Re: [PATCH v3 COLOPre 15/26] tools/libxl: Add back channel to allow migration target send data back

[Yang Hongyang <yanghy@cn.fujitsu.com>]

On 06/30/2015 06:07 PM, Ian Campbell wrote:
> On Thu, 2015-06-25 at 14:25 +0800, Yang Hongyang wrote:
>> + * LIBXL_HAVE_DOMAIN_CREATE_RESTORE_SEND_FD 1
>> + *
>> + * If this is defined, libxl_domain_create_restore()'s API has changed to
>> + * include a send_fd param which used for libxl migration back channel.
>
>                                     ^is
>
> Perhaps also end the sentence with "during $foo operations"? Since it is
> not used for standard restore.

IIRC, at hackthon, someone from alibaba also mentioned that they need a back
channel on normal migration...For the standard restore, just pass -1 as
send_fd.

>
>>   int libxl_domain_create_restore(libxl_ctx *ctx, libxl_domain_config *d_config,
>> -                                uint32_t *domid, int restore_fd,
>> +                                uint32_t *domid, int restore_fd, int send_fd,
>
> This is probably not a good idea, but what about "int fd[2]", i.e.
> mimicking pipe(2). I suspect this will just make things harder on

I suspect so...

> callers, especially those who wish to work with both versions. Thoughts?
>
> Ian.
>
> .
>

-- 
Thanks,
Yang.