target/riscv: add vector configure instruction

vsetvl and vsetvli are two configure instructions for vl, vtype. TB flags
should update after configure instructions. The (ill, lmul, sew ) of vtype
and the bit of (VSTART == 0 && VL == VLMAX) will be placed within tb_flags.

Backports 2b7168fc43fb270fb89e1dddc17ef54714712f3a from qemu

qemu/header_gen.py

@@ -6068,6 +6068,7 @@ riscv_symbols = (
     'helper_tlb_flush',
     'helper_set_rounding_mode',
     'helper_sret',
+    'helper_vsetvl',
     'pmp_hart_has_privs',
     'pmpaddr_csr_read',
     'pmpaddr_csr_write',

qemu/riscv32.h

@@ -3522,6 +3522,7 @@
 #define helper_tlb_flush helper_tlb_flush_riscv32
 #define helper_set_rounding_mode helper_set_rounding_mode_riscv32
 #define helper_sret helper_sret_riscv32
+#define helper_vsetvl helper_vsetvl_riscv32
 #define pmp_hart_has_privs pmp_hart_has_privs_riscv32
 #define pmpaddr_csr_read pmpaddr_csr_read_riscv32
 #define pmpaddr_csr_write pmpaddr_csr_write_riscv32

qemu/riscv64.h

@@ -3522,6 +3522,7 @@
 #define helper_tlb_flush helper_tlb_flush_riscv64
 #define helper_set_rounding_mode helper_set_rounding_mode_riscv64
 #define helper_sret helper_sret_riscv64
+#define helper_vsetvl helper_vsetvl_riscv64
 #define pmp_hart_has_privs pmp_hart_has_privs_riscv64
 #define pmpaddr_csr_read pmpaddr_csr_read_riscv64
 #define pmpaddr_csr_write pmpaddr_csr_write_riscv64

qemu/target/riscv/Makefile.objs

@@ -1,4 +1,4 @@
-obj-y += translate.o op_helper.o cpu_helper.o cpu.o csr.o fpu_helper.o pmp.o
+obj-y += translate.o op_helper.o cpu_helper.o cpu.o csr.o fpu_helper.o vector_helper.o pmp.o
 obj-y += unicorn.o
 
 DECODETREE = $(SRC_PATH)/scripts/decodetree.py

qemu/target/riscv/cpu.h

@@ -24,6 +24,7 @@
 
 #include "qemu-common.h"
 #include "qom/cpu.h"
+#include "hw/registerfields.h"
 #include "exec/cpu-defs.h"
 #include "fpu/softfloat-types.h"
 
@@ -98,6 +99,12 @@ typedef struct CPURISCVState CPURISCVState;
 
 #define RV_VLEN_MAX 512
 
+FIELD(VTYPE, VLMUL, 0, 2)
+FIELD(VTYPE, VSEW, 2, 3)
+FIELD(VTYPE, VEDIV, 5, 2)
+FIELD(VTYPE, RESERVED, 7, sizeof(target_ulong) * 8 - 9)
+FIELD(VTYPE, VILL, sizeof(target_ulong) * 8 - 2, 1)
+
 struct CPURISCVState {
     target_ulong gpr[32];
     uint64_t fpr[32]; /* assume both F and D extensions */
@@ -351,19 +358,62 @@ void riscv_cpu_set_fflags(CPURISCVState *env, target_ulong);
 #define TB_FLAGS_MMU_MASK   3
 #define TB_FLAGS_MSTATUS_FS MSTATUS_FS
 
-static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
-                                        target_ulong *cs_base, uint32_t *flags)
+typedef CPURISCVState CPUArchState;
+typedef RISCVCPU ArchCPU;
+#include "exec/cpu-all.h"
+
+FIELD(TB_FLAGS, VL_EQ_VLMAX, 2, 1)
+FIELD(TB_FLAGS, LMUL, 3, 2)
+FIELD(TB_FLAGS, SEW, 5, 3)
+FIELD(TB_FLAGS, VILL, 8, 1)
+
+/*
+ * A simplification for VLMAX
+ * = (1 << LMUL) * VLEN / (8 * (1 << SEW))
+ * = (VLEN << LMUL) / (8 << SEW)
+ * = (VLEN << LMUL) >> (SEW + 3)
+ * = VLEN >> (SEW + 3 - LMUL)
+ */
+static inline uint32_t vext_get_vlmax(RISCVCPU *cpu, target_ulong vtype)
 {
+    uint8_t sew, lmul;
+
+    sew = FIELD_EX64(vtype, VTYPE, VSEW);
+    lmul = FIELD_EX64(vtype, VTYPE, VLMUL);
+    return cpu->cfg.vlen >> (sew + 3 - lmul);
+}
+
+static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
+                                        target_ulong *cs_base, uint32_t *pflags)
+{
+    uint32_t flags = 0;
+
     *pc = env->pc;
     *cs_base = 0;
+
+    if (riscv_has_ext(env, RVV)) {
+        uint32_t vlmax = vext_get_vlmax(env_archcpu(env), env->vtype);
+        bool vl_eq_vlmax = (env->vstart == 0) && (vlmax == env->vl);
+        flags = FIELD_DP32(flags, TB_FLAGS, VILL,
+                    FIELD_EX64(env->vtype, VTYPE, VILL));
+        flags = FIELD_DP32(flags, TB_FLAGS, SEW,
+                    FIELD_EX64(env->vtype, VTYPE, VSEW));
+        flags = FIELD_DP32(flags, TB_FLAGS, LMUL,
+                    FIELD_EX64(env->vtype, VTYPE, VLMUL));
+        flags = FIELD_DP32(flags, TB_FLAGS, VL_EQ_VLMAX, vl_eq_vlmax);
+    } else {
+        flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
+    }
+
 #ifdef CONFIG_USER_ONLY
-    *flags = TB_FLAGS_MSTATUS_FS;
+    flags |= TB_FLAGS_MSTATUS_FS;
 #else
-    *flags = cpu_mmu_index(env, 0);
+    flags |= cpu_mmu_index(env, 0);
     if (riscv_cpu_fp_enabled(env)) {
-        *flags |= env->mstatus & MSTATUS_FS;
+        flags |= env->mstatus & MSTATUS_FS;
     }
 #endif
+    *pflags = flags;
 }
 
