[dpdk-dev] [PATCH v4 2/2] vhost: remove pending IOTLB entry if IOTLB MISS request sending failed

[Maxime Coquelin <maxime.coquelin@redhat.com>]

In case vhost_user_iotlb_miss returns an error, the pending IOTLB
entry has to be removed from the list as no IOTLB update will be
received.

Fixes: fed67a20ac94 ("vhost: introduce guest IOVA to backend VA helper")

Cc: stable@dpdk.org
Suggested-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/iotlb.c |  2 +-
 lib/librte_vhost/iotlb.h |  3 +++
 lib/librte_vhost/vhost.c | 13 ++++++++++---
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/lib/librte_vhost/iotlb.c b/lib/librte_vhost/iotlb.c
index 72cd27df8..c11ebcaac 100644
--- a/lib/librte_vhost/iotlb.c
+++ b/lib/librte_vhost/iotlb.c
@@ -120,7 +120,7 @@ vhost_user_iotlb_pending_insert(struct vhost_virtqueue *vq,
 	rte_rwlock_write_unlock(&vq->iotlb_pending_lock);
 }
 
-static void
+void
 vhost_user_iotlb_pending_remove(struct vhost_virtqueue *vq,
 				uint64_t iova, uint64_t size, uint8_t perm)
 {
diff --git a/lib/librte_vhost/iotlb.h b/lib/librte_vhost/iotlb.h
index f1a050e44..e7083e37b 100644
--- a/lib/librte_vhost/iotlb.h
+++ b/lib/librte_vhost/iotlb.h
@@ -71,6 +71,9 @@ bool vhost_user_iotlb_pending_miss(struct vhost_virtqueue *vq, uint64_t iova,
 						uint8_t perm);
 void vhost_user_iotlb_pending_insert(struct vhost_virtqueue *vq, uint64_t iova,
 						uint8_t perm);
+void vhost_user_iotlb_pending_remove(struct vhost_virtqueue *vq, uint64_t iova,
+						uint64_t size, uint8_t perm);
+
 int vhost_user_iotlb_init(struct virtio_net *dev, int vq_index);
 
 #endif /* _VHOST_IOTLB_H_ */
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 1dd9adbc7..a373444e9 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -42,7 +42,9 @@ __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	if (tmp_size == size)
 		return vva;
 
-	if (!vhost_user_iotlb_pending_miss(vq, iova + tmp_size, perm)) {
+	iova += tmp_size;
+
+	if (!vhost_user_iotlb_pending_miss(vq, iova, perm)) {
 		/*
 		 * iotlb_lock is read-locked for a full burst,
 		 * but it only protects the iotlb cache.
@@ -52,8 +54,13 @@ __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
 		 */
 		vhost_user_iotlb_rd_unlock(vq);
 
-		vhost_user_iotlb_pending_insert(vq, iova + tmp_size, perm);
-		vhost_user_iotlb_miss(dev, iova + tmp_size, perm);
+		vhost_user_iotlb_pending_insert(vq, iova, perm);
+		if (vhost_user_iotlb_miss(dev, iova, perm)) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+					"IOTLB miss req failed for IOVA 0x%" PRIx64 "\n",
+					iova);
+			vhost_user_iotlb_pending_remove(vq, iova, 1, perm);
+		}
 
 		vhost_user_iotlb_rd_lock(vq);
 	}
-- 
2.14.3