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 <[email protected]>
---
drivers/net/virtio_net.c | 191 +++++++++++++++++++++++++++++++++++++--
1 file changed, 185 insertions(+), 6 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1404e683a2fd..495aed524e33 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -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;
@@ -178,6 +196,7 @@ struct control_buf {
u8 allmulti;
__virtio16 vid;
__virtio64 offloads;
+ struct virtio_net_ctrl_rss rss;
};
struct virtnet_info {
@@ -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;
@@ -2184,6 +2209,56 @@ 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->rss_indir_table_size;
+ 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 - 1;
+ 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)
@@ -2412,6 +2487,71 @@ 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,
@@ -2427,6 +2567,11 @@ 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)
@@ -2679,6 +2824,16 @@ 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;
}
@@ -3073,6 +3228,8 @@ 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;
}
@@ -3113,13 +3270,14 @@ 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;
@@ -3207,6 +3365,23 @@ 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);
@@ -3275,6 +3450,9 @@ 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");
@@ -3406,7 +3584,8 @@ 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,
--
2.34.1
Hi all,
On Tue, Feb 8, 2022 at 10:37 PM Willem de Bruijn
<[email protected]> wrote:
>
> On Tue, Feb 8, 2022 at 1:19 PM Andrew Melnychenko <[email protected]> wrote:
> >
> > 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 <[email protected]>
> > ---
> > drivers/net/virtio_net.c | 191 +++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 185 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 1404e683a2fd..495aed524e33 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -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
>
> Future proof, may want to support larger sizes.
>
> netdevice.h defines NETDEV_RSS_KEY_LEN at 52.
>
> tools/testing/selftests/net/toeplitz.c supports up to 60
According to virtio specification, the length of the key is
40bytes(and an indirection table is 128 entries max).
So for now, we support a maximum of the spec regardless of what the
kernel is capable of.
>
> > +#define VIRTIO_NET_RSS_MAX_TABLE_LEN 128
> > +struct virtio_net_ctrl_rss {
> > + u32 hash_types;
>
> conversely, u32 is a bit extreme?
No, the structure virtio_net_ctrl_rss is specified by the specification.
>
> > + 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;
> > @@ -178,6 +196,7 @@ struct control_buf {
> > u8 allmulti;
> > __virtio16 vid;
> > __virtio64 offloads;
> > + struct virtio_net_ctrl_rss rss;
> > };
> >
> > struct virtnet_info {
> > @@ -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;
> >
> > @@ -2184,6 +2209,56 @@ 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->rss_indir_table_size;
> > + 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 - 1;
>
> Is table size always a power of two?
Yes, it should be.
>
> > + 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)
> > @@ -2412,6 +2487,71 @@ 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,
> > @@ -2427,6 +2567,11 @@ 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)
> > @@ -2679,6 +2824,16 @@ 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;
> > }
> >
> > @@ -3073,6 +3228,8 @@ 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;
> > }
> > @@ -3113,13 +3270,14 @@ 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));
>
> Instead of testing either feature and treating them as somewhat equal,
> shouldn't RSS be dependent on MQ?
No, RSS is dependent on CTRL_VQ. Technically RSS and MQ are similar features.
>
> >
> > /* 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;
> > @@ -3207,6 +3365,23 @@ 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;
>
> Only make the feature visible when the hash is actually reported in
> the skb, patch 3.
VirtioNET has two features: RSS(steering only) and hash(hash report in
vnet header)
Both features may be enabled/disabled separately:
1. rss on and hash off - packets steered to the corresponding vqs
2. rss off and hash on - packets steered by tap(like mq) but headers
have properly calculated hash.
3. rss on and hash on - packets steered to corresponding vqs and hash
is present in the header.
RXHASH feature allows the user to enable/disable the rss/hash(any combination).
I think it's a good idea to leave RXHASH in patch 2/4 to give the user
ability to manipulate the rss only feature.
But, if you think that it requires to move it to the 3/4, I'll do it.
>
> Also, clearly separate the feature patches (2) rss, (3) rxhash, (4)
> rxhash config.
Currently:
Patch 2/4 - adds VirtioNet rss feature.
Patch 3/4 - adds VirtioNet hash report feature.
Patch 4/4 - adds the ability to manipulate supported hash types.
Can you provide more detailed suggestions on how to move hunks?
> > > @@ -3113,13 +3270,14 @@ 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));
> >
> > Instead of testing either feature and treating them as somewhat equal,
> > shouldn't RSS be dependent on MQ?
>
> No, RSS is dependent on CTRL_VQ. Technically RSS and MQ are similar features.
RSS depends on having multiple queues.
What would enabling VIRTIO_NET_F_RSS without VIRTIO_NET_F_MQ do?
> >
> > >
> > > /* 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;
> > > @@ -3207,6 +3365,23 @@ 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;
> >
> > Only make the feature visible when the hash is actually reported in
> > the skb, patch 3.
>
> VirtioNET has two features: RSS(steering only) and hash(hash report in
> vnet header)
> Both features may be enabled/disabled separately:
> 1. rss on and hash off - packets steered to the corresponding vqs
> 2. rss off and hash on - packets steered by tap(like mq) but headers
> have properly calculated hash.
> 3. rss on and hash on - packets steered to corresponding vqs and hash
> is present in the header.
>
> RXHASH feature allows the user to enable/disable the rss/hash(any combination).
