Re: [Qemu-devel] [RFC PATCH RDMA support v4: 07/10] connection-establishment for RDMA

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

Acknowledged.

On 03/18/2013 04:56 AM, Paolo Bonzini wrote:
> In a "socket-like" abstraction, all of these steps except the initial 
> listen are part of "accept". Please move them to 
> qemu_rdma_migrate_accept (possibly renaming the existing 
> qemu_rdma_migrate_accept to a different name). Similarly, perhaps you 
> can merge qemu_rdma_server_prepare and qemu_rdma_migrate_listen. Try 
> to make the public API between modules as small as possible (but not 
> smaller :)), so that you can easily document it without too many 
> references to RDMA concepts. Thanks, Paolo
>> +    rdma->total_bytes = 0;
>> +    rdma->enabled = 1;
>> +    qemu_rdma_dump_gid("server_connect", rdma->rdma_ctx.cm_id);
>> +    return 0;
>> +
>> +err_rdma_server_wait:
>> +    qemu_rdma_cleanup(rdma);
>> +    return -1;
>> +
>> +}
>> +
>> +int rdma_start_incoming_migration(const char * host_port, Error **errp)
>> +{
>> +    RDMAData *rdma = g_malloc0(sizeof(RDMAData));
>> +    QEMUFile *f;
>> +    int ret;
>> +
>> +    if ((ret = qemu_rdma_data_init(rdma, host_port, errp)) < 0)
>> +        return ret;
>> +
>> +    ret = qemu_rdma_server_init(rdma, NULL);
>> +
>> +    DPRINTF("Starting RDMA-based incoming migration\n");
>> +
>> +    if (!ret) {
>> +        DPRINTF("qemu_rdma_server_init success\n");
>> +        ret = qemu_rdma_server_prepare(rdma, NULL);
>> +
>> +        if (!ret) {
>> +            DPRINTF("qemu_rdma_server_prepare success\n");
>> +
>> +            ret = rdma_accept_incoming_migration(rdma, NULL);
>> +            if(!ret)
>> +                DPRINTF("qemu_rdma_accept_incoming_migration success\n");
>> +            f = qemu_fopen_rdma(rdma, "rb");
>> +            if (f == NULL) {
>> +                fprintf(stderr, "could not qemu_fopen RDMA\n");
>> +                ret = -EIO;
>> +            }
>> +
>> +            process_incoming_migration(f);
>> +        }
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>> +void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp)
>> +{
>> +    RDMAData *rdma = g_malloc0(sizeof(RDMAData));
>> +    MigrationState *s = opaque;
>> +    int ret;
>> +
>> +    if (qemu_rdma_data_init(rdma, host_port, errp) < 0)
>> +        return;
>> +
>> +    ret = qemu_rdma_client_init(rdma, NULL);
>> +    if(!ret) {
>> +        DPRINTF("qemu_rdma_client_init success\n");
>> +        ret = qemu_rdma_client_connect(rdma, NULL);
>> +
>> +        if(!ret) {
>> +            s->file = qemu_fopen_rdma(rdma, "wb");
>> +            DPRINTF("qemu_rdma_client_connect success\n");
>> +            migrate_fd_connect(s);
>> +            return;
>> +        }
>> +    }
>> +
>> +    migrate_fd_error(s);
>> +}
>> +
>> +size_t save_rdma_page(QEMUFile *f, ram_addr_t block_offset, ram_addr_t offset, int cont, size_t size)
>> +{
>> +    int ret;
>> +    size_t bytes_sent = 0;
>> +    ram_addr_t current_addr;
>> +    RDMAData * rdma = migrate_use_rdma(f);
>> +
>> +    current_addr = block_offset + offset;
>> +
>> +    /*
>> +     * Add this page to the current 'chunk'. If the chunk
>> +     * is full, an actual RDMA write will occur.
>> +     */
>> +    if ((ret = qemu_rdma_write(rdma, current_addr, size)) < 0) {
>> +        fprintf(stderr, "rdma migration: write error! %d\n", ret);
>> +        return ret;
>> +    }
>> +
>> +    /*
>> +     * Drain the Completion Queue if possible.
>> +     * If not, the end of the iteration will do this
>> +     * again to make sure we don't overflow the
>> +     * request queue.
>> +     */
>> +    while (1) {
>> +        int ret = qemu_rdma_poll(rdma);
>> +        if (ret == RDMA_WRID_NONE) {
>> +            break;
>> +        }
>> +        if (ret < 0) {
>> +            fprintf(stderr, "rdma migration: polling error! %d\n", ret);
>> +            return ret;
>> +        }
>> +    }
>> +
>> +    bytes_sent += size;
>> +    return bytes_sent;
>> +}
>> +
>> +size_t qemu_rdma_fill(void * opaque, uint8_t *buf, int size)
>> +{
>> +    RDMAData * rdma = opaque;
>> +    size_t len = 0;
>> +
>> +    if(rdma->qemu_file_len) {
>> +        DPRINTF("RDMA %" PRId64 " of %d bytes already in buffer\n",
>> +	    rdma->qemu_file_len, size);
>> +
>> +        len = MIN(size, rdma->qemu_file_len);
>> +        memcpy(buf, rdma->qemu_file_curr, len);
>> +        rdma->qemu_file_curr += len;
>> +        rdma->qemu_file_len -= len;
>> +    }
>> +
>> +    return len;
>> +}
>>
>