Re: [PATCH 10/13] virtio_balloon: add higher-order page inflation

[David Hildenbrand (Arm)]

On 10/27/26 03:56, Kevin Loughlin wrote:
> In confidential computing guests requiring page state transitions,
> unaccepted memory tracking operates at the EFI unaccepted memory unit
> granularity (typically 2MB / order 9 on x86). Inflating the balloon
> with 4KB pages would prevent unaccepting the backing 2MB unit.
> 
> Inflate balloon pages at unaccepted_memory_order() when
> virtballoon_cc_needs_state_transition() is true, while retaining
> order-0 allocations for non-CoCo guests and CoCo guests that do not
> use unaccepted memory transitions. When a higher-order balloon page
> spans more 4KB balloon PFNs than VIRTIO_BALLOON_ARRAY_PFNS_MAX (256),
> transmit its PFNs to the host in VIRTIO_BALLOON_ARRAY_PFNS_MAX chunks.
> 
> Signed-off-by: Kevin Loughlin <kevinloughlin@xxxxxxxxxx>

Sorry, not happening. There is no migration support for these (large) things,
and there likely won't be any time soon.

NAK

-- 
Cheers,

David