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

["Varghese, Vipin" <Vipin.Varghese@amd.com>]

[AMD Official Use Only - General]

Apologies, marking this as `NA`. After recheck of this logic without use of ` rte_mbuf_data_iova` will result in mbuf meta-data corruption.

Need to fix this in a different way.

> -----Original Message-----
> From: Vipin Varghese <vipin.varghese@amd.com>
> Sent: Tuesday, August 15, 2023 8:41 PM
> To: thomas@monjalon.net; dev@dpdk.org
> Cc: Yigit, Ferruh <Ferruh.Yigit@amd.com>; cheng1.jiang@intel.com;
> stable@dpdk.org
> Subject: [PATCH] app/dma-perf: fix physical address seg-fault
>
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
>
>
> 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 VA address and not PA.
>
> this fix checks the iova mode and invokes rte_memcpy with the right
> arguments.
>
> Bugzilla ID: 1269
> Fixes: 623dc9364dc6 ("app/dma-perf: introduce DMA performance test")
> Cc: cheng1.jiang@intel.com
>
> Cc: stable@dpdk.org
>
> Signed-off-by: Vipin Varghese <vipin.varghese@amd.com>
> ---
>
> tested for both va and pa
>
> CMD:
> PA: dpdk-test-dma-perf --iova-mode=pa  -- --config test.ini
> VA: dpdk-test-dma-perf --iova-mode=va  -- --config test.ini
> DC: dpdk-test-dma-perf --iova-mode=dc  -- --config test.ini
>
> Log: fails for dc mode `EAL: invalid parameters for --iova-mode`
>
> test.ini:
> ```
> [case1]
> type=CPU_MEM_COPY
> mem_size=10
> buf_size=64,8192,2,MUL
> src_numa_node=0
> dst_numa_node=0
> cache_flush=0
> test_seconds=2
> lcore = 7
> eal_args=--in-memory --no-pci
> ```
> ---
>  app/test-dma-perf/benchmark.c | 36 ++++++++++++++++++++++++++---------
>  1 file changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/app/test-dma-perf/benchmark.c b/app/test-dma-perf/benchmark.c
> index 0601e0d171..73200e1935 100644
> --- a/app/test-dma-perf/benchmark.c
> +++ b/app/test-dma-perf/benchmark.c
> @@ -279,6 +279,10 @@ do_cpu_mem_copy(void *p)
>         struct rte_mbuf **srcs = para->srcs;
>         struct rte_mbuf **dsts = para->dsts;
>         uint32_t i;
> +       bool isAddrPaMode = false;
> +
> +       if (rte_eal_iova_mode() == RTE_IOVA_PA)
> +               isAddrPaMode = true;
>
>         worker_info->stop_flag = false;
>         worker_info->ready_flag = true;
> @@ -286,16 +290,30 @@ do_cpu_mem_copy(void *p)
>         while (!worker_info->start_flag)
>                 ;
>
> -       while (1) {
> -               for (i = 0; i < nr_buf; i++) {
> -                       /* 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);
> -                       worker_info->total_cpl++;
> +       if (true == isAddrPaMode) {
> +               while (1) {
> +                       for (i = 0; i < nr_buf; i++) {
> +                               /* copy buffer form src to dst */
> +                               rte_memcpy((void *)dsts[i],
> +                                       (void *)srcs[i],
> +                                       (size_t)buf_size);
> +                               worker_info->total_cpl++;
> +                       }
> +                       if (worker_info->stop_flag)
> +                               break;
> +               }
> +       } else {
> +               while (1) {
> +                       for (i = 0; i < nr_buf; i++) {
> +                               /* 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);
> +                               worker_info->total_cpl++;
> +                       }
> +                       if (worker_info->stop_flag)
> +                               break;
>                 }
> -               if (worker_info->stop_flag)
> -                       break;
>         }
>
>         return 0;
> --
> 2.34.1