2022-11-09 16:52:37

by Felix Fietkau

Subject: [PATCH net-next v2 08/12] net: dsa: add support for DSA rx offloading via metadata dst

If a metadata dst is present with the type METADATA_HW_PORT_MUX on a dsa cpu
port netdev, assume that it carries the port number and that there is no DSA
tag present in the skb data.

Signed-off-by: Felix Fietkau <[email protected]>
---
net/core/flow_dissector.c | 4 +++-
net/dsa/dsa.c | 18 +++++++++++++++++-
2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 25cd35f5922e..1f476abc25e1 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -972,11 +972,13 @@ bool __skb_flow_dissect(const struct net *net,
if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
proto == htons(ETH_P_XDSA))) {
const struct dsa_device_ops *ops;
+ struct metadata_dst *md_dst = skb_metadata_dst(skb);
int offset = 0;

ops = skb->dev->dsa_ptr->tag_ops;
/* Only DSA header taggers break flow dissection */
- if (ops->needed_headroom) {
+ if (ops->needed_headroom &&
+ (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
if (ops->flow_dissect)
ops->flow_dissect(skb, &proto, &offset);
else
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 64b14f655b23..a20440e82dec 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -11,6 +11,7 @@
#include <linux/netdevice.h>
#include <linux/sysfs.h>
#include <linux/ptp_classify.h>
+#include <net/dst_metadata.h>

#include "dsa_priv.h"

@@ -216,6 +217,7 @@ static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *unused)
{
+ struct metadata_dst *md_dst = skb_metadata_dst(skb);
struct dsa_port *cpu_dp = dev->dsa_ptr;
struct sk_buff *nskb = NULL;
struct dsa_slave_priv *p;
@@ -229,7 +231,21 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
if (!skb)
return 0;

- nskb = cpu_dp->rcv(skb, dev);
+ if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
+ unsigned int port = md_dst->u.port_info.port_id;
+
+ dsa_default_offload_fwd_mark(skb);
+ skb_dst_set(skb, NULL);
+ if (!skb_has_extensions(skb))
+ skb->slow_gro = 0;
+
+ skb->dev = dsa_master_find_slave(dev, 0, port);
+ if (skb->dev)
+ nskb = skb;
+ } else {
+ nskb = cpu_dp->rcv(skb, dev);
+ }
+
if (!nskb) {
kfree_skb(skb);
return 0;
--
2.38.1

2022-11-11 12:21:22

by Vladimir Oltean

Subject: Re: [PATCH net-next v2 08/12] net: dsa: add support for DSA rx offloading via metadata dst

On Wed, Nov 09, 2022 at 05:34:22PM +0100, Felix Fietkau wrote:
> If a metadata dst is present with the type METADATA_HW_PORT_MUX on a dsa cpu
> port netdev, assume that it carries the port number and that there is no DSA
> tag present in the skb data.
>
> Signed-off-by: Felix Fietkau <[email protected]>
> ---
> net/core/flow_dissector.c | 4 +++-
> net/dsa/dsa.c | 18 +++++++++++++++++-
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> index 25cd35f5922e..1f476abc25e1 100644
> --- a/net/core/flow_dissector.c
> +++ b/net/core/flow_dissector.c
> @@ -972,11 +972,13 @@ bool __skb_flow_dissect(const struct net *net,
> if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
> proto == htons(ETH_P_XDSA))) {
> const struct dsa_device_ops *ops;
> + struct metadata_dst *md_dst = skb_metadata_dst(skb);
> int offset = 0;
>
> ops = skb->dev->dsa_ptr->tag_ops;
> /* Only DSA header taggers break flow dissection */
> - if (ops->needed_headroom) {
> + if (ops->needed_headroom &&
> + (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
> if (ops->flow_dissect)
> ops->flow_dissect(skb, &proto, &offset);
> else
> diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
> index 64b14f655b23..a20440e82dec 100644
> --- a/net/dsa/dsa.c
> +++ b/net/dsa/dsa.c
> @@ -11,6 +11,7 @@
> #include <linux/netdevice.h>
> #include <linux/sysfs.h>
> #include <linux/ptp_classify.h>
> +#include <net/dst_metadata.h>
>
> #include "dsa_priv.h"
>
> @@ -216,6 +217,7 @@ static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
> static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
> struct packet_type *pt, struct net_device *unused)
> {
> + struct metadata_dst *md_dst = skb_metadata_dst(skb);
> struct dsa_port *cpu_dp = dev->dsa_ptr;
> struct sk_buff *nskb = NULL;
> struct dsa_slave_priv *p;
> @@ -229,7 +231,21 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
> if (!skb)
> return 0;
>
> - nskb = cpu_dp->rcv(skb, dev);
> + if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
> + unsigned int port = md_dst->u.port_info.port_id;
> +
> + dsa_default_offload_fwd_mark(skb);
> + skb_dst_set(skb, NULL);
> + if (!skb_has_extensions(skb))
> + skb->slow_gro = 0;

Paolo, does this look okay to you, hand rolled in DSA like that?
Do you see a way in which this would be done automatically once the
metadata dst pointer is unset?

> +
> + skb->dev = dsa_master_find_slave(dev, 0, port);
> + if (skb->dev)
> + nskb = skb;
> + } else {
> + nskb = cpu_dp->rcv(skb, dev);
> + }
> +
> if (!nskb) {
> kfree_skb(skb);
> return 0;
> --
> 2.38.1
>