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drivers/net/virtio_net: Added basic RSS support.
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Added features for RSS.
Added initialization, RXHASH feature and ethtool ops.
By default RSS/RXHASH is disabled.
Virtio RSS "IPv6 extensions" hashes disabled.
Added ethtools ops to set key and indirection table.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Link: https://lore.kernel.org/r/20220328175336.10802-3-andrew@daynix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Andrew Melnychenko authored and Michael S. Tsirkin committed Mar 28, 2022
1 parent c1ddc42 commit c7114b1
Showing 1 changed file with 186 additions and 6 deletions.
192 changes: 186 additions & 6 deletions drivers/net/virtio_net.c
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Original file line number Diff line number Diff line change
Expand Up @@ -169,6 +169,24 @@ struct receive_queue {
struct xdp_rxq_info xdp_rxq;
};

/* This structure can contain rss message with maximum settings for indirection table and keysize
* Note, that default structure that describes RSS configuration virtio_net_rss_config
* contains same info but can't handle table values.
* In any case, structure would be passed to virtio hw through sg_buf split by parts
* 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 max_tx_vq;
u8 hash_key_length;
u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
};

/* Control VQ buffers: protected by the rtnl lock */
struct control_buf {
struct virtio_net_ctrl_hdr hdr;
Expand All @@ -178,6 +196,7 @@ struct control_buf {
u8 allmulti;
__virtio16 vid;
__virtio64 offloads;
struct virtio_net_ctrl_rss rss;
};

struct virtnet_info {
Expand Down Expand Up @@ -206,6 +225,12 @@ struct virtnet_info {
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;

/* Host supports rss and/or hash report */
bool has_rss;
u8 rss_key_size;
u16 rss_indir_table_size;
u32 rss_hash_types_supported;

/* Has control virtqueue */
bool has_cvq;

Expand Down Expand Up @@ -2184,6 +2209,57 @@ static void virtnet_get_ringparam(struct net_device *dev,
ring->tx_pending = ring->tx_max_pending;
}

static bool virtnet_commit_rss_command(struct virtnet_info *vi)
{
struct net_device *dev = vi->dev;
struct scatterlist sgs[4];
unsigned int sg_buf_size;

/* prepare sgs */
sg_init_table(sgs, 4);

sg_buf_size = offsetof(struct virtio_net_ctrl_rss, indirection_table);
sg_set_buf(&sgs[0], &vi->ctrl->rss, sg_buf_size);

sg_buf_size = sizeof(uint16_t) * (vi->ctrl->rss.indirection_table_mask + 1);
sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);

sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
- offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
sg_set_buf(&sgs[2], &vi->ctrl->rss.max_tx_vq, sg_buf_size);

sg_buf_size = vi->rss_key_size;
sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);

if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
VIRTIO_NET_CTRL_MQ_RSS_CONFIG, sgs)) {
dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
return false;
}
return true;
}

static void virtnet_init_default_rss(struct virtnet_info *vi)
{
u32 indir_val = 0;
int i = 0;

vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
vi->ctrl->rss.indirection_table_mask = vi->rss_indir_table_size
? vi->rss_indir_table_size - 1 : 0;
vi->ctrl->rss.unclassified_queue = 0;

for (; i < vi->rss_indir_table_size; ++i) {
indir_val = ethtool_rxfh_indir_default(i, vi->curr_queue_pairs);
vi->ctrl->rss.indirection_table[i] = indir_val;
}

vi->ctrl->rss.max_tx_vq = vi->curr_queue_pairs;
vi->ctrl->rss.hash_key_length = vi->rss_key_size;

netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
}


static void virtnet_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
Expand Down Expand Up @@ -2412,6 +2488,71 @@ static void virtnet_update_settings(struct virtnet_info *vi)
vi->duplex = duplex;
}

static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
{
return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
}

static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
{
return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
}

static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
{
struct virtnet_info *vi = netdev_priv(dev);
int i;

