xref: /openbmc/qemu/target/riscv/cpu_helper.c (revision 38256529)
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 "pmu.h"
25 #include "exec/exec-all.h"
26 #include "instmap.h"
27 #include "tcg/tcg-op.h"
28 #include "trace.h"
29 #include "semihosting/common-semi.h"
30 #include "sysemu/cpu-timers.h"
31 #include "cpu_bits.h"
32 #include "debug.h"
33 
34 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
35 {
36 #ifdef CONFIG_USER_ONLY
37     return 0;
38 #else
39     return env->priv;
40 #endif
41 }
42 
43 void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
44                           target_ulong *cs_base, uint32_t *pflags)
45 {
46     CPUState *cs = env_cpu(env);
47     RISCVCPU *cpu = RISCV_CPU(cs);
48 
49     uint32_t flags = 0;
50 
51     *pc = env->xl == MXL_RV32 ? env->pc & UINT32_MAX : env->pc;
52     *cs_base = 0;
53 
54     if (cpu->cfg.ext_zve32f) {
55         /*
56          * If env->vl equals to VLMAX, we can use generic vector operation
57          * expanders (GVEC) to accerlate the vector operations.
58          * However, as LMUL could be a fractional number. The maximum
59          * vector size can be operated might be less than 8 bytes,
60          * which is not supported by GVEC. So we set vl_eq_vlmax flag to true
61          * only when maxsz >= 8 bytes.
62          */
63         uint32_t vlmax = vext_get_vlmax(cpu, env->vtype);
64         uint32_t sew = FIELD_EX64(env->vtype, VTYPE, VSEW);
65         uint32_t maxsz = vlmax << sew;
66         bool vl_eq_vlmax = (env->vstart == 0) && (vlmax == env->vl) &&
67                            (maxsz >= 8);
68         flags = FIELD_DP32(flags, TB_FLAGS, VILL, env->vill);
69         flags = FIELD_DP32(flags, TB_FLAGS, SEW, sew);
70         flags = FIELD_DP32(flags, TB_FLAGS, LMUL,
71                     FIELD_EX64(env->vtype, VTYPE, VLMUL));
72         flags = FIELD_DP32(flags, TB_FLAGS, VL_EQ_VLMAX, vl_eq_vlmax);
73         flags = FIELD_DP32(flags, TB_FLAGS, VTA,
74                     FIELD_EX64(env->vtype, VTYPE, VTA));
75         flags = FIELD_DP32(flags, TB_FLAGS, VMA,
76                     FIELD_EX64(env->vtype, VTYPE, VMA));
77     } else {
78         flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
79     }
80 
81 #ifdef CONFIG_USER_ONLY
82     flags |= TB_FLAGS_MSTATUS_FS;
83     flags |= TB_FLAGS_MSTATUS_VS;
84 #else
85     flags |= cpu_mmu_index(env, 0);
86     if (riscv_cpu_fp_enabled(env)) {
87         flags |= env->mstatus & MSTATUS_FS;
88     }
89 
90     if (riscv_cpu_vector_enabled(env)) {
91         flags |= env->mstatus & MSTATUS_VS;
92     }
93 
94     if (riscv_has_ext(env, RVH)) {
95         if (env->priv == PRV_M ||
96             (env->priv == PRV_S && !env->virt_enabled) ||
97             (env->priv == PRV_U && !env->virt_enabled &&
98                 get_field(env->hstatus, HSTATUS_HU))) {
99             flags = FIELD_DP32(flags, TB_FLAGS, HLSX, 1);
100         }
101 
102         flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_FS,
103                            get_field(env->mstatus_hs, MSTATUS_FS));
104 
105         flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
106                            get_field(env->mstatus_hs, MSTATUS_VS));
107     }
108     if (cpu->cfg.debug && !icount_enabled()) {
109         flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER, env->itrigger_enabled);
110     }
111 #endif
112 
113     flags = FIELD_DP32(flags, TB_FLAGS, XL, env->xl);
114     if (env->cur_pmmask < (env->xl == MXL_RV32 ? UINT32_MAX : UINT64_MAX)) {
115         flags = FIELD_DP32(flags, TB_FLAGS, PM_MASK_ENABLED, 1);
116     }
117     if (env->cur_pmbase != 0) {
118         flags = FIELD_DP32(flags, TB_FLAGS, PM_BASE_ENABLED, 1);
119     }
120 
121     *pflags = flags;
122 }
123 
124 void riscv_cpu_update_mask(CPURISCVState *env)
125 {
126     target_ulong mask = -1, base = 0;
127     /*
128      * TODO: Current RVJ spec does not specify
129      * how the extension interacts with XLEN.
130      */
131 #ifndef CONFIG_USER_ONLY
132     if (riscv_has_ext(env, RVJ)) {
133         switch (env->priv) {
134         case PRV_M:
135             if (env->mmte & M_PM_ENABLE) {
136                 mask = env->mpmmask;
137                 base = env->mpmbase;
138             }
139             break;
140         case PRV_S:
141             if (env->mmte & S_PM_ENABLE) {
142                 mask = env->spmmask;
143                 base = env->spmbase;
144             }
145             break;
146         case PRV_U:
147             if (env->mmte & U_PM_ENABLE) {
148                 mask = env->upmmask;
149                 base = env->upmbase;
150             }
151             break;
152         default:
153             g_assert_not_reached();
154         }
155     }
156 #endif
157     if (env->xl == MXL_RV32) {
158         env->cur_pmmask = mask & UINT32_MAX;
159         env->cur_pmbase = base & UINT32_MAX;
160     } else {
161         env->cur_pmmask = mask;
162         env->cur_pmbase = base;
163     }
164 }
165 
166 #ifndef CONFIG_USER_ONLY
167 
168 /*
169  * The HS-mode is allowed to configure priority only for the
170  * following VS-mode local interrupts:
171  *
172  * 0  (Reserved interrupt, reads as zero)
173  * 1  Supervisor software interrupt
174  * 4  (Reserved interrupt, reads as zero)
175  * 5  Supervisor timer interrupt
176  * 8  (Reserved interrupt, reads as zero)
177  * 13 (Reserved interrupt)
178  * 14 "
179  * 15 "
180  * 16 "
181  * 17 "
182  * 18 "
183  * 19 "
184  * 20 "
185  * 21 "
186  * 22 "
187  * 23 "
188  */
189 
190 static const int hviprio_index2irq[] = {
191     0, 1, 4, 5, 8, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 };
192 static const int hviprio_index2rdzero[] = {
193     1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
194 
195 int riscv_cpu_hviprio_index2irq(int index, int *out_irq, int *out_rdzero)
196 {
197     if (index < 0 || ARRAY_SIZE(hviprio_index2irq) <= index) {
198         return -EINVAL;
199     }
200 
201     if (out_irq) {
202         *out_irq = hviprio_index2irq[index];
203     }
204 
205     if (out_rdzero) {
206         *out_rdzero = hviprio_index2rdzero[index];
207     }
208 
209     return 0;
210 }
211 
212 /*
213  * Default priorities of local interrupts are defined in the
214  * RISC-V Advanced Interrupt Architecture specification.
