Re: [PATCH v4 12/18] migration/rdma: Create the multifd send channels for RDMA

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

* Chuan Zheng (zhengchuan@huawei.com) wrote:
> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
> ---
>  migration/multifd.c |  4 ++--
>  migration/multifd.h |  2 ++
>  migration/rdma.c    | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 61 insertions(+), 2 deletions(-)
> 
> diff --git a/migration/multifd.c b/migration/multifd.c
> index ae0b7f0..919a414 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -176,7 +176,7 @@ void multifd_register_ops(int method, MultiFDMethods *ops)
>      multifd_ops[method] = ops;
>  }
>  
> -static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
> +int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
>  {
>      MultiFDInit_t msg = {};
>      int ret;
> @@ -503,7 +503,7 @@ int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
>      return 1;
>  }
>  
> -static void multifd_send_terminate_threads(Error *err)
> +void multifd_send_terminate_threads(Error *err)
>  {
>      int i;
>  
> diff --git a/migration/multifd.h b/migration/multifd.h
> index b17a2c1..26d4489 100644
> --- a/migration/multifd.h
> +++ b/migration/multifd.h
> @@ -184,6 +184,8 @@ typedef struct {
>  #ifdef CONFIG_RDMA
>  extern MultiFDSetup multifd_rdma_ops;
>  #endif
> +void multifd_send_terminate_threads(Error *err);
> +int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp);
>  int get_multifd_send_param(int id, MultiFDSendParams **param);
>  int get_multifd_recv_param(int id, MultiFDRecvParams **param);
>  MultiFDSetup *multifd_setup_ops_init(void);
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 9654b87..cff9446 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -4261,9 +4261,54 @@ err:
>      g_free(rdma_return_path);
>  }
>  
> +static int multifd_channel_rdma_connect(void *opaque)
> +{
> +    MultiFDSendParams *p = opaque;
> +    Error *local_err = NULL;
> +    int ret = 0;
> +    MigrationState *s = migrate_get_current();
> +
> +    p->rdma = qemu_rdma_data_init(s->host_port, &local_err);
> +    if (p->rdma == NULL) {
> +        goto out;
> +    }
> +
> +    ret = qemu_rdma_source_init(p->rdma,
> +                                migrate_rdma_pin_all(),
> +                                &local_err);
> +    if (ret) {
> +        goto out;
> +    }
> +
> +    ret = qemu_rdma_connect(p->rdma, &local_err);
> +    if (ret) {
> +        goto out;
> +    }
> +
> +    p->file = qemu_fopen_rdma(p->rdma, "wb");
> +    if (p->file == NULL) {
> +        goto out;
> +    }
> +
> +    p->c = QIO_CHANNEL(getQIOChannel(p->file));
> +
> +out:
> +    if (local_err) {
> +        trace_multifd_send_error(p->id);
> +    }

If any of the previous steps have failed, but not the first step,
what cleans up?

> +    return ret;
> +}
> +
>  static void *multifd_rdma_send_thread(void *opaque)
>  {
>      MultiFDSendParams *p = opaque;
> +    Error *local_err = NULL;
> +
> +    trace_multifd_send_thread_start(p->id);
> +    if (multifd_send_initial_packet(p, &local_err) < 0) {
> +        goto out;
> +    }
>  
>      while (true) {
>          WITH_QEMU_LOCK_GUARD(&p->mutex) {
> @@ -4274,6 +4319,12 @@ static void *multifd_rdma_send_thread(void *opaque)
>          qemu_sem_wait(&p->sem);
>      }
>  
> +out:
> +    if (local_err) {
> +        trace_multifd_send_error(p->id);
> +        multifd_send_terminate_threads(local_err);
> +    }
> +
>      WITH_QEMU_LOCK_GUARD(&p->mutex) {
>          p->running = false;
>      }
> @@ -4285,6 +4336,12 @@ static void multifd_rdma_send_channel_setup(MultiFDSendParams *p)
>  {
>      Error *local_err = NULL;
>  
> +    if (multifd_channel_rdma_connect(p)) {
> +        error_setg(&local_err, "multifd: rdma channel %d not established",
> +                   p->id);
> +        return ;
> +    }
> +
>      if (p->quit) {
>          error_setg(&local_err, "multifd: send id %d already quit", p->id);
>          return ;
> -- 
> 1.8.3.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK