target/riscv: Set MMU_2STAGE_BIT in riscv_cpu_mmu_index

Incorporate the virt_enabled and MPV checks into the cpu_mmu_index
function, so we don't have to keep doing it within tlb_fill and
subroutines.  This also elides a flush on changes to MPV.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Tested-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230325105429.1142530-17-richard.henderson@linaro.org>
Message-Id: <20230412114333.118895-17-richard.henderson@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu_helper.c

@@ -37,19 +37,21 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
 #ifdef CONFIG_USER_ONLY
     return 0;
 #else
-    if (ifetch) {
-        return env->priv;
-    }
+    bool virt = env->virt_enabled;
+    int mode = env->priv;
 
     /* All priv -> mmu_idx mapping are here */
-    int mode = env->priv;
-    if (mode == PRV_M && get_field(env->mstatus, MSTATUS_MPRV)) {
-        mode = get_field(env->mstatus, MSTATUS_MPP);
-    }
-    if (mode == PRV_S && get_field(env->mstatus, MSTATUS_SUM)) {
-        return MMUIdx_S_SUM;
+    if (!ifetch) {
+        if (mode == PRV_M && get_field(env->mstatus, MSTATUS_MPRV)) {
+            mode = get_field(env->mstatus, MSTATUS_MPP);
+            virt = get_field(env->mstatus, MSTATUS_MPV);
+        }
+        if (mode == PRV_S && get_field(env->mstatus, MSTATUS_SUM)) {
+            mode = MMUIdx_S_SUM;
+        }
     }
-    return mode;
+
+    return mode | (virt ? MMU_2STAGE_BIT : 0);
 #endif
 }
 
@@ -1162,7 +1164,7 @@ void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
     }
 
     env->badaddr = addr;
-    env->two_stage_lookup = env->virt_enabled || mmuidx_2stage(mmu_idx);
+    env->two_stage_lookup = mmuidx_2stage(mmu_idx);
     env->two_stage_indirect_lookup = false;
     cpu_loop_exit_restore(cs, retaddr);
 }
@@ -1187,7 +1189,7 @@ void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
         g_assert_not_reached();
     }
     env->badaddr = addr;
-    env->two_stage_lookup = env->virt_enabled || mmuidx_2stage(mmu_idx);
+    env->two_stage_lookup = mmuidx_2stage(mmu_idx);
     env->two_stage_indirect_lookup = false;
     cpu_loop_exit_restore(cs, retaddr);
 }
@@ -1225,7 +1227,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     int prot, prot2, prot_pmp;
     bool pmp_violation = false;
     bool first_stage_error = true;
-    bool two_stage_lookup = false;
+    bool two_stage_lookup = mmuidx_2stage(mmu_idx);
     bool two_stage_indirect_error = false;
     int ret = TRANSLATE_FAIL;
     int mode = mmu_idx;
@@ -1237,24 +1239,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
                   __func__, address, access_type, mmu_idx);
 
-    /*
-     * MPRV does not affect the virtual-machine load/store
-     * instructions, HLV, HLVX, and HSV.
-     */
-    if (mmuidx_2stage(mmu_idx)) {
-        ;
-    } else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
-               get_field(env->mstatus, MSTATUS_MPRV)) {
-        mode = get_field(env->mstatus, MSTATUS_MPP);
-        if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
-            two_stage_lookup = true;
-        }
-    }
-
     pmu_tlb_fill_incr_ctr(cpu, access_type);
-    if (env->virt_enabled ||
-        ((mmuidx_2stage(mmu_idx) || two_stage_lookup) &&
-         access_type != MMU_INST_FETCH)) {
+    if (two_stage_lookup) {
         /* Two stage lookup */
         ret = get_physical_address(env, &pa, &prot, address,
                                    &env->guest_phys_fault_addr, access_type,
@@ -1350,8 +1336,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
         return false;
     } else {
         raise_mmu_exception(env, address, access_type, pmp_violation,
-                            first_stage_error,
-                            env->virt_enabled || mmuidx_2stage(mmu_idx),
+                            first_stage_error, two_stage_lookup,
                             two_stage_indirect_error);
         cpu_loop_exit_restore(cs, retaddr);
     }

target/riscv/csr.c

@@ -1294,7 +1294,7 @@ static RISCVException write_mstatus(CPURISCVState *env, int csrno,
     val = legalize_mpp(env, get_field(mstatus, MSTATUS_MPP), val);
 
     /* flush tlb on mstatus fields that affect VM */
-    if ((val ^ mstatus) & (MSTATUS_MXR | MSTATUS_MPV)) {
+    if ((val ^ mstatus) & MSTATUS_MXR) {
         tlb_flush(env_cpu(env));
     }
     mask = MSTATUS_SIE | MSTATUS_SPIE | MSTATUS_MIE | MSTATUS_MPIE |
@@ -1342,10 +1342,6 @@ static RISCVException write_mstatush(CPURISCVState *env, int csrno,
     uint64_t valh = (uint64_t)val << 32;
     uint64_t mask = MSTATUS_MPV | MSTATUS_GVA;
 
-    if ((valh ^ env->mstatus) & (MSTATUS_MPV)) {
-        tlb_flush(env_cpu(env));
-    }
-
     env->mstatus = (env->mstatus & ~mask) | (valh & mask);
 
     return RISCV_EXCP_NONE;