Re: [Qemu-ppc] [PATCHv3 for-2.9 0/6] HPT resizing for pseries guests (qemu part)

[Andrea Bolognani]

On Thu, 2016-12-15 at 17:11 +1100, David Gibson wrote:
> This series implements the host side of the PAPR ACR to allow runtime
> resizing of the Hashed Page Table (HPT) for pseries guests.
[...]
> Availability of the feature is controlled by a new 'resize-hpt'
> machine option: it can be set to "disabled", "enabled" or "required".

IIUC resize-hpt will be enabled by default for pseries-2.9
and newer. Do we want to expose a knob for controlling this
to the user at the libvirt level, or should we just enable
resize-hpt unconditionally whenever we detect that the QEMU
binary supports it?

Does enabling this change the guest ABI at all? If so, we
can't do the latter because it would cause existing guests
to undergo an ABI change when QEMU is upgraded.

-- 
Andrea Bolognani / Red Hat / Virtualization