On Sat, Jun 11, 2022 at 6:06 PM Anup Patel <apa...@ventanamicro.com> wrote:
>
> We should write transformed instruction encoding of the trapped
> instruction in [m|h]tinst CSR at time of taking trap as defined
> by the RISC-V privileged specification v1.12.
>
> Signed-off-by: Anup Patel <apa...@ventanamicro.com>
> ---
> target/riscv/cpu.h | 3 +
> target/riscv/cpu_helper.c | 214 ++++++++++++++++++++++++++++++++++++--
> target/riscv/instmap.h | 45 ++++++++
> 3 files changed, 256 insertions(+), 6 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 7d6397acdf..cac9e1876c 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -271,6 +271,9 @@ struct CPUArchState {
> /* Signals whether the current exception occurred with two-stage address
> translation active. */
> bool two_stage_lookup;
> + /* Signals whether the current exception occurred while doing two-stage
> + address translation for the VS-stage page table walk. */
Wrong comment style, otherwise
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
I can fix this up when I apply the series (unless you need to spin a
new version)
Alistair
> + bool two_stage_indirect_lookup;
>
> target_ulong scounteren;
> target_ulong mcounteren;
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 4a6700c890..3c8ebecf84 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -22,6 +22,7 @@
> #include "qemu/main-loop.h"
> #include "cpu.h"
> #include "exec/exec-all.h"
> +#include "instmap.h"
> #include "tcg/tcg-op.h"
> #include "trace.h"
> #include "semihosting/common-semi.h"
> @@ -1057,7 +1058,8 @@ restart:
>
> static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
> MMUAccessType access_type, bool
> pmp_violation,
> - bool first_stage, bool two_stage)
> + bool first_stage, bool two_stage,
> + bool two_stage_indirect)
> {
> CPUState *cs = env_cpu(env);
> int page_fault_exceptions, vm;
> @@ -1107,6 +1109,7 @@ static void raise_mmu_exception(CPURISCVState *env,
> target_ulong address,
> }
> env->badaddr = address;
> env->two_stage_lookup = two_stage;
> + env->two_stage_indirect_lookup = two_stage_indirect;
> }
>
> hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
> @@ -1152,6 +1155,7 @@ void riscv_cpu_do_transaction_failed(CPUState *cs,
> hwaddr physaddr,
> env->badaddr = addr;
> env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
> riscv_cpu_two_stage_lookup(mmu_idx);
> + env->two_stage_indirect_lookup = false;
> cpu_loop_exit_restore(cs, retaddr);
> }
>
> @@ -1177,6 +1181,7 @@ void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr
> addr,
> env->badaddr = addr;
> env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
> riscv_cpu_two_stage_lookup(mmu_idx);
> + env->two_stage_indirect_lookup = false;
> cpu_loop_exit_restore(cs, retaddr);
> }
>
> @@ -1192,6 +1197,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address,
> int size,
> bool pmp_violation = false;
> bool first_stage_error = true;
> bool two_stage_lookup = false;
> + bool two_stage_indirect_error = false;
> int ret = TRANSLATE_FAIL;
> int mode = mmu_idx;
> /* default TLB page size */
> @@ -1229,6 +1235,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address,
> int size,
> */
> if (ret == TRANSLATE_G_STAGE_FAIL) {
> first_stage_error = false;
> + two_stage_indirect_error = true;
> access_type = MMU_DATA_LOAD;
> }
>
> @@ -1312,12 +1319,182 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address,
> int size,
> raise_mmu_exception(env, address, access_type, pmp_violation,
> first_stage_error,
> riscv_cpu_virt_enabled(env) ||
> - riscv_cpu_two_stage_lookup(mmu_idx));
> + riscv_cpu_two_stage_lookup(mmu_idx),
> + two_stage_indirect_error);
> cpu_loop_exit_restore(cs, retaddr);
> }
>
> return true;
> }
> +
> +static target_ulong riscv_transformed_insn(CPURISCVState *env,
> + target_ulong insn,
> + bool addr_offset_nonzero,
> + target_ulong taddr)
> +{
> + target_ulong xinsn = 0, xinsn_access_bits = 0;
> +
> + /*
> + * Only Quadrant 0 and Quadrant 2 of RVC instruction space need to
> + * be uncompressed. The Quadrant 1 of RVC instruction space need
> + * not be transformed because these instructions won't generate
> + * any load/store trap.
> + */
> +
> + if ((insn & 0x3) != 0x3) {
> + /* Transform 16bit instruction into 32bit instruction */
> + switch (GET_C_OP(insn)) {
> + case OPC_RISC_C_OP_QUAD0: /* Quadrant 0 */
> + switch (GET_C_FUNC(insn)) {
> + case OPC_RISC_C_FUNC_FLD_LQ:
> + if (riscv_cpu_xlen(env) != 128) { /* C.FLD (RV32/64) */
> + xinsn = OPC_RISC_FLD;
> + xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_LW: /* C.LW */
> + xinsn = OPC_RISC_LW;
> + xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 2;
> + break;
> + case OPC_RISC_C_FUNC_FLW_LD:
> + if (riscv_cpu_xlen(env) == 32) { /* C.FLW (RV32) */
> + xinsn = OPC_RISC_FLW;
> + xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 2;
> + } else { /* C.LD (RV64/RV128) */
> + xinsn = OPC_RISC_LD;
> + xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_FSD_SQ:
> + if (riscv_cpu_xlen(env) != 128) { /* C.FSD (RV32/64) */
> + xinsn = OPC_RISC_FSD;
> + xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_SW: /* C.SW */
> + xinsn = OPC_RISC_SW;
> + xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 2;
> + break;
> + case OPC_RISC_C_FUNC_FSW_SD:
> + if (riscv_cpu_xlen(env) == 32) { /* C.FSW (RV32) */
> + xinsn = OPC_RISC_FSW;
> + xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 2;
> + } else { /* C.SD (RV64/RV128) */
> + xinsn = OPC_RISC_SD;
> + xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + default:
> + break;
> + }
> + break;
> + case OPC_RISC_C_OP_QUAD2: /* Quadrant 2 */
> + switch (GET_C_FUNC(insn)) {
> + case OPC_RISC_C_FUNC_FLDSP_LQSP:
> + if (riscv_cpu_xlen(env) != 128) { /* C.FLDSP (RV32/64) */
> + xinsn = OPC_RISC_FLD;
> + xinsn = SET_RD(xinsn, GET_C_RD(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_LWSP: /* C.LWSP */
> + xinsn = OPC_RISC_LW;
> + xinsn = SET_RD(xinsn, GET_C_RD(insn));
> + xinsn_access_bits = 2;
> + break;
> + case OPC_RISC_C_FUNC_FLWSP_LDSP:
> + if (riscv_cpu_xlen(env) == 32) { /* C.FLWSP (RV32) */
> + xinsn = OPC_RISC_FLW;
> + xinsn = SET_RD(xinsn, GET_C_RD(insn));
> + xinsn_access_bits = 2;
> + } else { /* C.LDSP (RV64/RV128) */
> + xinsn = OPC_RISC_LD;
> + xinsn = SET_RD(xinsn, GET_C_RD(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_FSDSP_SQSP:
> + if (riscv_cpu_xlen(env) != 128) { /* C.FSDSP (RV32/64) */
> + xinsn = OPC_RISC_FSD;
> + xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + case OPC_RISC_C_FUNC_SWSP: /* C.SWSP */
> + xinsn = OPC_RISC_SW;
> + xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
> + xinsn_access_bits = 2;
> + break;
> + case 7:
> + if (riscv_cpu_xlen(env) == 32) { /* C.FSWSP (RV32) */
> + xinsn = OPC_RISC_FSW;
> + xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
> + xinsn_access_bits = 2;
> + } else { /* C.SDSP (RV64/RV128) */
> + xinsn = OPC_RISC_SD;
> + xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
> + xinsn_access_bits = 3;
> + }
> + break;
> + default:
> + break;
> + }
> + break;
> + default:
> + break;
> + }
> +
> + /*
> + * Clear Bit1 of transformed instruction to indicate that
> + * original insruction was a 16bit instruction
> + */
> + xinsn &= ~((target_ulong)0x2);
> + } else {
> + /* Transform 32bit (or wider) instructions */
> + switch (MASK_OP_MAJOR(insn)) {
