arm64 jit compiler didn't support reading from a packet. Enable arm64 JIT to generate native code for (BPF_ABS | <size> | BPF_LD) and (BPF_IND | <size> | BPF_LD) instructions.
Both 'fast path' and 'slow path' are implemented, similar to the x86_64 JIT, where we call '__rte_pktmbuf_read' if the requested data is not in the first segment. Added unit test which focuses only on BPF_LD | BPF_ABS/BPF_IND and a BPF_LD | BPF_ABS slow path call. Signed-off-by: Christophe Fontaine <[email protected]> --- app/test/test_bpf.c | 121 ++++++++++++++++++++++++++++++++++++++++ lib/bpf/bpf_jit_arm64.c | 86 ++++++++++++++++++++++++++++ 2 files changed, 207 insertions(+) diff --git a/app/test/test_bpf.c b/app/test/test_bpf.c index dd24722450..799f9d30ca 100644 --- a/app/test/test_bpf.c +++ b/app/test/test_bpf.c @@ -2750,6 +2750,79 @@ static const struct rte_bpf_xsym test_call5_xsym[] = { }, }; +/* load mbuf (BPF_ABS/BPF_IND) test-cases */ +static const struct ebpf_insn test_ld_mbuf0_prog[] = { + /* BPF_ABS/BPF_IND implicitly expect mbuf ptr in R6 */ + { + .code = (EBPF_ALU64 | EBPF_MOV | BPF_X), + .dst_reg = EBPF_REG_6, + .src_reg = EBPF_REG_1, + }, + /* load IPv4 version and IHL */ + { + .code = (BPF_LD | BPF_ABS | BPF_B), + .imm = offsetof(struct rte_ipv4_hdr, version_ihl), + }, + { + .code = (BPF_JMP | EBPF_EXIT), + }, +}; + +/* load mbuf (BPF_ABS/BPF_IND) test-cases */ +static const struct ebpf_insn test_ld_slow_mbuf0_prog[] = { + /* BPF_ABS/BPF_IND implicitly expect mbuf ptr in R6 */ + { + .code = (EBPF_ALU64 | EBPF_MOV | BPF_X), + .dst_reg = EBPF_REG_6, + .src_reg = EBPF_REG_1, + }, + /* load from chained mbuf */ + { + .code = (BPF_LD | BPF_ABS | BPF_B), + /* 201: second mbuf, built by test_ld_mbuf1_prepare */ + .imm = 201 + 0x42, + }, + { + .code = (BPF_JMP | EBPF_EXIT), + }, +}; + +static const struct ebpf_insn test_ld_ind_mbuf0_prog[] = { + /* BPF_ABS/BPF_IND implicitly expect mbuf ptr in R6 */ + { + .code = (EBPF_ALU64 | EBPF_MOV | BPF_X), + .dst_reg = EBPF_REG_6, + .src_reg = EBPF_REG_1, + }, + { + /* Set return value to one. */ + .code = (EBPF_ALU64 | EBPF_MOV | BPF_K), + .dst_reg = EBPF_REG_0, + .imm = 0, + }, + /* load IPv4 version and IHL */ + { + .code = (BPF_LD | BPF_IND | BPF_B), + .src_reg = EBPF_REG_0, + .imm = offsetof(struct rte_ipv4_hdr, version_ihl), + }, + { + .code = (BPF_JMP | EBPF_EXIT), + }, +}; + +static int +test_ld_mbuf0_check(uint64_t rc, const void *arg) +{ + return cmp_res(__func__, 0x45, rc, arg, arg, 0); +} + +static int +test_ld_slow_mbuf0_check(uint64_t rc, const void *arg) +{ + return cmp_res(__func__, 0x42, rc, arg, arg, 0); +} + /* load mbuf (BPF_ABS/BPF_IND) test-cases */ static const struct ebpf_insn test_ld_mbuf1_prog[] = { @@ -3417,6 +3490,54 @@ static const struct bpf_test tests[] = { /* for now don't support function calls on 32 bit platform */ .allow_fail = (sizeof(uint64_t) != sizeof(uintptr_t)), }, + { + .name = "test_ld_abs_mbuf0", + .arg_sz = sizeof(struct dummy_mbuf), + .prm = { + .ins = test_ld_mbuf0_prog, + .nb_ins = RTE_DIM(test_ld_mbuf0_prog), + .prog_arg = { + .type = RTE_BPF_ARG_PTR_MBUF, + .buf_size = sizeof(struct dummy_mbuf), + }, + }, + .prepare = test_ld_mbuf1_prepare, + .check_result = test_ld_mbuf0_check, + /* mbuf as input argument is not supported on 32 bit platform */ + .allow_fail = (sizeof(uint64_t) != sizeof(uintptr_t)), + }, + { + .name = "test_ld_slow_mbuf0", + .arg_sz = sizeof(struct dummy_mbuf), + .prm = { + .ins = test_ld_slow_mbuf0_prog, + .nb_ins = RTE_DIM(test_ld_slow_mbuf0_prog), + .prog_arg = { + .type = RTE_BPF_ARG_PTR_MBUF, + .buf_size = sizeof(struct dummy_mbuf), + }, + }, + .prepare = test_ld_mbuf1_prepare, + .check_result = test_ld_slow_mbuf0_check, + /* mbuf as input argument is not supported on 32 bit platform */ + .allow_fail = (sizeof(uint64_t) != sizeof(uintptr_t)), + }, + { + .name = "test_ld_ind_mbuf0", + .arg_sz = sizeof(struct dummy_mbuf), + .prm = { + .ins = test_ld_ind_mbuf0_prog, + .nb_ins = RTE_DIM(test_ld_ind_mbuf0_prog), + .prog_arg = { + .type = RTE_BPF_ARG_PTR_MBUF, + .buf_size = sizeof(struct dummy_mbuf), + }, + }, + .prepare = test_ld_mbuf1_prepare, + .check_result = test_ld_mbuf0_check, + /* mbuf as input argument is not supported on 32 bit platform */ + .allow_fail = (sizeof(uint64_t) != sizeof(uintptr_t)), + }, { .name = "test_ld_mbuf1", .arg_sz = sizeof(struct dummy_mbuf), diff --git a/lib/bpf/bpf_jit_arm64.c b/lib/bpf/bpf_jit_arm64.c index 099822e9f1..5b3b80cb86 100644 --- a/lib/bpf/bpf_jit_arm64.c +++ b/lib/bpf/bpf_jit_arm64.c @@ -8,6 +8,7 @@ #include <rte_common.h> #include <rte_byteorder.h> +#include <rte_mbuf.h> #include "bpf_impl.h" @@ -1123,6 +1124,75 @@ emit_branch(struct a64_jit_ctx *ctx, uint8_t op, uint32_t i, int16_t off) emit_b_cond(ctx, ebpf_to_a64_cond(op), jump_offset_get(ctx, i, off)); } +/* + * Emit code for BPF_LD | BPF_ABS/IND: load from packet. + * Implements both a fast path, which computes the offset and read directly + * and a slow path, which calls __rte_pktmbuf_read(mbuf, off, len, buf) + * when the data is not in the first segment. + */ +static void +emit_ld_mbuf(struct a64_jit_ctx *ctx, uint32_t op, uint8_t tmp1, uint8_t tmp2, + uint8_t src, int32_t imm) +{ + uint8_t r0 = ebpf_to_a64_reg(ctx, EBPF_REG_0); + uint8_t r6 = ebpf_to_a64_reg(ctx, EBPF_REG_6); + uint32_t mode = BPF_MODE(op); + uint32_t opsz = BPF_SIZE(op); + uint32_t sz = bpf_size(opsz); + + /* r0 = mbuf (R6) */ + emit_mov_64(ctx, A64_R(0), r6); + + /* r1 = off: for ABS use imm, for IND use src + imm */ + if (mode == BPF_ABS) { + emit_mov_imm(ctx, 0, A64_R(1), imm); + } else { + emit_mov_imm(ctx, 0, tmp2, imm); + emit_add(ctx, 0, tmp2, src); + emit_mov_64(ctx, A64_R(1), tmp2); + } + + /* r2 = len, 1/2/4 bytes */ + emit_mov_imm32(ctx, 0, A64_R(2), sz); + /* r3 = buf (SP) */ + emit_mov_64(ctx, A64_R(3), A64_SP); + + /* tmp1 = mbuf->data_len */ + emit_mov_imm(ctx, 1, tmp1, offsetof(struct rte_mbuf, data_len)); + emit_ldr(ctx, BPF_W, tmp1, r6, tmp1); + + /* tmp2 = off + sz */ + emit_add_imm_64(ctx, tmp2, A64_R(1), sz); + /* if off+sz > data_len, jump to slow path */ + emit_cmp(ctx, 1, tmp2, tmp1); + emit_b_cond(ctx, A64_HI, 8); + + /* Fast path, read directly, pointer to the data will be in A64_R(0) */ + /* A64_R(0) = mbuf->buf_addr */ + emit_mov_imm(ctx, 1, tmp1, offsetof(struct rte_mbuf, buf_addr)); + emit_ldr(ctx, EBPF_DW, A64_R(0), r6, tmp1); + /* tmp2 = * mbuf->data_off */ + emit_mov_imm(ctx, 1, tmp2, offsetof(struct rte_mbuf, data_off)); + emit_ldr(ctx, BPF_H, tmp2, r6, tmp2); + + /* A64_R(0) += data_off + off */ + emit_add(ctx, 1, A64_R(0), tmp2); + emit_add(ctx, 1, A64_R(0), A64_R(1)); + + /* End of Fast Path, skip slow path */ + emit_b(ctx, 4); + + /* slow path, call __rte_pktmbuf_read */ + emit_call(ctx, tmp1, __rte_pktmbuf_read); + /* check return value of __rte_pktmbuf_read */ + emit_return_zero_if_src_zero(ctx, 1, A64_R(0)); + + /* A64_R(0) points to the data, load 1/2/4 bytes into r0*/ + emit_ldr(ctx, opsz, r0, A64_R(0), A64_ZR); + if (sz != sizeof(uint8_t)) + emit_be(ctx, r0, sz * CHAR_BIT); +} + static void check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) { @@ -1137,6 +1207,13 @@ check_program_has_call(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) switch (op) { /* Call imm */ case (BPF_JMP | EBPF_CALL): + /* BPF_LD | BPF_ABS/IND use __rte_pktmbuf_read */ + case (BPF_LD | BPF_ABS | BPF_B): + case (BPF_LD | BPF_ABS | BPF_H): + case (BPF_LD | BPF_ABS | BPF_W): + case (BPF_LD | BPF_IND | BPF_B): + case (BPF_LD | BPF_IND | BPF_H): + case (BPF_LD | BPF_IND | BPF_W): ctx->foundcall = 1; return; } @@ -1338,6 +1415,15 @@ emit(struct a64_jit_ctx *ctx, struct rte_bpf *bpf) emit_mov_imm(ctx, 1, dst, u64); i++; break; + /* load absolute/indirect from packet */ + case (BPF_LD | BPF_ABS | BPF_B): + case (BPF_LD | BPF_ABS | BPF_H): + case (BPF_LD | BPF_ABS | BPF_W): + case (BPF_LD | BPF_IND | BPF_B): + case (BPF_LD | BPF_IND | BPF_H): + case (BPF_LD | BPF_IND | BPF_W): + emit_ld_mbuf(ctx, op, tmp1, tmp2, src, imm); + break; /* *(size *)(dst + off) = src */ case (BPF_STX | BPF_MEM | BPF_B): case (BPF_STX | BPF_MEM | BPF_H): -- 2.53.0
