xref: /openbmc/qemu/target/riscv/cpu_helper.c (revision 02d9565b)
1 /*
2  * RISC-V CPU helpers for qemu.
3  *
4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
5  * Copyright (c) 2017-2018 SiFive, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/log.h"
22 #include "qemu/main-loop.h"
23 #include "cpu.h"
24 #include "exec/exec-all.h"
25 #include "tcg/tcg-op.h"
26 #include "trace.h"
27 #include "semihosting/common-semi.h"
28 
29 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
30 {
31 #ifdef CONFIG_USER_ONLY
32     return 0;
33 #else
34     return env->priv;
35 #endif
36 }
37 
38 void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
39                           target_ulong *cs_base, uint32_t *pflags)
40 {
41     CPUState *cs = env_cpu(env);
42     RISCVCPU *cpu = RISCV_CPU(cs);
43 
44     uint32_t flags = 0;
45 
46     *pc = env->xl == MXL_RV32 ? env->pc & UINT32_MAX : env->pc;
47     *cs_base = 0;
48 
49     if (riscv_has_ext(env, RVV) || cpu->cfg.ext_zve32f || cpu->cfg.ext_zve64f) {
50         /*
51          * If env->vl equals to VLMAX, we can use generic vector operation
52          * expanders (GVEC) to accerlate the vector operations.
53          * However, as LMUL could be a fractional number. The maximum
54          * vector size can be operated might be less than 8 bytes,
55          * which is not supported by GVEC. So we set vl_eq_vlmax flag to true
56          * only when maxsz >= 8 bytes.
57          */
58         uint32_t vlmax = vext_get_vlmax(env_archcpu(env), env->vtype);
59         uint32_t sew = FIELD_EX64(env->vtype, VTYPE, VSEW);
60         uint32_t maxsz = vlmax << sew;
61         bool vl_eq_vlmax = (env->vstart == 0) && (vlmax == env->vl) &&
62                            (maxsz >= 8);
63         flags = FIELD_DP32(flags, TB_FLAGS, VILL, env->vill);
64         flags = FIELD_DP32(flags, TB_FLAGS, SEW, sew);
65         flags = FIELD_DP32(flags, TB_FLAGS, LMUL,
66                     FIELD_EX64(env->vtype, VTYPE, VLMUL));
67         flags = FIELD_DP32(flags, TB_FLAGS, VL_EQ_VLMAX, vl_eq_vlmax);
68     } else {
69         flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
70     }
71 
72 #ifdef CONFIG_USER_ONLY
73     flags |= TB_FLAGS_MSTATUS_FS;
74     flags |= TB_FLAGS_MSTATUS_VS;
75 #else
76     flags |= cpu_mmu_index(env, 0);
77     if (riscv_cpu_fp_enabled(env)) {
78         flags |= env->mstatus & MSTATUS_FS;
79     }
80 
81     if (riscv_cpu_vector_enabled(env)) {
82         flags |= env->mstatus & MSTATUS_VS;
83     }
84 
85     if (riscv_has_ext(env, RVH)) {
86         if (env->priv == PRV_M ||
87             (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
88             (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
89                 get_field(env->hstatus, HSTATUS_HU))) {
90             flags = FIELD_DP32(flags, TB_FLAGS, HLSX, 1);
91         }
92 
93         flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_FS,
94                            get_field(env->mstatus_hs, MSTATUS_FS));
95 
96         flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
97                            get_field(env->mstatus_hs, MSTATUS_VS));
98     }
99 #endif
100 
101     flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
102     if (env->cur_pmmask < (env->xl == MXL_RV32 ? UINT32_MAX : UINT64_MAX)) {
103         flags = FIELD_DP32(flags, TB_FLAGS, PM_MASK_ENABLED, 1);
104     }
105     if (env->cur_pmbase != 0) {
106         flags = FIELD_DP32(flags, TB_FLAGS, PM_BASE_ENABLED, 1);
107     }
108 
109     *pflags = flags;
110 }
111 
112 void riscv_cpu_update_mask(CPURISCVState *env)
113 {
114     target_ulong mask = -1, base = 0;
115     /*
116      * TODO: Current RVJ spec does not specify
117      * how the extension interacts with XLEN.