> + case OPC_RISC_ATOMIC:
> + xinsn = insn;
> + xinsn_access_bits = GET_FUNCT3(xinsn);
> + break;
> + case OPC_RISC_LOAD:
> + case OPC_RISC_FP_LOAD:
> + xinsn = insn;
> + xinsn_access_bits = GET_FUNCT3(xinsn);
> + xinsn = SET_I_IMM(xinsn, 0);
> + break;
> + case OPC_RISC_STORE:
> + case OPC_RISC_FP_STORE:
> + xinsn = insn;
> + xinsn_access_bits = GET_FUNCT3(xinsn);
> + xinsn = SET_S_IMM(xinsn, 0);
> + break;
> + case OPC_RISC_SYSTEM:
> + if (MASK_OP_SYSTEM(insn) == OPC_RISC_HLVHSV) {
> + xinsn = insn;
> + xinsn_access_bits = 1 << ((GET_FUNCT7(xinsn) >> 1) & 0x3);
> + }
> + break;
> + default:
> + break;
> + }
> + }
> +
> + if (addr_offset_nonzero) {
> + xinsn = SET_RS1(xinsn, taddr & ((1 << xinsn_access_bits) - 1));
> + } else {
> + xinsn = SET_RS1(xinsn, 0);
> + }
> +
> + return xinsn;
> +}
> #endif /* !CONFIG_USER_ONLY */
>
> /*
> @@ -1342,6 +1519,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
> uint64_t deleg = async ? env->mideleg : env->medeleg;
> target_ulong tval = 0;
> + target_ulong tinst = 0;
> target_ulong htval = 0;
> target_ulong mtval2 = 0;
>
> @@ -1357,18 +1535,39 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> if (!async) {
> /* set tval to badaddr for traps with address information */
> switch (cause) {
> - case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
> case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
> case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
> - case RISCV_EXCP_INST_ADDR_MIS:
> - case RISCV_EXCP_INST_ACCESS_FAULT:
> case RISCV_EXCP_LOAD_ADDR_MIS:
> case RISCV_EXCP_STORE_AMO_ADDR_MIS:
> case RISCV_EXCP_LOAD_ACCESS_FAULT:
> case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
> - case RISCV_EXCP_INST_PAGE_FAULT:
> case RISCV_EXCP_LOAD_PAGE_FAULT:
> case RISCV_EXCP_STORE_PAGE_FAULT:
> + write_gva = env->two_stage_lookup;
> + tval = env->badaddr;
> + if (env->two_stage_indirect_lookup) {
> + /*
> + * special pseudoinstruction for G-stage fault taken while
> + * doing VS-stage page table walk.
> + */
> + tinst = (riscv_cpu_xlen(env) == 32) ? 0x00002000 :
> 0x00003000;
> + } else {
> + /*
> + * The "Addr. Offset" field in transformed instruction is
> + * non-zero only for misaligned load/store traps.
> + */
> + if (cause == RISCV_EXCP_LOAD_ADDR_MIS ||
> + cause == RISCV_EXCP_STORE_AMO_ACCESS_FAULT) {
> + tinst = riscv_transformed_insn(env, env->bins, true,
> tval);
> + } else {
> + tinst = riscv_transformed_insn(env, env->bins, false,
> tval);
> + }
> + }
> + break;
> + case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
> + case RISCV_EXCP_INST_ADDR_MIS:
> + case RISCV_EXCP_INST_ACCESS_FAULT:
> + case RISCV_EXCP_INST_PAGE_FAULT:
> write_gva = env->two_stage_lookup;
> tval = env->badaddr;
> break;
> @@ -1450,6 +1649,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> env->sepc = env->pc;
> env->stval = tval;
> env->htval = htval;
> + env->htinst = tinst;
> env->pc = (env->stvec >> 2 << 2) +
> ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
> riscv_cpu_set_mode(env, PRV_S);
> @@ -1480,6 +1680,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> env->mepc = env->pc;
> env->mtval = tval;
> env->mtval2 = mtval2;
