migration/multifd: Make MultiFDMethods const

The methods are defined at module_init time and don't ever
change. Make them const.

Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>

migration/multifd-nocomp.c

@@ -377,7 +377,7 @@ bool multifd_send_prepare_common(MultiFDSendParams *p)
     return true;
 }
 
-static MultiFDMethods multifd_nocomp_ops = {
+static const MultiFDMethods multifd_nocomp_ops = {
     .send_setup = multifd_nocomp_send_setup,
     .send_cleanup = multifd_nocomp_send_cleanup,
     .send_prepare = multifd_nocomp_send_prepare,

migration/multifd-qpl.c

@@ -694,7 +694,7 @@ static int multifd_qpl_recv(MultiFDRecvParams *p, Error **errp)
     return multifd_qpl_decompress_pages_slow_path(p, errp);
 }
 
-static MultiFDMethods multifd_qpl_ops = {
+static const MultiFDMethods multifd_qpl_ops = {
     .send_setup = multifd_qpl_send_setup,
     .send_cleanup = multifd_qpl_send_cleanup,
     .send_prepare = multifd_qpl_send_prepare,

migration/multifd-uadk.c

@@ -305,7 +305,7 @@ static int multifd_uadk_recv(MultiFDRecvParams *p, Error **errp)
     return 0;
 }
 
-static MultiFDMethods multifd_uadk_ops = {
+static const MultiFDMethods multifd_uadk_ops = {
     .send_setup = multifd_uadk_send_setup,
     .send_cleanup = multifd_uadk_send_cleanup,
     .send_prepare = multifd_uadk_send_prepare,

migration/multifd-zlib.c

@@ -277,7 +277,7 @@ static int multifd_zlib_recv(MultiFDRecvParams *p, Error **errp)
     return 0;
 }
 
-static MultiFDMethods multifd_zlib_ops = {
+static const MultiFDMethods multifd_zlib_ops = {
     .send_setup = multifd_zlib_send_setup,
     .send_cleanup = multifd_zlib_send_cleanup,
     .send_prepare = multifd_zlib_send_prepare,

migration/multifd-zstd.c

@@ -265,7 +265,7 @@ static int multifd_zstd_recv(MultiFDRecvParams *p, Error **errp)
     return 0;
 }
 
-static MultiFDMethods multifd_zstd_ops = {
+static const MultiFDMethods multifd_zstd_ops = {
     .send_setup = multifd_zstd_send_setup,
     .send_cleanup = multifd_zstd_send_cleanup,
     .send_prepare = multifd_zstd_send_prepare,

migration/multifd.c

@@ -76,7 +76,7 @@ struct {
      */
     int exiting;
     /* multifd ops */
-    MultiFDMethods *ops;
+    const MultiFDMethods *ops;
 } *multifd_send_state;
 
 struct {
@@ -93,7 +93,7 @@ struct {
     uint64_t packet_num;
     int exiting;
     /* multifd ops */
-    MultiFDMethods *ops;
+    const MultiFDMethods *ops;
 } *multifd_recv_state;
 
 MultiFDSendData *multifd_send_data_alloc(void)
@@ -128,9 +128,9 @@ void multifd_send_channel_created(void)
     qemu_sem_post(&multifd_send_state->channels_created);
 }
 
-static MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = {};
+static const MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = {};
 
-void multifd_register_ops(int method, MultiFDMethods *ops)
+void multifd_register_ops(int method, const MultiFDMethods *ops)
 {
     assert(0 <= method && method < MULTIFD_COMPRESSION__MAX);
     assert(!multifd_ops[method]);

migration/multifd.h

@@ -243,7 +243,7 @@ typedef struct {
     int (*recv)(MultiFDRecvParams *p, Error **errp);
 } MultiFDMethods;
 
-void multifd_register_ops(int method, MultiFDMethods *ops);
+void multifd_register_ops(int method, const MultiFDMethods *ops);
 void multifd_send_fill_packet(MultiFDSendParams *p);
 bool multifd_send_prepare_common(MultiFDSendParams *p);
 void multifd_send_zero_page_detect(MultiFDSendParams *p);