118      */
119 #ifndef CONFIG_USER_ONLY
120     if (riscv_has_ext(env, RVJ)) {
121         switch (env->priv) {
122         case PRV_M:
123             if (env->mmte & M_PM_ENABLE) {
124                 mask = env->mpmmask;
125                 base = env->mpmbase;
126             }
127             break;
128         case PRV_S:
129             if (env->mmte & S_PM_ENABLE) {
130                 mask = env->spmmask;
131                 base = env->spmbase;
132             }
133             break;
134         case PRV_U:
135             if (env->mmte & U_PM_ENABLE) {
136                 mask = env->upmmask;
137                 base = env->upmbase;
138             }
139             break;
140         default:
141             g_assert_not_reached();
142         }
143     }
144 #endif
145     if (env->xl == MXL_RV32) {
146         env->cur_pmmask = mask & UINT32_MAX;
147         env->cur_pmbase = base & UINT32_MAX;
148     } else {
149         env->cur_pmmask = mask;
150         env->cur_pmbase = base;
151     }
152 }
153 
154 #ifndef CONFIG_USER_ONLY
155 static int riscv_cpu_local_irq_pending(CPURISCVState *env)
156 {
157     target_ulong virt_enabled = riscv_cpu_virt_enabled(env);
158 
159     target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
160     target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
161 
162     target_ulong vsgemask =
163                 (target_ulong)1 << get_field(env->hstatus, HSTATUS_VGEIN);
164     target_ulong vsgein = (env->hgeip & vsgemask) ? MIP_VSEIP : 0;
165 
166     target_ulong pending = (env->mip | vsgein) & env->mie;
167 
168     target_ulong mie    = env->priv < PRV_M ||
169                           (env->priv == PRV_M && mstatus_mie);
170     target_ulong sie    = env->priv < PRV_S ||
171                           (env->priv == PRV_S && mstatus_sie);
172     target_ulong hsie   = virt_enabled || sie;
173     target_ulong vsie   = virt_enabled && sie;
174 
175     target_ulong irqs =
176             (pending & ~env->mideleg & -mie) |
177             (pending &  env->mideleg & ~env->hideleg & -hsie) |
178             (pending &  env->mideleg &  env->hideleg & -vsie);
179 
180     if (irqs) {
181         return ctz64(irqs); /* since non-zero */
182     } else {
183         return RISCV_EXCP_NONE; /* indicates no pending interrupt */
184     }
185 }
186 
187 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
188 {
189     if (interrupt_request & CPU_INTERRUPT_HARD) {
190         RISCVCPU *cpu = RISCV_CPU(cs);
191         CPURISCVState *env = &cpu->env;
192         int interruptno = riscv_cpu_local_irq_pending(env);
193         if (interruptno >= 0) {
194             cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
195             riscv_cpu_do_interrupt(cs);
196             return true;
197         }
198     }
199     return false;
200 }
201 
202 /* Return true is floating point support is currently enabled */
203 bool riscv_cpu_fp_enabled(CPURISCVState *env)
204 {
205     if (env->mstatus & MSTATUS_FS) {
206         if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
207             return false;
208         }
209         return true;
210     }
211 
212     return false;
213 }
214 
215 /* Return true is vector support is currently enabled */
216 bool riscv_cpu_vector_enabled(CPURISCVState *env)
217 {
218     if (env->mstatus & MSTATUS_VS) {
219         if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_VS)) {
220             return false;
221         }
222         return true;
223     }
224 
225     return false;
226 }
227 
228 void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
229 {
230     uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
231                             MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
232                             MSTATUS64_UXL | MSTATUS_VS;
233     bool current_virt = riscv_cpu_virt_enabled(env);
234 
235     g_assert(riscv_has_ext(env, RVH));
236 
237     if (current_virt) {
238         /* Current V=1 and we are about to change to V=0 */
239         env->vsstatus = env->mstatus & mstatus_mask;
240         env->mstatus &= ~mstatus_mask;
241         env->mstatus |= env->mstatus_hs;
242 
243         env->vstvec = env->stvec;
244         env->stvec = env->stvec_hs;
245 
246         env->vsscratch = env->sscratch;
247         env->sscratch = env->sscratch_hs;
248 
249         env->vsepc = env->sepc;
250         env->sepc = env->sepc_hs;
251 
252         env->vscause = env->scause;
253         env->scause = env->scause_hs;
254 
255         env->vstval = env->stval;
256         env->stval = env->stval_hs;
257 
258         env->vsatp = env->satp;
259         env->satp = env->satp_hs;
260     } else {
261         /* Current V=0 and we are about to change to V=1 */
262         env->mstatus_hs = env->mstatus & mstatus_mask;
263         env->mstatus &= ~mstatus_mask;
264         env->mstatus |= env->vsstatus;
265 
266         env->stvec_hs = env->stvec;
267         env->stvec = env->vstvec;
268 
269         env->sscratch_hs = env->sscratch;
270         env->sscratch = env->vsscratch;
271 
272         env->sepc_hs = env->sepc;
273         env->sepc = env->vsepc;
274 
275         env->scause_hs = env->scause;
276         env->scause = env->vscause;
277 
278         env->stval_hs = env->stval;
279         env->stval = env->vstval;
280 
281         env->satp_hs = env->satp;
282         env->satp = env->vsatp;
283     }
284 }
285 
286 target_ulong riscv_cpu_get_geilen(CPURISCVState *env)
287 {
288     if (!riscv_has_ext(env, RVH)) {
289         return 0;
290     }
291 
292     return env->geilen;
293 }
294 
295 void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen)
296 {
297     if (!riscv_has_ext(env, RVH)) {
298         return;
299     }
300 
301     if (geilen > (TARGET_LONG_BITS - 1)) {
302         return;
303     }
304 
305     env->geilen = geilen;
306 }
307 
308 bool riscv_cpu_virt_enabled(CPURISCVState *env)
309 {
310     if (!riscv_has_ext(env, RVH)) {
311         return false;
312     }
313 
314     return get_field(env->virt, VIRT_ONOFF);
315 }
316 
317 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
318 {
319     if (!riscv_has_ext(env, RVH)) {
320         return;
321     }
322 
323     /* Flush the TLB on all virt mode changes. */
324     if (get_field(env->virt, VIRT_ONOFF) != enable) {
325         tlb_flush(env_cpu(env));
326     }
327 
328     env->virt = set_field(env->virt, VIRT_ONOFF, enable);
329 
330     if (enable) {
331         /*
332          * The guest external interrupts from an interrupt controller are
333          * delivered only when the Guest/VM is running (i.e. V=1). This means
334          * any guest external interrupt which is triggered while the Guest/VM
335          * is not running (i.e. V=0) will be missed on QEMU resulting in guest
336          * with sluggish response to serial console input and other I/O events.
