libibverbs: Add ibv_reg_buf_mr() for provider-aware buffers Add ibv_reg_buf_mr() to register memory returned by ibv_alloc_buf(). Implement it as a thin wrapper: set IBV_REG_MR_MASK_BUF and forward the buffer handle to ibv_reg_mr_ex(), which resolves it to the appropriate addr-based or DMA-buf-based registration and validates the range against the stored buffer metadata. Keep it equivalent to calling ibv_reg_mr_ex() with IBV_REG_MR_MASK_BUF. Signed-off-by: Jiri Pirko <jiri@nvidia.com>
diff --git a/debian/libibverbs1.symbols b/debian/libibverbs1.symbols index 509383b..5378bd8 100644 --- a/debian/libibverbs1.symbols +++ b/debian/libibverbs1.symbols
@@ -114,6 +114,7 @@ ibv_rate_to_mbps@IBVERBS_1.1 1.1.8 ibv_rate_to_mult@IBVERBS_1.0 1.1.6 ibv_read_sysfs_file@IBVERBS_1.0 1.1.6 + ibv_reg_buf_mr@IBVERBS_1.17 64 ibv_reg_dmabuf_mr@IBVERBS_1.12 34 ibv_reg_mr@IBVERBS_1.0 1.1.6 ibv_reg_mr@IBVERBS_1.1 1.1.6
diff --git a/libibverbs/libibverbs.map.in b/libibverbs/libibverbs.map.in index d821124..300240b 100644 --- a/libibverbs/libibverbs.map.in +++ b/libibverbs/libibverbs.map.in
@@ -181,6 +181,7 @@ global: ibv_alloc_buf; ibv_free_buf; + ibv_reg_buf_mr; } IBVERBS_1.16; /* If any symbols in this stanza change ABI then the entire staza gets a new symbol
diff --git a/libibverbs/man/CMakeLists.txt b/libibverbs/man/CMakeLists.txt index 1711807..f0e2e7e 100644 --- a/libibverbs/man/CMakeLists.txt +++ b/libibverbs/man/CMakeLists.txt
@@ -88,6 +88,7 @@ ) rdma_alias_man_pages( ibv_alloc_buf.3 ibv_free_buf.3 + ibv_alloc_buf.3 ibv_reg_buf_mr.3 ibv_alloc_dm.3 ibv_free_dm.3 ibv_alloc_dm.3 ibv_reg_dm_mr.3 ibv_alloc_dm.3 ibv_memcpy_to_dm.3
diff --git a/libibverbs/man/ibv_alloc_buf.3.md b/libibverbs/man/ibv_alloc_buf.3.md index 310e9af..021c53f 100644 --- a/libibverbs/man/ibv_alloc_buf.3.md +++ b/libibverbs/man/ibv_alloc_buf.3.md
@@ -10,7 +10,7 @@ # NAME -ibv_alloc_buf, ibv_free_buf - allocate and free provider-aware buffers +ibv_alloc_buf, ibv_free_buf, ibv_reg_buf_mr - allocate provider-aware buffers and register them as memory regions # SYNOPSIS @@ -20,6 +20,9 @@ void *ibv_alloc_buf(struct ibv_pd *pd, size_t size, struct ibv_buf **buf); void ibv_free_buf(struct ibv_buf *buf); + +struct ibv_mr *ibv_reg_buf_mr(struct ibv_pd *pd, struct ibv_buf *buf, void *addr, + size_t length, int access); ``` # DESCRIPTION @@ -27,22 +30,61 @@ **ibv_alloc_buf()** allocates a buffer using the allocation method selected by the provider for the protection domain *pd*. On success it returns the mapped address and stores an opaque buffer handle in *buf*. The handle is used by -**ibv_free_buf()** and must not be interpreted by applications. +**ibv_free_buf()**, **ibv_reg_buf_mr()**, and **ibv_reg_mr_ex()** with +**IBV_REG_MR_MASK_BUF**, and must not be interpreted by applications. + +**ibv_free_buf()** releases a buffer handle returned by **ibv_alloc_buf()**. The +protection domain used for allocation must remain valid until the buffer is +freed. + +**ibv_reg_buf_mr()** registers a memory region for a buffer returned by +**ibv_alloc_buf()**. Applications can register the same buffer through +**ibv_reg_mr_ex()** by setting both **IBV_REG_MR_MASK_BUF** and +**IBV_REG_MR_MASK_ADDR**, passing the buffer handle in `mr_init_attr->buf` and +the address to register in `mr_init_attr->addr`. When **IBV_REG_MR_MASK_BUF** +is set the caller must not set **IBV_REG_MR_MASK_FD** or +**IBV_REG_MR_MASK_FD_OFFSET**, and, for a DMA-buf backed buffer, must not set +**IBV_REG_MR_MASK_IOVA**; libibverbs derives these from the buffer handle and +otherwise fails with **EINVAL**. The *pd* argument must be +the same protection domain that was used to allocate the buffer. +If a different protection domain is supplied, registration fails +with **EINVAL**. For ordinary memory it behaves like **ibv_reg_mr()**. +For provider