Re: [PATCH RFC 12/15] migration: Move migrate_allow_multifd and helpers into migration.c

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Peter Xu (peterx@redhat.com) wrote:
> This variable, along with its helpers, is used to detect whether multiple
> channel will be supported for migration.  In follow up patches, there'll be
> other capability that requires multi-channels.  Hence move it outside multifd
> specific code and make it public.  Meanwhile rename it from "multifd" to
> "multi_channels" to show its real meaning.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/migration.c | 22 +++++++++++++++++-----
>  migration/migration.h |  3 +++
>  migration/multifd.c   | 19 ++++---------------
>  migration/multifd.h   |  2 --
>  4 files changed, 24 insertions(+), 22 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 252ce1eaec..15a48b548a 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -180,6 +180,18 @@ static int migration_maybe_pause(MigrationState *s,
>                                   int new_state);
>  static void migrate_fd_cancel(MigrationState *s);
>  
> +static bool migrate_allow_multi_channels = true;
> +
> +void migrate_protocol_allow_multi_channels(bool allow)
> +{
> +    migrate_allow_multi_channels = allow;
> +}
> +
> +bool migrate_multi_channels_is_allowed(void)
> +{
> +    return migrate_allow_multi_channels;
> +}
> +
>  static gint page_request_addr_cmp(gconstpointer ap, gconstpointer bp)
>  {
>      uintptr_t a = (uintptr_t) ap, b = (uintptr_t) bp;
> @@ -463,12 +475,12 @@ static void qemu_start_incoming_migration(const char *uri, Error **errp)
>  {
>      const char *p = NULL;
>  
> -    migrate_protocol_allow_multifd(false); /* reset it anyway */
> +    migrate_protocol_allow_multi_channels(false); /* reset it anyway */
>      qapi_event_send_migration(MIGRATION_STATUS_SETUP);
>      if (strstart(uri, "tcp:", &p) ||
>          strstart(uri, "unix:", NULL) ||
>          strstart(uri, "vsock:", NULL)) {
> -        migrate_protocol_allow_multifd(true);
> +        migrate_protocol_allow_multi_channels(true);
>          socket_start_incoming_migration(p ? p : uri, errp);
>  #ifdef CONFIG_RDMA
>      } else if (strstart(uri, "rdma:", &p)) {
> @@ -1252,7 +1264,7 @@ static bool migrate_caps_check(bool *cap_list,
>  
>      /* incoming side only */
>      if (runstate_check(RUN_STATE_INMIGRATE) &&
> -        !migrate_multifd_is_allowed() &&
> +        !migrate_multi_channels_is_allowed() &&
>          cap_list[MIGRATION_CAPABILITY_MULTIFD]) {
>          error_setg(errp, "multifd is not supported by current protocol");
>          return false;
> @@ -2310,11 +2322,11 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>          }
>      }
>  
> -    migrate_protocol_allow_multifd(false);
> +    migrate_protocol_allow_multi_channels(false);
>      if (strstart(uri, "tcp:", &p) ||
>          strstart(uri, "unix:", NULL) ||
>          strstart(uri, "vsock:", NULL)) {
> -        migrate_protocol_allow_multifd(true);
> +        migrate_protocol_allow_multi_channels(true);
>          socket_start_outgoing_migration(s, p ? p : uri, &local_err);
>  #ifdef CONFIG_RDMA
>      } else if (strstart(uri, "rdma:", &p)) {
> diff --git a/migration/migration.h b/migration/migration.h
> index 34b79cb961..d0c0902ec9 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -425,4 +425,7 @@ void migration_cancel(const Error *error);
>  
>  void populate_vfio_info(MigrationInfo *info);
>  
> +bool migrate_multi_channels_is_allowed(void);
> +void migrate_protocol_allow_multi_channels(bool allow);
> +
>  #endif
> diff --git a/migration/multifd.c b/migration/multifd.c
> index 3242f688e5..64ca50de62 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -535,7 +535,7 @@ void multifd_save_cleanup(void)
>  {
>      int i;
>  
> -    if (!migrate_use_multifd() || !migrate_multifd_is_allowed()) {
> +    if (!migrate_use_multifd() || !migrate_multi_channels_is_allowed()) {
>          return;
>      }
>      multifd_send_terminate_threads(NULL);
> @@ -870,17 +870,6 @@ cleanup:
>      multifd_new_send_channel_cleanup(p, sioc, local_err);
>  }
>  
> -static bool migrate_allow_multifd = true;
> -void migrate_protocol_allow_multifd(bool allow)
> -{
> -    migrate_allow_multifd = allow;
> -}
> -
> -bool migrate_multifd_is_allowed(void)
> -{
> -    return migrate_allow_multifd;
> -}
> -
>  int multifd_save_setup(Error **errp)
>  {
>      int thread_count;
> @@ -891,7 +880,7 @@ int multifd_save_setup(Error **errp)
>      if (!migrate_use_multifd()) {
>          return 0;
>      }
> -    if (!migrate_multifd_is_allowed()) {
> +    if (!migrate_multi_channels_is_allowed()) {
>          error_setg(errp, "multifd is not supported by current protocol");
>          return -1;
>      }
> @@ -989,7 +978,7 @@ int multifd_load_cleanup(Error **errp)
>  {
>      int i;
>  
> -    if (!migrate_use_multifd() || !migrate_multifd_is_allowed()) {
> +    if (!migrate_use_multifd() || !migrate_multi_channels_is_allowed()) {
>          return 0;
>      }
>      multifd_recv_terminate_threads(NULL);
> @@ -1138,7 +1127,7 @@ int multifd_load_setup(Error **errp)
>      if (!migrate_use_multifd()) {
>          return 0;
>      }
> -    if (!migrate_multifd_is_allowed()) {
> +    if (!migrate_multi_channels_is_allowed()) {
>          error_setg(errp, "multifd is not supported by current protocol");
>          return -1;
>      }
> diff --git a/migration/multifd.h b/migration/multifd.h
> index e57adc783b..0ed07794b6 100644
> --- a/migration/multifd.h
> +++ b/migration/multifd.h
> @@ -13,8 +13,6 @@
>  #ifndef QEMU_MIGRATION_MULTIFD_H
>  #define QEMU_MIGRATION_MULTIFD_H
>  
> -bool migrate_multifd_is_allowed(void);
> -void migrate_protocol_allow_multifd(bool allow);
>  int multifd_save_setup(Error **errp);
>  void multifd_save_cleanup(void);
>  int multifd_load_setup(Error **errp);
> -- 
> 2.32.0
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK