On Fri, Apr 29, 2022 at 5:36 AM Anup Patel <apa...@ventanamicro.com> wrote:>
> Currently, the [m|s]tval CSRs are set with trapping instruction encoding
> only for illegal instruction traps taken at the time of instruction
> decoding.
>
> In RISC-V world, a valid instructions might also trap as illegal or
> virtual instruction based to trapping bits in various CSRs (such as
> mstatus.TVM or hstatus.VTVM).
>
> We improve setting of [m|s]tval CSRs for all types of illegal and
> virtual instruction traps.
>
> Signed-off-by: Anup Patel <apa...@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
> target/riscv/cpu.c | 2 ++
> target/riscv/cpu.h | 8 +++++++-
> target/riscv/cpu_helper.c | 1 +
> target/riscv/translate.c | 17 +++++++++++++----
> 4 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index dff4606585..f0a702fee6 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -406,6 +406,7 @@ void restore_state_to_opc(CPURISCVState *env,
> TranslationBlock *tb,
> } else {
> env->pc = data[0];
> }
> + env->bins = data[1];
> }
>
> static void riscv_cpu_reset(DeviceState *dev)
> @@ -445,6 +446,7 @@ static void riscv_cpu_reset(DeviceState *dev)
> env->mcause = 0;
> env->miclaim = MIP_SGEIP;
> env->pc = env->resetvec;
> + env->bins = 0;
> env->two_stage_lookup = false;
>
> /* Initialized default priorities of local interrupts. */
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index fe6c9a2c92..a55c918274 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -30,6 +30,12 @@
>
> #define TCG_GUEST_DEFAULT_MO 0
>
> +/*
> + * RISC-V-specific extra insn start words:
> + * 1: Original instruction opcode
> + */
> +#define TARGET_INSN_START_EXTRA_WORDS 1
> +
> #define TYPE_RISCV_CPU "riscv-cpu"
>
> #define RISCV_CPU_TYPE_SUFFIX "-" TYPE_RISCV_CPU
> @@ -140,7 +146,7 @@ struct CPUArchState {
> target_ulong frm;
>
> target_ulong badaddr;
> - uint32_t bins;
> + target_ulong bins;
>
> target_ulong guest_phys_fault_addr;
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index d83579accf..bba4fce777 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -1371,6 +1371,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> tval = env->badaddr;
> break;
> case RISCV_EXCP_ILLEGAL_INST:
> + case RISCV_EXCP_VIRT_INSTRUCTION_FAULT:
> tval = env->bins;
> break;
> default:
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index 0cd1d9ee94..55a4713af2 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -107,6 +107,8 @@ typedef struct DisasContext {
> /* PointerMasking extension */
> bool pm_mask_enabled;
> bool pm_base_enabled;
> + /* TCG of the current insn_start */
> + TCGOp *insn_start;
> } DisasContext;
>
> static inline bool has_ext(DisasContext *ctx, uint32_t ext)
> @@ -236,9 +238,6 @@ static void generate_exception_mtval(DisasContext *ctx,
> int excp)
>
> static void gen_exception_illegal(DisasContext *ctx)
> {
> - tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
> - offsetof(CPURISCVState, bins));
> -
> generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
> }
>
> @@ -1017,6 +1016,13 @@ static uint32_t opcode_at(DisasContextBase *dcbase,
> target_ulong pc)
> /* Include decoders for factored-out extensions */
> #include "decode-XVentanaCondOps.c.inc"
>
> +static inline void decode_save_opc(DisasContext *ctx, target_ulong opc)
> +{
> + assert(ctx->insn_start != NULL);
> + tcg_set_insn_start_param(ctx->insn_start, 1, opc);
> + ctx->insn_start = NULL;
> +}
> +
> static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t
> opcode)
> {
> /*
> @@ -1033,6 +1039,7 @@ static void decode_opc(CPURISCVState *env, DisasContext
> *ctx, uint16_t opcode)
>
> /* Check for compressed insn */
> if (extract16(opcode, 0, 2) != 3) {
> + decode_save_opc(ctx, opcode);
> if (!has_ext(ctx, RVC)) {
> gen_exception_illegal(ctx);
> } else {
> @@ -1047,6 +1054,7 @@ static void decode_opc(CPURISCVState *env, DisasContext
> *ctx, uint16_t opcode)
> opcode32 = deposit32(opcode32, 16, 16,
> translator_lduw(env, &ctx->base,
> ctx->base.pc_next + 2));
> + decode_save_opc(ctx, opcode32);
> ctx->opcode = opcode32;
> ctx->pc_succ_insn = ctx->base.pc_next + 4;
>
> @@ -1113,7 +1121,8 @@ static void riscv_tr_insn_start(DisasContextBase
> *dcbase, CPUState *cpu)
> {
> DisasContext *ctx = container_of(dcbase, DisasContext, base);
>
> - tcg_gen_insn_start(ctx->base.pc_next);
> + tcg_gen_insn_start(ctx->base.pc_next, 0);
> + ctx->insn_start = tcg_last_op();
> }
>
> static void riscv_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
> --
> 2.34.1
>
>