337          *
338          * To solve this, we check and inject interrupt after setting V=1.
339          */
340         riscv_cpu_update_mip(env_archcpu(env), 0, 0);
341     }
342 }
343 
344 bool riscv_cpu_two_stage_lookup(int mmu_idx)
345 {
346     return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
347 }
348 
349 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
350 {
351     CPURISCVState *env = &cpu->env;
352     if (env->miclaim & interrupts) {
353         return -1;
354     } else {
355         env->miclaim |= interrupts;
356         return 0;
357     }
358 }
359 
360 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
361 {
362     CPURISCVState *env = &cpu->env;
363     CPUState *cs = CPU(cpu);
364     uint32_t gein, vsgein = 0, old = env->mip;
365     bool locked = false;
366 
367     if (riscv_cpu_virt_enabled(env)) {
368         gein = get_field(env->hstatus, HSTATUS_VGEIN);
369         vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0;
370     }
371 
372     if (!qemu_mutex_iothread_locked()) {
373         locked = true;
374         qemu_mutex_lock_iothread();
375     }
376 
377     env->mip = (env->mip & ~mask) | (value & mask);
378 
379     if (env->mip | vsgein) {
380         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
381     } else {
382         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
383     }
384 
385     if (locked) {
386         qemu_mutex_unlock_iothread();
387     }
388 
389     return old;
390 }
391 
392 void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
393                              uint32_t arg)
394 {
395     env->rdtime_fn = fn;
396     env->rdtime_fn_arg = arg;
397 }
398 
399 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
400 {
401     if (newpriv > PRV_M) {
402         g_assert_not_reached();
403     }
404     if (newpriv == PRV_H) {
405         newpriv = PRV_U;
406     }
407     /* tlb_flush is unnecessary as mode is contained in mmu_idx */
408     env->priv = newpriv;
409     env->xl = cpu_recompute_xl(env);
410     riscv_cpu_update_mask(env);
411 
412     /*
413      * Clear the load reservation - otherwise a reservation placed in one
414      * context/process can be used by another, resulting in an SC succeeding
415      * incorrectly. Version 2.2 of the ISA specification explicitly requires
416      * this behaviour, while later revisions say that the kernel "should" use
417      * an SC instruction to force the yielding of a load reservation on a
418      * preemptive context switch. As a result, do both.
419      */
420     env->load_res = -1;
421 }
422 
423 /*
424  * get_physical_address_pmp - check PMP permission for this physical address
425  *
426  * Match the PMP region and check permission for this physical address and it's
427  * TLB page. Returns 0 if the permission checking was successful
428  *
429  * @env: CPURISCVState
430  * @prot: The returned protection attributes
431  * @tlb_size: TLB page size containing addr. It could be modified after PMP
432  *            permission checking. NULL if not set TLB page for addr.
433  * @addr: The physical address to be checked permission
434  * @access_type: The type of MMU access
435  * @mode: Indicates current privilege level.
436  */
437 static int get_physical_address_pmp(CPURISCVState *env, int *prot,
438                                     target_ulong *tlb_size, hwaddr addr,
439                                     int size, MMUAccessType access_type,
440                                     int mode)
441 {
442     pmp_priv_t pmp_priv;
443     target_ulong tlb_size_pmp = 0;
444 
445     if (!riscv_feature(env, RISCV_FEATURE_PMP)) {
446         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
447         return TRANSLATE_SUCCESS;
448     }
449 
450     if (!pmp_hart_has_privs(env, addr, size, 1 << access_type, &pmp_priv,
451                             mode)) {
452         *prot = 0;
453         return TRANSLATE_PMP_FAIL;
454     }
455 
456     *prot = pmp_priv_to_page_prot(pmp_priv);
457     if (tlb_size != NULL) {
458         if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1), &tlb_size_pmp)) {
459             *tlb_size = tlb_size_pmp;
460         }
461     }
462 
463     return TRANSLATE_SUCCESS;
464 }
465 
466 /* get_physical_address - get the physical address for this virtual address
467  *
468  * Do a page table walk to obtain the physical address corresponding to a
469  * virtual address. Returns 0 if the translation was successful
470  *
471  * Adapted from Spike's mmu_t::translate and mmu_t::walk
472  *
473  * @env: CPURISCVState
474  * @physical: This will be set to the calculated physical address
475  * @prot: The returned protection attributes
476  * @addr: The virtual address to be translated
477  * @fault_pte_addr: If not NULL, this will be set to fault pte address
478  *                  when a error occurs on pte address translation.
