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

[Zheng Chuan <zhengchuan@huawei.com>]

On 2021/2/4 3:52, Dr. David Alan Gilbert wrote:
> * 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?
> 
Yes，Sorry for that. I'll add cleanup in next v5.

>> +    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
>>

-- 
Regards.
Chuan