* [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading
@ 2020-08-28 11:18 Ciara Loftus
2020-09-10 11:40 ` Tahhan, Maryam
2020-09-18 2:54 ` Hu, Xuekun
0 siblings, 2 replies; 4+ messages in thread
From: Ciara Loftus @ 2020-08-28 11:18 UTC (permalink / raw)
To: dev; +Cc: Ciara Loftus
The new 'xdp_prog=<string>' vdev arg allows the user to specify the path to
a custom XDP program to be set on the device, instead of the default libbpf
one. The program must have an XSK_MAP of name 'xsks_map' which will allow
for the redirection of some packets to userspace and thus the PMD, using
some criteria defined in the program.
Note: a netdev may only load one program.
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
doc/guides/nics/af_xdp.rst | 1 +
drivers/net/af_xdp/rte_eth_af_xdp.c | 100 ++++++++++++++++++++++++++--
2 files changed, 95 insertions(+), 6 deletions(-)
diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index 07bdd29e29..19aefa80e8 100644
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -32,6 +32,7 @@ The following options can be provided to set up an af_xdp port in DPDK.
* ``iface`` - name of the Kernel interface to attach to (required);
* ``start_queue`` - starting netdev queue id (optional, default 0);
* ``queue_count`` - total netdev queue number (optional, default 1);
+* ``xdp_prog`` - path to custom xdp program (optional, default none);
Prerequisites
-------------
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 936d4a7d5f..6f70dba538 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -1,5 +1,5 @@
/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2019 Intel Corporation.
+ * Copyright(c) 2020 Intel Corporation.
*/
#include <unistd.h>
#include <errno.h>
@@ -118,6 +118,8 @@ struct pmd_internals {
int queue_cnt;
int max_queue_cnt;
int combined_queue_cnt;
+ char prog_path[PATH_MAX];
+ bool custom_prog_configured;
struct rte_ether_addr eth_addr;
@@ -128,11 +130,13 @@ struct pmd_internals {
#define ETH_AF_XDP_IFACE_ARG "iface"
#define ETH_AF_XDP_START_QUEUE_ARG "start_queue"
#define ETH_AF_XDP_QUEUE_COUNT_ARG "queue_count"
+#define ETH_AF_XDP_PROG_ARG "xdp_prog"
static const char * const valid_arguments[] = {
ETH_AF_XDP_IFACE_ARG,
ETH_AF_XDP_START_QUEUE_ARG,
ETH_AF_XDP_QUEUE_COUNT_ARG,
+ ETH_AF_XDP_PROG_ARG,
NULL
};
@@ -863,6 +867,45 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals,
return NULL;
}
+static int
+load_custom_xdp_prog(const char *prog_path, int if_index)
+{
+ int ret, prog_fd = -1;
+ struct bpf_object *obj;
+ struct bpf_map *map;
+
+ ret = bpf_prog_load(prog_path, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
+ if (ret) {
+ AF_XDP_LOG(ERR, "Failed to load program %s\n", prog_path);
+ return ret;
+ }
+
+ /*
+ * The loaded program must provision for a map of xsks, such that some
+ * traffic can be redirected to userspace. When the xsk is created,
+ * libbpf inserts it into the map.
