The bpf load kernel API can provide some useful diagnostics
on failure.
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
drivers/net/tap/tap_bpf_api.c | 44 +++++++++++++++++++++++++++--------
drivers/net/tap/tap_flow.c | 16 ++++++++-----
drivers/net/tap/tap_flow.h | 4 ++--
3 files changed, 46 insertions(+), 18 deletions(-)
diff --git a/drivers/net/tap/tap_bpf_api.c b/drivers/net/tap/tap_bpf_api.c
index c754c167a764..29223b7f0ea7 100644
--- a/drivers/net/tap/tap_bpf_api.c
+++ b/drivers/net/tap/tap_bpf_api.c
@@ -15,8 +15,10 @@
#include <tap_bpf.h>
#include <tap_bpf_insns.h>
-static int bpf_load(enum bpf_prog_type type, const struct bpf_insn *insns,
- size_t insns_cnt, const char *license);
+static int bpf_load(enum bpf_prog_type type,
+ const struct bpf_insn *insns, size_t insns_cnt,
+ char *log_buf, size_t log_size,
+ const char *license);
/**
* Load BPF program (section cls_q) into the kernel and return a bpf fd
@@ -24,15 +26,22 @@ static int bpf_load(enum bpf_prog_type type, const struct
bpf_insn *insns,
* @param queue_idx
* Queue index matching packet cb
*
+ * @param log_buf
+ * Buffer to place resulting error message (optional)
+ *
+ * @param log_size
+ * Size of log_buf
+ *
* @return
* -1 if the BPF program couldn't be loaded. An fd (int) otherwise.
*/
-int tap_flow_bpf_cls_q(__u32 queue_idx)
+int tap_flow_bpf_cls_q(__u32 queue_idx, char *log_buf, size_t log_size)
{
cls_q_insns[1].imm = queue_idx;
return bpf_load(BPF_PROG_TYPE_SCHED_CLS,
cls_q_insns, RTE_DIM(cls_q_insns),
+ log_buf, log_size,
"Dual BSD/GPL");
}
@@ -45,16 +54,23 @@ int tap_flow_bpf_cls_q(__u32 queue_idx)
* @param[in] map_fd
* BPF RSS map file descriptor
*
+ * @param log_buf
+ * Buffer to place resulting error message (optional)
+ *
+ * @param log_size
+ * Size of log_buf
+ *
* @return
* -1 if the BPF program couldn't be loaded. An fd (int) otherwise.
*/
-int tap_flow_bpf_calc_l3_l4_hash(__u32 key_idx, int map_fd)
+int tap_flow_bpf_calc_l3_l4_hash(__u32 key_idx, int map_fd, char *log_buf,
size_t log_size)
{
l3_l4_hash_insns[4].imm = key_idx;
l3_l4_hash_insns[9].imm = map_fd;
return bpf_load(BPF_PROG_TYPE_SCHED_ACT,
l3_l4_hash_insns, RTE_DIM(l3_l4_hash_insns),
+ log_buf, log_size,
"Dual BSD/GPL");
}
@@ -105,6 +121,12 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr
*attr,
* @param[in] insns_cnt
* Number of BPF instructions (size of array)
*
+ * @param[out] log_buf
+ * Space for log message
+ *
+ * @param[in] log_size
+ * Number of characters available in log_buf
+ *
* @param[in] license
* License string that must be acknowledged by the kernel
*
@@ -112,9 +134,8 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr
*attr,
* -1 if the BPF program couldn't be loaded, fd (file descriptor) otherwise
*/
static int bpf_load(enum bpf_prog_type type,
- const struct bpf_insn *insns,
- size_t insns_cnt,
- const char *license)
+ const struct bpf_insn *insns, size_t insns_cnt,
+ char *log_buf, size_t log_size, const char *license)
{
union bpf_attr attr = {};
@@ -122,9 +143,12 @@ static int bpf_load(enum bpf_prog_type type,
attr.insn_cnt = (__u32)insns_cnt;
attr.insns = ptr_to_u64(insns);
attr.license = ptr_to_u64(license);
- attr.log_buf = ptr_to_u64(NULL);
- attr.log_level = 0;
- attr.kern_version = 0;
+
+ if (log_size > 0) {
+ attr.log_level = 2;
+ attr.log_buf = ptr_to_u64(log_buf);
+ attr.log_size = log_size;
+ }
return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index ed4d42f92f9f..897d71acbad1 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -18,6 +18,8 @@
#include <tap_tcmsgs.h>
#include <tap_rss.h>
+#define BPF_LOG_BUFSIZ 1024
+
#ifndef HAVE_TC_FLOWER
/*
* For kernels < 4.2, this enum is not defined. Runtime checks will be made to
@@ -1885,11 +1887,13 @@ static int rss_enable(struct pmd_internals *pmd,
* the correct queue.
