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

[Anoob Joseph <anoobj@marvell.com>]

Hi Vipin,

Would using 'rte_pktmbuf_mtod' in 'do_cpu_mem_copy' function resolve the issue?

Thanks,
Anoob

> -----Original Message-----
> From: Varghese, Vipin <Vipin.Varghese@amd.com>
> Sent: Tuesday, August 15, 2023 8:45 PM
> To: Varghese, Vipin <Vipin.Varghese@amd.com>; thomas@monjalon.net;
> dev@dpdk.org
> Cc: Yigit, Ferruh <Ferruh.Yigit@amd.com>; cheng1.jiang@intel.com;
> stable@dpdk.org
> Subject: [EXT] RE: [PATCH] app/dma-perf: fix physical address seg-fault
> 
> External Email
> 
> ----------------------------------------------------------------------
> [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