+ */
+ map = bpf_object__find_map_by_name(obj, "xsks_map");
+ if (!map) {
+ AF_XDP_LOG(ERR, "Failed to find xsks_map in %s\n", prog_path);
+ return -1;
+ }
+
+ /* Link the program with the given network device */
+ ret = bpf_set_link_xdp_fd(if_index, prog_fd,
+ XDP_FLAGS_UPDATE_IF_NOEXIST);
+ if (ret) {
+ AF_XDP_LOG(ERR, "Failed to set prog fd %d on interface\n",
+ prog_fd);
+ return -1;
+ }
+
+ AF_XDP_LOG(INFO, "Successfully loaded XDP program %s with fd %d\n",
+ prog_path, prog_fd);
+
+ return 0;
+}
+
static int
xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
int ring_size)
@@ -888,6 +931,18 @@ xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
cfg.bind_flags |= XDP_USE_NEED_WAKEUP;
#endif
+ if (strnlen(internals->prog_path, PATH_MAX) &&
+ !internals->custom_prog_configured) {
+ ret = load_custom_xdp_prog(internals->prog_path,
+ internals->if_index);
+ if (ret) {
+ AF_XDP_LOG(ERR, "Failed to load custom XDP program %s\n",
+ internals->prog_path);
+ goto err;
+ }
+ internals->custom_prog_configured = 1;
+ }
+
ret = xsk_socket__create(&rxq->xsk, internals->if_name,
rxq->xsk_queue_idx, rxq->umem->umem, &rxq->rx,
&txq->tx, &cfg);
@@ -1099,6 +1154,30 @@ parse_name_arg(const char *key __rte_unused,
return 0;
}
+/** parse xdp prog argument */
+static int
+parse_prog_arg(const char *key __rte_unused,
+ const char *value, void *extra_args)
+{
+ char *path = extra_args;
+
+ if (strnlen(value, PATH_MAX) > PATH_MAX - 1) {
+ AF_XDP_LOG(ERR, "Invalid path %s, should be less than %u bytes.\n",
+ value, PATH_MAX);
+ return -EINVAL;
+ }
+
+ if (access(value, F_OK) != 0) {
+ AF_XDP_LOG(ERR, "Error accessing %s: %s\n",
+ value, strerror(errno));
+ return -EINVAL;
+ }
+
+ strlcpy(path, value, PATH_MAX);
+
+ return 0;
+}
+
static int
xdp_get_channels_info(const char *if_name, int *max_queues,
int *combined_queues)
@@ -1142,7 +1221,7 @@ xdp_get_channels_info(const char *if_name, int *max_queues,
static int
parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
- int *queue_cnt)
+ int *queue_cnt, char *prog_path)
{
int ret;
@@ -1163,6 +1242,11 @@ parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
goto free_kvlist;
}
+ ret = rte_kvargs_process(kvlist, ETH_AF_XDP_PROG_ARG,
+ &parse_prog_arg, prog_path);
+ if (ret < 0)
+ goto free_kvlist;
+
free_kvlist:
rte_kvargs_free(kvlist);
return ret;
@@ -1200,7 +1284,7 @@ get_iface_info(const char *if_name,
static struct rte_eth_dev *
init_internals(struct rte_vdev_device *dev, const char *if_name,
- int start_queue_idx, int queue_cnt)
+ int start_queue_idx, int queue_cnt, const char *prog_path)
{
const char *name = rte_vdev_device_name(dev);
const unsigned int numa_node = dev->device.numa_node;
@@ -1216,6 +1300,8 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
internals->start_queue_idx = start_queue_idx;
internals->queue_cnt = queue_cnt;
strlcpy(internals->if_name, if_name, IFNAMSIZ);
+ strlcpy(internals->prog_path, prog_path, PATH_MAX);
+ internals->custom_prog_configured = 0;
if (xdp_get_channels_info(if_name, &internals->max_queue_cnt,
&internals->combined_queue_cnt)) {
@@ -1292,6 +1378,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
char if_name[IFNAMSIZ] = {'\0'};
int xsk_start_queue_idx = ETH_AF_XDP_DFLT_START_QUEUE_IDX;
int xsk_queue_cnt = ETH_AF_XDP_DFLT_QUEUE_COUNT;
+ char prog_path[PATH_MAX] = {'\0'};
struct rte_eth_dev *eth_dev = NULL;
const char *name;
@@ -1321,7 +1408,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
dev->device.numa_node = rte_socket_id();
if (parse_parameters(kvlist, if_name, &xsk_start_queue_idx,
- &xsk_queue_cnt) < 0) {
+ &xsk_queue_cnt, prog_path) < 0) {
AF_XDP_LOG(ERR, "Invalid kvargs value\n");
return -EINVAL;
}
@@ -1332,7 +1419,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
}
eth_dev = init_internals(dev, if_name, xsk_start_queue_idx,
- xsk_queue_cnt);
+ xsk_queue_cnt, prog_path);
if (eth_dev == NULL) {
AF_XDP_LOG(ERR, "Failed to init internals\n");
return -1;
@@ -1375,4 +1462,5 @@ RTE_PMD_REGISTER_VDEV(net_af_xdp, pmd_af_xdp_drv);
RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
"iface=<string> "
"start_queue=<int> "