 int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
@@ -402,11 +452,6 @@ typedef struct {
 void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops);
 void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);
 
-typedef CPURISCVState CPUArchState;
-typedef RISCVCPU ArchCPU;
-
-#include "exec/cpu-all.h"
-
 // Unicorn-specific
 void riscv_cpu_register_types(void *opaque);
 

qemu/target/riscv/helper.h

@@ -84,3 +84,6 @@ DEF_HELPER_1(tlb_flush, void, env)
 #ifndef CONFIG_USER_ONLY
 DEF_HELPER_1(hyp_tlb_flush, void, env)
 #endif
+
+/* Vector functions */
+DEF_HELPER_3(vsetvl, tl, env, tl, tl)

qemu/target/riscv/insn32.decode

@@ -62,6 +62,7 @@
 @r_rm    .......   ..... ..... ... ..... ....... %rs2 %rs1 %rm %rd
 @r2_rm   .......   ..... ..... ... ..... ....... %rs1 %rm %rd
 @r2      .......   ..... ..... ... ..... ....... %rs1 %rd
+@r2_zimm . zimm:11  ..... ... ..... ....... %rs1 %rd
 
 @hfence_gvma ....... ..... .....   ... ..... ....... %rs2 %rs1
 @hfence_vvma ....... ..... .....   ... ..... ....... %rs2 %rs1
@@ -209,3 +210,7 @@ fcvt_d_wu  1101001  00001 ..... ... ..... 1010011 @r2_rm
 # *** RV32H Base Instruction Set ***
 hfence_gvma 0110001  .....  ..... 000 00000 1110011 @hfence_gvma
 hfence_vvma 0010001  .....  ..... 000 00000 1110011 @hfence_vvma
+
+# *** RV32V Extension ***
+vsetvli         0 ........... ..... 111 ..... 1010111  @r2_zimm
+vsetvl          1000000 ..... ..... 111 ..... 1010111  @r

qemu/target/riscv/insn_trans/trans_rvv.inc.c

@@ -0,0 +1,81 @@
+/*
+ * RISC-V translation routines for the RVV Standard Extension.
+ *
+ * Copyright (c) 2020 T-Head Semiconductor Co., Ltd. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+static bool trans_vsetvl(DisasContext *ctx, arg_vsetvl *a)
+{
+    TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
+    TCGv s1, s2, dst;
+
+    if (!has_ext(ctx, RVV)) {
+        return false;
+    }
+
+    s2 = tcg_temp_new(tcg_ctx);
+    dst = tcg_temp_new(tcg_ctx);
+
+    /* Using x0 as the rs1 register specifier, encodes an infinite AVL */
+    if (a->rs1 == 0) {
+        /* As the mask is at least one bit, RV_VLEN_MAX is >= VLMAX */
+        s1 = tcg_const_tl(tcg_ctx, RV_VLEN_MAX);
+    } else {
+        s1 = tcg_temp_new(tcg_ctx);
+        gen_get_gpr(ctx, s1, a->rs1);
+    }
+    gen_get_gpr(ctx, s2, a->rs2);
+    gen_helper_vsetvl(tcg_ctx, dst, tcg_ctx->cpu_env, s1, s2);
+    gen_set_gpr(ctx, a->rd, dst);
+    tcg_gen_movi_tl(tcg_ctx, tcg_ctx->cpu_pc_risc, ctx->pc_succ_insn);
+    lookup_and_goto_ptr(ctx);
+    ctx->base.is_jmp = DISAS_NORETURN;
+
+    tcg_temp_free(tcg_ctx, s1);
+    tcg_temp_free(tcg_ctx, s2);
+    tcg_temp_free(tcg_ctx, dst);
+    return true;
+}
+
+static bool trans_vsetvli(DisasContext *ctx, arg_vsetvli *a)
+{
+    TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
+    TCGv s1, s2, dst;
+
+    if (!has_ext(ctx, RVV)) {
+        return false;
+    }
+
+    s2 = tcg_const_tl(tcg_ctx, a->zimm);
+    dst = tcg_temp_new(tcg_ctx);
+
+    /* Using x0 as the rs1 register specifier, encodes an infinite AVL */
+    if (a->rs1 == 0) {
+        /* As the mask is at least one bit, RV_VLEN_MAX is >= VLMAX */
+        s1 = tcg_const_tl(tcg_ctx, RV_VLEN_MAX);
+    } else {
+        s1 = tcg_temp_new(tcg_ctx);
+        gen_get_gpr(ctx, s1, a->rs1);
+    }
+    gen_helper_vsetvl(tcg_ctx, dst, tcg_ctx->cpu_env, s1, s2);
+    gen_set_gpr(ctx, a->rd, dst);
+    gen_goto_tb(ctx, 0, ctx->pc_succ_insn);
+    ctx->base.is_jmp = DISAS_NORETURN;
+
+    tcg_temp_free(tcg_ctx, s1);
+    tcg_temp_free(tcg_ctx, s2);
+    tcg_temp_free(tcg_ctx, dst);
+    return true;
+}

