Re: [Qemu-devel] [PATCH 0/4] command line fd passing using fd sets

[Corey Bryant <coreyb@linux.vnet.ibm.com>]

On 10/05/2012 02:26 PM, Eric Blake wrote:
> On 10/05/2012 12:07 PM, Corey Bryant wrote:
>> This series adds command line file descriptor passing support
>> to the -drive option.  This is a follow-on to the existing
>> QMP fd passing support provided in the following patch series:
>> comments.gmane.org/gmane.comp.emulators.qemu/165463
>>
>> An example of using the new -drive fd and opaque options:
>> qemu-kvm -drive fd=24,opaque="rdwr:/path/file",index=0,media=disk
>
> This feels wrong.  Now you have to special-case encode the
> fd=nn,opaque=xyz handling to EVERY command line argument that takes a
> file name, not just -drive.
>
> I'd much rather see:
>
> qemu-kvm -fdset set=1,fds=24,25 \
>    -drive file=/def/fdset/1,index=0,media=disk
>
> Where the creation of fdsets happens independently from use of those
> sets, and therefore all other arguments that take file names can just
> magically take the /dev/fdset/nnn notation that we already support from
> the monitor.
>
> Besides, my approach will let me pass in an O_RDONLY fd on 24 and O_RDWR
> on 25 into the same set, whereas your approach creates a new set per fd,
> so I can't add new fds to the set until the monitor is up and running.
>

Thanks for the quick feedback.  I like your idea here.  Much more flexible.

-- 
Regards,
Corey Bryant