Commit 86a48a00 authored by Philo Lu's avatar Philo Lu Committed by Paolo Abeni
Browse files

virtio_net: Support dynamic rss indirection table size 



When reading/writing virtio_net_ctrl_rss, we get the indirection table
size from vi->rss_indir_table_size, which is initialized in
virtnet_probe(). However, the actual size of indirection_table was set
as VIRTIO_NET_RSS_MAX_TABLE_LEN=128. This collision may cause issues if
the vi->rss_indir_table_size exceeds 128.

This patch instead uses dynamic indirection table, allocated with
vi->rss after vi->rss_indir_table_size initialized. And free it in
virtnet_remove().

In virtnet_commit_rss_command(), sgs for rss is initialized differently
with hash_report. So indirection_table is not used if !vi->has_rss, and
then we don't need to alloc indirection_table for hash_report only uses.

Fixes: c7114b12 ("drivers/net/virtio_net: Added basic RSS support.")
Signed-off-by: default avatarPhilo Lu <lulie@linux.alibaba.com>
Signed-off-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: default avatarJoe Damato <jdamato@fastly.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 25d70702

drivers/net/virtio_net.c

+34 −5
Original line number Diff line number Diff line
@@ -368,15 +368,16 @@ struct receive_queue { 
 * because table sizes may be differ according to the device configuration.

 */

#define VIRTIO_NET_RSS_MAX_KEY_SIZE     40

#define VIRTIO_NET_RSS_MAX_TABLE_LEN    128

struct virtio_net_ctrl_rss {

	u32 hash_types;

	u16 indirection_table_mask;

	u16 unclassified_queue;

	u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];

	u16 hash_cfg_reserved; /* for HASH_CONFIG (see virtio_net_hash_config for details) */

	u16 max_tx_vq;

	u8 hash_key_length;

	u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];



	u16 *indirection_table;

};



/* Control VQ buffers: protected by the rtnl lock */
@@ -512,6 +513,25 @@ static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, 
					       struct page *page, void *buf,

					       int len, int truesize);



static int rss_indirection_table_alloc(struct virtio_net_ctrl_rss *rss, u16 indir_table_size)

{

	if (!indir_table_size) {

		rss->indirection_table = NULL;

		return 0;

	}



	rss->indirection_table = kmalloc_array(indir_table_size, sizeof(u16), GFP_KERNEL);

	if (!rss->indirection_table)

		return -ENOMEM;



	return 0;

}



static void rss_indirection_table_free(struct virtio_net_ctrl_rss *rss)

{

	kfree(rss->indirection_table);

}



static bool is_xdp_frame(void *ptr)

{

	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
@@ -3828,11 +3848,15 @@ static bool virtnet_commit_rss_command(struct virtnet_info *vi) 
	/* prepare sgs */

	sg_init_table(sgs, 4);



	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);

	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, hash_cfg_reserved);

	sg_set_buf(&sgs[0], &vi->rss, sg_buf_size);



	sg_buf_size = sizeof(uint16_t) * (vi->rss.indirection_table_mask + 1);

	if (vi->has_rss) {

		sg_buf_size = sizeof(uint16_t) * vi->rss_indir_table_size;

		sg_set_buf(&sgs[1], vi->rss.indirection_table, sg_buf_size);

	} else {

		sg_set_buf(&sgs[1], &vi->rss.hash_cfg_reserved, sizeof(uint16_t));

	}



	sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)

			- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
@@ -6420,6 +6444,9 @@ static int virtnet_probe(struct virtio_device *vdev) 
			virtio_cread16(vdev, offsetof(struct virtio_net_config,

				rss_max_indirection_table_length));

	}

	err = rss_indirection_table_alloc(&vi->rss, vi->rss_indir_table_size);

	if (err)

		goto free;



	if (vi->has_rss || vi->has_rss_hash_report) {

		vi->rss_key_size =
@@ -6674,6 +6701,8 @@ static void virtnet_remove(struct virtio_device *vdev) 


	remove_vq_common(vi);



	rss_indirection_table_free(&vi->rss);



	free_netdev(vi->dev);

}