> + env->mtinst = tinst;
> env->pc = (env->mtvec >> 2 << 2) +
> ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
> riscv_cpu_set_mode(env, PRV_M);
> @@ -1492,6 +1693,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> */
>
> env->two_stage_lookup = false;
> + env->two_stage_indirect_lookup = false;
> #endif
> cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
> }
> diff --git a/target/riscv/instmap.h b/target/riscv/instmap.h
> index 40b6d2b64d..f877530576 100644
> --- a/target/riscv/instmap.h
> +++ b/target/riscv/instmap.h
> @@ -184,6 +184,8 @@ enum {
> OPC_RISC_CSRRWI = OPC_RISC_SYSTEM | (0x5 << 12),
> OPC_RISC_CSRRSI = OPC_RISC_SYSTEM | (0x6 << 12),
> OPC_RISC_CSRRCI = OPC_RISC_SYSTEM | (0x7 << 12),
> +
> + OPC_RISC_HLVHSV = OPC_RISC_SYSTEM | (0x4 << 12),
> };
>
> #define MASK_OP_FP_LOAD(op) (MASK_OP_MAJOR(op) | (op & (0x7 << 12)))
> @@ -310,12 +312,20 @@ enum {
> | (extract32(inst, 12, 8) << 12) \
> | (sextract64(inst, 31, 1) << 20))
>
> +#define GET_FUNCT3(inst) extract32(inst, 12, 3)
> +#define GET_FUNCT7(inst) extract32(inst, 25, 7)
> #define GET_RM(inst) extract32(inst, 12, 3)
> #define GET_RS3(inst) extract32(inst, 27, 5)
> #define GET_RS1(inst) extract32(inst, 15, 5)
> #define GET_RS2(inst) extract32(inst, 20, 5)
> #define GET_RD(inst) extract32(inst, 7, 5)
> #define GET_IMM(inst) sextract64(inst, 20, 12)
> +#define SET_RS1(inst, val) deposit32(inst, 15, 5, val)
> +#define SET_RS2(inst, val) deposit32(inst, 20, 5, val)
> +#define SET_RD(inst, val) deposit32(inst, 7, 5, val)
> +#define SET_I_IMM(inst, val) deposit32(inst, 20, 12, val)
> +#define SET_S_IMM(inst, val) \
> + deposit32(deposit32(inst, 7, 5, val), 25, 7, (val) >> 5)
>
> /* RVC decoding macros */
> #define GET_C_IMM(inst) (extract32(inst, 2, 5) \
> @@ -346,6 +356,8 @@ enum {
> | (extract32(inst, 5, 1) << 6))
> #define GET_C_LD_IMM(inst) ((extract16(inst, 10, 3) << 3) \
> | (extract16(inst, 5, 2) << 6))
> +#define GET_C_SW_IMM(inst) GET_C_LW_IMM(inst)
> +#define GET_C_SD_IMM(inst) GET_C_LD_IMM(inst)
> #define GET_C_J_IMM(inst) ((extract32(inst, 3, 3) << 1) \
> | (extract32(inst, 11, 1) << 4) \
> | (extract32(inst, 2, 1) << 5) \
> @@ -366,4 +378,37 @@ enum {
> #define GET_C_RS1S(inst) (8 + extract16(inst, 7, 3))
> #define GET_C_RS2S(inst) (8 + extract16(inst, 2, 3))
>
> +#define GET_C_FUNC(inst) extract32(inst, 13, 3)
> +#define GET_C_OP(inst) extract32(inst, 0, 2)
> +
> +enum {
> + /* RVC Quadrants */
> + OPC_RISC_C_OP_QUAD0 = 0x0,
> + OPC_RISC_C_OP_QUAD1 = 0x1,
> + OPC_RISC_C_OP_QUAD2 = 0x2
> +};
> +
> +enum {
> + /* RVC Quadrant 0 */
> + OPC_RISC_C_FUNC_ADDI4SPN = 0x0,
> + OPC_RISC_C_FUNC_FLD_LQ = 0x1,
> + OPC_RISC_C_FUNC_LW = 0x2,
> + OPC_RISC_C_FUNC_FLW_LD = 0x3,
> + OPC_RISC_C_FUNC_FSD_SQ = 0x5,
> + OPC_RISC_C_FUNC_SW = 0x6,
> + OPC_RISC_C_FUNC_FSW_SD = 0x7
> +};
> +
> +enum {
> + /* RVC Quadrant 2 */
> + OPC_RISC_C_FUNC_SLLI_SLLI64 = 0x0,
> + OPC_RISC_C_FUNC_FLDSP_LQSP = 0x1,
> + OPC_RISC_C_FUNC_LWSP = 0x2,
> + OPC_RISC_C_FUNC_FLWSP_LDSP = 0x3,
> + OPC_RISC_C_FUNC_JR_MV_EBREAK_JALR_ADD = 0x4,
> + OPC_RISC_C_FUNC_FSDSP_SQSP = 0x5,
> + OPC_RISC_C_FUNC_SWSP = 0x6,
> + OPC_RISC_C_FUNC_FSWSP_SDSP = 0x7
> +};
> +
> #endif
> --
> 2.34.1
>
>