215  *
216  * ----------------------------------------------------------------
217  *  Default  |
218  *  Priority | Major Interrupt Numbers
219  * ----------------------------------------------------------------
220  *  Highest  | 47, 23, 46, 45, 22, 44,
221  *           | 43, 21, 42, 41, 20, 40
222  *           |
223  *           | 11 (0b),  3 (03),  7 (07)
224  *           |  9 (09),  1 (01),  5 (05)
225  *           | 12 (0c)
226  *           | 10 (0a),  2 (02),  6 (06)
227  *           |
228  *           | 39, 19, 38, 37, 18, 36,
229  *  Lowest   | 35, 17, 34, 33, 16, 32
230  * ----------------------------------------------------------------
231  */
232 static const uint8_t default_iprio[64] = {
233  /* Custom interrupts 48 to 63 */
234  [63] = IPRIO_MMAXIPRIO,
235  [62] = IPRIO_MMAXIPRIO,
236  [61] = IPRIO_MMAXIPRIO,
237  [60] = IPRIO_MMAXIPRIO,
238  [59] = IPRIO_MMAXIPRIO,
239  [58] = IPRIO_MMAXIPRIO,
240  [57] = IPRIO_MMAXIPRIO,
241  [56] = IPRIO_MMAXIPRIO,
242  [55] = IPRIO_MMAXIPRIO,
243  [54] = IPRIO_MMAXIPRIO,
244  [53] = IPRIO_MMAXIPRIO,
245  [52] = IPRIO_MMAXIPRIO,
246  [51] = IPRIO_MMAXIPRIO,
247  [50] = IPRIO_MMAXIPRIO,
248  [49] = IPRIO_MMAXIPRIO,
249  [48] = IPRIO_MMAXIPRIO,
250 
251  /* Custom interrupts 24 to 31 */
252  [31] = IPRIO_MMAXIPRIO,
253  [30] = IPRIO_MMAXIPRIO,
254  [29] = IPRIO_MMAXIPRIO,
255  [28] = IPRIO_MMAXIPRIO,
256  [27] = IPRIO_MMAXIPRIO,
257  [26] = IPRIO_MMAXIPRIO,
258  [25] = IPRIO_MMAXIPRIO,
259  [24] = IPRIO_MMAXIPRIO,
260 
261  [47] = IPRIO_DEFAULT_UPPER,
262  [23] = IPRIO_DEFAULT_UPPER + 1,
263  [46] = IPRIO_DEFAULT_UPPER + 2,
264  [45] = IPRIO_DEFAULT_UPPER + 3,
265  [22] = IPRIO_DEFAULT_UPPER + 4,
266  [44] = IPRIO_DEFAULT_UPPER + 5,
267 
268  [43] = IPRIO_DEFAULT_UPPER + 6,
269  [21] = IPRIO_DEFAULT_UPPER + 7,
270  [42] = IPRIO_DEFAULT_UPPER + 8,
271  [41] = IPRIO_DEFAULT_UPPER + 9,
272  [20] = IPRIO_DEFAULT_UPPER + 10,
273  [40] = IPRIO_DEFAULT_UPPER + 11,
274 
275  [11] = IPRIO_DEFAULT_M,
276  [3]  = IPRIO_DEFAULT_M + 1,
277  [7]  = IPRIO_DEFAULT_M + 2,
278 
279  [9]  = IPRIO_DEFAULT_S,
280  [1]  = IPRIO_DEFAULT_S + 1,
281  [5]  = IPRIO_DEFAULT_S + 2,
282 
283  [12] = IPRIO_DEFAULT_SGEXT,
284 
285  [10] = IPRIO_DEFAULT_VS,
286  [2]  = IPRIO_DEFAULT_VS + 1,
287  [6]  = IPRIO_DEFAULT_VS + 2,
288 
289  [39] = IPRIO_DEFAULT_LOWER,
290  [19] = IPRIO_DEFAULT_LOWER + 1,
291  [38] = IPRIO_DEFAULT_LOWER + 2,
292  [37] = IPRIO_DEFAULT_LOWER + 3,
293  [18] = IPRIO_DEFAULT_LOWER + 4,
294  [36] = IPRIO_DEFAULT_LOWER + 5,
295 
296  [35] = IPRIO_DEFAULT_LOWER + 6,
297  [17] = IPRIO_DEFAULT_LOWER + 7,
298  [34] = IPRIO_DEFAULT_LOWER + 8,
299  [33] = IPRIO_DEFAULT_LOWER + 9,
300  [16] = IPRIO_DEFAULT_LOWER + 10,
301  [32] = IPRIO_DEFAULT_LOWER + 11,
302 };
303 
304 uint8_t riscv_cpu_default_priority(int irq)
305 {
306     if (irq < 0 || irq > 63) {
307         return IPRIO_MMAXIPRIO;
308     }
309 
310     return default_iprio[irq] ? default_iprio[irq] : IPRIO_MMAXIPRIO;
311 };
312 
313 static int riscv_cpu_pending_to_irq(CPURISCVState *env,
314                                     int extirq, unsigned int extirq_def_prio,
315                                     uint64_t pending, uint8_t *iprio)
316 {
317     int irq, best_irq = RISCV_EXCP_NONE;
318     unsigned int prio, best_prio = UINT_MAX;
319 
320     if (!pending) {
321         return RISCV_EXCP_NONE;
322     }
323 
324     irq = ctz64(pending);
325     if (!((extirq == IRQ_M_EXT) ? riscv_cpu_cfg(env)->ext_smaia :
326                                   riscv_cpu_cfg(env)->ext_ssaia)) {
327         return irq;
328     }
329 
330     pending = pending >> irq;
331     while (pending) {
332         prio = iprio[irq];
333         if (!prio) {
334             if (irq == extirq) {
335                 prio = extirq_def_prio;
336             } else {
337                 prio = (riscv_cpu_default_priority(irq) < extirq_def_prio) ?
