[dpdk-stable] patch 'vhost: fix virtqueues metadata allocation' has been queued to stable release 19.11.6

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/11/20. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/59bdbb385cfbfa370af8e7f1c8176231596b358a

Thanks.

Luca Boccassi

---
>From 59bdbb385cfbfa370af8e7f1c8176231596b358a Mon Sep 17 00:00:00 2001
From: Maxime Coquelin <maxime.coquelin at redhat.com>
Date: Mon, 19 Oct 2020 19:34:09 +0200
Subject: [PATCH] vhost: fix virtqueues metadata allocation

[ upstream commit 8acd7c21335305426fbbc0a3aea2978734d0b2a8 ]

The Vhost-user backend implementation assumes there will be
no holes in the device's array of virtqueues metadata
pointers.

It can happen though, and would cause segmentation faults,
memory leaks or undefined behaviour.

This patch keep the assumption that there is no holes in this
array, and allocate all uninitialized virtqueues metadata up
to requested index.

Fixes: 160cbc815b41 ("vhost: remove a hack on queue allocation")

Suggested-by: Adrian Moreno <amorenoz at redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>
---
 lib/librte_vhost/vhost.c | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 20fda61518..0d65719f33 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -560,22 +560,29 @@ int
 alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 {
 	struct vhost_virtqueue *vq;
+	uint32_t i;
 
-	vq = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0);
-	if (vq == NULL) {
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"Failed to allocate memory for vring:%u.\n", vring_idx);
-		return -1;
+	/* Also allocate holes, if any, up to requested vring index. */
+	for (i = 0; i <= vring_idx; i++) {
+		if (dev->virtqueue[i])
+			continue;
+
+		vq = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0);
+		if (vq == NULL) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"Failed to allocate memory for vring:%u.\n", i);
+			return -1;
+		}
+
+		dev->virtqueue[i] = vq;
+		init_vring_queue(dev, vring_idx);
+		rte_spinlock_init(&vq->access_lock);
+		vq->avail_wrap_counter = 1;
+		vq->used_wrap_counter = 1;
+		vq->signalled_used_valid = false;
 	}
 
-	dev->virtqueue[vring_idx] = vq;
-	init_vring_queue(dev, vring_idx);
-	rte_spinlock_init(&vq->access_lock);
-	vq->avail_wrap_counter = 1;
-	vq->used_wrap_counter = 1;
-	vq->signalled_used_valid = false;
-
-	dev->nr_vring += 1;
+	dev->nr_vring = RTE_MAX(dev->nr_vring, vring_idx + 1);
 
 	return 0;
 }
-- 
2.27.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-11-09 18:40:12.780792043 +0000
+++ 0040-vhost-fix-virtqueues-metadata-allocation.patch	2020-11-09 18:40:11.163311780 +0000
@@ -1 +1 @@
-From 8acd7c21335305426fbbc0a3aea2978734d0b2a8 Mon Sep 17 00:00:00 2001
+From 59bdbb385cfbfa370af8e7f1c8176231596b358a Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 8acd7c21335305426fbbc0a3aea2978734d0b2a8 ]
+
@@ -18 +19,0 @@
-Cc: stable at dpdk.org
@@ -28 +29 @@
-index 6068c38ec6..0c9ba3b3af 100644
+index 20fda61518..0d65719f33 100644
@@ -31 +32 @@
-@@ -579,22 +579,29 @@ int
+@@ -560,22 +560,29 @@ int
@@ -39 +40 @@
--		VHOST_LOG_CONFIG(ERR,
+-		RTE_LOG(ERR, VHOST_CONFIG,
@@ -49 +50 @@
-+			VHOST_LOG_CONFIG(ERR,
++			RTE_LOG(ERR, VHOST_CONFIG,