479  *                  This will already be shifted to match htval.
480  * @access_type: The type of MMU access
481  * @mmu_idx: Indicates current privilege level
482  * @first_stage: Are we in first stage translation?
483  *               Second stage is used for hypervisor guest translation
484  * @two_stage: Are we going to perform two stage translation
485  * @is_debug: Is this access from a debugger or the monitor?
486  */
487 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
488                                 int *prot, target_ulong addr,
489                                 target_ulong *fault_pte_addr,
490                                 int access_type, int mmu_idx,
491                                 bool first_stage, bool two_stage,
492                                 bool is_debug)
493 {
494     /* NOTE: the env->pc value visible here will not be
495      * correct, but the value visible to the exception handler
496      * (riscv_cpu_do_interrupt) is correct */
497     MemTxResult res;
498     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
499     int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
500     bool use_background = false;
501 
502     /*
503      * Check if we should use the background registers for the two
504      * stage translation. We don't need to check if we actually need
505      * two stage translation as that happened before this function
506      * was called. Background registers will be used if the guest has
507      * forced a two stage translation to be on (in HS or M mode).
508      */
509     if (!riscv_cpu_virt_enabled(env) && two_stage) {
510         use_background = true;
511     }
512 
513     /* MPRV does not affect the virtual-machine load/store
514        instructions, HLV, HLVX, and HSV. */
515     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
516         mode = get_field(env->hstatus, HSTATUS_SPVP);
517     } else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
518         if (get_field(env->mstatus, MSTATUS_MPRV)) {
519             mode = get_field(env->mstatus, MSTATUS_MPP);
520         }
521     }
522 
523     if (first_stage == false) {
524         /* We are in stage 2 translation, this is similar to stage 1. */
525         /* Stage 2 is always taken as U-mode */
526         mode = PRV_U;
527     }
528 
529     if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
530         *physical = addr;
531         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
532         return TRANSLATE_SUCCESS;
533     }
534 
535     *prot = 0;
536 
537     hwaddr base;
538     int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
539 
540     if (first_stage == true) {
541         mxr = get_field(env->mstatus, MSTATUS_MXR);
542     } else {
543         mxr = get_field(env->vsstatus, MSTATUS_MXR);
544     }
545 
546     if (first_stage == true) {
547         if (use_background) {
548             if (riscv_cpu_mxl(env) == MXL_RV32) {
549                 base = (hwaddr)get_field(env->vsatp, SATP32_PPN) << PGSHIFT;
550                 vm = get_field(env->vsatp, SATP32_MODE);
551             } else {
552                 base = (hwaddr)get_field(env->vsatp, SATP64_PPN) << PGSHIFT;
553                 vm = get_field(env->vsatp, SATP64_MODE);
554             }
555         } else {
556             if (riscv_cpu_mxl(env) == MXL_RV32) {
557                 base = (hwaddr)get_field(env->satp, SATP32_PPN) << PGSHIFT;
558                 vm = get_field(env->satp, SATP32_MODE);
559             } else {
560                 base = (hwaddr)get_field(env->satp, SATP64_PPN) << PGSHIFT;
561                 vm = get_field(env->satp, SATP64_MODE);
562             }
563         }
564         widened = 0;
565     } else {
566         if (riscv_cpu_mxl(env) == MXL_RV32) {
567             base = (hwaddr)get_field(env->hgatp, SATP32_PPN) << PGSHIFT;
568             vm = get_field(env->hgatp, SATP32_MODE);
569         } else {
570             base = (hwaddr)get_field(env->hgatp, SATP64_PPN) << PGSHIFT;
571             vm = get_field(env->hgatp, SATP64_MODE);
572         }
573         widened = 2;
574     }
575     /* status.SUM will be ignored if execute on background */
576     sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
577     switch (vm) {
578     case VM_1_10_SV32:
579       levels = 2; ptidxbits = 10; ptesize = 4; break;
580     case VM_1_10_SV39:
581       levels = 3; ptidxbits = 9; ptesize = 8; break;
582     case VM_1_10_SV48:
583       levels = 4; ptidxbits = 9; ptesize = 8; break;
584     case VM_1_10_SV57:
585       levels = 5; ptidxbits = 9; ptesize = 8; break;
586     case VM_1_10_MBARE:
587         *physical = addr;
588         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
589         return TRANSLATE_SUCCESS;
590     default:
591       g_assert_not_reached();
592     }
593 
594     CPUState *cs = env_cpu(env);
595     int va_bits = PGSHIFT + levels * ptidxbits + widened;
596     target_ulong mask, masked_msbs;
597 
598     if (TARGET_LONG_BITS > (va_bits - 1)) {