I find that confusing, but.. I see that there is prior art where some
drivers enable/disable entire RSS load balancing based on this flag.
So ok.
> I think it's a good idea to leave RXHASH in patch 2/4 to give the user
> ability to manipulate the rss only feature.
> But, if you think that it requires to move it to the 3/4, I'll do it.
>
> >
> > Also, clearly separate the feature patches (2) rss, (3) rxhash, (4)
> > rxhash config.
>
> Currently:
> Patch 2/4 - adds VirtioNet rss feature.
> Patch 3/4 - adds VirtioNet hash report feature.
> Patch 4/4 - adds the ability to manipulate supported hash types.
>
> Can you provide more detailed suggestions on how to move hunks?
I gave one in the follow-on patch, to which you responded. That's probably it.
Hi all,
On Mon, Feb 14, 2022 at 12:09 AM Willem de Bruijn
<[email protected]> wrote:
>
> > > > @@ -3113,13 +3270,14 @@ 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));
> > >
> > > Instead of testing either feature and treating them as somewhat equal,
> > > shouldn't RSS be dependent on MQ?
> >
> > No, RSS is dependent on CTRL_VQ. Technically RSS and MQ are similar features.
>
> RSS depends on having multiple queues.
>
> What would enabling VIRTIO_NET_F_RSS without VIRTIO_NET_F_MQ do?
RSS would work.
According to virtio spec article 5.1.6.5.5:
> A device MAY support one of these features or both. The driver MAY negotiate any set of these features
> that the device supports.
Also, in 5.1.3.1:
> VIRTIO_NET_F_RSS Requires VIRTIO_NET_F_CTRL_VQ.
>
> > >
> > > >
> > > > /* 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;
> > > > @@ -3207,6 +3365,23 @@ 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;
> > >
> > > Only make the feature visible when the hash is actually reported in
> > > the skb, patch 3.
> >
> > VirtioNET has two features: RSS(steering only) and hash(hash report in
> > vnet header)
> > Both features may be enabled/disabled separately:
> > 1. rss on and hash off - packets steered to the corresponding vqs
> > 2. rss off and hash on - packets steered by tap(like mq) but headers
> > have properly calculated hash.
> > 3. rss on and hash on - packets steered to corresponding vqs and hash
> > is present in the header.
> >
> > RXHASH feature allows the user to enable/disable the rss/hash(any combination).
>
> I find that confusing, but.. I see that there is prior art where some
> drivers enable/disable entire RSS load balancing based on this flag.
> So ok.
>
> > I think it's a good idea to leave RXHASH in patch 2/4 to give the user
> > ability to manipulate the rss only feature.
> > But, if you think that it requires to move it to the 3/4, I'll do it.
> >
> > >
> > > Also, clearly separate the feature patches (2) rss, (3) rxhash, (4)
> > > rxhash config.
> >
> > Currently:
> > Patch 2/4 - adds VirtioNet rss feature.
> > Patch 3/4 - adds VirtioNet hash report feature.
> > Patch 4/4 - adds the ability to manipulate supported hash types.
> >
> > Can you provide more detailed suggestions on how to move hunks?
>
> I gave one in the follow-on patch, to which you responded. That's probably it.
I'll add zero size table check and move hunk for padded header length
from 3/4 to 1/4.
On Thu, Feb 17, 2022 at 12:05 PM Andrew Melnichenko <[email protected]> wrote:
>
> Hi all,
>
> On Mon, Feb 14, 2022 at 12:09 AM Willem de Bruijn
> <[email protected]> wrote:
> >
> > > > > @@ -3113,13 +3270,14 @@ 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));
> > > >
> > > > Instead of testing either feature and treating them as somewhat equal,
> > > > shouldn't RSS be dependent on MQ?
> > >
> > > No, RSS is dependent on CTRL_VQ. Technically RSS and MQ are similar features.
> >
> > RSS depends on having multiple queues.
> >
> > What would enabling VIRTIO_NET_F_RSS without VIRTIO_NET_F_MQ do?
>
> RSS would work.
What does that mean, exactly? RSS is load balancing, does that not
require multi-queue?
On Fri, Feb 18, 2022 at 08:43:20AM -0700, Willem de Bruijn wrote:
> On Thu, Feb 17, 2022 at 12:05 PM Andrew Melnichenko <[email protected]> wrote:
> >
> > Hi all,
> >
> > On Mon, Feb 14, 2022 at 12:09 AM Willem de Bruijn
> > <[email protected]> wrote:
> > >
> > > > > > @@ -3113,13 +3270,14 @@ 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));
> > > > >
> > > > > Instead of testing either feature and treating them as somewhat equal,
> > > > > shouldn't RSS be dependent on MQ?
> > > >
> > > > No, RSS is dependent on CTRL_VQ. Technically RSS and MQ are similar features.
> > >
> > > RSS depends on having multiple queues.
> > >
> > > What would enabling VIRTIO_NET_F_RSS without VIRTIO_NET_F_MQ do?
> >
> > RSS would work.
>
> What does that mean, exactly? RSS is load balancing, does that not
> require multi-queue?
It does, but VIRTIO_NET_F_MQ is a misnomer.
\item[VIRTIO_NET_F_MQ(22)] Device supports multiqueue with automatic
receive steering.
VIRTIO_NET_F_RSS implies multi queue and does not depend on VIRTIO_NET_F_MQ.
--
MST