[v3,for-next,0/2] RDMA: Provide an API for drivers to disassociate mmap pages

Message

Junxian Huang Aug. 28, 2024, 6:46 a.m. UTC

Provide an API rdma_user_mmap_disassociate() for drivers to disassociate
mmap pages. Use this API in hns to prevent userspace from ringing doorbell
when HW is reset.

v2 -> v3:
* Walk all ufiles of a device in rdma_user_mmap_disassociate() as Jason
  commented, so drivers don't need to maintain their own list of ucontexts.
* Add a disassociation_lock in uverbs_user_mmap_disassociate() as Jason
  commented to avoid racing between different threads.
* Add a disassociated flag indicating whether mmaps have been disabled
  to prevent new mmap after the disassociation.

v1 -> v2:
* Keep uverbs_user_mmap_disassociate() in uverbs_main.c. The new api
  rdma_user_mmap_disassociate() is also moved to this file.
* Add "#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)" to hns's
  rdma_user_mmap_disassociate() call.

Chengchang Tang (2):
  RDMA/core: Provide rdma_user_mmap_disassociate() to disassociate mmap
    pages
  RDMA/hns: Disassociate mmap pages for all uctx when HW is being reset

 drivers/infiniband/core/uverbs.h           |  3 ++
 drivers/infiniband/core/uverbs_main.c      | 45 +++++++++++++++++++++-
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c |  9 +++++
 include/rdma/ib_verbs.h                    |  8 ++++
 4 files changed, 63 insertions(+), 2 deletions(-)

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2.33.0