2014-12-09 18:35, Paolo Bonzini: > >>>> 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 th > >> 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. > > I wonder if this might be papering over a bug in the host cpufreq > driver. If the guest is not doing much and leaving a lot of idle CPU > time, the host should scale down the frequency of that CPU. In the case > of pinned VCPUs this should really "just work". What is the problem > that is being solved? > > Paolo
Alan, Pablo, please could you explain your logic with VM power management? -- Thomas