qemu/target/riscv/translate.c

@@ -54,6 +54,12 @@ typedef struct DisasContext {
        to reset this known value.  */
     int frm;
     bool ext_ifencei;
+    /* vector extension */
+    bool vill;
+    uint8_t lmul;
+    uint8_t sew;
+    uint16_t vlen;
+    bool vl_eq_vlmax;
 
     // Unicorn engine
     struct uc_struct *uc;
@@ -743,6 +749,7 @@ static bool gen_shift(DisasContext *ctx, arg_r *a,
 #include "insn_trans/trans_rvf.inc.c"
 #include "insn_trans/trans_rvd.inc.c"
 #include "insn_trans/trans_rvh.inc.c"
+#include "insn_trans/trans_rvv.inc.c"
 #include "insn_trans/trans_privileged.inc.c"
 
 /* Include the auto-generated decoder for 16 bit insn */
@@ -774,11 +781,12 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     DisasContext *ctx = container_of(dcbase, DisasContext, base);
     CPURISCVState *env = cs->env_ptr;
     RISCVCPU *cpu = RISCV_CPU(cs->uc, cs);
+    uint32_t tb_flags = ctx->base.tb->flags;
 
     ctx->uc = cs->uc;
     ctx->pc_succ_insn = ctx->base.pc_first;
-    ctx->mem_idx = ctx->base.tb->flags & TB_FLAGS_MMU_MASK;
-    ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
+    ctx->mem_idx = tb_flags & TB_FLAGS_MMU_MASK;
+    ctx->mstatus_fs = tb_flags & TB_FLAGS_MSTATUS_FS;
     ctx->priv_ver = env->priv_ver;
 #if !defined(CONFIG_USER_ONLY)
     if (riscv_has_ext(env, RVH)) {
@@ -802,6 +810,11 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->misa = env->misa;
     ctx->frm = -1;  /* unknown rounding mode */
     ctx->ext_ifencei = cpu->cfg.ext_ifencei;
+    ctx->vlen = cpu->cfg.vlen;
+    ctx->vill = FIELD_EX32(tb_flags, TB_FLAGS, VILL);
+    ctx->sew = FIELD_EX32(tb_flags, TB_FLAGS, SEW);
+    ctx->lmul = FIELD_EX32(tb_flags, TB_FLAGS, LMUL);
+    ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
 }
 
 static void riscv_tr_tb_start(DisasContextBase *db, CPUState *cpu)

qemu/target/riscv/vector_helper.c

@@ -0,0 +1,53 @@
+/*
+ * RISC-V Vector Extension Helpers for QEMU.
+ *
+ * Copyright (c) 2020 T-Head Semiconductor Co., Ltd. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include <math.h>
+
+target_ulong HELPER(vsetvl)(CPURISCVState *env, target_ulong s1,
+                            target_ulong s2)
+{
+    int vlmax, vl;
+    RISCVCPU *cpu = env_archcpu(env);
+    uint16_t sew = 8 << FIELD_EX64(s2, VTYPE, VSEW);
+    uint8_t ediv = FIELD_EX64(s2, VTYPE, VEDIV);
+    bool vill = FIELD_EX64(s2, VTYPE, VILL);
+    target_ulong reserved = FIELD_EX64(s2, VTYPE, RESERVED);
+
+    if ((sew > cpu->cfg.elen) || vill || (ediv != 0) || (reserved != 0)) {
+        /* only set vill bit. */
+        env->vtype = FIELD_DP64(0, VTYPE, VILL, 1);
+        env->vl = 0;
+        env->vstart = 0;
+        return 0;
+    }
+
+    vlmax = vext_get_vlmax(cpu, s2);
+    if (s1 <= vlmax) {
+        vl = s1;
+    } else {
+        vl = vlmax;
+    }
+    env->vl = vl;
+    env->vtype = s2;
+    env->vstart = 0;
+    return vl;
+}