Memory region should support 2 placement types: IB_ACCESS_FLUSH_PERSISTENT
and IB_ACCESS_FLUSH_GLOBAL_VISIBILITY, and only pmem/nvdimm has ability to
persist data(IB_ACCESS_FLUSH_PERSISTENT).
It prevents local user from registering a persistent access flag to
a non-pmem MR.
+------------------------+------------------+--------------+
| HCA attributes | register access flags |
| and +-----------------+---------------+
| MR attribute(is_pmem) |global visibility | persistence |
|------------------------+------------------+--------------+
| global visibility(DRAM)| O | X |
|------------------------+------------------+--------------+
| global visibility(PMEM)| O | X |
|------------------------+------------------+--------------+
| persistence(DRAM) | X | X |
|------------------------+------------------+--------------+
| persistence(PMEM) | X | O |
+------------------------+------------------+--------------+
PMEM: is_pmem is true
DRAM: is_pmem is false
O: allow to register such access flag
X: otherwise
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxxxxx>
---
V2: update commit message, get rid of confusing ib_check_flush_access_flags() # Tom
---
drivers/infiniband/sw/rxe/rxe_mr.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 0427baea8c06..89a3bb4e8b71 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -258,7 +258,15 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
set->offset = ib_umem_offset(umem);
// iova_in_pmem() must be called after set is updated
- mr->ibmr.is_pmem = iova_in_pmem(mr, iova, length);
+ if (iova_in_pmem(mr, iova, length))
+ mr->ibmr.is_pmem = true;
+ else if (access & IB_ACCESS_FLUSH_PERSISTENT) {
+ pr_warn("Cannot register IB_ACCESS_FLUSH_PERSISTENT for non-pmem memory\n");
+ mr->state = RXE_MR_STATE_INVALID;
+ mr->umem = NULL;
+ err = -EINVAL;
+ goto err_release_umem;
+ }
return 0;
--
2.31.1
