app/testpmd: add mempool with external data buffers

The new mbuf pool type is added to testpmd. To engage the
mbuf pool with externally attached data buffers the parameter
"--mp-alloc=xbuf" should be specified in testpmd command line.

The objective of this patch is just to test whether mbuf pool
with externally attached data buffers works OK. The memory for
data buffers is allocated from DPDK memory, so this is not
"true" external memory from some physical device (this is
supposed the most common use case for such kind of mbuf pool).

The user should be aware that not all drivers support the mbuf
with EXT_ATTACHED_BUF flags set in newly allocated mbuf (many
PMDs just overwrite ol_flags field and flag value is getting
lost).

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

app/test-pmd/config.c

@@ -2422,6 +2422,8 @@ mp_alloc_to_str(uint8_t mode)
 		return "xmem";
 	case MP_ALLOC_XMEM_HUGE:
 		return "xmemhuge";
+	case MP_ALLOC_XBUF:
+		return "xbuf";
 	default:
 		return "invalid";
 	}

app/test-pmd/flowgen.c

@@ -199,7 +199,8 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 							   sizeof(*ip_hdr));
 		pkt->nb_segs		= 1;
 		pkt->pkt_len		= pkt_size;
-		pkt->ol_flags		= ol_flags;
+		pkt->ol_flags		&= EXT_ATTACHED_MBUF;
+		pkt->ol_flags		|= ol_flags;
 		pkt->vlan_tci		= vlan_tci;
 		pkt->vlan_tci_outer	= vlan_tci_outer;
 		pkt->l2_len		= sizeof(struct rte_ether_hdr);

app/test-pmd/parameters.c

@@ -841,6 +841,8 @@ launch_args_parse(int argc, char** argv)
 					mp_alloc_type = MP_ALLOC_XMEM;
 				else if (!strcmp(optarg, "xmemhuge"))
 					mp_alloc_type = MP_ALLOC_XMEM_HUGE;
+				else if (!strcmp(optarg, "xbuf"))
+					mp_alloc_type = MP_ALLOC_XBUF;
 				else
 					rte_exit(EXIT_FAILURE,
 						"mp-alloc %s invalid - must be: "

app/test-pmd/testpmd.c

@@ -78,6 +78,7 @@
 #endif
 
 #define EXTMEM_HEAP_NAME "extmem"
+#define EXTBUF_ZONE_SIZE RTE_PGSIZE_2M
 
 uint16_t verbose_level = 0; /**< Silent by default. */
 int testpmd_logtype; /**< Log type for testpmd logs */
@@ -868,6 +869,66 @@ dma_map_cb(struct rte_mempool *mp __rte_unused, void *opaque __rte_unused,
 	}
 }
 