338                        1 : IPRIO_MMAXIPRIO;
339             }
340         }
341         if ((pending & 0x1) && (prio <= best_prio)) {
342             best_irq = irq;
343             best_prio = prio;
344         }
345         irq++;
346         pending = pending >> 1;
347     }
348 
349     return best_irq;
350 }
351 
352 uint64_t riscv_cpu_all_pending(CPURISCVState *env)
353 {
354     uint32_t gein = get_field(env->hstatus, HSTATUS_VGEIN);
355     uint64_t vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0;
356     uint64_t vstip = (env->vstime_irq) ? MIP_VSTIP : 0;
357 
358     return (env->mip | vsgein | vstip) & env->mie;
359 }
360 
361 int riscv_cpu_mirq_pending(CPURISCVState *env)
362 {
363     uint64_t irqs = riscv_cpu_all_pending(env) & ~env->mideleg &
364                     ~(MIP_SGEIP | MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
365 
366     return riscv_cpu_pending_to_irq(env, IRQ_M_EXT, IPRIO_DEFAULT_M,
367                                     irqs, env->miprio);
368 }
369 
370 int riscv_cpu_sirq_pending(CPURISCVState *env)
371 {
372     uint64_t irqs = riscv_cpu_all_pending(env) & env->mideleg &
373                     ~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
374 
375     return riscv_cpu_pending_to_irq(env, IRQ_S_EXT, IPRIO_DEFAULT_S,
376                                     irqs, env->siprio);
377 }
378 
379 int riscv_cpu_vsirq_pending(CPURISCVState *env)
380 {
381     uint64_t irqs = riscv_cpu_all_pending(env) & env->mideleg &
382                     (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
383 
384     return riscv_cpu_pending_to_irq(env, IRQ_S_EXT, IPRIO_DEFAULT_S,
385                                     irqs >> 1, env->hviprio);
386 }
387 
388 static int riscv_cpu_local_irq_pending(CPURISCVState *env)
389 {
390     int virq;
391     uint64_t irqs, pending, mie, hsie, vsie;
392 
393     /* Determine interrupt enable state of all privilege modes */
394     if (env->virt_enabled) {
395         mie = 1;
396         hsie = 1;
397         vsie = (env->priv < PRV_S) ||
398                (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_SIE));
399     } else {
400         mie = (env->priv < PRV_M) ||
401               (env->priv == PRV_M && get_field(env->mstatus, MSTATUS_MIE));
402         hsie = (env->priv < PRV_S) ||
403                (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_SIE));
404         vsie = 0;
405     }
406 
407     /* Determine all pending interrupts */
408     pending = riscv_cpu_all_pending(env);
409 
410     /* Check M-mode interrupts */
411     irqs = pending & ~env->mideleg & -mie;
412     if (irqs) {
413         return riscv_cpu_pending_to_irq(env, IRQ_M_EXT, IPRIO_DEFAULT_M,
414                                         irqs, env->miprio);
415     }
416 
417     /* Check HS-mode interrupts */
418     irqs = pending & env->mideleg & ~env->hideleg & -hsie;
419     if (irqs) {
420         return riscv_cpu_pending_to_irq(env, IRQ_S_EXT, IPRIO_DEFAULT_S,
421                                         irqs, env->siprio);
422     }
423 
424     /* Check VS-mode interrupts */
425     irqs = pending & env->mideleg & env->hideleg & -vsie;
426     if (irqs) {
427         virq = riscv_cpu_pending_to_irq(env, IRQ_S_EXT, IPRIO_DEFAULT_S,
428                                         irqs >> 1, env->hviprio);
429         return (virq <= 0) ? virq : virq + 1;
430     }
431 
432     /* Indicate no pending interrupt */
433     return RISCV_EXCP_NONE;
434 }
435 
436 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
437 {
438     if (interrupt_request & CPU_INTERRUPT_HARD) {
439         RISCVCPU *cpu = RISCV_CPU(cs);
440         CPURISCVState *env = &cpu->env;
441         int interruptno = riscv_cpu_local_irq_pending(env);
442         if (interruptno >= 0) {
443             cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
444             riscv_cpu_do_interrupt(cs);
445             return true;
446         }
447     }
448     return false;
449 }
450 
451 /* Return true is floating point support is currently enabled */
452 bool riscv_cpu_fp_enabled(CPURISCVState *env)
453 {
454     if (env->mstatus & MSTATUS_FS) {
455         if (env->virt_enabled && !(env->mstatus_hs & MSTATUS_FS)) {
456             return false;
457         }
458         return true;
459     }
460 
461     return false;
462 }
463 
464 /* Return true is vector support is currently enabled */
465 bool riscv_cpu_vector_enabled(CPURISCVState *env)
466 {
467     if (env->mstatus & MSTATUS_VS) {
468         if (env->virt_enabled && !(env->mstatus_hs & MSTATUS_VS)) {
469             return false;
470         }
471         return true;
472     }
473 
474     return false;
475 }
476 
477 void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
478 {
479     uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM |
480                             MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
481                             MSTATUS64_UXL | MSTATUS_VS;
482 
483     if (riscv_has_ext(env, RVF)) {
484         mstatus_mask |= MSTATUS_FS;
485     }
486     bool current_virt = env->virt_enabled;
487 
488     g_assert(riscv_has_ext(env, RVH));
489 
490     if (current_virt) {
491         /* Current V=1 and we are about to change to V=0 */
492         env->vsstatus = env->mstatus & mstatus_mask;
493         env->mstatus &= ~mstatus_mask;
494         env->mstatus |= env->mstatus_hs;
495 
496         env->vstvec = env->stvec;
497         env->stvec = env->stvec_hs;
498 
499         env->vsscratch = env->sscratch;
500         env->sscratch = env->sscratch_hs;
501 
502         env->vsepc = env->sepc;
503         env->sepc = env->sepc_hs;
504 
505         env->vscause = env->scause;
506         env->scause = env->scause_hs;
507 
508         env->vstval = env->stval;
509         env->stval = env->stval_hs;
510 
511         env->vsatp = env->satp;
512         env->satp = env->satp_hs;
513     } else {
514         /* Current V=0 and we are about to change to V=1 */
515         env->mstatus_hs = env->mstatus & mstatus_mask;
516         env->mstatus &= ~mstatus_mask;
517         env->mstatus |= env->vsstatus;
518 
519         env->stvec_hs = env->stvec;
520         env->stvec = env->vstvec;
521 
522         env->sscratch_hs = env->sscratch;
523         env->sscratch = env->vsscratch;
524 
525         env->sepc_hs = env->sepc;
526         env->sepc = env->vsepc;
527 
528         env->scause_hs = env->scause;
529         env->scause = env->vscause;
530 
531         env->stval_hs = env->stval;
532         env->stval = env->vstval;
533 
534         env->satp_hs = env->satp;
535         env->satp = env->vsatp;
536     }
537 }
538 
539 target_ulong riscv_cpu_get_geilen(CPURISCVState *env)
540 {
541     if (!riscv_has_ext(env, RVH)) {
542         return 0;
543     }
544 
545     return env->geilen;
546 }
547 
548 void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen)
549 {
550     if (!riscv_has_ext(env, RVH)) {
551         return;
552     }
553 
554     if (geilen > (TARGET_LONG_BITS - 1)) {
555         return;
556     }
557 
558     env->geilen = geilen;
559 }
560 
561 /* This function can only be called to set virt when RVH is enabled */
562 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
563 {
564     /* Flush the TLB on all virt mode changes. */
565     if (env->virt_enabled != enable) {
566         tlb_flush(env_cpu(env));
567     }
568 
569     env->virt_enabled = enable;
570 
571     if (enable) {
572         /*
573          * The guest external interrupts from an interrupt controller are
574          * delivered only when the Guest/VM is running (i.e. V=1). This means
575          * any guest external interrupt which is triggered while the Guest/VM
576          * is not running (i.e. V=0) will be missed on QEMU resulting in guest
577          * with sluggish response to serial console input and other I/O events.