599         mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
600     } else {
601         mask = 0;
602     }
603     masked_msbs = (addr >> (va_bits - 1)) & mask;
604 
605     if (masked_msbs != 0 && masked_msbs != mask) {
606         return TRANSLATE_FAIL;
607     }
608 
609     int ptshift = (levels - 1) * ptidxbits;
610     int i;
611 
612 #if !TCG_OVERSIZED_GUEST
613 restart:
614 #endif
615     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
616         target_ulong idx;
617         if (i == 0) {
618             idx = (addr >> (PGSHIFT + ptshift)) &
619                            ((1 << (ptidxbits + widened)) - 1);
620         } else {
621             idx = (addr >> (PGSHIFT + ptshift)) &
622                            ((1 << ptidxbits) - 1);
623         }
624 
625         /* check that physical address of PTE is legal */
626         hwaddr pte_addr;
627 
628         if (two_stage && first_stage) {
629             int vbase_prot;
630             hwaddr vbase;
631 
632             /* Do the second stage translation on the base PTE address. */
633             int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
634                                                  base, NULL, MMU_DATA_LOAD,
635                                                  mmu_idx, false, true,
636                                                  is_debug);
637 
638             if (vbase_ret != TRANSLATE_SUCCESS) {
639                 if (fault_pte_addr) {
640                     *fault_pte_addr = (base + idx * ptesize) >> 2;
641                 }
642                 return TRANSLATE_G_STAGE_FAIL;
643             }
644 
645             pte_addr = vbase + idx * ptesize;
646         } else {
647             pte_addr = base + idx * ptesize;
648         }
649 
650         int pmp_prot;
651         int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
652                                                sizeof(target_ulong),
653                                                MMU_DATA_LOAD, PRV_S);
654         if (pmp_ret != TRANSLATE_SUCCESS) {
655             return TRANSLATE_PMP_FAIL;
656         }
657 
658         target_ulong pte;
659         if (riscv_cpu_mxl(env) == MXL_RV32) {
660             pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
661         } else {
662             pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
663         }
664 
665         if (res != MEMTX_OK) {
666             return TRANSLATE_FAIL;
667         }
668 
669         hwaddr ppn = pte >> PTE_PPN_SHIFT;
670 
671         if (!(pte & PTE_V)) {
672             /* Invalid PTE */
673             return TRANSLATE_FAIL;
674         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
675             /* Inner PTE, continue walking */
676             base = ppn << PGSHIFT;
677         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
678             /* Reserved leaf PTE flags: PTE_W */
679             return TRANSLATE_FAIL;
680         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
681             /* Reserved leaf PTE flags: PTE_W + PTE_X */
682             return TRANSLATE_FAIL;
683         } else if ((pte & PTE_U) && ((mode != PRV_U) &&
684                    (!sum || access_type == MMU_INST_FETCH))) {
685             /* User PTE flags when not U mode and mstatus.SUM is not set,
686                or the access type is an instruction fetch */
687             return TRANSLATE_FAIL;
688         } else if (!(pte & PTE_U) && (mode != PRV_S)) {
689             /* Supervisor PTE flags when not S mode */
690             return TRANSLATE_FAIL;
691         } else if (ppn & ((1ULL << ptshift) - 1)) {
692             /* Misaligned PPN */
693             return TRANSLATE_FAIL;
694         } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
695                    ((pte & PTE_X) && mxr))) {
696             /* Read access check failed */
697             return TRANSLATE_FAIL;
698         } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
699             /* Write access check failed */
700             return TRANSLATE_FAIL;
701         } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
702             /* Fetch access check failed */
703             return TRANSLATE_FAIL;
704         } else {
705             /* if necessary, set accessed and dirty bits. */
706             target_ulong updated_pte = pte | PTE_A |
707                 (access_type == MMU_DATA_STORE ? PTE_D : 0);
708 
709             /* Page table updates need to be atomic with MTTCG enabled */
710             if (updated_pte != pte) {
711                 /*
712                  * - if accessed or dirty bits need updating, and the PTE is
713                  *   in RAM, then we do so atomically with a compare and swap.
714                  * - if the PTE is in IO space or ROM, then it can't be updated
715                  *   and we return TRANSLATE_FAIL.
716                  * - if the PTE changed by the time we went to update it, then
717                  *   it is no longer valid and we must re-walk the page table.
