[PATCH vhost v2 13/19] virtio_net: set premapped mode by find_vqs()

[Xuan Zhuo]

Now, the virtio core can set the premapped mode by find_vqs().
If the premapped can be enabled, the dma array will not be
allocated. So virtio-net use the api of find_vqs to enable the
premapped.

Judge the premapped mode by the vq->premapped instead of saving
local variable.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c      | 57 +++++++++++++++++------------------
 include/linux/virtio_config.h | 16 ++--------
 2 files changed, 29 insertions(+), 44 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d7ce4a1011ea..140b2c155650 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -208,9 +208,6 @@ struct receive_queue {
 
 	/* Record the last dma info to free after new pages is allocated. */
 	struct virtnet_rq_dma *last_dma;
-
-	/* Do dma by self */
-	bool do_dma;
 };
 
 /* This structure can contain rss message with maximum settings for indirection table and keysize
@@ -657,7 +654,7 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
 	void *buf;
 
 	buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
-	if (buf && rq->do_dma)
+	if (buf && rq->vq->premapped)
 		virtnet_rq_unmap(rq, buf, *len);
 
 	return buf;
@@ -670,7 +667,7 @@ static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
 	u32 offset;
 	void *head;
 
-	if (!rq->do_dma) {
+	if (!rq->vq->premapped) {
 		sg_init_one(rq->sg, buf, len);
 		return;
 	}
@@ -700,7 +697,7 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
 
 	head = page_address(alloc_frag->page);
 
-	if (rq->do_dma) {
+	if (rq->vq->premapped) {
 		dma = head;
 
 		/* new pages */
@@ -746,22 +743,6 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
 	return buf;
 }
 
-static void virtnet_rq_set_premapped(struct virtnet_info *vi)
-{
-	int i;
-
-	/* disable for big mode */
-	if (!vi->mergeable_rx_bufs && vi->big_packets)
-		return;
-
-	for (i = 0; i < vi->max_queue_pairs; i++) {
-		if (virtqueue_set_dma_premapped(vi->rq[i].vq))
-			continue;
-
-		vi->rq[i].do_dma = true;
-	}
-}
-
 static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
 {
 	struct virtnet_info *vi = vq->vdev->priv;
@@ -770,7 +751,7 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
 
 	rq = &vi->rq[i];
 
-	if (rq->do_dma)
+	if (rq->vq->premapped)
 		virtnet_rq_unmap(rq, buf, 0);
 
 	virtnet_rq_free_buf(vi, rq, buf);
@@ -1865,7 +1846,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 
 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 	if (err < 0) {
-		if (rq->do_dma)
+		if (rq->vq->premapped)
 			virtnet_rq_unmap(rq, buf, 0);
 		put_page(virt_to_head_page(buf));
 	}
@@ -1980,7 +1961,7 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
 	ctx = mergeable_len_to_ctx(len + room, headroom);
 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 	if (err < 0) {
-		if (rq->do_dma)
+		if (rq->vq->premapped)
 			virtnet_rq_unmap(rq, buf, 0);
 		put_page(virt_to_head_page(buf));
 	}
@@ -4229,7 +4210,7 @@ static void free_receive_page_frags(struct virtnet_info *vi)
 	int i;
 	for (i = 0; i < vi->max_queue_pairs; i++)
 		if (vi->rq[i].alloc_frag.page) {
-			if (vi->rq[i].do_dma && vi->rq[i].last_dma)
+			if (vi->rq[i].vq->premapped && vi->rq[i].last_dma)
 				virtnet_rq_unmap(&vi->rq[i], vi->rq[i].last_dma, 0);
 			put_page(vi->rq[i].alloc_frag.page);
 		}
@@ -4293,11 +4274,13 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu
 
 static int virtnet_find_vqs(struct virtnet_info *vi)
 {
+	struct virtio_vq_config cfg = {};
 	vq_callback_t **callbacks;
 	struct virtqueue **vqs;
 	const char **names;
 	int ret = -ENOMEM;
 	int total_vqs;
+	bool *premapped;
 	bool *ctx;
 	u16 i;
 
@@ -4322,8 +4305,13 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
 		ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
 		if (!ctx)
 			goto err_ctx;
+
+		premapped = kcalloc(total_vqs, sizeof(*premapped), GFP_KERNEL);
+		if (!ctx)
+			goto err_premapped;
 	} else {
 		ctx = NULL;
+		premapped = NULL;
 	}
 
 	/* Parameters for control virtqueue, if any */
@@ -4342,10 +4330,19 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
 		names[txq2vq(i)] = vi->sq[i].name;
 		if (ctx)
 			ctx[rxq2vq(i)] = true;
+
+		if (premapped)
+			premapped[rxq2vq(i)] = true;
 	}
 
-	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
-				  names, ctx, NULL);
+	cfg.nvqs      = total_vqs;
+	cfg.vqs       = vqs;
+	cfg.callbacks = callbacks;
+	cfg.names     = names;
+	cfg.ctx       = ctx;
+	cfg.premapped = premapped;
+
+	ret = virtio_find_vqs_cfg(vi->vdev, &cfg);
 	if (ret)
 		goto err_find;
 
@@ -4365,6 +4362,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
 
 
 err_find:
+	kfree(premapped);
+err_premapped:
 	kfree(ctx);
 err_ctx:
 	kfree(names);
@@ -4437,8 +4436,6 @@ static int init_vqs(struct virtnet_info *vi)
 	if (ret)
 		goto err_free;
 
-	virtnet_rq_set_premapped(vi);
-
 	cpus_read_lock();
 	virtnet_set_affinity(vi);
 	cpus_read_unlock();
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index f1f62e57f395..e40509fef5fe 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -260,21 +260,9 @@ int virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 }
 
 static inline
-int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
-			struct virtqueue *vqs[], vq_callback_t *callbacks[],
-			const char * const names[], const bool *ctx,
-			struct irq_affinity *desc)
+int virtio_find_vqs_cfg(struct virtio_device *vdev, struct virtio_vq_config *cfg)
 {
-	struct virtio_vq_config cfg = {};
-
-	cfg.nvqs = nvqs;
-	cfg.vqs = vqs;
-	cfg.callbacks = callbacks;
-	cfg.names = (const char **)names;
-	cfg.ctx = ctx;
-	cfg.desc = desc;
-
-	return vdev->config->find_vqs(vdev, &cfg);
+	return vdev->config->find_vqs(vdev, cfg);
 }
 
 /**
-- 
2.32.0.3.g01195cf9f