[0/2] enable fsdax rdma migration

Message

Li Zhijian July 31, 2021, 2:03 p.m. UTC

Previous qemu face 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.

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

 migration/rdma.c       | 67 ++++++++++++++++++++++++++++++++++++------
 migration/trace-events |  2 ++
 2 files changed, 60 insertions(+), 9 deletions(-)

Comments

Zhijian Li (Fujitsu) Aug. 16, 2021, 2:10 a.m. UTC | #1

ping...

Hey Dave, could you help to take a look :)

Thanks
Zhijian


On 31/07/2021 22:03, Li Zhijian wrote:
> Previous qemu face 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.
>
> Li Zhijian (2):
>    migration/rdma: Try to register On-Demand Paging memory region
>    migration/rdma: advise prefetch write for ODP region
>
>   migration/rdma.c       | 67 ++++++++++++++++++++++++++++++++++++------
>   migration/trace-events |  2 ++
>   2 files changed, 60 insertions(+), 9 deletions(-)
>