[dpdk-dev] [PATCH V2 4/5] pipeline: add header look-ahead instruction
Cristian Dumitrescu
cristian.dumitrescu at intel.com
Tue Jul 27 19:43:39 CEST 2021
Added look-ahead instruction to read a header from the input packet
without advancing the extraction pointer. This is typically used in
correlation with the special extract instruction to extract variable
size headers from the input packet: the first few header fields are
read without advancing the extraction pointer, just enough to detect
the actual length of the header (e.g. IPv4 IHL field); then the full
header is extracted.
Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu at intel.com>
---
lib/pipeline/rte_swx_pipeline.c | 61 +++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
diff --git a/lib/pipeline/rte_swx_pipeline.c b/lib/pipeline/rte_swx_pipeline.c
index d87fe77d91..13028bcc6a 100644
--- a/lib/pipeline/rte_swx_pipeline.c
+++ b/lib/pipeline/rte_swx_pipeline.c
@@ -306,6 +306,9 @@ enum instruction_type {
/* extract h.header m.last_field_size */
INSTR_HDR_EXTRACT_M,
+ /* lookahead h.header */
+ INSTR_HDR_LOOKAHEAD,
+
/* emit h.header */
INSTR_HDR_EMIT,
INSTR_HDR_EMIT_TX,
@@ -3123,6 +3126,31 @@ instr_hdr_extract_translate(struct rte_swx_pipeline *p,
return 0;
}
+static int
+instr_hdr_lookahead_translate(struct rte_swx_pipeline *p,
+ struct action *action,
+ char **tokens,
+ int n_tokens,
+ struct instruction *instr,
+ struct instruction_data *data __rte_unused)
+{
+ struct header *h;
+
+ CHECK(!action, EINVAL);
+ CHECK(n_tokens == 2, EINVAL);
+
+ h = header_parse(p, tokens[1]);
+ CHECK(h, EINVAL);
+ CHECK(!h->st->var_size, EINVAL);
+
+ instr->type = INSTR_HDR_LOOKAHEAD;
+ instr->io.hdr.header_id[0] = h->id;
+ instr->io.hdr.struct_id[0] = h->struct_id;
+ instr->io.hdr.n_bytes[0] = 0; /* Unused. */
+
+ return 0;
+}
+
static inline void
__instr_hdr_extract_exec(struct rte_swx_pipeline *p, uint32_t n_extract);
@@ -3299,6 +3327,30 @@ instr_hdr_extract_m_exec(struct rte_swx_pipeline *p)
thread_ip_inc(p);
}
+static inline void
+instr_hdr_lookahead_exec(struct rte_swx_pipeline *p)
+{
+ struct thread *t = &p->threads[p->thread_id];
+ struct instruction *ip = t->ip;
+
+ uint64_t valid_headers = t->valid_headers;
+ uint8_t *ptr = t->ptr;
+
+ uint32_t header_id = ip->io.hdr.header_id[0];
+ uint32_t struct_id = ip->io.hdr.struct_id[0];
+
+ TRACE("[Thread %2u]: lookahead header %u\n",
+ p->thread_id,
+ header_id);
+
+ /* Headers. */
+ t->structs[struct_id] = ptr;
+ t->valid_headers = MASK64_BIT_SET(valid_headers, header_id);
+
+ /* Thread. */
+ thread_ip_inc(p);
+}
+
/*
* emit.
*/
@@ -7916,6 +7968,14 @@ instr_translate(struct rte_swx_pipeline *p,
instr,
data);
+ if (!strcmp(tokens[tpos], "lookahead"))
+ return instr_hdr_lookahead_translate(p,
+ action,
+ &tokens[tpos],
+ n_tokens - tpos,
+ instr,
+ data);
+
if (!strcmp(tokens[tpos], "emit"))
return instr_hdr_emit_translate(p,
action,
@@ -8905,6 +8965,7 @@ static instr_exec_t instruction_table[] = {
[INSTR_HDR_EXTRACT7] = instr_hdr_extract7_exec,
[INSTR_HDR_EXTRACT8] = instr_hdr_extract8_exec,
[INSTR_HDR_EXTRACT_M] = instr_hdr_extract_m_exec,
+ [INSTR_HDR_LOOKAHEAD] = instr_hdr_lookahead_exec,
[INSTR_HDR_EMIT] = instr_hdr_emit_exec,
[INSTR_HDR_EMIT_TX] = instr_hdr_emit_tx_exec,
--
2.17.1
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