[PATCH v3] app/dma-perf: fix physical address seg-fault

[Vipin Varghese]

do_cpu_mem_copy uses DPDK API rte_mbuf_data_iova to return
the start of the virtual address for both src and dst.
But in case of iova mode set as PA, this results in seg-fault.
This is because rte_memcpy uses VA address and not PA.

This fix invokes `rte_pktmbuf_mtod` for both src and dst.

Bugzilla ID: 1269
Fixes: 623dc9364dc6 ("app/dma-perf: introduce DMA performance test")
Cc: cheng1.jiang at intel.com

Cc: stable at dpdk.org

Signed-off-by: Vipin Varghese <vipin.varghese at amd.com>
Suggested-by: Anoob Joseph <anoobj at marvell.com>
Suggested-by: Jerin Jacob <jerinj at marvell.com>

---

v2:
 - suggest use of pktmbuf_mtod for both va and pa by Anoob.

V3:
 - add const to src suggested by Jerin.
---
 app/test-dma-perf/benchmark.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/app/test-dma-perf/benchmark.c b/app/test-dma-perf/benchmark.c
index 0601e0d171..9b1f58c78c 100644
--- a/app/test-dma-perf/benchmark.c
+++ b/app/test-dma-perf/benchmark.c
@@ -288,10 +288,11 @@ do_cpu_mem_copy(void *p)
 
 	while (1) {
 		for (i = 0; i < nr_buf; i++) {
+			const void *src = rte_pktmbuf_mtod(dsts[i], void *);
+			void *dst = rte_pktmbuf_mtod(srcs[i], void *);
+
 			/* copy buffer form src to dst */
-			rte_memcpy((void *)(uintptr_t)rte_mbuf_data_iova(dsts[i]),
-				(void *)(uintptr_t)rte_mbuf_data_iova(srcs[i]),
-				(size_t)buf_size);
+			rte_memcpy(dst, src, (size_t)buf_size);
 			worker_info->total_cpl++;
 		}
 		if (worker_info->stop_flag)
-- 
2.34.1