578          *
579          * To solve this, we check and inject interrupt after setting V=1.
580          */
581         riscv_cpu_update_mip(env, 0, 0);
582     }
583 }
584 
585 bool riscv_cpu_two_stage_lookup(int mmu_idx)
586 {
587     return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
588 }
589 
590 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint64_t interrupts)
591 {
592     CPURISCVState *env = &cpu->env;
593     if (env->miclaim & interrupts) {
594         return -1;
595     } else {
596         env->miclaim |= interrupts;
597         return 0;
598     }
599 }
600 
601 uint64_t riscv_cpu_update_mip(CPURISCVState *env, uint64_t mask,
602                               uint64_t value)
603 {
604     CPUState *cs = env_cpu(env);
605     uint64_t gein, vsgein = 0, vstip = 0, old = env->mip;
606 
607     if (env->virt_enabled) {
608         gein = get_field(env->hstatus, HSTATUS_VGEIN);
609         vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0;
610     }
611 
612     vstip = env->vstime_irq ? MIP_VSTIP : 0;
613 
614     QEMU_IOTHREAD_LOCK_GUARD();
615 
616     env->mip = (env->mip & ~mask) | (value & mask);
617 
618     if (env->mip | vsgein | vstip) {
619         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
620     } else {
621         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
622     }
623 
624     return old;
625 }
626 
627 void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void *),
628                              void *arg)
629 {
630     env->rdtime_fn = fn;
631     env->rdtime_fn_arg = arg;
632 }
633 
634 void riscv_cpu_set_aia_ireg_rmw_fn(CPURISCVState *env, uint32_t priv,
635                                    int (*rmw_fn)(void *arg,
636                                                  target_ulong reg,
637                                                  target_ulong *val,
638                                                  target_ulong new_val,
639                                                  target_ulong write_mask),
640                                    void *rmw_fn_arg)
641 {
642     if (priv <= PRV_M) {
643         env->aia_ireg_rmw_fn[priv] = rmw_fn;
644         env->aia_ireg_rmw_fn_arg[priv] = rmw_fn_arg;
645     }
646 }
647 
648 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
649 {
650     if (newpriv > PRV_M) {
651         g_assert_not_reached();
652     }
653     if (newpriv == PRV_H) {
654         newpriv = PRV_U;
655     }
656     if (icount_enabled() && newpriv != env->priv) {
657         riscv_itrigger_update_priv(env);
658     }
659     /* tlb_flush is unnecessary as mode is contained in mmu_idx */
660     env->priv = newpriv;
661     env->xl = cpu_recompute_xl(env);
662     riscv_cpu_update_mask(env);
663 
664     /*
665      * Clear the load reservation - otherwise a reservation placed in one
666      * context/process can be used by another, resulting in an SC succeeding
667      * incorrectly. Version 2.2 of the ISA specification explicitly requires
668      * this behaviour, while later revisions say that the kernel "should" use
669      * an SC instruction to force the yielding of a load reservation on a
670      * preemptive context switch. As a result, do both.
671      */
672     env->load_res = -1;
673 }
674 
675 /*
676  * get_physical_address_pmp - check PMP permission for this physical address
677  *
678  * Match the PMP region and check permission for this physical address and it's
679  * TLB page. Returns 0 if the permission checking was successful
680  *
681  * @env: CPURISCVState
682  * @prot: The returned protection attributes
683  * @tlb_size: TLB page size containing addr. It could be modified after PMP
684  *            permission checking. NULL if not set TLB page for addr.
685  * @addr: The physical address to be checked permission
686  * @access_type: The type of MMU access
687  * @mode: Indicates current privilege level.
688  */
689 static int get_physical_address_pmp(CPURISCVState *env, int *prot,
690                                     target_ulong *tlb_size, hwaddr addr,
691                                     int size, MMUAccessType access_type,
692                                     int mode)
693 {
694     pmp_priv_t pmp_priv;
695     int pmp_index = -1;
696 
697     if (!riscv_cpu_cfg(env)->pmp) {
698         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
699         return TRANSLATE_SUCCESS;
700     }
701 
702     pmp_index = pmp_hart_has_privs(env, addr, size, 1 << access_type,
703                                    &pmp_priv, mode);
704     if (pmp_index < 0) {
705         *prot = 0;
706         return TRANSLATE_PMP_FAIL;
707     }
708 
709     *prot = pmp_priv_to_page_prot(pmp_priv);
710     if ((tlb_size != NULL) && pmp_index != MAX_RISCV_PMPS) {
711         target_ulong tlb_sa = addr & ~(TARGET_PAGE_SIZE - 1);
712         target_ulong tlb_ea = tlb_sa + TARGET_PAGE_SIZE - 1;
713 
714         *tlb_size = pmp_get_tlb_size(env, pmp_index, tlb_sa, tlb_ea);
715     }
716 
717     return TRANSLATE_SUCCESS;
718 }
719 
720 /* get_physical_address - get the physical address for this virtual address
721  *
722  * Do a page table walk to obtain the physical address corresponding to a
723  * virtual address. Returns 0 if the translation was successful
724  *
725  * Adapted from Spike's mmu_t::translate and mmu_t::walk
726  *
727  * @env: CPURISCVState
728  * @physical: This will be set to the calculated physical address
729  * @prot: The returned protection attributes
730  * @addr: The virtual address or guest physical address to be translated
731  * @fault_pte_addr: If not NULL, this will be set to fault pte address
732  *                  when a error occurs on pte address translation.
