Re: [RFC net-next 14/15] net/mlx5e: Add Rx data path offload

Willem de Bruijn
2024-05-13T01:54:40Z

Jakub Kicinski wrote:
> From: Raed Salem <raeds@nvidia.com>
>
> On receive flow inspect received packets for PSP offload indication using
> the cqe, for PSP offloaded packets set SKB PSP metadata i.e spi, header
> length and key generation number to stack for further processing.
>
> Signed-off-by: Raed Salem <raeds@nvidia.com>
> Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> .../mellanox/mlx5/core/en_accel/ipsec_rxtx.h | 2 +-
> .../mellanox/mlx5/core/en_accel/nisp_rxtx.c | 79 +++++++++++++++++++
> .../mellanox/mlx5/core/en_accel/nisp_rxtx.h | 28 +++++++
> .../net/ethernet/mellanox/mlx5/core/en_rx.c | 10 +++
> 4 files changed, 118 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h
> index 82064614846f..9f025c80a6ef 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h
> @@ -40,7 +40,7 @@
> #include "en/txrx.h"
>
> /* Bit31: IPsec marker, Bit30: reserved, Bit29-24: IPsec syndrome, Bit23-0: IPsec obj id */
> -#define MLX5_IPSEC_METADATA_MARKER(metadata) (((metadata) >> 31) & 0x1)
> +#define MLX5_IPSEC_METADATA_MARKER(metadata) ((((metadata) >> 30) & 0x3) == 0x2)
> #define MLX5_IPSEC_METADATA_SYNDROM(metadata) (((metadata) >> 24) & GENMASK(5, 0))
> #define MLX5_IPSEC_METADATA_HANDLE(metadata) ((metadata) & GENMASK(23, 0))
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nisp_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nisp_rxtx.c
> index c719b2916677..17f42b8d9fd8 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nisp_rxtx.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nisp_rxtx.c
> @@ -15,6 +15,12 @@
> #include "en_accel/nisp.h"
> #include "lib/psp_defs.h"
>
> +enum {
> + MLX5E_NISP_OFFLOAD_RX_SYNDROME_DECRYPTED,
> + MLX5E_NISP_OFFLOAD_RX_SYNDROME_AUTH_FAILED,
> + MLX5E_NISP_OFFLOAD_RX_SYNDROME_BAD_TRAILER,
> +};
> +
> static void mlx5e_nisp_set_swp(struct sk_buff *skb,
> struct mlx5e_accel_tx_nisp_state *nisp_st,
> struct mlx5_wqe_eth_seg *eseg)
> @@ -114,6 +120,79 @@ static bool mlx5e_nisp_set_state(struct mlx5e_priv *priv,
> return ret;
> }
>
> +void mlx5e_nisp_csum_complete(struct net_device *netdev, struct sk_buff *skb)
> +{
> + pskb_trim(skb, skb->len - PSP_TRL_SIZE);
> +}
> +
> +/* Receive handler for PSP packets.
> + *
> + * Presently it accepts only already-authenticated packets and does not
> + * support optional fields, such as virtualization cookies.
> + */
> +static int psp_rcv(struct sk_buff *skb)
> +{
> + const struct psphdr *psph;
> + int depth = 0, end_depth;
> + struct psp_skb_ext *pse;
> + struct ipv6hdr *ipv6h;
> + struct ethhdr *eth;
> + __be16 proto;
> + u32 spi;
> +
> + eth = (struct ethhdr *)(skb->data);
> + proto = __vlan_get_protocol(skb, eth->h_proto, &depth);
> + if (proto != htons(ETH_P_IPV6))
> + return -EINVAL;
> +
> + ipv6h = (struct ipv6hdr *)(skb->data + depth);
> + depth += sizeof(*ipv6h);
> + end_depth = depth + sizeof(struct udphdr) + sizeof(struct psphdr);
> +
> + if (unlikely(end_depth > skb_headlen(skb)))
> + return -EINVAL;
> +
> + pse = skb_ext_add(skb, SKB_EXT_PSP);
> + if (!pse)
> + return -EINVAL;
> +
> + psph = (const struct psphdr *)(skb->data + depth + sizeof(struct udphdr));
> + pse->spi = psph->spi;
> + spi = ntohl(psph->spi);
> + pse->generation = 0;
> + pse->version = FIELD_GET(PSPHDR_VERFL_VERSION, psph->verfl);
> +
> + ipv6h->nexthdr = psph->nexthdr;
> + ipv6h->payload_len =
> + htons(ntohs(ipv6h->payload_len) - PSP_ENCAP_HLEN - PSP_TRL_SIZE);
> +
> + memmove(skb->data + PSP_ENCAP_HLEN, skb->data, depth);
> + skb_pull(skb, PSP_ENCAP_HLEN);
> +
> + return 0;
> +}
> +
> +void mlx5e_nisp_offload_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
> + struct mlx5_cqe64 *cqe)
> +{
> + u32 nisp_meta_data = be32_to_cpu(cqe->ft_metadata);
> +
> + /* TBD: report errors as SW counters to ethtool, any further handling ? */
> + switch (MLX5_NISP_METADATA_SYNDROM(nisp_meta_data)) {
> + case MLX5E_NISP_OFFLOAD_RX_SYNDROME_DECRYPTED:
> + if (psp_rcv(skb))
> + netdev_warn_once(netdev, "PSP handling failed");
> + skb->decrypted = 1;

Do not set skb->decrypted if psp_rcv failed? But drop the packet and
account the drop, likely.

> + break;
> + case MLX5E_NISP_OFFLOAD_RX_SYNDROME_AUTH_FAILED:
> + break;
> + case MLX5E_NISP_OFFLOAD_RX_SYNDROME_BAD_TRAILER:
> + break;
> + default:
> + break;
> + }
> +}