Re: [PATCH v2 14/25] migration/rdma: Use common connection paths

[Peter Xu <peterx@redhat.com>]

On Mon, Jan 05, 2026 at 04:06:31PM -0300, Fabiano Rosas wrote:
> Use the common connection paths for the incoming and outgoing sides of
> rdma migration. This removes one usage of QEMUFile from rdma.c. It
> also allows further unification of the connection code in next
> patches.
> 
> Move the channels enum to channel.h so rdma.c can access it. The RDMA
> channel is considered a CH_MAIN channel.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Peter Xu <peterx@redhat.com>

One nitpick inline.

> ---
>  migration/channel.h   |  7 +++++++
>  migration/migration.c | 13 -------------
>  migration/migration.h |  1 -
>  migration/rdma.c      | 23 +++++++++++------------
>  4 files changed, 18 insertions(+), 26 deletions(-)
> 
> diff --git a/migration/channel.h b/migration/channel.h
> index ccfeaaef18..93dedbf52b 100644
> --- a/migration/channel.h
> +++ b/migration/channel.h
> @@ -18,6 +18,13 @@
>  
>  #include "io/channel.h"
>  
> +/* Migration channel types */
> +enum {
> +    CH_MAIN,
> +    CH_MULTIFD,
> +    CH_POSTCOPY
> +};
> +
>  void migration_channel_process_incoming(QIOChannel *ioc);
>  
>  void migration_channel_connect(MigrationState *s, QIOChannel *ioc);
> diff --git a/migration/migration.c b/migration/migration.c
> index dc8fe80cf8..906f0bdab3 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -91,9 +91,6 @@ enum mig_rp_message_type {
>      MIG_RP_MSG_MAX
>  };
>  
> -/* Migration channel types */
> -enum { CH_MAIN, CH_MULTIFD, CH_POSTCOPY };
> -
>  /* When we add fault tolerance, we could have several
>     migrations at once.  For now we don't need to add
>     dynamic creation of migration */
> @@ -1021,16 +1018,6 @@ void migration_incoming_process(void)
>      qemu_coroutine_enter(co);
>  }
>  
> -void migration_fd_process_incoming(QEMUFile *f)
> -{
> -    MigrationIncomingState *mis = migration_incoming_get_current();
> -
> -    assert(!mis->from_src_file);
> -    mis->from_src_file = f;
> -    qemu_file_set_blocking(f, false, &error_abort);
> -    migration_incoming_process();

This is removed very soon here..  That's OK.

> -}
> -
>  static bool migration_has_main_and_multifd_channels(void)
>  {
>      MigrationIncomingState *mis = migration_incoming_get_current();
> diff --git a/migration/migration.h b/migration/migration.h
> index 4dcf299719..cd6cfd62ba 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -527,7 +527,6 @@ struct MigrationState {
>  void migrate_set_state(MigrationStatus *state, MigrationStatus old_state,
>                         MigrationStatus new_state);
>  
> -void migration_fd_process_incoming(QEMUFile *f);
>  void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp);
>  void migration_incoming_process(void);
>  bool migration_incoming_setup(QIOChannel *ioc, uint8_t channel, Error **errp);
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 596a1aba0b..788ae183c1 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -15,6 +15,7 @@
>   */
>  
>  #include "qemu/osdep.h"
> +#include "channel.h"
>  #include "qapi/error.h"
>  #include "qemu/cutils.h"
>  #include "exec/target_page.h"
> @@ -384,7 +385,6 @@ struct QIOChannelRDMA {
>      QIOChannel parent;
>      RDMAContext *rdmain;
>      RDMAContext *rdmaout;
> -    QEMUFile *file;
>      bool blocking; /* XXX we don't actually honour this yet */
>  };
>  
> @@ -3836,32 +3836,30 @@ static void qio_channel_rdma_register_types(void)
>  
>  type_init(qio_channel_rdma_register_types);
>  
> -static QEMUFile *rdma_new_input(RDMAContext *rdma)
> +static QIOChannel *rdma_new_input(RDMAContext *rdma)
>  {
>      QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(object_new(TYPE_QIO_CHANNEL_RDMA));
>  
> -    rioc->file = qemu_file_new_input(QIO_CHANNEL(rioc));
>      rioc->rdmain = rdma;
>      rioc->rdmaout = rdma->return_path;
>  
> -    return rioc->file;
> +    return QIO_CHANNEL(rioc);
>  }
>  
> -static QEMUFile *rdma_new_output(RDMAContext *rdma)
> +static QIOChannel *rdma_new_output(RDMAContext *rdma)
>  {
>      QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(object_new(TYPE_QIO_CHANNEL_RDMA));
>  
> -    rioc->file = qemu_file_new_output(QIO_CHANNEL(rioc));
>      rioc->rdmaout = rdma;
>      rioc->rdmain = rdma->return_path;
>  
> -    return rioc->file;
> +    return QIO_CHANNEL(rioc);
>  }
>  
>  static void rdma_accept_incoming_migration(void *opaque)
>  {
>      RDMAContext *rdma = opaque;
> -    QEMUFile *f;
> +    QIOChannel *ioc;
>  
>      trace_qemu_rdma_accept_incoming_migration();
>      if (qemu_rdma_accept(rdma) < 0) {
> @@ -3875,15 +3873,16 @@ static void rdma_accept_incoming_migration(void *opaque)
>          return;
>      }
>  
> -    f = rdma_new_input(rdma);
> -    if (f == NULL) {
> +    ioc = rdma_new_input(rdma);
> +    if (ioc == NULL) {
>          error_report("RDMA ERROR: could not open RDMA for input");
>          qemu_rdma_cleanup(rdma);
>          return;
>      }
>  
>      rdma->migration_started_on_destination = 1;
> -    migration_fd_process_incoming(f);
> +    migration_incoming_setup(ioc, CH_MAIN, NULL);

Maybe error_abort?

> +    migration_incoming_process();
>  }
>  
>  void rdma_start_incoming_migration(InetSocketAddress *host_port,
> @@ -3995,8 +3994,8 @@ void rdma_start_outgoing_migration(void *opaque,
>  
>      trace_rdma_start_outgoing_migration_after_rdma_connect();
>  
> -    s->to_dst_file = rdma_new_output(rdma);
>      s->rdma_migration = true;
> +    migration_outgoing_setup(rdma_new_output(rdma));
>      migration_connect(s);
>      return;
>  return_path_err:
> -- 
> 2.51.0
> 

-- 
Peter Xu