733  *                  This will already be shifted to match htval.
734  * @access_type: The type of MMU access
735  * @mmu_idx: Indicates current privilege level
736  * @first_stage: Are we in first stage translation?
737  *               Second stage is used for hypervisor guest translation
738  * @two_stage: Are we going to perform two stage translation
739  * @is_debug: Is this access from a debugger or the monitor?
740  */
741 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
742                                 int *prot, vaddr addr,
743                                 target_ulong *fault_pte_addr,
744                                 int access_type, int mmu_idx,
745                                 bool first_stage, bool two_stage,
746                                 bool is_debug)
747 {
748     /* NOTE: the env->pc value visible here will not be
749      * correct, but the value visible to the exception handler
750      * (riscv_cpu_do_interrupt) is correct */
751     MemTxResult res;
752     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
753     int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
754     bool use_background = false;
755     hwaddr ppn;
756     int napot_bits = 0;
757     target_ulong napot_mask;
758 
759     /*
760      * Check if we should use the background registers for the two
761      * stage translation. We don't need to check if we actually need
762      * two stage translation as that happened before this function
763      * was called. Background registers will be used if the guest has
764      * forced a two stage translation to be on (in HS or M mode).
765      */
766     if (!env->virt_enabled && two_stage) {
767         use_background = true;
768     }
769 
770     /* MPRV does not affect the virtual-machine load/store
771        instructions, HLV, HLVX, and HSV. */
772     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
773         mode = get_field(env->hstatus, HSTATUS_SPVP);
774     } else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
775         if (get_field(env->mstatus, MSTATUS_MPRV)) {
776             mode = get_field(env->mstatus, MSTATUS_MPP);
777         }
778     }
779 
780     if (first_stage == false) {
781         /* We are in stage 2 translation, this is similar to stage 1. */
782         /* Stage 2 is always taken as U-mode */
783         mode = PRV_U;
784     }
785 
786     if (mode == PRV_M || !riscv_cpu_cfg(env)->mmu) {
787         *physical = addr;
788         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
789         return TRANSLATE_SUCCESS;
790     }
791 
792     *prot = 0;
793 
794     hwaddr base;
795     int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
796 
797     if (first_stage == true) {
798         mxr = get_field(env->mstatus, MSTATUS_MXR);
799     } else {
800         mxr = get_field(env->vsstatus, MSTATUS_MXR);
801     }
802 
803     if (first_stage == true) {
804         if (use_background) {
805             if (riscv_cpu_mxl(env) == MXL_RV32) {
806                 base = (hwaddr)get_field(env->vsatp, SATP32_PPN) << PGSHIFT;
807                 vm = get_field(env->vsatp, SATP32_MODE);
808             } else {
809                 base = (hwaddr)get_field(env->vsatp, SATP64_PPN) << PGSHIFT;
810                 vm = get_field(env->vsatp, SATP64_MODE);
811             }
812         } else {
813             if (riscv_cpu_mxl(env) == MXL_RV32) {
814                 base = (hwaddr)get_field(env->satp, SATP32_PPN) << PGSHIFT;
815                 vm = get_field(env->satp, SATP32_MODE);
816             } else {
817                 base = (hwaddr)get_field(env->satp, SATP64_PPN) << PGSHIFT;
818                 vm = get_field(env->satp, SATP64_MODE);
819             }
820         }
821         widened = 0;
822     } else {
823         if (riscv_cpu_mxl(env) == MXL_RV32) {
824             base = (hwaddr)get_field(env->hgatp, SATP32_PPN) << PGSHIFT;
825             vm = get_field(env->hgatp, SATP32_MODE);
826         } else {
827             base = (hwaddr)get_field(env->hgatp, SATP64_PPN) << PGSHIFT;
828             vm = get_field(env->hgatp, SATP64_MODE);
829         }
830         widened = 2;
831     }
832     /* status.SUM will be ignored if execute on background */
833     sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
834     switch (vm) {
835     case VM_1_10_SV32:
836       levels = 2; ptidxbits = 10; ptesize = 4; break;
837     case VM_1_10_SV39:
838       levels = 3; ptidxbits = 9; ptesize = 8; break;
839     case VM_1_10_SV48:
840       levels = 4; ptidxbits = 9; ptesize = 8; break;
841     case VM_1_10_SV57:
842       levels = 5; ptidxbits = 9; ptesize = 8; break;
843     case VM_1_10_MBARE:
844         *physical = addr;
845         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
846         return TRANSLATE_SUCCESS;
847     default:
848       g_assert_not_reached();
849     }
850 
851     CPUState *cs = env_cpu(env);
852     int va_bits = PGSHIFT + levels * ptidxbits + widened;
853     target_ulong mask, masked_msbs;
854 
855     if (TARGET_LONG_BITS > (va_bits - 1)) {
856         mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
857     } else {
858         mask = 0;
859     }
860     masked_msbs = (addr >> (va_bits - 1)) & mask;
861 
862     if (masked_msbs != 0 && masked_msbs != mask) {
863         return TRANSLATE_FAIL;
864     }
865 
866     int ptshift = (levels - 1) * ptidxbits;
867     int i;
868 
869 #if !TCG_OVERSIZED_GUEST
870 restart:
871 #endif
872     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
873         target_ulong idx;
874         if (i == 0) {
875             idx = (addr >> (PGSHIFT + ptshift)) &
876                            ((1 << (ptidxbits + widened)) - 1);
877         } else {
878             idx = (addr >> (PGSHIFT + ptshift)) &
879                            ((1 << ptidxbits) - 1);
880         }
881 
882         /* check that physical address of PTE is legal */
883         hwaddr pte_addr;
884 
885         if (two_stage && first_stage) {
886             int vbase_prot;
887             hwaddr vbase;
888 
889             /* Do the second stage translation on the base PTE address. */
890             int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
891                                                  base, NULL, MMU_DATA_LOAD,
892                                                  mmu_idx, false, true,
893                                                  is_debug);
894 
895             if (vbase_ret != TRANSLATE_SUCCESS) {
896                 if (fault_pte_addr) {
897                     *fault_pte_addr = (base + idx * ptesize) >> 2;
898                 }
899                 return TRANSLATE_G_STAGE_FAIL;
900             }
901 
902             pte_addr = vbase + idx * ptesize;
903         } else {
904             pte_addr = base + idx * ptesize;
905         }
906 
907         int pmp_prot;
908         int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
909                                                sizeof(target_ulong),
910                                                MMU_DATA_LOAD, PRV_S);
911         if (pmp_ret != TRANSLATE_SUCCESS) {
912             return TRANSLATE_PMP_FAIL;
913         }
914 
915         target_ulong pte;
916         if (riscv_cpu_mxl(env) == MXL_RV32) {
917             pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
918         } else {
919             pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
920         }
921 
922         if (res != MEMTX_OK) {
