[dpdk-dev] [RFC 08/11] malloc: allow adding memory to named heaps

[Anatoly Burakov <anatoly.burakov@intel.com>]

Add an API to add externally allocated memory to malloc heap. The
memory will be stored in memseg lists like regular DPDK memory.
Multiple segments are allowed within a heap. If IOVA table is
not provided, IOVA addresses are filled in with RTE_BAD_IOVA.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/common/include/rte_malloc.h | 44 ++++++++++++++
 lib/librte_eal/common/malloc_heap.c        | 70 ++++++++++++++++++++++
 lib/librte_eal/common/malloc_heap.h        |  4 ++
 lib/librte_eal/common/rte_malloc.c         | 39 ++++++++++++
 lib/librte_eal/rte_eal_version.map         |  1 +
 5 files changed, 158 insertions(+)

diff --git a/lib/librte_eal/common/include/rte_malloc.h b/lib/librte_eal/common/include/rte_malloc.h
index fa6de073a..5f933993b 100644
--- a/lib/librte_eal/common/include/rte_malloc.h
+++ b/lib/librte_eal/common/include/rte_malloc.h
@@ -274,6 +274,50 @@ rte_free(void *ptr);
 int __rte_experimental
 rte_malloc_heap_create(const char *heap_name);
 
+/**
+ * Add more memory to heap with specified name.
+ *
+ * @note Concurrently adding memory to or removing memory from different heaps
+ *   is not safe.
+ *
+ * @note This function does not need to be called in multiple processes, as
+ *   multiprocess synchronization will happen automatically as far as heap data
+ *   is concerned. However, before accessing pointers to memory in this heap, it
+ *   is responsibility of the user to ensure that the heap memory is accessible
+ *   in all processes.
+ *
+ * @note Memory must be previously allocated for DPDK to be able to use it as a
+ *   malloc heap. Failing to do so will result in undefined behavior, up to and
+ *   including crashes.
+ *
+ * @note Adding memory to heap may fail in multiple processes scenario, as
+ *   attaching to ``rte_fbarray`` structures may not always be successful in
+ *   secondary processes.
+ *
+ * @param heap_name
+ *   Name of the heap to create.
+ * @param va_addr
+ *   Start of virtual area to add to the heap.
+ * @param len
+ *   Length of virtual area to add to the heap.
+ * @param iova_addrs
+ *   Array of page IOVA addresses corresponding to each page in this memory
+ *   area. Can be NULL, in which case page IOVA addresses will be set to
+ *   RTE_BAD_IOVA.
+ * @param n_pages
+ *   Number of elements in the iova_addrs array. Must be zero of ``iova_addrs``
+ *   is NULL.
+ * @param page_sz
+ *   Page size of the underlying memory.
+ *
+ * @return
+ *   - 0 on successful creation.
+ *   - -1 on error.
+ */
+int __rte_experimental
+rte_malloc_heap_add_memory(const char *heap_name, void *va_addr, size_t len,
+		rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz);
+
 /**
  * If malloc debug is enabled, check a memory block for header
  * and trailer markers to indicate that all is well with the block.
diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index f5d103626..29446cac9 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -892,6 +892,76 @@ malloc_heap_dump(struct malloc_heap *heap, FILE *f)
 	rte_spinlock_unlock(&heap->lock);
 }
 
