[dpdk-dev] [PATCH v4 40/70] eal: add virt2memseg function

Anatoly Burakov anatoly.burakov at intel.com
Sun Apr 8 22:18:13 CEST 2018


This can be used as a virt2iova function that only looks up
memory that is owned by DPDK (as opposed to doing pagemap walks).
Using this will result in less dependency on internals of mem API.

Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/common/eal_common_memory.c  | 37 ++++++++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_memory.h | 11 +++++++++
 lib/librte_eal/rte_eal_version.map         |  1 +
 3 files changed, 49 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index ea3c5a7..fd78d2f 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -161,6 +161,43 @@ rte_mem_iova2virt(rte_iova_t iova)
 	return vi.virt;
 }
 
+struct virtms {
+	const void *virt;
+	struct rte_memseg *ms;
+};
+static int
+find_memseg(const struct rte_memseg *ms, void *arg)
+{
+	struct virtms *vm = arg;
+
+	if (arg >= ms->addr && arg < RTE_PTR_ADD(ms->addr, ms->len)) {
+		struct rte_memseg *memseg, *found_ms;
+		int idx;
+
+		memseg = rte_eal_get_configuration()->mem_config->memseg;
+		idx = ms - memseg;
+		found_ms = &memseg[idx];
+
+		vm->ms = found_ms;
+		return 1;
+	}
+	return 0;
+}
+
+__rte_experimental struct rte_memseg *
+rte_mem_virt2memseg(const void *addr)
+{
+	struct virtms vm;
+
+	memset(&vm, 0, sizeof(vm));
+
+	vm.virt = addr;
+
+	rte_memseg_walk(find_memseg, &vm);
+
+	return vm.ms;
+}
+
 static int
 physmem_size(const struct rte_memseg *ms, void *arg)
 {
diff --git a/lib/librte_eal/common/include/rte_memory.h b/lib/librte_eal/common/include/rte_memory.h
index 5c60b91..b3d7e61 100644
--- a/lib/librte_eal/common/include/rte_memory.h
+++ b/lib/librte_eal/common/include/rte_memory.h
@@ -143,6 +143,17 @@ __rte_experimental void *
 rte_mem_iova2virt(rte_iova_t iova);
 
 /**
+ * Get memseg to which a particular virtual address belongs.
+ *
+ * @param virt
+ *   The virtual address.
+ * @return
+ *   Memseg pointer on success, or NULL on error.
+ */
+__rte_experimental struct rte_memseg *
+rte_mem_virt2memseg(const void *virt);
+
+/**
  * Memseg walk function prototype.
  *
  * Returning 0 will continue walk
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index dccfc35..79433b7 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -224,6 +224,7 @@ EXPERIMENTAL {
 	rte_log_register_type_and_pick_level;
 	rte_malloc_dump_heaps;
 	rte_mem_iova2virt;
+	rte_mem_virt2memseg;
 	rte_memseg_contig_walk;
 	rte_memseg_walk;
 	rte_mp_action_register;
-- 
2.7.4


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