923             return TRANSLATE_FAIL;
924         }
925 
926         bool pbmte = env->menvcfg & MENVCFG_PBMTE;
927         bool hade = env->menvcfg & MENVCFG_HADE;
928 
929         if (first_stage && two_stage && env->virt_enabled) {
930             pbmte = pbmte && (env->henvcfg & HENVCFG_PBMTE);
931             hade = hade && (env->henvcfg & HENVCFG_HADE);
932         }
933 
934         if (riscv_cpu_sxl(env) == MXL_RV32) {
935             ppn = pte >> PTE_PPN_SHIFT;
936         } else if (pbmte || riscv_cpu_cfg(env)->ext_svnapot) {
937             ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
938         } else {
939             ppn = pte >> PTE_PPN_SHIFT;
940             if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
941                 return TRANSLATE_FAIL;
942             }
943         }
944 
945         if (!(pte & PTE_V)) {
946             /* Invalid PTE */
947             return TRANSLATE_FAIL;
948         } else if (!pbmte && (pte & PTE_PBMT)) {
949             return TRANSLATE_FAIL;
950         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
951             /* Inner PTE, continue walking */
952             if (pte & (PTE_D | PTE_A | PTE_U | PTE_ATTR)) {
953                 return TRANSLATE_FAIL;
954             }
955             base = ppn << PGSHIFT;
956         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
957             /* Reserved leaf PTE flags: PTE_W */
958             return TRANSLATE_FAIL;
959         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
960             /* Reserved leaf PTE flags: PTE_W + PTE_X */
961             return TRANSLATE_FAIL;
962         } else if ((pte & PTE_U) && ((mode != PRV_U) &&
963                    (!sum || access_type == MMU_INST_FETCH))) {
964             /* User PTE flags when not U mode and mstatus.SUM is not set,
965                or the access type is an instruction fetch */
966             return TRANSLATE_FAIL;
967         } else if (!(pte & PTE_U) && (mode != PRV_S)) {
968             /* Supervisor PTE flags when not S mode */
969             return TRANSLATE_FAIL;
970         } else if (ppn & ((1ULL << ptshift) - 1)) {
971             /* Misaligned PPN */
972             return TRANSLATE_FAIL;
973         } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
974                    ((pte & PTE_X) && mxr))) {
975             /* Read access check failed */
976             return TRANSLATE_FAIL;
977         } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
978             /* Write access check failed */
979             return TRANSLATE_FAIL;
980         } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
981             /* Fetch access check failed */
982             return TRANSLATE_FAIL;
983         } else {
984             /* if necessary, set accessed and dirty bits. */
985             target_ulong updated_pte = pte | PTE_A |
986                 (access_type == MMU_DATA_STORE ? PTE_D : 0);
987 
988             /* Page table updates need to be atomic with MTTCG enabled */
989             if (updated_pte != pte) {
990                 if (!hade) {
991                     return TRANSLATE_FAIL;
992                 }
993 
994                 /*
995                  * - if accessed or dirty bits need updating, and the PTE is
996                  *   in RAM, then we do so atomically with a compare and swap.
997                  * - if the PTE is in IO space or ROM, then it can't be updated
998                  *   and we return TRANSLATE_FAIL.
999                  * - if the PTE changed by the time we went to update it, then
1000                  *   it is no longer valid and we must re-walk the page table.
1001                  */
1002                 MemoryRegion *mr;
1003                 hwaddr l = sizeof(target_ulong), addr1;
1004                 mr = address_space_translate(cs->as, pte_addr,
1005                     &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
1006                 if (memory_region_is_ram(mr)) {
1007                     target_ulong *pte_pa =
1008                         qemu_map_ram_ptr(mr->ram_block, addr1);
1009 #if TCG_OVERSIZED_GUEST
1010                     /* MTTCG is not enabled on oversized TCG guests so
1011                      * page table updates do not need to be atomic */
1012                     *pte_pa = pte = updated_pte;
1013 #else
1014                     target_ulong old_pte =
1015                         qatomic_cmpxchg(pte_pa, pte, updated_pte);
1016                     if (old_pte != pte) {
1017                         goto restart;
1018                     } else {
1019                         pte = updated_pte;
1020                     }
1021 #endif
1022                 } else {
1023                     /* misconfigured PTE in ROM (AD bits are not preset) or
1024                      * PTE is in IO space and can't be updated atomically */
1025                     return TRANSLATE_FAIL;
1026                 }
1027             }
1028 
1029             /* for superpage mappings, make a fake leaf PTE for the TLB's
1030                benefit. */
1031             target_ulong vpn = addr >> PGSHIFT;
1032 
1033             if (riscv_cpu_cfg(env)->ext_svnapot && (pte & PTE_N)) {
1034                 napot_bits = ctzl(ppn) + 1;
1035                 if ((i != (levels - 1)) || (napot_bits != 4)) {
1036                     return TRANSLATE_FAIL;
1037                 }
1038             }
1039 
1040             napot_mask = (1 << napot_bits) - 1;
1041             *physical = (((ppn & ~napot_mask) | (vpn & napot_mask) |
1042                           (vpn & (((target_ulong)1 << ptshift) - 1))
1043                          ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
1044 
1045             /* set permissions on the TLB entry */
1046             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
1047                 *prot |= PAGE_READ;
1048             }
1049             if (pte & PTE_X) {
1050                 *prot |= PAGE_EXEC;
1051             }
1052             /* add write permission on stores or if the page is already dirty,
1053                so that we TLB miss on later writes to update the dirty bit */
1054             if ((pte & PTE_W) &&
1055                     (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
1056                 *prot |= PAGE_WRITE;
1057             }
1058             return TRANSLATE_SUCCESS;
1059         }
1060     }
1061     return TRANSLATE_FAIL;
1062 }
1063 
1064 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
1065                                 MMUAccessType access_type, bool pmp_violation,
1066                                 bool first_stage, bool two_stage,
1067                                 bool two_stage_indirect)
1068 {
1069     CPUState *cs = env_cpu(env);
1070     int page_fault_exceptions, vm;
1071     uint64_t stap_mode;
1072 
1073     if (riscv_cpu_mxl(env) == MXL_RV32) {
1074         stap_mode = SATP32_MODE;
1075     } else {
1076         stap_mode = SATP64_MODE;
1077     }
1078 
1079     if (first_stage) {
1080         vm = get_field(env->satp, stap_mode);
1081     } else {
1082         vm = get_field(env->hgatp, stap_mode);
1083     }
1084 
1085     page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
1086 
1087     switch (access_type) {
1088     case MMU_INST_FETCH:
1089         if (env->virt_enabled && !first_stage) {
1090             cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
1091         } else {
1092             cs->exception_index = page_fault_exceptions ?