- "queue_count=<int> ");
+ "queue_count=<int> "
+ "xdp_prog=<string> ");
--
2.17.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading
2020-08-28 11:18 [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading Ciara Loftus
@ 2020-09-10 11:40 ` Tahhan, Maryam
2020-09-14 13:07 ` Loftus, Ciara
2020-09-18 2:54 ` Hu, Xuekun
1 sibling, 1 reply; 4+ messages in thread
From: Tahhan, Maryam @ 2020-09-10 11:40 UTC (permalink / raw)
To: Loftus, Ciara, dev
> -----Original Message-----
> From: Loftus, Ciara <ciara.loftus@intel.com>
> Sent: Friday 28 August 2020 12:18
> To: dev@dpdk.org
> Cc: Loftus, Ciara <ciara.loftus@intel.com>
> Subject: [PATCH] net/af_xdp: custom XDP program loading
>
> The new 'xdp_prog=<string>' vdev arg allows the user to specify the path to
> a custom XDP program to be set on the device, instead of the default libbpf
> one. The program must have an XSK_MAP of name 'xsks_map' which will
> allow for the redirection of some packets to userspace and thus the PMD,
> using some criteria defined in the program.
> Note: a netdev may only load one program.
>
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
[MT] Stupid question :), AF_XDP is specifically related to loading an XDP program that allows you to redirect packets to an XSK...
why would you want to allow a custom XDP program to be loaded?
Other than that the code itself looked GTM
<snip>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading
2020-09-10 11:40 ` Tahhan, Maryam
@ 2020-09-14 13:07 ` Loftus, Ciara
0 siblings, 0 replies; 4+ messages in thread
From: Loftus, Ciara @ 2020-09-14 13:07 UTC (permalink / raw)
To: Tahhan, Maryam; +Cc: dev
> >
> > The new 'xdp_prog=<string>' vdev arg allows the user to specify the path
> to
> > a custom XDP program to be set on the device, instead of the default libbpf
> > one. The program must have an XSK_MAP of name 'xsks_map' which will
> > allow for the redirection of some packets to userspace and thus the PMD,
> > using some criteria defined in the program.
> > Note: a netdev may only load one program.
> >
> > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> > ---
>
> [MT] Stupid question :), AF_XDP is specifically related to loading an XDP
> program that allows you to redirect packets to an XSK...
> why would you want to allow a custom XDP program to be loaded?
>
> Other than that the code itself looked GTM
Hi Maryam,
Thanks for your feedback. It's a good question, and I will update the commit message in the v2 with the reasoning.
Sometimes it might be desired to redirect some not all packets to the xsk/PMD. eg. if the user wishes to drop or process a certain type of packet in the kernel. That logic can be put in the custom program. The key is that the custom program allows for *some* packets to still hit the xsk, and we check for that through checking the presence of the xsks_map.
Thanks,
Ciara
>
> <snip>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading
2020-08-28 11:18 [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading Ciara Loftus
2020-09-10 11:40 ` Tahhan, Maryam
@ 2020-09-18 2:54 ` Hu, Xuekun
1 sibling, 0 replies; 4+ messages in thread
From: Hu, Xuekun @ 2020-09-18 2:54 UTC (permalink / raw)
To: Loftus, Ciara, dev; +Cc: Loftus, Ciara
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Ciara Loftus
> Sent: Friday, August 28, 2020 7:18 PM
> To: dev@dpdk.org
> Cc: Loftus, Ciara <ciara.loftus@intel.com>
> Subject: [dpdk-dev] [PATCH] net/af_xdp: custom XDP program loading
>
> The new 'xdp_prog=<string>' vdev arg allows the user to specify the path to a
> custom XDP program to be set on the device, instead of the default libbpf
> one. The program must have an XSK_MAP of name 'xsks_map' which will
> allow for the redirection of some packets to userspace and thus the PMD,
> using some criteria defined in the program.
> Note: a netdev may only load one program.
>
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
Tested-by: Xuekun Hu <xuekun.hu@intel.com)>
^ permalink raw reply [flat|nested] 4+ messages in thread
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