[dpdk-dev] [PATCH 1/3] vhost: Fix wrong handling of virtqueue array index

[Tetsuya Mukawa <mukawa@igel.co.jp>]

The patch fixes wrong handling of virtqueue array index.

GET_VRING_BASE:
The vhost backend will receive the message per virtqueue.
Also we should call a destroy callback when both RXQ and TXQ receives
the message.

SET_BACKEND:
Because vhost library supports multiple queue, the index may be over 2.
Also a vhost frontend(QEMU) may send such a index.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 lib/librte_vhost/vhost_user/virtio-net-user.c | 22 +++++++++++-----------
 lib/librte_vhost/virtio-net.c                 |  5 +++--
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index a998ad8..3e8dfea 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -283,12 +283,10 @@ user_get_vring_base(struct vhost_device_ctx ctx,
 	struct vhost_vring_state *state)
 {
 	struct virtio_net *dev = get_device(ctx);
+	uint16_t base_idx = state->index / VIRTIO_QNUM;
 
 	if (dev == NULL)
 		return -1;
-	/* We have to stop the queue (virtio) if it is running. */
-	if (dev->flags & VIRTIO_DEV_RUNNING)
-		notify_ops->destroy_device(dev);
 
 	/* Here we are safe to get the last used index */
 	ops->get_vring_base(ctx, state->index, state);
@@ -300,15 +298,17 @@ user_get_vring_base(struct vhost_device_ctx ctx,
 	 * sent and only sent in vhost_vring_stop.
 	 * TODO: cleanup the vring, it isn't usable since here.
 	 */
-	if (dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd >= 0) {
-		close(dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd);
-		dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd = -1;
-	}
-	if (dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd >= 0) {
-		close(dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd);
-		dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd = -1;
+	if (dev->virtqueue[state->index]->kickfd >= 0) {
+		close(dev->virtqueue[state->index]->kickfd);
+		dev->virtqueue[state->index]->kickfd = -1;
 	}
 
+	/* We have to stop the queue (virtio) if it is running. */
+	if ((dev->flags & VIRTIO_DEV_RUNNING) &&
+			(dev->virtqueue[base_idx + VIRTIO_RXQ]->kickfd == -1) &&
+			(dev->virtqueue[base_idx + VIRTIO_TXQ]->kickfd == -1))
+		notify_ops->destroy_device(dev);
+
 	return 0;
 }
 
@@ -321,7 +321,7 @@ user_set_vring_enable(struct vhost_device_ctx ctx,
 		      struct vhost_vring_state *state)
 {
 	struct virtio_net *dev = get_device(ctx);
-	uint16_t base_idx = state->index;
+	uint16_t base_idx = state->index / VIRTIO_QNUM;
 	int enable = (int)state->num;
 
 	RTE_LOG(INFO, VHOST_CONFIG,
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 97213c5..ee2e84d 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -778,6 +778,7 @@ static int
 set_backend(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
 {
 	struct virtio_net *dev;
+	uint32_t base_idx = file->index / VIRTIO_QNUM;
 
 	dev = get_device(ctx);
 	if (dev == NULL)
@@ -791,8 +792,8 @@ set_backend(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
 	 * we add the device.
 	 */
 	if (!(dev->flags & VIRTIO_DEV_RUNNING)) {
-		if (((int)dev->virtqueue[VIRTIO_TXQ]->backend != VIRTIO_DEV_STOPPED) &&
-			((int)dev->virtqueue[VIRTIO_RXQ]->backend != VIRTIO_DEV_STOPPED)) {
+		if (((int)dev->virtqueue[base_idx + VIRTIO_RXQ]->backend != VIRTIO_DEV_STOPPED) &&
+			((int)dev->virtqueue[base_idx + VIRTIO_TXQ]->backend != VIRTIO_DEV_STOPPED)) {
 			return notify_ops->new_device(dev);
 		}
 	/* Otherwise we remove it. */
-- 
2.1.4