patch 'net/virtio: fix crash when configured twice' has been queued to stable release 20.11.7

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/05/22. 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.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/da94f7c81e620ef271a0458f6f8133102ce75760

Thanks.

Luca Boccassi

---
>From da94f7c81e620ef271a0458f6f8133102ce75760 Mon Sep 17 00:00:00 2001
From: Alexander Chernavin <achernavin at netgate.com>
Date: Tue, 27 Sep 2022 10:15:04 +0000
Subject: [PATCH] net/virtio: fix crash when configured twice

[ upstream commit 52bd03e969e9b38a7357287aece2488c7f92158f ]

When first attempt to configure a device with RX interrupt enabled fails
for some reason (e.g. because "Multiple intr vector not supported"),
second attempt to configure the device with RX interrupt disabled and
feature set unchanged will succeed but will leave virtio queues not
allocated. Accessing the queues will cause a segfault.

First attempt:
  - virtio_dev_configure()
    - virtio_init_device() is called to reinit the device because
      "dev->data->dev_conf.intr_conf.rxq" is "1"
      - virtio_configure_intr() fails and returns an error
      - virtio_free_queues() frees previously allocated virtio queues
    - virtio_init_device() fails and returns an error
  - virtio_dev_configure() fails and returns an error

Second attempt:
  - virtio_dev_configure()
    - This time virtio_init_device() is not called, virtio queues
      are not allocated

With this fix, reinit the device during configuration if virtio queues
are not allocated.

Fixes: 2b38151f745a ("net/virtio: fix queue memory leak on error")

Signed-off-by: Alexander Chernavin <achernavin at netgate.com>
Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>
---
 drivers/net/virtio/virtio_ethdev.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 511735a6bf..ce612f7400 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -2356,6 +2356,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return ret;
 	}
 
+	/* if queues are not allocated, reinit the device */
+	if (hw->vqs == NULL) {
+		ret = virtio_init_device(dev, hw->req_guest_features);
+		if (ret < 0)
+			return ret;
+	}
+
 	if ((rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
 			    DEV_RX_OFFLOAD_TCP_CKSUM)) &&
 		!vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM)) {
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-11-03 09:27:27.804086418 +0000
+++ 0039-net-virtio-fix-crash-when-configured-twice.patch	2022-11-03 09:27:25.413423215 +0000
@@ -1 +1 @@
-From 52bd03e969e9b38a7357287aece2488c7f92158f Mon Sep 17 00:00:00 2001
+From da94f7c81e620ef271a0458f6f8133102ce75760 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 52bd03e969e9b38a7357287aece2488c7f92158f ]
+
@@ -30 +31,0 @@
-Cc: stable at dpdk.org
@@ -39 +40 @@
-index 7e07270a8b..574f671158 100644
+index 511735a6bf..ce612f7400 100644
@@ -42 +43 @@
-@@ -2617,6 +2617,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
+@@ -2356,6 +2356,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
@@ -53,3 +54,3 @@
- 	if ((rxmode->mq_mode & RTE_ETH_MQ_RX_RSS_FLAG) &&
- 			!virtio_with_feature(hw, VIRTIO_NET_F_RSS)) {
- 		PMD_DRV_LOG(ERR, "RSS support requested but not supported by the device");
+ 	if ((rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
+ 			    DEV_RX_OFFLOAD_TCP_CKSUM)) &&
+ 		!vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM)) {