[dpdk-dev] [PATCH v6 3/4] example/kni: add IOVA support for kni application

[vattunuru at marvell.com]

From: Vamsi Attunuru <vattunuru at marvell.com>

Current KNI implementation operates in IOVA = PA mode,
Patch adds support for IOVA = VA mode by addressing
the issues with page address translations(IOVA <==> KVA).

In this patch KNI application creates mempool with
"MEMPOOL_F_NO_PAGE_BOUND" flag to ensure all mbuf memory
is with in the page boundaries and subsequently kernel KNI
module uses iommu_iova_to_phys() and phys_to_virt() APIs
to get the kernel virtual addresses.

Signed-off-by: Vamsi Attunuru <vattunuru at marvell.com>
Signed-off-by: Kiran Kumar K <kirankumark at marvell.com>
---
 examples/kni/main.c                               | 53 ++++++++++++++++++++++-
 lib/librte_eal/linux/eal/eal.c                    |  8 ----
 lib/librte_eal/linux/eal/include/rte_kni_common.h |  1 +
 lib/librte_kni/rte_kni.c                          |  2 +
 4 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/examples/kni/main.c b/examples/kni/main.c
index 4710d71..13083a7 100644
--- a/examples/kni/main.c
+++ b/examples/kni/main.c
@@ -37,6 +37,7 @@
 #include <rte_ethdev.h>
 #include <rte_mempool.h>
 #include <rte_mbuf.h>
+#include <rte_mbuf_pool_ops.h>
 #include <rte_string_fns.h>
 #include <rte_cycles.h>
 #include <rte_malloc.h>
@@ -945,6 +946,56 @@ kni_free_kni(uint16_t port_id)
 	return 0;
 }
 
+static struct rte_mempool *
+kni_packet_pool_create(const char *name, unsigned int n,
+	unsigned int cache_size, uint16_t priv_size, uint16_t data_room_size,
+	int socket_id)
+{
+	struct rte_pktmbuf_pool_private mbp_priv;
+	const char *mp_ops_name;
+	struct rte_mempool *mp;
+	unsigned int elt_size;
+	int ret;
+
+	if (RTE_ALIGN(priv_size, RTE_MBUF_PRIV_ALIGN) != priv_size) {
+		RTE_LOG(ERR, MBUF, "mbuf priv_size=%u is not aligned\n",
+			priv_size);
+		rte_errno = EINVAL;
+		return NULL;
+	}
+	elt_size = sizeof(struct rte_mbuf) + (unsigned int)priv_size +
+		(unsigned int)data_room_size;
+	mbp_priv.mbuf_data_room_size = data_room_size;
+	mbp_priv.mbuf_priv_size = priv_size;
+
+	mp = rte_mempool_create_empty(name, n, elt_size, cache_size,
+		 sizeof(struct rte_pktmbuf_pool_private), socket_id,
+		 MEMPOOL_F_NO_PAGE_BOUND);
+	if (mp == NULL)
+		return NULL;
+
+	mp_ops_name = rte_mbuf_best_mempool_ops();
+	ret = rte_mempool_set_ops_byname(mp, mp_ops_name, NULL);
+	if (ret != 0) {
+		RTE_LOG(ERR, MBUF, "error setting mempool handler\n");
+		rte_mempool_free(mp);
+		rte_errno = -ret;
+		return NULL;
+	}
+	rte_pktmbuf_pool_init(mp, &mbp_priv);
+
+	ret = rte_mempool_populate_default(mp);
+	if (ret < 0) {
+		rte_mempool_free(mp);
+		rte_errno = -ret;
+		return NULL;
+	}
+
+	rte_mempool_obj_iter(mp, rte_pktmbuf_init, NULL);
+
+	return mp;
+}
+
 /* Initialise ports/queues etc. and start main loop on each core */
 int
 main(int argc, char** argv)
@@ -975,7 +1026,7 @@ main(int argc, char** argv)
 		rte_exit(EXIT_FAILURE, "Could not parse input parameters\n");
 
 	/* Create the mbuf pool */
-	pktmbuf_pool = rte_pktmbuf_pool_create("mbuf_pool", NB_MBUF,
+	pktmbuf_pool = kni_packet_pool_create("mbuf_pool", NB_MBUF,
 		MEMPOOL_CACHE_SZ, 0, MBUF_DATA_SZ, rte_socket_id());
 	if (pktmbuf_pool == NULL) {
 		rte_exit(EXIT_FAILURE, "Could not initialise mbuf pool\n");
diff --git a/lib/librte_eal/linux/eal/eal.c b/lib/librte_eal/linux/eal/eal.c
index 3e1d6eb..d143c49 100644
--- a/lib/librte_eal/linux/eal/eal.c
+++ b/lib/librte_eal/linux/eal/eal.c
@@ -1041,14 +1041,6 @@ rte_eal_init(int argc, char **argv)
 		rte_eal_get_configuration()->iova_mode =
 			rte_bus_get_iommu_class();
 
-		/* Workaround for KNI which requires physical address to work */
-		if (rte_eal_get_configuration()->iova_mode == RTE_IOVA_VA &&
-				rte_eal_check_module("rte_kni") == 1) {
-			rte_eal_get_configuration()->iova_mode = RTE_IOVA_PA;
-			RTE_LOG(WARNING, EAL,
-				"Some devices want IOVA as VA but PA will be used because.. "
-				"KNI module inserted\n");
-		}
 	} else {
 		rte_eal_get_configuration()->iova_mode =
 			internal_config.iova_mode;
diff --git a/lib/librte_eal/linux/eal/include/rte_kni_common.h b/lib/librte_eal/linux/eal/include/rte_kni_common.h
index 5db5a13..404c85d 100644
--- a/lib/librte_eal/linux/eal/include/rte_kni_common.h
+++ b/lib/librte_eal/linux/eal/include/rte_kni_common.h
@@ -128,6 +128,7 @@ struct rte_kni_device_info {
 	unsigned mbuf_size;
 	unsigned int mtu;
 	uint8_t mac_addr[6];
+	uint8_t iova_mode;
 };
 
 #define KNI_DEVICE "kni"
diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
index 99c4bf5..4263f21 100644
--- a/lib/librte_kni/rte_kni.c
+++ b/lib/librte_kni/rte_kni.c
@@ -300,6 +300,8 @@ rte_kni_alloc(struct rte_mempool *pktmbuf_pool,
 	kni->group_id = conf->group_id;
 	kni->mbuf_size = conf->mbuf_size;
 
+	dev_info.iova_mode = (rte_eal_iova_mode() == RTE_IOVA_VA) ? 1 : 0;
+
 	ret = ioctl(kni_fd, RTE_KNI_IOCTL_CREATE, &dev_info);
 	if (ret < 0)
 		goto ioctl_fail;
-- 
2.8.4