[dpdk-stable] patch 'vhost: fix shadowed descriptors not flushed' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. 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.

Thanks.

Luca Boccassi

---
>From 74a51ef091b2366b7c7751594da270eaa34187d6 Mon Sep 17 00:00:00 2001
From: Marvin Liu <yong.liu at intel.com>
Date: Fri, 17 Apr 2020 09:16:09 +0800
Subject: [PATCH] vhost: fix shadowed descriptors not flushed

[ upstream commit c7de6f9be56793a681964b2ff3ee234e9d1d551a ]

When ring size or enqueue packets not aligned with batch number, it is
possible that descs update still kept in shadowed used structure when
batched enqueue. Fix this issue by flushing remained shadowed used descs
before batch flush.

Fixes: f41516c309d7 ("vhost: flush batched enqueue descs directly")

Signed-off-by: Marvin Liu <yong.liu at intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 lib/librte_vhost/virtio_net.c | 65 +++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 30 deletions(-)

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 4c7ae29a36..22dcdf72bd 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -43,6 +43,36 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)
 	return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
 }
 
+static inline void
+do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+	struct batch_copy_elem *elem = vq->batch_copy_elems;
+	uint16_t count = vq->batch_copy_nb_elems;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
+		vhost_log_cache_write_iova(dev, vq, elem[i].log_addr,
+					   elem[i].len);
+		PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
+	}
+
+	vq->batch_copy_nb_elems = 0;
+}
+
+static inline void
+do_data_copy_dequeue(struct vhost_virtqueue *vq)
+{
+	struct batch_copy_elem *elem = vq->batch_copy_elems;
+	uint16_t count = vq->batch_copy_nb_elems;
+	int i;
+
+	for (i = 0; i < count; i++)
+		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
+
+	vq->batch_copy_nb_elems = 0;
+}
+
 static __rte_always_inline void
 do_flush_shadow_used_ring_split(struct virtio_net *dev,
 			struct vhost_virtqueue *vq,
@@ -186,6 +216,11 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
 	uint16_t i;
 	uint16_t flags;
 
+	if (vq->shadow_used_idx) {
+		do_data_copy_enqueue(dev, vq);
+		vhost_flush_enqueue_shadow_packed(dev, vq);
+	}
+
 	flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter);
 
 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
@@ -325,36 +360,6 @@ vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue *vq,
 	vq_inc_last_used_packed(vq, count);
 }
 
-static inline void
-do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
-{
-	struct batch_copy_elem *elem = vq->batch_copy_elems;
-	uint16_t count = vq->batch_copy_nb_elems;
-	int i;
-
-	for (i = 0; i < count; i++) {
-		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
-		vhost_log_cache_write_iova(dev, vq, elem[i].log_addr,
-					   elem[i].len);
-		PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
-	}
-
-	vq->batch_copy_nb_elems = 0;
-}
-
-static inline void
-do_data_copy_dequeue(struct vhost_virtqueue *vq)
-{
-	struct batch_copy_elem *elem = vq->batch_copy_elems;
-	uint16_t count = vq->batch_copy_nb_elems;
-	int i;
-
-	for (i = 0; i < count; i++)
-		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
-
-	vq->batch_copy_nb_elems = 0;
-}
-
 static __rte_always_inline void
 vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
 				   struct vhost_virtqueue *vq,
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 14:04:48.535325259 +0100
+++ 0100-vhost-fix-shadowed-descriptors-not-flushed.patch	2020-05-19 14:04:44.312650112 +0100
@@ -1,15 +1,16 @@
-From c7de6f9be56793a681964b2ff3ee234e9d1d551a Mon Sep 17 00:00:00 2001
+From 74a51ef091b2366b7c7751594da270eaa34187d6 Mon Sep 17 00:00:00 2001
 From: Marvin Liu <yong.liu at intel.com>
 Date: Fri, 17 Apr 2020 09:16:09 +0800
 Subject: [PATCH] vhost: fix shadowed descriptors not flushed
 
+[ upstream commit c7de6f9be56793a681964b2ff3ee234e9d1d551a ]
+
 When ring size or enqueue packets not aligned with batch number, it is
 possible that descs update still kept in shadowed used structure when
 batched enqueue. Fix this issue by flushing remained shadowed used descs
 before batch flush.
 
 Fixes: f41516c309d7 ("vhost: flush batched enqueue descs directly")
-Cc: stable at dpdk.org
 
 Signed-off-by: Marvin Liu <yong.liu at intel.com>
 Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
@@ -18,7 +19,7 @@
  1 file changed, 35 insertions(+), 30 deletions(-)
 
 diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
-index 4a75319432..1fc30c6819 100644
+index 4c7ae29a36..22dcdf72bd 100644
 --- a/lib/librte_vhost/virtio_net.c
 +++ b/lib/librte_vhost/virtio_net.c
 @@ -43,6 +43,36 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)