[PATCH V2 11/11] selftests: ublk: add test for checking zero copy related parameter

Ming Lei
2025-03-27T09:52:35Z

ublk zero copy usually requires to set dma and segment parameter correctly,
so hard-code null target's dma & segment parameter in non-default value,
and verify if they are setup correctly by ublk driver.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
tools/testing/selftests/ublk/Makefile | 1 +
tools/testing/selftests/ublk/null.c | 11 +++++++-
.../testing/selftests/ublk/test_generic_03.sh | 28 +++++++++++++++++++
3 files changed, 39 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/ublk/test_generic_03.sh

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index 7a8c994de244..d98680d64a2f 100644
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -5,6 +5,7 @@ LDLIBS += -lpthread -lm -luring

TEST_PROGS := test_generic_01.sh
TEST_PROGS += test_generic_02.sh
+TEST_PROGS += test_generic_03.sh

TEST_PROGS += test_null_01.sh
TEST_PROGS += test_null_02.sh
diff --git a/tools/testing/selftests/ublk/null.c b/tools/testing/selftests/ublk/null.c
index 899875ff50fe..91fec3690d4b 100644
--- a/tools/testing/selftests/ublk/null.c
+++ b/tools/testing/selftests/ublk/null.c
@@ -17,7 +17,8 @@ static int ublk_null_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)

dev->tgt.dev_size = dev_size;
dev->tgt.params = (struct ublk_params) {
- .types = UBLK_PARAM_TYPE_BASIC,
+ .types = UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DMA_ALIGN |
+ UBLK_PARAM_TYPE_SEGMENT,
.basic = {
.logical_bs_shift = 9,
.physical_bs_shift = 12,
@@ -26,6 +27,14 @@ static int ublk_null_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
.max_sectors = info->max_io_buf_bytes >> 9,
.dev_sectors = dev_size >> 9,
},
+ .dma = {
+ .alignment = 4095,
+ },
+ .seg = {
+ .seg_boundary_mask = 4095,
+ .max_segment_size = 32 << 10,
+ .max_segments = 32,
+ },
};

if (info->flags & UBLK_F_SUPPORT_ZERO_COPY)
diff --git a/tools/testing/selftests/ublk/test_generic_03.sh b/tools/testing/selftests/ublk/test_generic_03.sh
new file mode 100755
index 000000000000..b551aa76cb0d
--- /dev/null
+++ b/tools/testing/selftests/ublk/test_generic_03.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+TID="generic_03"
+ERR_CODE=0
+
+_prep_test "null" "check dma & segment limits for zero copy"
+
+dev_id=$(_add_ublk_dev -t null -z)
+_check_add_dev $TID $?
+
+sysfs_path=/sys/block/ublkb"${dev_id}"
+dma_align=$(cat "$sysfs_path"/queue/dma_alignment)
+max_segments=$(cat "$sysfs_path"/queue/max_segments)
+max_segment_size=$(cat "$sysfs_path"/queue/max_segment_size)
+if [ "$dma_align" != "4095" ]; then
+ ERR_CODE=255
+fi
+if [ "$max_segments" != "32" ]; then
+ ERR_CODE=255
+fi
+if [ "$max_segment_size" != "32768" ]; then
+ ERR_CODE=255
+fi
+_cleanup_test "null"
+_show_result $TID $ERR_CODE
--
2.47.0