+static unsigned int
+setup_extbuf(uint32_t nb_mbufs, uint16_t mbuf_sz, unsigned int socket_id,
+	    char *pool_name, struct rte_pktmbuf_extmem **ext_mem)
+{
+	struct rte_pktmbuf_extmem *xmem;
+	unsigned int ext_num, zone_num, elt_num;
+	uint16_t elt_size;
+
+	elt_size = RTE_ALIGN_CEIL(mbuf_sz, RTE_CACHE_LINE_SIZE);
+	elt_num = EXTBUF_ZONE_SIZE / elt_size;
+	zone_num = (nb_mbufs + elt_num - 1) / elt_num;
+
+	xmem = malloc(sizeof(struct rte_pktmbuf_extmem) * zone_num);
+	if (xmem == NULL) {
+		TESTPMD_LOG(ERR, "Cannot allocate memory for "
+				 "external buffer descriptors\n");
+		*ext_mem = NULL;
+		return 0;
+	}
+	for (ext_num = 0; ext_num < zone_num; ext_num++) {
+		struct rte_pktmbuf_extmem *xseg = xmem + ext_num;
+		const struct rte_memzone *mz;
+		char mz_name[RTE_MEMZONE_NAMESIZE];
+		int ret;
+
+		ret = snprintf(mz_name, sizeof(mz_name),
+			RTE_MEMPOOL_MZ_FORMAT "_xb_%u", pool_name, ext_num);
+		if (ret < 0 || ret >= (int)sizeof(mz_name)) {
+			errno = ENAMETOOLONG;
+			ext_num = 0;
+			break;
+		}
+		mz = rte_memzone_reserve_aligned(mz_name, EXTBUF_ZONE_SIZE,
+						 socket_id,
+						 RTE_MEMZONE_IOVA_CONTIG |
+						 RTE_MEMZONE_1GB |
+						 RTE_MEMZONE_SIZE_HINT_ONLY,
+						 EXTBUF_ZONE_SIZE);
+		if (mz == NULL) {
+			/*
+			 * The caller exits on external buffer creation
+			 * error, so there is no need to free memzones.
+			 */
+			errno = ENOMEM;
+			ext_num = 0;
+			break;
+		}
+		xseg->buf_ptr = mz->addr;
+		xseg->buf_iova = mz->iova;
+		xseg->buf_len = EXTBUF_ZONE_SIZE;
+		xseg->elt_size = elt_size;
+	}
+	if (ext_num == 0 && xmem != NULL) {
+		free(xmem);
+		xmem = NULL;
+	}
+	*ext_mem = xmem;
+	return ext_num;
+}
+
 /*
  * Configuration initialisation done once at init time.
  */
@@ -936,6 +997,26 @@ mbuf_pool_create(uint16_t mbuf_seg_size, unsigned nb_mbuf,
 					heap_socket);
 			break;
 		}
+	case MP_ALLOC_XBUF:
+		{
+			struct rte_pktmbuf_extmem *ext_mem;
+			unsigned int ext_num;
+
+			ext_num = setup_extbuf(nb_mbuf,	mbuf_seg_size,
+					       socket_id, pool_name, &ext_mem);
+			if (ext_num == 0)
+				rte_exit(EXIT_FAILURE,
+					 "Can't create pinned data buffers\n");
+
+			TESTPMD_LOG(INFO, "preferred mempool ops selected: %s\n",
+					rte_mbuf_best_mempool_ops());
+			rte_mp = rte_pktmbuf_pool_create_extbuf
+					(pool_name, nb_mbuf, mb_mempool_cache,
+					 0, mbuf_seg_size, socket_id,
+					 ext_mem, ext_num);
+			free(ext_mem);
+			break;
+		}
 	default:
 		{
 			rte_exit(EXIT_FAILURE, "Invalid mempool creation mode\n");

app/test-pmd/testpmd.h

@@ -76,8 +76,10 @@ enum {
 	/**< allocate mempool natively, but populate using anonymous memory */
 	MP_ALLOC_XMEM,
 	/**< allocate and populate mempool using anonymous memory */
-	MP_ALLOC_XMEM_HUGE
+	MP_ALLOC_XMEM_HUGE,
 	/**< allocate and populate mempool using anonymous hugepage memory */
+	MP_ALLOC_XBUF
+	/**< allocate mempool natively, use rte_pktmbuf_pool_create_extbuf */
 };
 
 #ifdef RTE_TEST_PMD_RECORD_BURST_STATS

app/test-pmd/txonly.c

@@ -170,7 +170,8 @@ pkt_burst_prepare(struct rte_mbuf *pkt, struct rte_mempool *mbp,
 
 	rte_pktmbuf_reset_headroom(pkt);
 	pkt->data_len = tx_pkt_seg_lengths[0];
-	pkt->ol_flags = ol_flags;
+	pkt->ol_flags &= EXT_ATTACHED_MBUF;
+	pkt->ol_flags |= ol_flags;
 	pkt->vlan_tci = vlan_tci;
 	pkt->vlan_tci_outer = vlan_tci_outer;
 	pkt->l2_len = sizeof(struct rte_ether_hdr);