Hey folks, These patches are going to implement a *NEW* RDMA opcode "RDMA FLUSH". In IB SPEC 1.5[1][2], 2 new opcodes, ATOMIC WRITE and RDMA FLUSH were added in the MEMORY PLACEMENT EXTENSIONS section. FLUSH is used by the requesting node to achieve guarantees on the data placement within the memory subsystem of preceding accesses to a single memory region, such as those performed by RDMA WRITE, Atomics and ATOMIC WRITE requests. The operation indicates the virtual address space of a destination node and where the guarantees should apply. This range must be contiguous in the virtual space of the memory key but it is not necessarily a contiguous range of physical memory. FLUSH packets carry FLUSH extended transport header (see below) to specify the placement type and the selectivity level of the operation and RDMA extended header (RETH, see base document RETH definition) to specify the R_Key VA and Length associated with this request following the BTH in RC, RDETH in RD and XRCETH in XRC. RC FLUSH: +----+------+------+ |BTH | FETH | RETH | +----+------+------+ RD FLUSH: +----+------+------+------+ |BTH | RDETH| FETH | RETH | +----+------+------+------+ XRC FLUSH: +----+-------+------+------+ |BTH | XRCETH| FETH | RETH | +----+-------+------+------+ Currently, we introduce RC and RD services only, since XRC has not been implemented by rxe yet. NOTE: only RC service is tested now, and since other HCAs have not added/implemented FLUSH yet, we can only test FLUSH operation in both SoftRoCE/rxe devices. The corresponding rdma-core and FLUSH example are available on: https://github.com/zhijianli88/rdma-core/tree/rfc Below list some details about FLUSH transport packet: A FLUSH message is built upon FLUSH request packet and is responded successfully by RDMA READ response of zero size. oA19-2: FLUSH shall be single packet message and shall have no payload. oA19-2: FLUSH shall be single packet message and shall have no payload. oA19-5: FLUSH BTH shall hold the Opcode = 0x1C FLUSH Extended Transport Header(FETH) +-----+-----------+------------------------+----------------------+ |Bits | 31-6 | 5-4 | 3-0 | +-----+-----------+------------------------+----------------------+ | | Reserved | Selectivity Level(SEL) | Placement Type(PLT) | +-----+-----------+------------------------+----------------------+ Selectivity Level (SEL) – defines the memory region scope the FLUSH should apply on. Values are as follows: • b’00 - Memory Region Range: FLUSH applies for all preceding memory updates to the RETH range on this QP. All RETH fields shall be valid in this selectivity mode. RETH:DMALen field shall be between zero and (2 31 -1) bytes (inclusive). • b’01 - Memory Region: FLUSH applies for all preceding memory up- dates to RETH.R_key on this QP. RETH:DMALen and RETH:VA shall be ignored in this mode. • b'10 - Reserved. • b'11 - Reserved. Placement Type (PLT) – Defines the memory placement guarantee of this FLUSH. Multiple bits may be set in this field. Values are as follows: • Bit 0 if set to '1' indicated that the FLUSH should guarantee Global Visibility. • Bit 1 if set to '1' indicated that the FLUSH should guarantee Persistence. • Bits 3:2 are reserved [1]: https://www.infinibandta.org/ibta-specification/ # login required [2]: https://www.infinibandta.org/wp-content/uploads/2021/08/IBTA-Overview-of-IBTA-Volume-1-Release-1.5-and-MPE-2021-08-17-Secure.pptx CC: Jason Gunthorpe <jgg@xxxxxxxx> CC: Zhu Yanjun <zyjzyj2000@xxxxxxxxx CC: Leon Romanovsky <leon@xxxxxxxxxx> CC: Bob Pearson <rpearsonhpe@xxxxxxxxx> CC: Weihang Li <liweihang@xxxxxxxxxx> CC: Mark Bloch <mbloch@xxxxxxxxxx> CC: Wenpeng Liang <liangwenpeng@xxxxxxxxxx> CC: Aharon Landau <aharonl@xxxxxxxxxx> CC: linux-rdma@xxxxxxxxxxxxxxx CC: linux-kernel@xxxxxxxxxxxxxxx Li Zhijian (10): RDMA: mr: Introduce is_pmem RDMA: Allow registering MR with flush access flags RDMA/rxe: Allow registering FLUSH flags for supported device only RDMA/rxe: Enable IB_DEVICE_RDMA_FLUSH for rxe device RDMA/rxe: Allow registering persistent flag for pmem MR only RDMA/rxe: Implement RC RDMA FLUSH service in requester side RDMA/rxe: Set BTH's SE to zero for FLUSH packet RDMA/rxe: Implement flush execution in responder side RDMA/rxe: Implement flush completion RDMA/rxe: Add RD FLUSH service support drivers/infiniband/core/uverbs_cmd.c | 16 +++ drivers/infiniband/sw/rxe/rxe_comp.c | 4 +- drivers/infiniband/sw/rxe/rxe_hdr.h | 52 ++++++++++ drivers/infiniband/sw/rxe/rxe_loc.h | 2 + drivers/infiniband/sw/rxe/rxe_mr.c | 63 +++++++++++- drivers/infiniband/sw/rxe/rxe_opcode.c | 33 ++++++ drivers/infiniband/sw/rxe/rxe_opcode.h | 3 + drivers/infiniband/sw/rxe/rxe_param.h | 3 +- drivers/infiniband/sw/rxe/rxe_req.c | 14 ++- drivers/infiniband/sw/rxe/rxe_resp.c | 131 +++++++++++++++++++++++- include/rdma/ib_pack.h | 3 + include/rdma/ib_verbs.h | 22 +++- include/uapi/rdma/ib_user_ioctl_verbs.h | 2 + include/uapi/rdma/ib_user_verbs.h | 18 ++++ include/uapi/rdma/rdma_user_rxe.h | 6 ++ 15 files changed, 362 insertions(+), 10 deletions(-) -- 2.31.1
