migration/rdma: Check sooner if we are in postcopy for save_page()

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231011203527.9061-11-quintela@redhat.com>

migration/rdma.c

@@ -3240,10 +3240,6 @@ static int qemu_rdma_save_page(QEMUFile *f, ram_addr_t block_offset,
     RDMAContext *rdma;
     int ret;
 
-    if (migration_in_postcopy()) {
-        return RAM_SAVE_CONTROL_NOT_SUPP;
-    }
-
     RCU_READ_LOCK_GUARD();
     rdma = qatomic_rcu_read(&rioc->rdmaout);
 
@@ -3317,7 +3313,7 @@ static int qemu_rdma_save_page(QEMUFile *f, ram_addr_t block_offset,
 int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset,
                            ram_addr_t offset, size_t size)
 {
-    if (!migrate_rdma()) {
+    if (!migrate_rdma() || migration_in_postcopy()) {
         return RAM_SAVE_CONTROL_NOT_SUPP;
     }