* [PATCH] net/af_xdp: enable AF_XDP program attachment mode
@ 2025-07-23 7:42 Shivaji Kant
2025-07-23 12:30 ` Ivan Malov
0 siblings, 1 reply; 2+ messages in thread
From: Shivaji Kant @ 2025-07-23 7:42 UTC (permalink / raw)
To: Ciara Loftus, Maryam Tahhan; +Cc: dev, Joshua Washington, Shivaji Kant
Currently, the AF_XDP PMD attaches its XDP program using a fixed
set of flags,defaulting to `XDP_FLAGS_UPDATE_IF_NOEXIST`. This lacks
flexibility for users who might need to explicitly control the XDP
mode based on their specific hardware capabilities or performance
requirements.
This patch introduces a new vdev argument, `mode`, for the `net_af_xdp`
PMD. This argument allows users to explicitly specify the desired
XDP program attachment mode:
`drv` (XDP_FLAGS_DRV_MODE),
`skb` (XDP_FLAGS_SKB_MODE),
`hw` (XDP_FLAGS_HW_MODE).
(If needed more can be added)
This change provides greater control and flexibility for users to
fine-tune AF_XDP behavior, enabling them to leverage native driver
or hardware offload capabilities when available, or fall back to
generic SKB mode for broader compatibility.
Signed-off-by: Shivaji Kant <shivajikant@google.com>
---
drivers/net/af_xdp/rte_eth_af_xdp.c | 61 +++++++++++++++++++++++++----
1 file changed, 54 insertions(+), 7 deletions(-)
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 5f65850a27..e39f2b4935 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -104,6 +104,8 @@ RTE_LOG_REGISTER_DEFAULT(af_xdp_logtype, NOTICE);
static int afxdp_dev_count;
+static __u32 mode_flag = XDP_FLAGS_UPDATE_IF_NOEXIST;
+
/* Message header to synchronize fds via IPC */
struct ipc_hdr {
char port_name[RTE_DEV_NAME_MAX_LEN];
@@ -198,6 +200,26 @@ struct pmd_process_private {
#define ETH_AF_XDP_USE_CNI_ARG "use_cni"
#define ETH_AF_XDP_USE_PINNED_MAP_ARG "use_pinned_map"
#define ETH_AF_XDP_DP_PATH_ARG "dp_path"
+#define ETH_AF_XDP_MODE_ARG "mode"
+
+/* Define different modes for af_xdp prog to attach */
+#define ETH_AF_XDP_DRV_MODE_ARG "drv"
+#define ETH_AF_XDP_SKB_MODE_ARG "skb"
+#define ETH_AF_XDP_HW_MODE_ARG "hw"
+#define ETH_AF_XDP_NUM_MODE_ARG 3
+
+static const char * const mode_arguments[] = {
+ ETH_AF_XDP_DRV_MODE_ARG,
+ ETH_AF_XDP_SKB_MODE_ARG,
+ ETH_AF_XDP_HW_MODE_ARG,
+ NULL
+};
+
+static const unsigned int mode_flags[] = {
+ XDP_FLAGS_DRV_MODE,
+ XDP_FLAGS_SKB_MODE,
+ XDP_FLAGS_HW_MODE
+};
static const char * const valid_arguments[] = {
ETH_AF_XDP_IFACE_ARG,
@@ -210,6 +232,7 @@ static const char * const valid_arguments[] = {
ETH_AF_XDP_USE_CNI_ARG,
ETH_AF_XDP_USE_PINNED_MAP_ARG,
ETH_AF_XDP_DP_PATH_ARG,
+ ETH_AF_XDP_MODE_ARG,
NULL
};
@@ -950,14 +973,14 @@ remove_xdp_program(struct pmd_internals *internals)
uint32_t curr_prog_id = 0;
int ret;
- ret = bpf_xdp_query_id(internals->if_index, XDP_FLAGS_UPDATE_IF_NOEXIST,
+ ret = bpf_xdp_query_id(internals->if_index, mode_flag,
&curr_prog_id);
if (ret != 0) {
AF_XDP_LOG_LINE(ERR, "bpf_xdp_query_id failed");
return ret;
}
- ret = bpf_xdp_detach(internals->if_index, XDP_FLAGS_UPDATE_IF_NOEXIST,
+ ret = bpf_xdp_detach(internals->if_index, mode_flag,
NULL);
if (ret != 0)
AF_XDP_LOG_LINE(ERR, "bpf_xdp_detach failed");
@@ -978,14 +1001,14 @@ remove_xdp_program(struct pmd_internals *internals)
int ret;
ret = bpf_get_link_xdp_id(internals->if_index, &curr_prog_id,
- XDP_FLAGS_UPDATE_IF_NOEXIST);
+ mode_flag);
if (ret != 0) {
AF_XDP_LOG_LINE(ERR, "bpf_get_link_xdp_id failed");
return ret;
}
ret = bpf_set_link_xdp_fd(internals->if_index, -1,
- XDP_FLAGS_UPDATE_IF_NOEXIST);
+ mode_flag);
if (ret != 0)
AF_XDP_LOG_LINE(ERR, "bpf_set_link_xdp_fd failed");
return ret;
@@ -1328,7 +1351,7 @@ load_custom_xdp_prog(const char *prog_path, int if_index, struct bpf_map **map)
/* Link the program with the given network device */
ret = link_xdp_prog_with_dev(if_index, prog_fd,
- XDP_FLAGS_UPDATE_IF_NOEXIST);
+ mode_flag);
if (ret) {
AF_XDP_LOG_LINE(ERR, "Failed to set prog fd %d on interface",
prog_fd);
@@ -1679,7 +1702,7 @@ xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
cfg.rx_size = ring_size;
cfg.tx_size = ring_size;
cfg.libbpf_flags = 0;
- cfg.xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+ cfg.xdp_flags = mode_flag;
cfg.bind_flags = 0;
/* Force AF_XDP socket into copy mode when users want it */
@@ -2017,6 +2040,25 @@ parse_name_arg(const char *key __rte_unused,
return 0;
}
+/** parse name argument */
+static int
+parse_mode_arg(const char *key __rte_unused,
+ const char *value, void *extra_args)
+{
+ unsigned int *mode = extra_args;
+ unsigned int i;
+
+ for (i = 0; i < ETH_AF_XDP_NUM_MODE_ARG; i++) {
+ if (strcmp(value, mode_arguments[i]) == 0) {
+ *mode |= mode_flags[i];
+ return 0;
+ }
+ }
+
+ AF_XDP_LOG_LINE(ERR, "Invalid af_xdp mode, choose correct mode to attach af_xdp program.");
+ return -EINVAL;
+}
+
/** parse xdp prog argument */
static int
parse_prog_arg(const char *key __rte_unused,
@@ -2147,6 +2189,10 @@ parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
ret = rte_kvargs_process(kvlist, ETH_AF_XDP_DP_PATH_ARG,
&parse_prog_arg, dp_path);
+
+ ret = rte_kvargs_process(kvlist, ETH_AF_XDP_MODE_ARG,
+ &parse_mode_arg, &mode_flag);
+
if (ret < 0)
goto free_kvlist;
@@ -2587,4 +2633,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
"force_copy=<int> "
"use_cni=<int> "
"use_pinned_map=<int> "
- "dp_path=<string> ");
+ "dp_path=<string> "
+ "mode=<string> ");
--
2.50.0.727.gbf7dc18ff4-goog
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] net/af_xdp: enable AF_XDP program attachment mode
2025-07-23 7:42 [PATCH] net/af_xdp: enable AF_XDP program attachment mode Shivaji Kant
@ 2025-07-23 12:30 ` Ivan Malov
0 siblings, 0 replies; 2+ messages in thread
From: Ivan Malov @ 2025-07-23 12:30 UTC (permalink / raw)
To: Shivaji Kant; +Cc: Ciara Loftus, Maryam Tahhan, dev, Joshua Washington
Hi Shivaji,
(please see below)
On Wed, 23 Jul 2025, Shivaji Kant wrote:
> Currently, the AF_XDP PMD attaches its XDP program using a fixed
> set of flags,defaulting to `XDP_FLAGS_UPDATE_IF_NOEXIST`. This lacks
> flexibility for users who might need to explicitly control the XDP
> mode based on their specific hardware capabilities or performance
> requirements.
>
> This patch introduces a new vdev argument, `mode`, for the `net_af_xdp`
> PMD. This argument allows users to explicitly specify the desired
> XDP program attachment mode:
> `drv` (XDP_FLAGS_DRV_MODE),
> `skb` (XDP_FLAGS_SKB_MODE),
> `hw` (XDP_FLAGS_HW_MODE).
> (If needed more can be added)
>
> This change provides greater control and flexibility for users to
> fine-tune AF_XDP behavior, enabling them to leverage native driver
> or hardware offload capabilities when available, or fall back to
> generic SKB mode for broader compatibility.
>
> Signed-off-by: Shivaji Kant <shivajikant@google.com>
> ---
> drivers/net/af_xdp/rte_eth_af_xdp.c | 61 +++++++++++++++++++++++++----
> 1 file changed, 54 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 5f65850a27..e39f2b4935 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -104,6 +104,8 @@ RTE_LOG_REGISTER_DEFAULT(af_xdp_logtype, NOTICE);
>
> static int afxdp_dev_count;
>
> +static __u32 mode_flag = XDP_FLAGS_UPDATE_IF_NOEXIST;
If one seeks to add a per-device argument, then why is this static/driver-wide?
This belongs in 'struct pmd_internals'.
Thank you.
> +
> /* Message header to synchronize fds via IPC */
> struct ipc_hdr {
> char port_name[RTE_DEV_NAME_MAX_LEN];
> @@ -198,6 +200,26 @@ struct pmd_process_private {
> #define ETH_AF_XDP_USE_CNI_ARG "use_cni"
> #define ETH_AF_XDP_USE_PINNED_MAP_ARG "use_pinned_map"
> #define ETH_AF_XDP_DP_PATH_ARG "dp_path"
> +#define ETH_AF_XDP_MODE_ARG "mode"
> +
> +/* Define different modes for af_xdp prog to attach */
> +#define ETH_AF_XDP_DRV_MODE_ARG "drv"
> +#define ETH_AF_XDP_SKB_MODE_ARG "skb"
> +#define ETH_AF_XDP_HW_MODE_ARG "hw"
> +#define ETH_AF_XDP_NUM_MODE_ARG 3
> +
> +static const char * const mode_arguments[] = {
> + ETH_AF_XDP_DRV_MODE_ARG,
> + ETH_AF_XDP_SKB_MODE_ARG,
> + ETH_AF_XDP_HW_MODE_ARG,
> + NULL
> +};
> +
> +static const unsigned int mode_flags[] = {
> + XDP_FLAGS_DRV_MODE,
> + XDP_FLAGS_SKB_MODE,
> + XDP_FLAGS_HW_MODE
> +};
>
> static const char * const valid_arguments[] = {
> ETH_AF_XDP_IFACE_ARG,
> @@ -210,6 +232,7 @@ static const char * const valid_arguments[] = {
> ETH_AF_XDP_USE_CNI_ARG,
> ETH_AF_XDP_USE_PINNED_MAP_ARG,
> ETH_AF_XDP_DP_PATH_ARG,
> + ETH_AF_XDP_MODE_ARG,
> NULL
> };
>
> @@ -950,14 +973,14 @@ remove_xdp_program(struct pmd_internals *internals)
> uint32_t curr_prog_id = 0;
> int ret;
>
> - ret = bpf_xdp_query_id(internals->if_index, XDP_FLAGS_UPDATE_IF_NOEXIST,
> + ret = bpf_xdp_query_id(internals->if_index, mode_flag,
> &curr_prog_id);
> if (ret != 0) {
> AF_XDP_LOG_LINE(ERR, "bpf_xdp_query_id failed");
> return ret;
> }
>
> - ret = bpf_xdp_detach(internals->if_index, XDP_FLAGS_UPDATE_IF_NOEXIST,
> + ret = bpf_xdp_detach(internals->if_index, mode_flag,
> NULL);
> if (ret != 0)
> AF_XDP_LOG_LINE(ERR, "bpf_xdp_detach failed");
> @@ -978,14 +1001,14 @@ remove_xdp_program(struct pmd_internals *internals)
> int ret;
>
> ret = bpf_get_link_xdp_id(internals->if_index, &curr_prog_id,
> - XDP_FLAGS_UPDATE_IF_NOEXIST);
> + mode_flag);
> if (ret != 0) {
> AF_XDP_LOG_LINE(ERR, "bpf_get_link_xdp_id failed");
> return ret;
> }
>
> ret = bpf_set_link_xdp_fd(internals->if_index, -1,
> - XDP_FLAGS_UPDATE_IF_NOEXIST);
> + mode_flag);
> if (ret != 0)
> AF_XDP_LOG_LINE(ERR, "bpf_set_link_xdp_fd failed");
> return ret;
> @@ -1328,7 +1351,7 @@ load_custom_xdp_prog(const char *prog_path, int if_index, struct bpf_map **map)
>
> /* Link the program with the given network device */
> ret = link_xdp_prog_with_dev(if_index, prog_fd,
> - XDP_FLAGS_UPDATE_IF_NOEXIST);
> + mode_flag);
> if (ret) {
> AF_XDP_LOG_LINE(ERR, "Failed to set prog fd %d on interface",
> prog_fd);
> @@ -1679,7 +1702,7 @@ xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
> cfg.rx_size = ring_size;
> cfg.tx_size = ring_size;
> cfg.libbpf_flags = 0;
> - cfg.xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
> + cfg.xdp_flags = mode_flag;
> cfg.bind_flags = 0;
>
> /* Force AF_XDP socket into copy mode when users want it */
> @@ -2017,6 +2040,25 @@ parse_name_arg(const char *key __rte_unused,
> return 0;
> }
>
> +/** parse name argument */
> +static int
> +parse_mode_arg(const char *key __rte_unused,
> + const char *value, void *extra_args)
> +{
> + unsigned int *mode = extra_args;
> + unsigned int i;
> +
> + for (i = 0; i < ETH_AF_XDP_NUM_MODE_ARG; i++) {
> + if (strcmp(value, mode_arguments[i]) == 0) {
> + *mode |= mode_flags[i];
> + return 0;
> + }
> + }
> +
> + AF_XDP_LOG_LINE(ERR, "Invalid af_xdp mode, choose correct mode to attach af_xdp program.");
> + return -EINVAL;
> +}
> +
> /** parse xdp prog argument */
> static int
> parse_prog_arg(const char *key __rte_unused,
> @@ -2147,6 +2189,10 @@ parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
>
> ret = rte_kvargs_process(kvlist, ETH_AF_XDP_DP_PATH_ARG,
> &parse_prog_arg, dp_path);
> +
> + ret = rte_kvargs_process(kvlist, ETH_AF_XDP_MODE_ARG,
> + &parse_mode_arg, &mode_flag);
> +
> if (ret < 0)
> goto free_kvlist;
>
> @@ -2587,4 +2633,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
> "force_copy=<int> "
> "use_cni=<int> "
> "use_pinned_map=<int> "
> - "dp_path=<string> ");
> + "dp_path=<string> "
> + "mode=<string> ");
> --
> 2.50.0.727.gbf7dc18ff4-goog
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-07-23 7:42 [PATCH] net/af_xdp: enable AF_XDP program attachment mode Shivaji Kant
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