[ Upstream commit be5802795c ]
Currently there are known potential issues for balloon and hot-add on
ARM64:
* Unballoon requests from Hyper-V should only unballoon ranges
that are guest page size aligned, otherwise guests cannot handle
because it's impossible to partially free a page. This is a
problem when guest page size > 4096 bytes.
* Memory hot-add requests from Hyper-V should provide the NUMA
node id of the added ranges or ARM64 should have a functional
memory_add_physaddr_to_nid(), otherwise the node id is missing
for add_memory().
These issues require discussions on design and implementation. In the
meanwhile, post_status() is working and essential to guest monitoring.
Therefore instead of disabling the entire hv_balloon driver, the
ballooning (when page size > 4096 bytes) and hot-add are disabled
accordingly for now. Once the issues are fixed, they can be re-enable in
these cases.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220325023212.1570049-3-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
eb35da973c