Re: [PATCHv2 00/11] KVM implementation of PAPR HPT resizing extension

From: Paul Mackerras
Date: Tue Jan 31 2017 - 17:18:35 EST


On Tue, Dec 20, 2016 at 04:48:56PM +1100, David Gibson wrote:
> Here is the KVM implementation for the proposed PAPR extension which
> allows the runtime resizing of a PAPR guest's Hashed Page Table (HPT).
>
> Using this requires a guest kernel with support for the extension.
> Patches for guest side support in Linux were posted earlier:
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-December/152164.html
>
> It also requires userspace (i.e. qemu) to intercept the HPT resizing
> hypercalls and invoke the KVM ioctl()s to implement them. This is
> done instead of having KVM direclty intercept the hypercalls, so that
> userspace can, if useful, impose additional restrictions on resizes:
> for example it could refuse them entirely if policy for the VM
> precludes resizing, or it could limit the size of HPT the guest can
> request to meet resource limits.
>
> Patches to implement the userspace part of HPT resizing are proposed
> for qemu-2.9, and can be found at:
> https://github.com/dgibson/qemu/tree/hpt-resize
>
> I'm posting these now, in the hopes that both these and the
> corresponding guest side patches can be staged and merged for the 4.11
> window.

Thanks, series applied to my kvm-ppc-next branch.

Next time, please cc kvm-ppc@xxxxxxxxxxxxxxx so I shows up in
patchwork and I don't miss it.

Paul.