1093                 RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
1094         }
1095         break;
1096     case MMU_DATA_LOAD:
1097         if (two_stage && !first_stage) {
1098             cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
1099         } else {
1100             cs->exception_index = page_fault_exceptions ?
1101                 RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
1102         }
1103         break;
1104     case MMU_DATA_STORE:
1105         if (two_stage && !first_stage) {
1106             cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
1107         } else {
1108             cs->exception_index = page_fault_exceptions ?
1109                 RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
1110         }
1111         break;
1112     default:
1113         g_assert_not_reached();
1114     }
1115     env->badaddr = address;
1116     env->two_stage_lookup = two_stage;
1117     env->two_stage_indirect_lookup = two_stage_indirect;
1118 }
1119 
1120 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
1121 {
1122     RISCVCPU *cpu = RISCV_CPU(cs);
1123     CPURISCVState *env = &cpu->env;
1124     hwaddr phys_addr;
1125     int prot;
1126     int mmu_idx = cpu_mmu_index(&cpu->env, false);
1127 
1128     if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
1129                              true, env->virt_enabled, true)) {
1130         return -1;
1131     }
1132 
1133     if (env->virt_enabled) {
1134         if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
1135                                  0, mmu_idx, false, true, true)) {
1136             return -1;
1137         }
1138     }
1139 
1140     return phys_addr & TARGET_PAGE_MASK;
1141 }
1142 
1143 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
1144                                      vaddr addr, unsigned size,
1145                                      MMUAccessType access_type,
1146                                      int mmu_idx, MemTxAttrs attrs,
1147                                      MemTxResult response, uintptr_t retaddr)
1148 {
1149     RISCVCPU *cpu = RISCV_CPU(cs);
1150     CPURISCVState *env = &cpu->env;
1151 
1152     if (access_type == MMU_DATA_STORE) {
1153         cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
1154     } else if (access_type == MMU_DATA_LOAD) {
1155         cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
1156     } else {
1157         cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT;
1158     }
1159 
1160     env->badaddr = addr;
1161     env->two_stage_lookup = env->virt_enabled ||
1162                             riscv_cpu_two_stage_lookup(mmu_idx);
1163     env->two_stage_indirect_lookup = false;
1164     cpu_loop_exit_restore(cs, retaddr);
1165 }
1166 
1167 void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
1168                                    MMUAccessType access_type, int mmu_idx,
1169                                    uintptr_t retaddr)
1170 {
1171     RISCVCPU *cpu = RISCV_CPU(cs);
1172     CPURISCVState *env = &cpu->env;
1173     switch (access_type) {
1174     case MMU_INST_FETCH:
1175         cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
1176         break;
1177     case MMU_DATA_LOAD:
1178         cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
1179         break;
1180     case MMU_DATA_STORE:
1181         cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
1182         break;
1183     default:
1184         g_assert_not_reached();
1185     }
1186     env->badaddr = addr;
1187     env->two_stage_lookup = env->virt_enabled ||
1188                             riscv_cpu_two_stage_lookup(mmu_idx);
1189     env->two_stage_indirect_lookup = false;
1190     cpu_loop_exit_restore(cs, retaddr);
1191 }
1192 
1193 
1194 static void pmu_tlb_fill_incr_ctr(RISCVCPU *cpu, MMUAccessType access_type)
1195 {
1196     enum riscv_pmu_event_idx pmu_event_type;
1197 
1198     switch (access_type) {
1199     case MMU_INST_FETCH:
1200         pmu_event_type = RISCV_PMU_EVENT_CACHE_ITLB_PREFETCH_MISS;
1201         break;
1202     case MMU_DATA_LOAD:
1203         pmu_event_type = RISCV_PMU_EVENT_CACHE_DTLB_READ_MISS;
1204         break;
1205     case MMU_DATA_STORE:
1206         pmu_event_type = RISCV_PMU_EVENT_CACHE_DTLB_WRITE_MISS;
1207         break;
1208     default:
1209         return;
1210     }
1211 
1212     riscv_pmu_incr_ctr(cpu, pmu_event_type);
1213 }
1214 
1215 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
1216                         MMUAccessType access_type, int mmu_idx,
1217                         bool probe, uintptr_t retaddr)
1218 {
1219     RISCVCPU *cpu = RISCV_CPU(cs);
1220     CPURISCVState *env = &cpu->env;
1221     vaddr im_address;
1222     hwaddr pa = 0;
1223     int prot, prot2, prot_pmp;
1224     bool pmp_violation = false;
1225     bool first_stage_error = true;
1226     bool two_stage_lookup = false;
1227     bool two_stage_indirect_error = false;
1228     int ret = TRANSLATE_FAIL;
1229     int mode = mmu_idx;
1230     /* default TLB page size */
1231     target_ulong tlb_size = TARGET_PAGE_SIZE;
1232 
1233     env->guest_phys_fault_addr = 0;
1234 
1235     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
1236                   __func__, address, access_type, mmu_idx);
1237 
1238     /* MPRV does not affect the virtual-machine load/store
1239        instructions, HLV, HLVX, and HSV. */
1240     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
1241         mode = get_field(env->hstatus, HSTATUS_SPVP);
1242     } else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
1243                get_field(env->mstatus, MSTATUS_MPRV)) {
1244         mode = get_field(env->mstatus, MSTATUS_MPP);
1245         if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
1246             two_stage_lookup = true;
1247         }
1248     }
1249 
1250     pmu_tlb_fill_incr_ctr(cpu, access_type);
1251     if (env->virt_enabled ||
1252         ((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
1253          access_type != MMU_INST_FETCH)) {
1254         /* Two stage lookup */
1255         ret = get_physical_address(env, &pa, &prot, address,
1256                                    &env->guest_phys_fault_addr, access_type,
1257                                    mmu_idx, true, true, false);
1258 
1259         /*
1260          * A G-stage exception may be triggered during two state lookup.
1261          * And the env->guest_phys_fault_addr has already been set in
1262          * get_physical_address().
