[dpdk-dev] [PATCH] kni: fix compilation issue on kernel 3.19

[Pablo de Lara]

Due to commit c0371da6 in kernel 3.19, which removed msg_iov
and msg_iovlen from struct msghdr, DPDK would not build.

This patch makes use of struct iov_iter, which has references
to those two variables.

Reported-by: Thomas Monjalon <thomas.monjalon at 6wind.com>
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
---
 lib/librte_eal/linuxapp/kni/compat.h    |    4 ++++
 lib/librte_eal/linuxapp/kni/kni_vhost.c |   13 ++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eal/linuxapp/kni/compat.h b/lib/librte_eal/linuxapp/kni/compat.h
index 1313523..1ad22ba 100644
--- a/lib/librte_eal/linuxapp/kni/compat.h
+++ b/lib/librte_eal/linuxapp/kni/compat.h
@@ -19,3 +19,7 @@
 #define sk_sleep(s) (s)->sk_sleep
 
 #endif /* < 2.6.35 */
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0)
+#define HAVE_IOV_ITER_MSGHDR
+#endif
diff --git a/lib/librte_eal/linuxapp/kni/kni_vhost.c b/lib/librte_eal/linuxapp/kni/kni_vhost.c
index 7141f83..a2fd97f 100644
--- a/lib/librte_eal/linuxapp/kni/kni_vhost.c
+++ b/lib/librte_eal/linuxapp/kni/kni_vhost.c
@@ -76,7 +76,7 @@ static struct proto kni_raw_proto = {
 };
 
 static inline int
-kni_vhost_net_tx(struct kni_dev *kni, struct iovec *iov,
+kni_vhost_net_tx(struct kni_dev *kni, const struct iovec *iov,
 		 unsigned offset, unsigned len)
 {
 	struct rte_kni_mbuf *pkt_kva = NULL;
@@ -143,7 +143,7 @@ drop:
 }
 
 static inline int
-kni_vhost_net_rx(struct kni_dev *kni, struct iovec *iov,
+kni_vhost_net_rx(struct kni_dev *kni, const struct iovec *iov,
 		 unsigned offset, unsigned len)
 {
 	uint32_t pkt_len;
@@ -361,8 +361,11 @@ kni_sock_sndmsg(struct kiocb *iocb, struct socket *sock,
 
 	if (unlikely(len < ETH_HLEN + q->vnet_hdr_sz))
 		return -EINVAL;
-
+#ifdef HAVE_IOV_ITER_MSGHDR
+	return kni_vhost_net_tx(q->kni, m->msg_iter.iov, vnet_hdr_len, len);
+#else
 	return kni_vhost_net_tx(q->kni, m->msg_iov, vnet_hdr_len, len);
+#endif
 }
 
 static int
@@ -391,7 +394,11 @@ kni_sock_rcvmsg(struct kiocb *iocb, struct socket *sock,
 #endif
 
 	if (unlikely(0 == (pkt_len = kni_vhost_net_rx(q->kni,
+#ifdef HAVE_IOV_ITER_MSGHDR
+		m->msg_iter.iov, vnet_hdr_len, len))))
+#else
 		m->msg_iov, vnet_hdr_len, len))))
+#endif
 		return 0;
 
 #ifdef RTE_KNI_VHOST_VNET_HDR_EN
-- 
1.7.4.1