Re: [Qemu-devel] Live migration - exec: support to be reintroduced?

[Anthony Liguori <anthony@codemonkey.ws>]

Avi Kivity wrote:
> Daniel P. Berrange wrote:
>> We used it to implement save-to-file, exec'ing 'dd'. I'd rather prefer
>> that we had a more explicit 'migrate to a file' capability rather than
>> the hack of execing dd.
>>   
>
> (qemu) acceptfd blah
> receives an file descriptor from the monitor using SCM_RIGHTS and 
> assigns it to the tag 'blah'
> (qemu) migrate fd:blah
> migrates to the fd denominated by the tag 'blah'
> (qemu) closefd blah

This could be generally useful for other things too (like char device 
redirection).

I'm not sure how many people would really use it though, you're talking 
about serious unix-fu here.

Regards,

Anthony Liguori

> You can use literal numbers instead of tags to refer to file 
> descriptors inherited from the environment:
>
> (qemu) migrate fd:17
>