Re: [libvirt] [Qemu-devel] [PATCH v4 0/7] file descriptor passing using pass-fd
On 06/26/2012 04:50 PM, Luiz Capitulino wrote:
On Tue, 26 Jun 2012 13:45:52 +0200
Kevin Wolf <kwolf(a)redhat.com> wrote:
> Am 26.06.2012 11:10, schrieb Daniel P. Berrange:
>> I was thinking about some of the sources complexity when using
>> FD passing from libvirt and wanted to raise one idea for discussion
>> before we continue.
>>
>> With this proposed series, we have usage akin to:
>>
>> 1. pass_fd FDSET={M} -> returns a string "/dev/fd/N" showing
QEMU's
>> view of the FD
>> 2. drive_add file=/dev/fd/N
>> 3. if failure:
>> close_fd "/dev/fd/N"
>
> In fact, there are more steps:
>
> 4. use it successfully
> 5. close_fd "/dev/fd/N"
>
> I think it would well be possible that qemu just closes the fd when it's
> not used internally any more.
pass-fd could have a flag indicating qemu to do that.
It seems like libvirt would be in a better position to understand when a
file is no longer in use, and then it can call close_fd. No? Of course
the the only fd that needs to be closed is the originally passed fd.
The dup'd fd's are closed by QEMU.
--
Regards,
Corey