allocations backed by a DMA-buf, it registers +the corresponding DMA-buf range using the metadata stored in +the opaque *buf* handle. # ARGUMENTS *pd* -: The protection domain (or parent domain) to allocate from; its provider selects the buffer's backing allocation method. It must remain valid until the buffer is freed with **ibv_free_buf()**. +: For **ibv_alloc_buf()**, the protection domain (or parent domain) to allocate from; its provider selects the buffer's backing allocation method. It must remain valid until the buffer is freed with **ibv_free_buf()**. For **ibv_reg_buf_mr()**, the same protection domain that allocated *buf* (otherwise registration fails with **EINVAL**). *size* -: Size of the buffer to allocate, in bytes. +: Size of the buffer to allocate, in bytes (**ibv_alloc_buf()**). *buf* -: For **ibv_alloc_buf()**, an output parameter set on success to an opaque buffer handle. For **ibv_free_buf()**, the buffer handle returned by **ibv_alloc_buf()** that is to be released. +: For **ibv_alloc_buf()**, an output parameter set on success to an opaque buffer handle. For **ibv_free_buf()** and **ibv_reg_buf_mr()**, the buffer handle returned by **ibv_alloc_buf()** to be released or registered, respectively. + +*addr* +: The start address to register (**ibv_reg_buf_mr()**): the buffer base returned by **ibv_alloc_buf()** or an address within that buffer. + +*length* +: Length in bytes to register (**ibv_reg_buf_mr()**); *addr* + *length* must stay within the buffer. + +*access* +: Access flags for the memory region (**ibv_reg_buf_mr()**), the same as for **ibv_reg_mr()**. # RETURN VALUE **ibv_alloc_buf()** returns the mapped buffer address on success, or NULL if the request fails. +**ibv_reg_buf_mr()** returns a pointer to the registered MR on success, or NULL +if the request fails. + **ibv_free_buf()** does not return a value. + +# SEE ALSO + +**ibv_reg_mr**(3), +**ibv_reg_mr_ex**(3), +**ibv_reg_dmabuf_mr**(3)
diff --git a/libibverbs/verbs.c b/libibverbs/verbs.c index 8e5244d..0565be2 100644 --- a/libibverbs/verbs.c +++ b/libibverbs/verbs.c
@@ -440,6 +440,20 @@ return get_ops(pd->context)->alloc_buf(pd, size, buf); } +struct ibv_mr *ibv_reg_buf_mr(struct ibv_pd *pd, struct ibv_buf *buf, + void *addr, size_t length, int access) +{ + struct ibv_mr_init_attr mr_init_attr = { + .length = length, + .access = access, + .comp_mask = IBV_REG_MR_MASK_BUF | IBV_REG_MR_MASK_ADDR, + .addr = addr, + .buf = buf, + }; + + return ibv_reg_mr_ex(pd, &mr_init_attr); +} + void ibv_free_buf(struct ibv_buf *buf) { get_ops(buf->pd->context)->free_buf(buf);
diff --git a/libibverbs/verbs.h b/libibverbs/verbs.h index 9a90f21..67832e4 100644 --- a/libibverbs/verbs.h +++ b/libibverbs/verbs.h
@@ -3208,6 +3208,9 @@ * @size: Buffer size in bytes * @buf: On success, set to a handle for ibv_free_buf() * + * The returned address is at least page aligned, so it can be registered + * with ibv_reg_buf_mr() regardless of how the buffer is backed. + * * Returns the usable buffer address on success, or NULL on failure with * errno set. */ @@ -3220,6 +3223,20 @@ void ibv_free_buf(struct ibv_buf *buf); /** + * ibv_reg_buf_mr - Register an MR for a buffer from ibv_alloc_buf + * @pd: Protection domain + * @buf: Handle from ibv_alloc_buf() + * @addr: Start address to register; the buffer base returned by + * ibv_alloc_buf() or an address within that buffer + * @length: Length in bytes; @addr + @length must stay within the buffer + * @access: Access flags (IBV_ACCESS_*) + * + * Returns the registered MR on success, or NULL on failure with errno set. + */ +struct ibv_mr *ibv_reg_buf_mr(struct ibv_pd *pd, struct ibv_buf *buf, + void *addr, size_t length, int access); + +/** * ibv_alloc_dmah - Allocate a dma handle */ struct ibv_dmah *ibv_alloc_dmah(struct ibv_context *context,