+int
+malloc_heap_add_external_memory(struct malloc_heap *heap, void *va_addr,
+		rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	char fbarray_name[RTE_FBARRAY_NAME_LEN];
+	struct rte_memseg_list *msl = NULL;
+	struct rte_fbarray *arr;
+	size_t seg_len = n_pages * page_sz;
+	unsigned int i;
+
+	/* first, find a free memseg list */
+	for (i = 0; i < RTE_MAX_MEMSEG_LISTS; i++) {
+		struct rte_memseg_list *tmp = &mcfg->memsegs[i];
+		if (tmp->base_va == NULL) {
+			msl = tmp;
+			break;
+		}
+	}
+	if (msl == NULL) {
+		RTE_LOG(ERR, EAL, "Couldn't find empty memseg list\n");
+		rte_errno = ENOSPC;
+		return -1;
+	}
+
+	snprintf(fbarray_name, sizeof(fbarray_name) - 1, "%s_%p",
+			heap->name, va_addr);
+
+	/* create the backing fbarray */
+	if (rte_fbarray_init(&msl->memseg_arr, fbarray_name, n_pages,
+			sizeof(struct rte_memseg)) < 0) {
+		RTE_LOG(ERR, EAL, "Couldn't create fbarray backing the memseg list\n");
+		return -1;
+	}
+	arr = &msl->memseg_arr;
+
+	/* fbarray created, fill it up */
+	for (i = 0; i < n_pages; i++) {
+		struct rte_memseg *ms;
+
+		rte_fbarray_set_used(arr, i);
+		ms = rte_fbarray_get(arr, i);
+		ms->addr = RTE_PTR_ADD(va_addr, n_pages * page_sz);
+		ms->iova = iova_addrs == NULL ? RTE_BAD_IOVA : iova_addrs[i];
+		ms->hugepage_sz = page_sz;
+		ms->len = page_sz;
+		ms->nchannel = rte_memory_get_nchannel();
+		ms->nrank = rte_memory_get_nrank();
+		ms->socket_id = -1; /* invalid socket ID */
+	}
+
+	/* set up the memseg list */
+	msl->base_va = va_addr;
+	msl->page_sz = page_sz;
+	msl->socket_id = -1; /* invalid socket ID */
+	msl->version = 0;
+	msl->external = true;
+
+	/* now, add newly minted memory to the malloc heap */
+	malloc_heap_add_memory(heap, msl, va_addr, seg_len);
+
+	heap->total_size += seg_len;
+
+	/* all done! */
+	RTE_LOG(DEBUG, EAL, "Added segment for heap %s starting at %p\n",
+			heap->name, va_addr);
+
+	return 0;
+}
+
 int
 malloc_heap_create(struct malloc_heap *heap, const char *heap_name)
 {
diff --git a/lib/librte_eal/common/malloc_heap.h b/lib/librte_eal/common/malloc_heap.h
index aa819ef65..3be4656d0 100644
--- a/lib/librte_eal/common/malloc_heap.h
+++ b/lib/librte_eal/common/malloc_heap.h
@@ -38,6 +38,10 @@ malloc_heap_alloc_on_heap_id(const char *type, size_t size,
 int
 malloc_heap_create(struct malloc_heap *heap, const char *heap_name);
 
+int
+malloc_heap_add_external_memory(struct malloc_heap *heap, void *va_addr,
+		rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz);
+
 int
 malloc_heap_find_named_heap_idx(const char *name);
 
diff --git a/lib/librte_eal/common/rte_malloc.c b/lib/librte_eal/common/rte_malloc.c
index e000dc5b7..db0f604ad 100644
--- a/lib/librte_eal/common/rte_malloc.c
+++ b/lib/librte_eal/common/rte_malloc.c
@@ -274,6 +274,45 @@ rte_malloc_virt2iova(const void *addr)
 	return ms->iova + RTE_PTR_DIFF(addr, ms->addr);
 }
 
+int
+rte_malloc_heap_add_memory(const char *heap_name, void *va_addr, size_t len,
+		rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz)
+{
+	struct malloc_heap *heap = NULL;
+	unsigned int n;
+	int ret;
+
+	/* iova_addrs is allowed to be NULL */
+	if (heap_name == NULL || va_addr == NULL ||
+			/* n_pages can be 0 if iova_addrs is NULL */
+			((iova_addrs != NULL) == (n_pages == 0)) ||
+			page_sz == 0 || !rte_is_power_of_2(page_sz) ||
+			strnlen(heap_name, RTE_HEAP_NAME_MAX_LEN) == 0 ||
+			strnlen(heap_name, RTE_HEAP_NAME_MAX_LEN) ==
+				RTE_HEAP_NAME_MAX_LEN) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+	/* find our heap */
+	heap = malloc_heap_find_named_heap(heap_name);
+	if (heap == NULL) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+	n = len / page_sz;
+	if (n != n_pages && iova_addrs != NULL) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+
+	rte_spinlock_lock(&heap->lock);
+	ret = malloc_heap_add_external_memory(heap, va_addr, iova_addrs, n,
+			page_sz);
+	rte_spinlock_unlock(&heap->lock);
+
+	return ret;
+}
+
 int
 rte_malloc_heap_create(const char *heap_name)
 {
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index f3c375156..6290cc910 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -280,6 +280,7 @@ EXPERIMENTAL {
 	rte_malloc_dump_heaps;
 	rte_malloc_from_heap;
 	rte_malloc_get_stats_from_heap;
+	rte_malloc_heap_add_memory;
 	rte_malloc_heap_create;
 	rte_mem_alloc_validator_register;
 	rte_mem_alloc_validator_unregister;
-- 
2.17.1