Re: [Qemu-devel] [PATCH 2/3] QMP: Introduce Human Monitor passthrough command

[Anthony Liguori]

On 11/11/2010 10:39 AM, Daniel P. Berrange wrote:
> IIUC, the FDs sent/received via struct cmsghdr are in a strictly
> ordered array, so why not just define a placeholder syntax for
> the commands that maps to the array indexes. eg
>
>    netdev_add tap,fd=$0,vhost_fd=$1,id=hostnet0
>
> The '$' sign is not valid for a normal FD number, so use of a $0,
> $1, $2, etc can reliably be substituted with the real FD number from
> the cmsghdr array elements 0, 1, 2, etc
>    

Character devices are streaming so it's hard to refer to array indexes 
in a single message.  You could count it for the entire session but 
session boundaries aren't really well defined.

I don't think it's an obvious win.

Regards,

Anthony Liguori

> Regards,
> Daniel
>