if (indir) {
for (i = 0; i < vi->rss_indir_table_size; ++i)
indir[i] = vi->ctrl->rss.indirection_table[i];
}

if (key)
memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);

if (hfunc)
*hfunc = ETH_RSS_HASH_TOP;

return 0;
}

static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
{
struct virtnet_info *vi = netdev_priv(dev);
int i;

if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
return -EOPNOTSUPP;

if (indir) {
for (i = 0; i < vi->rss_indir_table_size; ++i)
vi->ctrl->rss.indirection_table[i] = indir[i];
}
if (key)
memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);

virtnet_commit_rss_command(vi);

return 0;
}

static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
{
struct virtnet_info *vi = netdev_priv(dev);
int rc = 0;

switch (info->cmd) {
case ETHTOOL_GRXRINGS:
info->data = vi->curr_queue_pairs;
break;
default:
rc = -EOPNOTSUPP;
}

return rc;
}

static const struct ethtool_ops virtnet_ethtool_ops = {
.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
.get_drvinfo = virtnet_get_drvinfo,
Expand All @@ -2427,6 +2568,11 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
.set_link_ksettings = virtnet_set_link_ksettings,
.set_coalesce = virtnet_set_coalesce,
.get_coalesce = virtnet_get_coalesce,
.get_rxfh_key_size = virtnet_get_rxfh_key_size,
.get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
.get_rxfh = virtnet_get_rxfh,
.set_rxfh = virtnet_set_rxfh,
.get_rxnfc = virtnet_get_rxnfc,
};

static void virtnet_freeze_down(struct virtio_device *vdev)
Expand Down Expand Up @@ -2679,6 +2825,16 @@ static int virtnet_set_features(struct net_device *dev,
vi->guest_offloads = offloads;
}

if ((dev->features ^ features) & NETIF_F_RXHASH) {
if (features & NETIF_F_RXHASH)
vi->ctrl->rss.hash_types = vi->rss_hash_types_supported;
else
vi->ctrl->rss.hash_types = VIRTIO_NET_HASH_REPORT_NONE;

if (!virtnet_commit_rss_command(vi))
return -EINVAL;
}

return 0;
}

Expand Down Expand Up @@ -3073,6 +3229,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
"VIRTIO_NET_F_CTRL_VQ") ||
VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
"VIRTIO_NET_F_CTRL_VQ") ||
VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
"VIRTIO_NET_F_CTRL_VQ"))) {
return false;
}
Expand Down Expand Up @@ -3113,13 +3271,14 @@ static int virtnet_probe(struct virtio_device *vdev)
u16 max_queue_pairs;
int mtu;

/* Find if host supports multiqueue virtio_net device */
err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
struct virtio_net_config,
max_virtqueue_pairs, &max_queue_pairs);
/* Find if host supports multiqueue/rss virtio_net device */
max_queue_pairs = 1;
if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
max_queue_pairs =
virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));

/* We need at least 2 queue's */
if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
max_queue_pairs = 1;
Expand Down Expand Up @@ -3207,6 +3366,23 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;

if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
vi->has_rss = true;
vi->rss_indir_table_size =
virtio_cread16(vdev, offsetof(struct virtio_net_config,
rss_max_indirection_table_length));
vi->rss_key_size =
virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));

vi->rss_hash_types_supported =
virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
vi->rss_hash_types_supported &=
~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);

dev->hw_features |= NETIF_F_RXHASH;
}
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
Expand Down Expand Up @@ -3275,6 +3451,9 @@ static int virtnet_probe(struct virtio_device *vdev)
}
}

if (vi->has_rss)
virtnet_init_default_rss(vi);

err = register_netdev(dev);
if (err) {
pr_debug("virtio_net: registering device failed\n");
Expand Down Expand Up @@ -3406,7 +3585,8 @@ static struct virtio_device_id id_table[] = {
VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
VIRTIO_NET_F_CTRL_MAC_ADDR, \
VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
VIRTIO_NET_F_RSS

static unsigned int features[] = {
VIRTNET_FEATURES,
Expand Down

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