*/
for (i = 0; i < pmd->dev->data->nb_rx_queues; i++) {
- pmd->bpf_fd[i] = tap_flow_bpf_cls_q(i);
+ char log_buf[BPF_LOG_BUFSIZ];
+
+ pmd->bpf_fd[i] = tap_flow_bpf_cls_q(i, log_buf,
sizeof(log_buf));
if (pmd->bpf_fd[i] < 0) {
TAP_LOG(ERR,
- "Failed to load BPF section %s for queue %d",
- SEC_NAME_CLS_Q, i);
+ "Failed to load BPF section %s for queue %u:
%s",
+ SEC_NAME_CLS_Q, i, log_buf);
rte_flow_error_set(
error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE,
NULL,
@@ -2074,6 +2078,7 @@ static int rss_add_actions(struct rte_flow *flow, struct
pmd_internals *pmd,
/* 4096 is the maximum number of instructions for a BPF program */
unsigned int i;
int err;
+ char log_buf[BPF_LOG_BUFSIZ];
struct rss_key rss_entry = { .hash_fields = 0,
.key_size = 0 };
@@ -2124,9 +2129,8 @@ static int rss_add_actions(struct rte_flow *flow, struct
pmd_internals *pmd,
/*
* Load bpf rules to calculate hash for this key_idx
*/
-
- flow->bpf_fd[SEC_L3_L4] =
- tap_flow_bpf_calc_l3_l4_hash(flow->key_idx, pmd->map_fd);
+ flow->bpf_fd[SEC_L3_L4] = tap_flow_bpf_calc_l3_l4_hash(flow->key_idx,
pmd->map_fd,
+ log_buf,
sizeof(log_buf));
if (flow->bpf_fd[SEC_L3_L4] < 0) {
TAP_LOG(ERR,
"Failed to load BPF section %s (%d): %s",
diff --git a/drivers/net/tap/tap_flow.h b/drivers/net/tap/tap_flow.h
index 240fbc3dfaef..fb30b495fda1 100644
--- a/drivers/net/tap/tap_flow.h
+++ b/drivers/net/tap/tap_flow.h
@@ -57,8 +57,8 @@ int tap_flow_implicit_destroy(struct pmd_internals *pmd,
int tap_flow_implicit_flush(struct pmd_internals *pmd,
struct rte_flow_error *error);
-int tap_flow_bpf_cls_q(__u32 queue_idx);
-int tap_flow_bpf_calc_l3_l4_hash(__u32 key_idx, int map_fd);
+int tap_flow_bpf_cls_q(__u32 queue_idx, char *log_buf, size_t log_size);
+int tap_flow_bpf_calc_l3_l4_hash(__u32 key_idx, int map_fd, char *log_buf,
size_t log_size);
int tap_flow_bpf_rss_map_create(unsigned int key_size, unsigned int value_size,
unsigned int max_entries);
int tap_flow_bpf_update_rss_elem(int fd, void *key, void *value);
--
2.43.0
