Messages in this thread | | | Date | Tue, 31 Oct 2023 16:52:23 +0800 | Subject | Re: [PATCH RFC 1/2] RDMA/rxe: don't allow registering !PAGE_SIZE mr | From | Zhu Yanjun <> |
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在 2023/10/30 20:40, Jason Gunthorpe 写道: > On Mon, Oct 30, 2023 at 07:51:41AM +0000, Zhijian Li (Fujitsu) wrote: >> >> >> On 27/10/2023 13:41, Li Zhijian wrote: >>> mr->page_list only encodes *page without page offset, when >>> page_size != PAGE_SIZE, we cannot restore the address with a wrong >>> page_offset. >>> >>> Note that this patch will break some ULPs that try to register 4K >>> MR when PAGE_SIZE is not 4K. >>> SRP and nvme over RXE is known to be impacted. >>> >>> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> >>> --- >>> drivers/infiniband/sw/rxe/rxe_mr.c | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c >>> index f54042e9aeb2..61a136ea1d91 100644 >>> --- a/drivers/infiniband/sw/rxe/rxe_mr.c >>> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c >>> @@ -234,6 +234,12 @@ int rxe_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sgl, >>> struct rxe_mr *mr = to_rmr(ibmr); >>> unsigned int page_size = mr_page_size(mr); >>> >>> + if (page_size != PAGE_SIZE) { >> >> It seems this condition is too strict, it should be: >> if (!IS_ALIGNED(page_size, PAGE_SIZE)) >> >> So that, page_size with (N * PAGE_SIZE) can work as previously. >> Because the offset(mr.iova & page_mask) will get lost only when !IS_ALIGNED(page_size, PAGE_SIZE) > > That makes sense
I read all the discussions very carefully.
Thanks, Greg.
Because RXE only supports PAGE_SIZE, when CONFIG_ARM64_64K_PAGES is enabled, the PAGE_SIZE is 64K, when CONFIG_ARM64_64K_PAGES is disabled, PAGE_SIZE is 4K.
But NVMe calls ib_map_mr_sg with a fixed size SZ_4K. When CONFIG_ARM64_64K_PAGES is enabled, it is still 4K. This is not a problem in RXE. This problem is in NVMe.
If this problem in NVMe is not fixed, NVMe still can not use RXE to make tests with blktests when CONFIG_ARM64_64K_PAGES is enabled.
This is not a problem in RXE, it should not be fixed in RXE.
Zhu Yanjun
> > Jason
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