[dpdk-stable] patch 'net/virtio: revert not claiming IP checksum offload' has been queued to stable release 17.08.1

[Yuanhan Liu]

Hi,

FYI, your patch has been queued to stable release 17.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/24/17. So please
shout if anyone has objections.

Thanks.

	--yliu

---
>From 71208f62d7f569899207f4d77371833bd1b0c12b Mon Sep 17 00:00:00 2001
From: Olivier Matz <olivier.matz at 6wind.com>
Date: Thu, 7 Sep 2017 14:13:39 +0200
Subject: [PATCH] net/virtio: revert not claiming IP checksum offload

[ upstream commit d67d86ce5b0a149946f86161e507402ddce2038d ]

This reverts
commit 4dab342b7522 ("net/virtio: do not falsely claim to do IP checksum").

The description of rxmode->hw_ip_checksum is:

     hw_ip_checksum   : 1, /**< IP/UDP/TCP checksum offload enable. */

Despite its name, this field can be set by an application to enable L3
and L4 checksums. In case of virtio, only L4 checksum is supported and
L3 checksums flags will always be set to "unknown".

Fixes: 4dab342b7522 ("net/virtio: do not falsely claim to do IP checksum")

Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
Acked-by: Yuanhan Liu <yliu at fridaylinux.org>
---
 drivers/net/virtio/virtio_ethdev.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index eb2d95a..7a84817 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1671,12 +1671,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return ret;
 	}
 
-	/* Virtio does L4 checksum but not L3! */
-	if (rxmode->hw_ip_checksum) {
-		PMD_DRV_LOG(NOTICE,
-			    "virtio does not support IP checksum");
-		return -ENOTSUP;
-	}
+	/* The name hw_ip_checksum is a bit confusing since it can be
+	 * set by the application to request L3 and/or L4 checksums. In
+	 * case of virtio, only L4 checksum is supported.
+	 */
+	if (rxmode->hw_ip_checksum)
+		req_features |= (1ULL << VIRTIO_NET_F_GUEST_CSUM);
+
 	if (rxmode->enable_lro)
 		req_features |=
 			(1ULL << VIRTIO_NET_F_GUEST_TSO4) |
@@ -1689,6 +1690,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return ret;
 	}
 
+	if (rxmode->hw_ip_checksum &&
+		!vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM)) {
+		PMD_DRV_LOG(NOTICE,
+			"rx checksum not available on this host");
+		return -ENOTSUP;
+	}
+
 	if (rxmode->enable_lro &&
 		(!vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
 			!vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4))) {
-- 
2.7.4