[dpdk-dev] [PATCH 2/5] common/mlx5: add wrapped MR create API

[Matan Azrad]

As a workaround to kernel driver/FW issues of the mlx5 devices, it is
needed to use MR, which is an indirect mkey pointing to direct mkey
created by the kernel for any DevX command uses an MR.

Add an API to create and destroy this wrapped MR.

Fixes: 5382d28c2110 ("net/mlx5: accelerate DV flow counter transactions")
Fixes: 9d39e57f21ac ("vdpa/mlx5: support live migration")
Cc: stable at dpdk.org

Signed-off-by: Michael Baum <michaelba at oss.nvidia.com>
Signed-off-by: Matan Azrad <matan at nvidia.com>
---
 drivers/common/mlx5/linux/mlx5_common_os.c | 56 ++++++++++++++++++++++
 drivers/common/mlx5/mlx5_common.h          | 18 +++++++
 drivers/common/mlx5/version.map            |  3 ++
 3 files changed, 77 insertions(+)

diff --git a/drivers/common/mlx5/linux/mlx5_common_os.c b/drivers/common/mlx5/linux/mlx5_common_os.c
index b516564b79..0d3e24e04e 100644
--- a/drivers/common/mlx5/linux/mlx5_common_os.c
+++ b/drivers/common/mlx5/linux/mlx5_common_os.c
@@ -744,3 +744,59 @@ mlx5_get_device_guid(const struct rte_pci_addr *dev, uint8_t *guid, size_t len)
 	fclose(id_file);
 	return ret;
 }
+
+/*
+ * Create direct mkey using the kernel ibv_reg_mr API and wrap it with a new
+ * indirect mkey created by the DevX API.
+ * This mkey should be used for DevX commands requesting mkey as a parameter.
+ */
+int
+mlx5_os_wrapped_mkey_create(void *ctx, void *pd, uint32_t pdn, void *addr,
+			    size_t length, struct mlx5_pmd_wrapped_mr *pmd_mr)
+{
+	struct mlx5_klm klm = {
+		.byte_count = length,
+		.address = (uintptr_t)addr,
+	};
+	struct mlx5_devx_mkey_attr mkey_attr = {
+		.pd = pdn,
+		.klm_array = &klm,
+		.klm_num = 1,
+	};
+	struct mlx5_devx_obj *mkey;
+	struct ibv_mr *ibv_mr = mlx5_glue->reg_mr(pd, addr, length,
+						  IBV_ACCESS_LOCAL_WRITE |
+						  (haswell_broadwell_cpu ? 0 :
+						  IBV_ACCESS_RELAXED_ORDERING));
+
+	if (!ibv_mr) {
+		rte_errno = errno;
+		return -rte_errno;
+	}
+	klm.mkey = ibv_mr->lkey;
+	mkey_attr.addr = (uintptr_t)addr;
+	mkey_attr.size = length;
+	mkey = mlx5_devx_cmd_mkey_create(ctx, &mkey_attr);
+	if (!mkey) {
+		claim_zero(mlx5_glue->dereg_mr(ibv_mr));
+		return -rte_errno;
+	}
+	pmd_mr->addr = addr;
+	pmd_mr->len = length;
+	pmd_mr->obj = (void *)ibv_mr;
+	pmd_mr->imkey = mkey;
+	pmd_mr->lkey = mkey->id;
+	return 0;
+}
+
+void
+mlx5_os_wrapped_mkey_destroy(struct mlx5_pmd_wrapped_mr *pmd_mr)
+{
+	if (!pmd_mr)
+		return;
+	if (pmd_mr->imkey)
+		claim_zero(mlx5_devx_cmd_destroy(pmd_mr->imkey));
+	if (pmd_mr->obj)
+		claim_zero(mlx5_glue->dereg_mr(pmd_mr->obj));
+	memset(pmd_mr, 0, sizeof(*pmd_mr));
+}
diff --git a/drivers/common/mlx5/mlx5_common.h b/drivers/common/mlx5/mlx5_common.h
index 744c6a72b3..62109a671a 100644
--- a/drivers/common/mlx5/mlx5_common.h
+++ b/drivers/common/mlx5/mlx5_common.h
@@ -429,4 +429,22 @@ mlx5_mr_mb2mr(struct mlx5_common_device *cdev, struct mlx5_mp_id *mp_id,
 int mlx5_os_open_device(struct mlx5_common_device *cdev, uint32_t classes);
 int mlx5_os_pd_create(struct mlx5_common_device *cdev);
 
+/* mlx5 PMD wrapped MR struct. */
+struct mlx5_pmd_wrapped_mr {
+	uint32_t	     lkey;
+	void		     *addr;
+	size_t		     len;
+	void		     *obj; /* verbs mr object or devx umem object. */
+	void		     *imkey; /* DevX indirect mkey object. */
+};
+
+__rte_internal
+int
+mlx5_os_wrapped_mkey_create(void *ctx, void *pd, uint32_t pdn, void *addr,
+			    size_t length, struct mlx5_pmd_wrapped_mr *pmd_mr);
+
+__rte_internal
+void
+mlx5_os_wrapped_mkey_destroy(struct mlx5_pmd_wrapped_mr *pmd_mr);
+
 #endif /* RTE_PMD_MLX5_COMMON_H_ */
diff --git a/drivers/common/mlx5/version.map b/drivers/common/mlx5/version.map
index 6e17a7b8b8..b6c045c110 100644
--- a/drivers/common/mlx5/version.map
+++ b/drivers/common/mlx5/version.map
@@ -133,6 +133,9 @@ INTERNAL {
 	mlx5_os_umem_dereg;
 	mlx5_os_umem_reg;
 
+	mlx5_os_wrapped_mkey_create; # WINDOWS_NO_EXPORT
+	mlx5_os_wrapped_mkey_destroy; # WINDOWS_NO_EXPORT
+
 	mlx5_realloc;
 
 	mlx5_translate_port_name; # WINDOWS_NO_EXPORT
-- 
2.25.1