[dpdk-stable] patch 'net/virtio: disable LSC interrupt if MSIX not enabled' has been queued to stable release 17.02.1

[Yuanhan Liu]

Hi,

FYI, your patch has been queued to stable release 17.02.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/28/17. So please
shout if anyone has objections.

Thanks.

	--yliu

---
>From 3e74b26bb2d9dff9a01c917bc83309d6da36afec Mon Sep 17 00:00:00 2001
From: Matt Peters <matt.peters at windriver.com>
Date: Thu, 9 Mar 2017 15:28:02 -0500
Subject: [PATCH] net/virtio: disable LSC interrupt if MSIX not enabled

[ upstream commit a5ed844846aefeefb1df3df15e6588c265452f19 ]

The link state change interrupt can only be configured if the virtio device
supports MSIX.  Prior to this change the writing of the vector to the PCI
config space was causing it to overwrite the initial part of the MAC
address since the MSIX vector is not in the config space and is occupied by
the MAC address.

This has been reproduced in Virtual Box (v5.0.30.r112061) in Windows 7.

Fixes: 954ea11540b6 ("virtio: do not report link state feature unless available")

Signed-off-by: Matt Peters <matt.peters at windriver.com>
Signed-off-by: Allain Legacy <allain.legacy at windriver.com>
---
 drivers/net/virtio/virtio_ethdev.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 4dc03b9..66770fc 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1338,11 +1338,11 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 		rte_eth_copy_pci_info(eth_dev, pci_dev);
 	}
 
-	/* If host does not support status then disable LSC */
-	if (!vtpci_with_feature(hw, VIRTIO_NET_F_STATUS))
-		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
-	else
+	/* If host does not support both status and MSI-X then disable LSC */
+	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) && hw->use_msix)
 		eth_dev->data->dev_flags |= RTE_ETH_DEV_INTR_LSC;
+	else
+		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
 
 	rx_func_get(eth_dev);
 
-- 
1.9.0