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

From: Junxian Huang
Date: Wed Aug 28 2024 - 02:52:08 EST


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