[PATCH 2/4] nvme: add support for mlx5 RDMA devices

[Max Gurtovoy <mgurtovoy@nvidia.com>]

Until now, the tests for RDMA transport were only supported on top of
software RDMA devices (rxe/siw). This commit adds support for running
tests on top of mlx5 hardware RDMA devices, allowing for more
comprehensive testing of NVMe-oF RDMA functionality.

Prerequisites:
- RDMA network interfaces must be configured prior to running tests
- User should set USE_MLX5=1 environment variable to use mlx5 devices

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
---
 common/multipath-over-rdma |  7 +++++++
 common/nvme                | 16 +++++++++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/common/multipath-over-rdma b/common/multipath-over-rdma
index e157e0a..9367662 100644
--- a/common/multipath-over-rdma
+++ b/common/multipath-over-rdma
@@ -98,6 +98,13 @@ rdma_network_interfaces() {
 		sort -u
 }
 
+# Lists RDMA capable network interface names associated with mlx5 devices, e.g. ib0 ib1.
+rdma_mlx5_network_interfaces() {
+	rdma link show | grep mlx5 |
+		sed -n 's/^.*[[:blank:]]netdev[[:blank:]]\+\([^[:blank:]]*\)[[:blank:]]*/\1/p' |
+		sort -u
+}
+
 # Check whether any stacked block device holds block device $1. If so, echo
 # the name of the holder.
 held_by() {
diff --git a/common/nvme b/common/nvme
index 3d43790..01d054d 100644
--- a/common/nvme
+++ b/common/nvme
@@ -218,7 +218,9 @@ _cleanup_nvmet() {
 	fi
 	modprobe -rq nvmet 2>/dev/null
 	if [[ "${nvme_trtype}" == "rdma" ]]; then
-		stop_soft_rdma
+		if [ -z "$USE_MLX5" ]; then
+			stop_soft_rdma
+		fi
 	fi
 
 	_cleanup_blkdev
@@ -243,8 +245,14 @@ _setup_nvmet() {
 	fi
 	modprobe -q nvme-"${nvme_trtype}"
 	if [[ "${nvme_trtype}" == "rdma" ]]; then
-		start_soft_rdma
-		for i in $(rdma_network_interfaces)
+		local interfaces
+		if [ -z "$USE_MLX5" ]; then
+			start_soft_rdma
+			interfaces="$(rdma_network_interfaces)"
+		else
+			interfaces="$(rdma_mlx5_network_interfaces)"
+		fi
+		for i in $interfaces
 		do
 			if [[ "${nvme_adrfam}" == "ipv6" ]]; then
 				ipv6_addr=$(get_ipv6_ll_addr "$i")
@@ -1180,6 +1188,8 @@ _nvme_requires() {
 		_have_program rdma
 		if [ -n "$USE_RXE" ]; then
 			_have_driver rdma_rxe
+		elif [ -n "$USE_MLX5" ]; then
+			_have_driver mlx5_ib
 		else
 			_have_driver siw
 		fi
-- 
2.18.1