[dpdk-stable] patch 'net/tap: fix getting max iovec' has been queued to LTS release 18.11.2

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 04/24/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Kevin Traynor

---
>From 454c44c9b9d1801e4210b7c4c0f40c42b324a96a Mon Sep 17 00:00:00 2001
From: Oleg Polyakov <olegp123 at walla.co.il>
Date: Mon, 18 Mar 2019 14:20:47 -0400
Subject: [PATCH] net/tap: fix getting max iovec

[ upstream commit efa28ae847546a1376b2112544490251dd0ea5cd ]

If the value _SC_IOV_MAX is missing, sysconf returns -1.
In this case, iov_max is set to a default value of 1024.
This should never happen except for redhat bug:
   https://bugzilla.redhat.com/show_bug.cgi?id=1504165

Fixes: ec12df9504fe ("net/tap: fix support for large Rx queues")

Signed-off-by: Oleg Polyakov <olegp123 at walla.co.il>
Acked-by: Keith Wiles <keith.wiles at intel.com>
---
 drivers/net/tap/rte_eth_tap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 17273eb68..d16bc8c7f 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -68,4 +68,6 @@
 #define TAP_MP_KEY "tap_mp_sync_queues"
 
+#define TAP_IOV_DEFAULT_MAX 1024
+
 static int tap_devices_count;
 static struct rte_vdev_driver pmd_tap_drv;
@@ -1327,4 +1329,11 @@ tap_rx_queue_setup(struct rte_eth_dev *dev,
 	struct rte_mbuf **tmp = &rxq->pool;
 	long iov_max = sysconf(_SC_IOV_MAX);
+
+	if (iov_max <= 0) {
+		TAP_LOG(WARNING,
+			"_SC_IOV_MAX is not defined. Using %d as default",
+			TAP_IOV_DEFAULT_MAX);
+		iov_max = TAP_IOV_DEFAULT_MAX;
+	}
 	uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
 	struct iovec (*iovecs)[nb_desc + 1];
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-04-16 15:34:26.750037671 +0100
+++ 0035-net-tap-fix-getting-max-iovec.patch	2019-04-16 15:34:25.186179817 +0100
@@ -1,15 +1,16 @@
-From efa28ae847546a1376b2112544490251dd0ea5cd Mon Sep 17 00:00:00 2001
+From 454c44c9b9d1801e4210b7c4c0f40c42b324a96a Mon Sep 17 00:00:00 2001
 From: Oleg Polyakov <olegp123 at walla.co.il>
 Date: Mon, 18 Mar 2019 14:20:47 -0400
 Subject: [PATCH] net/tap: fix getting max iovec
 
+[ upstream commit efa28ae847546a1376b2112544490251dd0ea5cd ]
+
 If the value _SC_IOV_MAX is missing, sysconf returns -1.
 In this case, iov_max is set to a default value of 1024.
 This should never happen except for redhat bug:
    https://bugzilla.redhat.com/show_bug.cgi?id=1504165
 
 Fixes: ec12df9504fe ("net/tap: fix support for large Rx queues")
-Cc: stable at dpdk.org
 
 Signed-off-by: Oleg Polyakov <olegp123 at walla.co.il>
 Acked-by: Keith Wiles <keith.wiles at intel.com>
@@ -18,10 +19,10 @@
  1 file changed, 9 insertions(+)
 
 diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
-index 6f5109fca..9aae4c77f 100644
+index 17273eb68..d16bc8c7f 100644
 --- a/drivers/net/tap/rte_eth_tap.c
 +++ b/drivers/net/tap/rte_eth_tap.c
-@@ -69,4 +69,6 @@
+@@ -68,4 +68,6 @@
  #define TAP_MP_KEY "tap_mp_sync_queues"
  
 +#define TAP_IOV_DEFAULT_MAX 1024