How to change pinned CPUs for a VM in RHEV 3 ?

Issue

• How to change pinned CPUs for a VM in RHEV 3? For ex. need to move pinned CPUs from 16-20 to 12-15.

[RHEVM shell (connected)]# show vm VM-NAME

<snip>
cpu-cpu_tune-vcpu_pin-cpu_set: 20
cpu-cpu_tune-vcpu_pin-vcpu   : 0
cpu-cpu_tune-vcpu_pin-cpu_set: 21
cpu-cpu_tune-vcpu_pin-vcpu   : 1
cpu-cpu_tune-vcpu_pin-cpu_set: 22
cpu-cpu_tune-vcpu_pin-vcpu   : 2
cpu-cpu_tune-vcpu_pin-cpu_set: 23
cpu-cpu_tune-vcpu_pin-vcpu   : 3
<snip>

• When local storage is used for the VMs, they do not have the an option to change cpu pinning from RHEV-M GUI using
  Edit VM -> Show Advanced Options -> Resource Allocation => CPU Shares and CPU Pinning . So we need an alternate way to change CPU pinning.

• Updating CPU pinning using rhevm-shell fails when VM is already pinned to certain set of CPU's. Need an option to unpin and pin the VM again

[RHEVM shell (connected)]# update vm VM-NAME  --cpu-cpu_tune-vcpu_pin "vcpu_pin.cpu_set=12,vcpu_pin.vcpu=0" --cpu-cpu_tune-vcpu_pin "vcpu_pin.cpu_set=13,vcpu_pin.vcpu=1" --cpu-cpu_tune-vcpu_pin "vcpu_pin.cpu_set=14,vcpu_pin.vcpu=2" --cpu-cpu_tune-vcpu_pin "vcpu_pin.cpu_set=15,vcpu_pin.vcpu=3"

status: 400
reason: Bad Request
detail: Cannot configure CPU pinning twice to the same vCPU.