[v3,0/2] enable fsdax rdma migration

Message

Li Zhijian Sept. 10, 2021, 7:02 a.m. UTC

Previous qemu are facing 2 problems when migrating a fsdax memory backend with
RDMA protocol.
(1) ibv_reg_mr failed with Operation not supported
(2) requester(source) side could receive RNR NAK.

For the (1), we can try to register memory region with ODP feature which
has already been implemented in some modern HCA hardware/drivers.
For the (2), IB provides advise API to prefetch pages in specific memory
region. It can help driver reduce the page fault on responder(destination)
side during RDMA_WRITE.

V3: fix FreeBSD compling error


Li Zhijian (2):
  migration/rdma: Try to register On-Demand Paging memory region
  migration/rdma: advise prefetch write for ODP region

 meson.build            |   6 +++
 migration/rdma.c       | 115 ++++++++++++++++++++++++++++++++++-------
 migration/trace-events |   2 +
 3 files changed, 103 insertions(+), 20 deletions(-)