On Thu, Feb 07, 2019 at 03:56:50PM +1100, Suraj Jitindar Singh wrote: > Devices on the KVM_FAST_MMIO_BUS by definition have length zero and are > thus used for notification purposes rather than data transfer. For > example eventfd for virtio devices. > > This means that when emulating mmio instructions which target devices on > this bus we can immediately handle them and return without needing to load > the instruction from guest memory. > > For now we restrict this to stores as this is the only use case at > present. > > For a normal guest the effect is negligible, however for a nested guest > we save on the order of 5us per access. > > Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx> Thanks, applied to my kvm-ppc-next tree. Paul.
