[dpdk-dev] [PATCH v4 00/10] VM Power Management

[Zhu, Heqing]

Pablo just sent a new patch set. This is a significant effort and it addressed a valid technical problem statement. 
I express my support to this feature into the DPDK mainline. 

IMHO, the previous *rejection* reason are not solid. It is important to encourage the real contribution like this. 


-----Original Message-----
From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of O'driscoll, Tim
Sent: Monday, November 10, 2014 10:54 AM
To: Carew, Alan; Thomas Monjalon
Cc: dev at dpdk.org
Subject: Re: [dpdk-dev] [PATCH v4 00/10] VM Power Management

> From: Carew, Alan
> 
> > Did you make any progress in Qemu/KVM community?
> > We need to be sync'ed up with them to be sure we share the same goal.
> > I want also to avoid using a solution which doesn't fit with their plan.
> > Remember that we already had this problem with ivshmem which was 
> > planned to be dropped.
> >
. . .
> 
> Unfortunately, I have not yet received any feedback:
> http://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg01103.html

Just to add to what Alan said above, this capability does not exist in qemu at the moment, and based on there having been no feedback on the qemu mailing list so far, I think it's reasonable to assume that it will not be implemented in the immediate future. The VM Power Management feature has also been designed to allow easy migration to a qemu-based solution when this is supported in future. Therefore, I'd be in favour of accepting this feature into DPDK now.

It's true that the implementation is a work-around, but there have been similar cases in DPDK in the past. One recent example that comes to mind is userspace vhost. The original implementation could also be considered a work-around, but it met the needs of many in the community. Now, with support for vhost-user in qemu 2.1, that implementation is being improved. I'd see VM Power Management following a similar path when this capability is supported in qemu.


Tim