Re: [Qemu-devel] [dpdk-dev] [PATCH v4 00/10] VM Power Management

[Paolo Bonzini <pbonzini@redhat.com>]

On 12/12/2014 14:00, Carew, Alan wrote:
> The problem is deterministic control of host CPU frequency and the DPDK usage
> model.
> A hands-off power governor will scale based on workload, whether this is a host
> application or VM, so no problems or bug there.
> 
> Where this solution fits is where an application wants to control its own
> power policy, for example l3fwd_power uses librte_power library to change
> frequency via apci_cpufreq based on application heuristics rather than
> relying on an inbuilt policy for example ondemand or performance.
> 
> This ability has existed in DPDK for host usage for some time and VM power
> management allows this use case to be extended to cater for virtual machines
> by re-using the librte_power interface to encapsulate the VM->Host
> comms and provide an example means of managing such communications.
> 
>  I hope this clears it up a bit.

Ok, this looks specific enough that an out-of-band solution within DPDK
sounds like the best approach.  It seems unnecessary to involve the
hypervisor (neither KVM nor QEMU).

Paolo