-    pages->packet_num = 0;
     pages->block = NULL;
     g_free(pages->offset);
     pages->offset = NULL;
@@ -391,7 +390,7 @@ struct {
  * false.
  */
 
-static int multifd_send_pages(QEMUFile *f)
+static int multifd_send_pages(void)
 {
     int i;
     static int next_channel;
@@ -437,7 +436,7 @@ static int multifd_send_pages(QEMUFile *f)
     return 1;
 }
 
-int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
+int multifd_queue_page(RAMBlock *block, ram_addr_t offset)
 {
     MultiFDPages_t *pages = multifd_send_state->pages;
     bool changed = false;
@@ -457,12 +456,12 @@ int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
         changed = true;
     }
 
-    if (multifd_send_pages(f) < 0) {
+    if (multifd_send_pages() < 0) {
         return -1;
     }
 
     if (changed) {
-        return multifd_queue_page(f, block, offset);
+        return multifd_queue_page(block, offset);
     }
 
     return 1;
@@ -584,7 +583,7 @@ static int multifd_zero_copy_flush(QIOChannel *c)
     return ret;
 }
 
-int multifd_send_sync_main(QEMUFile *f)
+int multifd_send_sync_main(void)
 {
     int i;
     bool flush_zero_copy;
@@ -593,7 +592,7 @@ int multifd_send_sync_main(QEMUFile *f)
         return 0;
     }
     if (multifd_send_state->pages->num) {
-        if (multifd_send_pages(f) < 0) {
+        if (multifd_send_pages() < 0) {
             error_report("%s: multifd_send_pages fail", __func__);
             return -1;
         }
diff --git a/migration/multifd.h b/migration/multifd.h
index a835643..35d11f1 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -21,8 +21,8 @@ void multifd_load_shutdown(void);
 bool multifd_recv_all_channels_created(void);
 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
 void multifd_recv_sync_main(void);
-int multifd_send_sync_main(QEMUFile *f);
-int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset);
+int multifd_send_sync_main(void);
+int multifd_queue_page(RAMBlock *block, ram_addr_t offset);
 
 /* Multifd Compression flags */
 #define MULTIFD_FLAG_SYNC (1 << 0)
@@ -58,8 +58,6 @@ typedef struct {
     uint32_t num;
     /* number of allocated pages */
     uint32_t allocated;
-    /* global number of generated multifd packets */
-    uint64_t packet_num;
     /* offset of each page */
     ram_addr_t *offset;
     RAMBlock *block;
diff --git a/migration/ram.c b/migration/ram.c
index 890f31c..c0cdccc 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1250,10 +1250,9 @@ static int ram_save_page(RAMState *rs, PageSearchStatus *pss)
     return pages;
 }
 
-static int ram_save_multifd_page(QEMUFile *file, RAMBlock *block,
-                                 ram_addr_t offset)
+static int ram_save_multifd_page(RAMBlock *block, ram_addr_t offset)
 {
-    if (multifd_queue_page(file, block, offset) < 0) {
+    if (multifd_queue_page(block, offset) < 0) {
         return -1;
     }
     stat64_add(&mig_stats.normal_pages, 1);
@@ -1336,7 +1335,7 @@ static int find_dirty_block(RAMState *rs, PageSearchStatus *pss)
             if (migrate_multifd() &&
                 !migrate_multifd_flush_after_each_section()) {
                 QEMUFile *f = rs->pss[RAM_CHANNEL_PRECOPY].pss_channel;
-                int ret = multifd_send_sync_main(f);
+                int ret = multifd_send_sync_main();
                 if (ret < 0) {
                     return ret;
                 }
@@ -2067,7 +2066,7 @@ static int ram_save_target_page_legacy(RAMState *rs, PageSearchStatus *pss)
      * still see partially copied pages which is data corruption.
      */
     if (migrate_multifd() && !migration_in_postcopy()) {
-        return ram_save_multifd_page(pss->pss_channel, block, offset);
+        return ram_save_multifd_page(block, offset);
     }
 
     return ram_save_page(rs, pss);
@@ -2985,7 +2984,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     migration_ops->ram_save_target_page = ram_save_target_page_legacy;
 
     bql_unlock();
-    ret = multifd_send_sync_main(f);
+    ret = multifd_send_sync_main();
     bql_lock();
     if (ret < 0) {
         return ret;
@@ -3109,7 +3108,7 @@ out:
     if (ret >= 0
         && migration_is_setup_or_active(migrate_get_current()->state)) {
         if (migrate_multifd() && migrate_multifd_flush_after_each_section()) {
-            ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
+            ret = multifd_send_sync_main();
             if (ret < 0) {
                 return ret;
             }
@@ -3183,7 +3182,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
         }
     }
 
-    ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
+    ret = multifd_send_sync_main();
     if (ret < 0) {
         return ret;
     }
diff --git a/migration/rdma.c b/migration/rdma.c
index 94c0f87..a355dce 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -238,6 +238,7 @@ static const char *control_desc(unsigned int rdma_control)
     return strs[rdma_control];
 }
 
+#if !defined(htonll)
 static uint64_t htonll(uint64_t v)
 {
     union { uint32_t lv[2]; uint64_t llv; } u;
@@ -245,13 +246,16 @@ static uint64_t htonll(uint64_t v)
     u.lv[1] = htonl(v & 0xFFFFFFFFULL);
     return u.llv;
 }
+#endif
 
+#if !defined(ntohll)
 static uint64_t ntohll(uint64_t v)
 {
     union { uint32_t lv[2]; uint64_t llv; } u;
     u.llv = v;
     return ((uint64_t)ntohl(u.lv[0]) << 32) | (uint64_t) ntohl(u.lv[1]);
 }
+#endif
 
 static void dest_block_to_network(RDMADestBlock *db)
 {