Re: [dpdk-dev] could not l2fwd in DOM0

["Liu, Jijiang" <jijiang.liu@intel.com>]

Hi,

I have checked source codes of xen_create_contiguous_region function in kernel 3.14, and found the dma_handle cannot be NULL.

int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
                                 unsigned int address_bits,
                                 dma_addr_t *dma_handle)
{
        unsigned long *in_frames = discontig_frames, out_frame;
        unsigned long  flags;
        int            success;
        unsigned long vstart = (unsigned long)phys_to_virt(pstart);
    ...
        *dma_handle = virt_to_machine(vstart).maddr;
        return success ? 0 : -ENOMEM;
}

Thanks
Frank Liu

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Samuel Monderer
Sent: Wednesday, April 30, 2014 1:54 AM
To: dev@dpdk.org<mailto:dev@dpdk.org>
Cc: Shimon Zadok
Subject: [dpdk-dev] could not l2fwd in DOM0

Hi,

First I've encountered a compiling problem when compiling for DOM0 due to prototype change of the function xen_create_contiguous_region I made the following changes:

diff --git a/lib/librte_eal/linuxapp/xen_dom0/dom0_mm_misc.c b/lib/librte_eal/linuxapp/xen index 87fa3e6..8addc21 100644
--- a/lib/librte_eal/linuxapp/xen_dom0/dom0_mm_misc.c
+++ b/lib/librte_eal/linuxapp/xen_dom0/dom0_mm_misc.c
@@ -64,6 +64,7 @@
 #include <linux/errno.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
+//#include <linux/types.h>

 #include <xen/xen.h>
 #include <xen/page.h>
@@ -309,6 +310,7 @@ dom0_prepare_memsegs(struct memory_info* meminfo, struct dom0_mm_data
        uint64_t pfn, vstart, vaddr;
        uint32_t i, num_block, size;
        int idx;
+       dma_addr_t *dma_handle = NULL;

        /* Allocate 2M memory once */
        num_block = meminfo->size / 2;
@@ -344,7 +346,7 @@ dom0_prepare_memsegs(struct memory_info* meminfo, struct dom0_mm_data
                 * contiguous physical addresses, its maximum size is 2M.
                 */
                if (xen_create_contiguous_region(mm_data->block_info[i].vir_addr,
-                                   DOM0_CONTIG_NUM_ORDER, 0) == 0) {
+                                   DOM0_CONTIG_NUM_ORDER, 0,
+ dma_handle) == 0) {
                        mm_data->block_info[i].exchange_flag = 1;
                        mm_data->block_info[i].mfn =
                                pfn_to_mfn(mm_data->block_info[i].pfn);

After that I tried to run l2fwd example and got a segmentation fault

root@Smart:~/samuelm/dpdk/dpdk# modprobe uio root@Smart:~/samuelm/dpdk/dpdk# insmod ./x86_64-default-linuxapp-gcc/kmod/igb_uio.ko
root@Smart:~/samuelm/dpdk/dpdk# insmod ./x86_64-default-linuxapp-gcc/kmod/rte_dom0_mm.ko
root@Smart:~/samuelm/dpdk/dpdk# cd examples/l2fwd/build/ root@Smart:~/samuelm/dpdk/dpdk/examples/l2fwd/build# echo 2048 > /sys/kernel/mm/dom0-mm/memsize-mB/memsize
root@Smart:~/samuelm/dpdk/dpdk/examples/l2fwd/build# ./l2fwd -c 3 -n 4 --xen-dom0 -- -q 1 -p 3
EAL: Detected lcore 0 as core 0 on socket 0
EAL: Detected lcore 1 as core 0 on socket 0
EAL: Setting up memory...
Segmentation fault
root@Smart:~/samuelm/dpdk/dpdk/examples/l2fwd/build#

Has anyone already encountered this problem?

Samuelm