migration: Create migrate_rdma()

Helper to say if we are doing a migration over rdma.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230509120700.78359-2-quintela@redhat.com>

migration/migration.c

@@ -1405,6 +1405,7 @@ void migrate_init(MigrationState *s)
     s->vm_old_state = -1;
     s->iteration_initial_bytes = 0;
     s->threshold_size = 0;
+    s->rdma_migration = false;
 }
 
 int migrate_add_blocker_internal(Error *reason, Error **errp)

migration/migration.h

@@ -440,6 +440,9 @@ struct MigrationState {
 
     /* QEMU_VM_VMDESCRIPTION content filled for all non-iterable devices. */
     JSONWriter *vmdesc;
+
+    /* Is this a rdma migration */
+    bool rdma_migration;
 };
 
 void migrate_set_state(int *state, int old_state, int new_state);

migration/options.c

@@ -350,6 +350,13 @@ bool migrate_postcopy(void)
     return migrate_postcopy_ram() || migrate_dirty_bitmaps();
 }
 
+bool migrate_rdma(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return s->rdma_migration;
+}
+
 bool migrate_tls(void)
 {
     MigrationState *s = migrate_get_current();

migration/options.h

@@ -54,6 +54,7 @@ bool migrate_zero_copy_send(void);
 
 bool migrate_multifd_flush_after_each_section(void);
 bool migrate_postcopy(void);
+bool migrate_rdma(void);
 bool migrate_tls(void);
 
 /* capabilities helpers */

migration/rdma.c

@@ -4122,6 +4122,7 @@ void rdma_start_incoming_migration(const char *host_port, Error **errp)
     int ret;
     RDMAContext *rdma;
     Error *local_err = NULL;
+    MigrationState *s = migrate_get_current();
 
     trace_rdma_start_incoming_migration();
 
@@ -4152,7 +4153,7 @@ void rdma_start_incoming_migration(const char *host_port, Error **errp)
     }
 
     trace_rdma_start_incoming_migration_after_rdma_listen();
-
+    s->rdma_migration = true;
     qemu_set_fd_handler(rdma->channel->fd, rdma_accept_incoming_migration,
                         NULL, (void *)(intptr_t)rdma);
     return;
@@ -4228,6 +4229,7 @@ void rdma_start_outgoing_migration(void *opaque,
 
     trace_rdma_start_outgoing_migration_after_rdma_connect();
 
+    s->rdma_migration = true;
     s->to_dst_file = qemu_fopen_rdma(rdma, "wb");
     migrate_fd_connect(s, NULL);
     return;