Since Hyper-V always uses 4k pages, hv_balloon has some difficulties
working on ARM64 with larger pages[1]. Besides the memory hot add
messages of Hyper-V doesn't have the information of NUMA node id of the
added memory range, and ARM64 currently doesn't provide the conversion
from a physical address to a node id, as a result the hv_balloon driver
couldn't handle hot add properly when there are more than one NUMA node.

Among these issues, post_status() is easy to fix, while the unballoon
issue and the hot-add issue requires more discussion. To make the
hv_balloon driver work at the best effort, this patchset fixes the
post_status() and temporarily disable the balloon and hot-add
accordingly.

Looking forwards to comments and suggestions.

Regards,
Boqun

[1]: https://lore.kernel.org/lkml/20220105165028.1343706-1-vkuznets@redhat.com/

Boqun Feng (2):
  Drivers: hv: balloon: Support status report for larger page sizes
  Drivers: hv: balloon: Disable balloon and hot-add accordingly

 drivers/hv/hv_balloon.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

-- 
2.35.1