718                  */
719                 MemoryRegion *mr;
720                 hwaddr l = sizeof(target_ulong), addr1;
721                 mr = address_space_translate(cs->as, pte_addr,
722                     &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
723                 if (memory_region_is_ram(mr)) {
724                     target_ulong *pte_pa =
725                         qemu_map_ram_ptr(mr->ram_block, addr1);
726 #if TCG_OVERSIZED_GUEST
727                     /* MTTCG is not enabled on oversized TCG guests so
728                      * page table updates do not need to be atomic */
729                     *pte_pa = pte = updated_pte;
730 #else
731                     target_ulong old_pte =
732                         qatomic_cmpxchg(pte_pa, pte, updated_pte);
733                     if (old_pte != pte) {
734                         goto restart;
735                     } else {
736                         pte = updated_pte;
737                     }
738 #endif
739                 } else {
740                     /* misconfigured PTE in ROM (AD bits are not preset) or
741                      * PTE is in IO space and can't be updated atomically */
742                     return TRANSLATE_FAIL;
743                 }
744             }
745 
746             /* for superpage mappings, make a fake leaf PTE for the TLB's
747                benefit. */
748             target_ulong vpn = addr >> PGSHIFT;
749             *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
750                         (addr & ~TARGET_PAGE_MASK);
751 
752             /* set permissions on the TLB entry */
753             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
754                 *prot |= PAGE_READ;
755             }
756             if ((pte & PTE_X)) {
757                 *prot |= PAGE_EXEC;
758             }
759             /* add write permission on stores or if the page is already dirty,
760                so that we TLB miss on later writes to update the dirty bit */
761             if ((pte & PTE_W) &&
762                     (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
763                 *prot |= PAGE_WRITE;
764             }
765             return TRANSLATE_SUCCESS;
766         }
767     }
768     return TRANSLATE_FAIL;
769 }
770 
771 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
772                                 MMUAccessType access_type, bool pmp_violation,
773                                 bool first_stage, bool two_stage)
774 {
775     CPUState *cs = env_cpu(env);
776     int page_fault_exceptions, vm;
777     uint64_t stap_mode;
778 
779     if (riscv_cpu_mxl(env) == MXL_RV32) {
780         stap_mode = SATP32_MODE;
781     } else {
782         stap_mode = SATP64_MODE;
783     }
784 
785     if (first_stage) {
786         vm = get_field(env->satp, stap_mode);
787     } else {
788         vm = get_field(env->hgatp, stap_mode);
789     }
790 
791     page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
792 
793     switch (access_type) {
794     case MMU_INST_FETCH:
795         if (riscv_cpu_virt_enabled(env) && !first_stage) {
796             cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
797         } else {
798             cs->exception_index = page_fault_exceptions ?
799                 RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
800         }
801         break;
802     case MMU_DATA_LOAD:
803         if (two_stage && !first_stage) {
804             cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
805         } else {
806             cs->exception_index = page_fault_exceptions ?
807                 RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
808         }
809         break;
810     case MMU_DATA_STORE:
811         if (two_stage && !first_stage) {
812             cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
813         } else {
814             cs->exception_index = page_fault_exceptions ?
815                 RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
816         }
817         break;
818     default:
819         g_assert_not_reached();
820     }
821     env->badaddr = address;
822     env->two_stage_lookup = two_stage;
823 }
824 
825 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
826 {
827     RISCVCPU *cpu = RISCV_CPU(cs);
828     CPURISCVState *env = &cpu->env;
829     hwaddr phys_addr;
830     int prot;
831     int mmu_idx = cpu_mmu_index(&cpu->env, false);
832 
833     if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
834                              true, riscv_cpu_virt_enabled(env), true)) {
835         return -1;
836     }
837 
838     if (riscv_cpu_virt_enabled(env)) {
839         if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
840                                  0, mmu_idx, false, true, true)) {
841             return -1;
842         }
843     }
844 
845     return phys_addr & TARGET_PAGE_MASK;
846 }
847 
848 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
849                                      vaddr addr, unsigned size,
850                                      MMUAccessType access_type,
851                                      int mmu_idx, MemTxAttrs attrs,
852                                      MemTxResult response, uintptr_t retaddr)
853 {
854     RISCVCPU *cpu = RISCV_CPU(cs);
855     CPURISCVState *env = &cpu->env;
856 
857     if (access_type == MMU_DATA_STORE) {
858         cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
859     } else if (access_type == MMU_DATA_LOAD) {
860         cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
861     } else {
862         cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT;
863     }
864 
865     env->badaddr = addr;
866     env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
867                             riscv_cpu_two_stage_lookup(mmu_idx);
868     riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
869 }
870 
871 void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
872                                    MMUAccessType access_type, int mmu_idx,
873                                    uintptr_t retaddr)
874 {
875     RISCVCPU *cpu = RISCV_CPU(cs);
876     CPURISCVState *env = &cpu->env;
877     switch (access_type) {
878     case MMU_INST_FETCH:
879         cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
880         break;
881     case MMU_DATA_LOAD:
882         cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
883         break;
884     case MMU_DATA_STORE:
885         cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
886         break;
887     default:
888         g_assert_not_reached();
889     }
890     env->badaddr = addr;
891     env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
892                             riscv_cpu_two_stage_lookup(mmu_idx);
893     riscv_raise_exception(env, cs->exception_index, retaddr);
894 }
895 
896 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
897                         MMUAccessType access_type, int mmu_idx,
898                         bool probe, uintptr_t retaddr)
899 {
900     RISCVCPU *cpu = RISCV_CPU(cs);
901     CPURISCVState *env = &cpu->env;
902     vaddr im_address;
903     hwaddr pa = 0;
904     int prot, prot2, prot_pmp;
905     bool pmp_violation = false;
906     bool first_stage_error = true;
907     bool two_stage_lookup = false;
908     int ret = TRANSLATE_FAIL;
909     int mode = mmu_idx;
910     /* default TLB page size */
911     target_ulong tlb_size = TARGET_PAGE_SIZE;
912 
913     env->guest_phys_fault_addr = 0;
914 
915     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
916                   __func__, address, access_type, mmu_idx);
917 
918     /* MPRV does not affect the virtual-machine load/store
919        instructions, HLV, HLVX, and HSV. */
920     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
921         mode = get_field(env->hstatus, HSTATUS_SPVP);
922     } else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
923                get_field(env->mstatus, MSTATUS_MPRV)) {
924         mode = get_field(env->mstatus, MSTATUS_MPP);
925         if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
926             two_stage_lookup = true;
927         }
928     }
929 
930     if (riscv_cpu_virt_enabled(env) ||
931         ((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
932          access_type != MMU_INST_FETCH)) {
933         /* Two stage lookup */
934         ret = get_physical_address(env, &pa, &prot, address,
935                                    &env->guest_phys_fault_addr, access_type,
936                                    mmu_idx, true, true, false);
937 
938         /*
939          * A G-stage exception may be triggered during two state lookup.
940          * And the env->guest_phys_fault_addr has already been set in
941          * get_physical_address().
942          */
943         if (ret == TRANSLATE_G_STAGE_FAIL) {
944             first_stage_error = false;
945             access_type = MMU_DATA_LOAD;
946         }
947 
948         qemu_log_mask(CPU_LOG_MMU,
949                       "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
950                       TARGET_FMT_plx " prot %d\n",
951                       __func__, address, ret, pa, prot);
952 
953         if (ret == TRANSLATE_SUCCESS) {
954             /* Second stage lookup */
955             im_address = pa;
956 
957             ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
958                                        access_type, mmu_idx, false, true,
959                                        false);
960 
961             qemu_log_mask(CPU_LOG_MMU,
962                     "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
963                     TARGET_FMT_plx " prot %d\n",
964                     __func__, im_address, ret, pa, prot2);
965 
966             prot &= prot2;
967 
968             if (ret == TRANSLATE_SUCCESS) {
969                 ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
970                                                size, access_type, mode);
971 
972                 qemu_log_mask(CPU_LOG_MMU,
973                               "%s PMP address=" TARGET_FMT_plx " ret %d prot"
974                               " %d tlb_size " TARGET_FMT_lu "\n",
975                               __func__, pa, ret, prot_pmp, tlb_size);
976 
977                 prot &= prot_pmp;
978             }
979 
980             if (ret != TRANSLATE_SUCCESS) {
981                 /*
982                  * Guest physical address translation failed, this is a HS
983                  * level exception
984                  */
985                 first_stage_error = false;
986                 env->guest_phys_fault_addr = (im_address |
987                                               (address &
988                                                (TARGET_PAGE_SIZE - 1))) >> 2;
989             }
990         }
991     } else {
992         /* Single stage lookup */
993         ret = get_physical_address(env, &pa, &prot, address, NULL,
994                                    access_type, mmu_idx, true, false, false);
995 
996         qemu_log_mask(CPU_LOG_MMU,
997                       "%s address=%" VADDR_PRIx " ret %d physical "
998                       TARGET_FMT_plx " prot %d\n",
999                       __func__, address, ret, pa, prot);
1000 
1001         if (ret == TRANSLATE_SUCCESS) {
1002             ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
1003                                            size, access_type, mode);
1004 
1005             qemu_log_mask(CPU_LOG_MMU,
1006                           "%s PMP address=" TARGET_FMT_plx " ret %d prot"
1007                           " %d tlb_size " TARGET_FMT_lu "\n",
1008                           __func__, pa, ret, prot_pmp, tlb_size);
1009 
1010             prot &= prot_pmp;
1011         }
1012     }
1013 
1014     if (ret == TRANSLATE_PMP_FAIL) {
1015         pmp_violation = true;
1016     }
1017 
1018     if (ret == TRANSLATE_SUCCESS) {
1019         tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
1020                      prot, mmu_idx, tlb_size);
1021         return true;
1022     } else if (probe) {
1023         return false;
1024     } else {
1025         raise_mmu_exception(env, address, access_type, pmp_violation,
1026                             first_stage_error,
1027                             riscv_cpu_virt_enabled(env) ||
1028                                 riscv_cpu_two_stage_lookup(mmu_idx));
1029         riscv_raise_exception(env, cs->exception_index, retaddr);
1030     }
1031 
1032     return true;
1033 }
1034 #endif /* !CONFIG_USER_ONLY */
1035 
1036 /*
1037  * Handle Traps
1038  *
1039  * Adapted from Spike's processor_t::take_trap.
1040  *
1041  */
1042 void riscv_cpu_do_interrupt(CPUState *cs)
1043 {
1044 #if !defined(CONFIG_USER_ONLY)
1045 
1046     RISCVCPU *cpu = RISCV_CPU(cs);
1047     CPURISCVState *env = &cpu->env;
1048     bool write_gva = false;
1049     uint64_t s;
1050 
1051     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
1052      * so we mask off the MSB and separate into trap type and cause.
1053      */
1054     bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
1055     target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
1056     target_ulong deleg = async ? env->mideleg : env->medeleg;
1057     target_ulong tval = 0;
1058     target_ulong htval = 0;
1059     target_ulong mtval2 = 0;
1060 
1061     if  (cause == RISCV_EXCP_SEMIHOST) {
1062         if (env->priv >= PRV_S) {
1063             env->gpr[xA0] = do_common_semihosting(cs);
1064             env->pc += 4;
1065             return;
1066         }
1067         cause = RISCV_EXCP_BREAKPOINT;
1068     }
1069 
1070     if (!async) {
1071         /* set tval to badaddr for traps with address information */
1072         switch (cause) {
1073         case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
1074         case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
1075         case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
1076         case RISCV_EXCP_INST_ADDR_MIS:
1077         case RISCV_EXCP_INST_ACCESS_FAULT:
1078         case RISCV_EXCP_LOAD_ADDR_MIS:
1079         case RISCV_EXCP_STORE_AMO_ADDR_MIS:
1080         case RISCV_EXCP_LOAD_ACCESS_FAULT:
1081         case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
1082         case RISCV_EXCP_INST_PAGE_FAULT:
1083         case RISCV_EXCP_LOAD_PAGE_FAULT:
1084         case RISCV_EXCP_STORE_PAGE_FAULT:
1085             write_gva = true;
1086             tval = env->badaddr;
1087             break;
1088         case RISCV_EXCP_ILLEGAL_INST:
1089             tval = env->bins;
1090             break;
1091         default:
1092             break;
1093         }
1094         /* ecall is dispatched as one cause so translate based on mode */
1095         if (cause == RISCV_EXCP_U_ECALL) {
1096             assert(env->priv <= 3);
1097 
1098             if (env->priv == PRV_M) {
1099                 cause = RISCV_EXCP_M_ECALL;
1100             } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
1101                 cause = RISCV_EXCP_VS_ECALL;
1102             } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
1103                 cause = RISCV_EXCP_S_ECALL;
1104             } else if (env->priv == PRV_U) {
1105                 cause = RISCV_EXCP_U_ECALL;
1106             }
1107         }
1108     }
1109 
1110     trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
1111                      riscv_cpu_get_trap_name(cause, async));
1112 
1113     qemu_log_mask(CPU_LOG_INT,
1114                   "%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
1115                   "epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
1116                   __func__, env->mhartid, async, cause, env->pc, tval,
1117                   riscv_cpu_get_trap_name(cause, async));
1118 
1119     if (env->priv <= PRV_S &&
1120             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
1121         /* handle the trap in S-mode */
1122         if (riscv_has_ext(env, RVH)) {
1123             target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
1124 
1125             if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1)) {
1126                 /* Trap to VS mode */
1127                 /*
1128                  * See if we need to adjust cause. Yes if its VS mode interrupt
1129                  * no if hypervisor has delegated one of hs mode's interrupt
1130                  */
1131                 if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
1132                     cause == IRQ_VS_EXT) {
1133                     cause = cause - 1;
1134                 }
1135                 write_gva = false;
1136             } else if (riscv_cpu_virt_enabled(env)) {
1137                 /* Trap into HS mode, from virt */
1138                 riscv_cpu_swap_hypervisor_regs(env);
1139                 env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
1140                                          env->priv);
1141                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
1142                                          riscv_cpu_virt_enabled(env));
1143 
1144 
1145                 htval = env->guest_phys_fault_addr;
1146 
1147                 riscv_cpu_set_virt_enabled(env, 0);
1148             } else {
1149                 /* Trap into HS mode */
1150                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
1151                 htval = env->guest_phys_fault_addr;
1152                 write_gva = false;
1153             }
1154             env->hstatus = set_field(env->hstatus, HSTATUS_GVA, write_gva);
1155         }
1156 
1157         s = env->mstatus;
1158         s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
1159         s = set_field(s, MSTATUS_SPP, env->priv);
1160         s = set_field(s, MSTATUS_SIE, 0);
1161         env->mstatus = s;
1162         env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
1163         env->sepc = env->pc;
1164         env->stval = tval;
1165         env->htval = htval;
1166         env->pc = (env->stvec >> 2 << 2) +
1167             ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
1168         riscv_cpu_set_mode(env, PRV_S);
1169     } else {
1170         /* handle the trap in M-mode */
1171         if (riscv_has_ext(env, RVH)) {
1172             if (riscv_cpu_virt_enabled(env)) {
1173                 riscv_cpu_swap_hypervisor_regs(env);
1174             }
1175             env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
1176                                      riscv_cpu_virt_enabled(env));
1177             if (riscv_cpu_virt_enabled(env) && tval) {
1178                 env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
1179             }
1180 
1181             mtval2 = env->guest_phys_fault_addr;
1182 
1183             /* Trapping to M mode, virt is disabled */
1184             riscv_cpu_set_virt_enabled(env, 0);
1185         }
1186 
1187         s = env->mstatus;
1188         s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
1189         s = set_field(s, MSTATUS_MPP, env->priv);
1190         s = set_field(s, MSTATUS_MIE, 0);
1191         env->mstatus = s;
1192         env->mcause = cause | ~(((target_ulong)-1) >> async);
1193         env->mepc = env->pc;
1194         env->mtval = tval;
1195         env->mtval2 = mtval2;
1196         env->pc = (env->mtvec >> 2 << 2) +
1197             ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
1198         riscv_cpu_set_mode(env, PRV_M);
1199     }
1200 
1201     /* NOTE: it is not necessary to yield load reservations here. It is only
1202      * necessary for an SC from "another hart" to cause a load reservation
1203      * to be yielded. Refer to the memory consistency model section of the
1204      * RISC-V ISA Specification.
1205      */
1206 
1207     env->two_stage_lookup = false;
1208 #endif
1209     cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
1210 }
1211