1263          */
1264         if (ret == TRANSLATE_G_STAGE_FAIL) {
1265             first_stage_error = false;
1266             two_stage_indirect_error = true;
1267             access_type = MMU_DATA_LOAD;
1268         }
1269 
1270         qemu_log_mask(CPU_LOG_MMU,
1271                       "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
1272                       HWADDR_FMT_plx " prot %d\n",
1273                       __func__, address, ret, pa, prot);
1274 
1275         if (ret == TRANSLATE_SUCCESS) {
1276             /* Second stage lookup */
1277             im_address = pa;
1278 
1279             ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
1280                                        access_type, mmu_idx, false, true,
1281                                        false);
1282 
1283             qemu_log_mask(CPU_LOG_MMU,
1284                     "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
1285                     HWADDR_FMT_plx " prot %d\n",
1286                     __func__, im_address, ret, pa, prot2);
1287 
1288             prot &= prot2;
1289 
1290             if (ret == TRANSLATE_SUCCESS) {
1291                 ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
1292                                                size, access_type, mode);
1293 
1294                 qemu_log_mask(CPU_LOG_MMU,
1295                               "%s PMP address=" HWADDR_FMT_plx " ret %d prot"
1296                               " %d tlb_size " TARGET_FMT_lu "\n",
1297                               __func__, pa, ret, prot_pmp, tlb_size);
1298 
1299                 prot &= prot_pmp;
1300             }
1301 
1302             if (ret != TRANSLATE_SUCCESS) {
1303                 /*
1304                  * Guest physical address translation failed, this is a HS
1305                  * level exception
1306                  */
1307                 first_stage_error = false;
1308                 env->guest_phys_fault_addr = (im_address |
1309                                               (address &
1310                                                (TARGET_PAGE_SIZE - 1))) >> 2;
1311             }
1312         }
1313     } else {
1314         /* Single stage lookup */
1315         ret = get_physical_address(env, &pa, &prot, address, NULL,
1316                                    access_type, mmu_idx, true, false, false);
1317 
1318         qemu_log_mask(CPU_LOG_MMU,
1319                       "%s address=%" VADDR_PRIx " ret %d physical "
1320                       HWADDR_FMT_plx " prot %d\n",
1321                       __func__, address, ret, pa, prot);
1322 
1323         if (ret == TRANSLATE_SUCCESS) {
1324             ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
1325                                            size, access_type, mode);
1326 
1327             qemu_log_mask(CPU_LOG_MMU,
1328                           "%s PMP address=" HWADDR_FMT_plx " ret %d prot"
1329                           " %d tlb_size " TARGET_FMT_lu "\n",
1330                           __func__, pa, ret, prot_pmp, tlb_size);
1331 
1332             prot &= prot_pmp;
1333         }
1334     }
1335 
1336     if (ret == TRANSLATE_PMP_FAIL) {
1337         pmp_violation = true;
1338     }
1339 
1340     if (ret == TRANSLATE_SUCCESS) {
1341         tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
1342                      prot, mmu_idx, tlb_size);
1343         return true;
1344     } else if (probe) {
1345         return false;
1346     } else {
1347         raise_mmu_exception(env, address, access_type, pmp_violation,
1348                             first_stage_error,
1349                             env->virt_enabled ||
1350                                 riscv_cpu_two_stage_lookup(mmu_idx),
1351                             two_stage_indirect_error);
1352         cpu_loop_exit_restore(cs, retaddr);
1353     }
1354 
1355     return true;
1356 }
1357 
1358 static target_ulong riscv_transformed_insn(CPURISCVState *env,
1359                                            target_ulong insn,
1360                                            target_ulong taddr)
1361 {
1362     target_ulong xinsn = 0;
1363     target_ulong access_rs1 = 0, access_imm = 0, access_size = 0;
1364 
1365     /*
1366      * Only Quadrant 0 and Quadrant 2 of RVC instruction space need to
1367      * be uncompressed. The Quadrant 1 of RVC instruction space need
1368      * not be transformed because these instructions won't generate
1369      * any load/store trap.
1370      */
1371 
1372     if ((insn & 0x3) != 0x3) {
1373         /* Transform 16bit instruction into 32bit instruction */
1374         switch (GET_C_OP(insn)) {
1375         case OPC_RISC_C_OP_QUAD0: /* Quadrant 0 */
1376             switch (GET_C_FUNC(insn)) {
1377             case OPC_RISC_C_FUNC_FLD_LQ:
1378                 if (riscv_cpu_xlen(env) != 128) { /* C.FLD (RV32/64) */
1379                     xinsn = OPC_RISC_FLD;
1380                     xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
1381                     access_rs1 = GET_C_RS1S(insn);
1382                     access_imm = GET_C_LD_IMM(insn);
1383                     access_size = 8;
1384                 }
1385                 break;
1386             case OPC_RISC_C_FUNC_LW: /* C.LW */
1387                 xinsn = OPC_RISC_LW;
1388                 xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
1389                 access_rs1 = GET_C_RS1S(insn);
1390                 access_imm = GET_C_LW_IMM(insn);
1391                 access_size = 4;
1392                 break;
1393             case OPC_RISC_C_FUNC_FLW_LD:
1394                 if (riscv_cpu_xlen(env) == 32) { /* C.FLW (RV32) */
1395                     xinsn = OPC_RISC_FLW;
1396                     xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
1397                     access_rs1 = GET_C_RS1S(insn);
1398                     access_imm = GET_C_LW_IMM(insn);
1399                     access_size = 4;
1400                 } else { /* C.LD (RV64/RV128) */
1401                     xinsn = OPC_RISC_LD;
1402                     xinsn = SET_RD(xinsn, GET_C_RS2S(insn));
1403                     access_rs1 = GET_C_RS1S(insn);
1404                     access_imm = GET_C_LD_IMM(insn);
1405                     access_size = 8;
1406                 }
1407                 break;
1408             case OPC_RISC_C_FUNC_FSD_SQ:
1409                 if (riscv_cpu_xlen(env) != 128) { /* C.FSD (RV32/64) */
1410                     xinsn = OPC_RISC_FSD;
1411                     xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
1412                     access_rs1 = GET_C_RS1S(insn);
1413                     access_imm = GET_C_SD_IMM(insn);
1414                     access_size = 8;
1415                 }
1416                 break;
1417             case OPC_RISC_C_FUNC_SW: /* C.SW */
1418                 xinsn = OPC_RISC_SW;
1419                 xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
1420                 access_rs1 = GET_C_RS1S(insn);
1421                 access_imm = GET_C_SW_IMM(insn);
1422                 access_size = 4;
1423                 break;
1424             case OPC_RISC_C_FUNC_FSW_SD:
1425                 if (riscv_cpu_xlen(env) == 32) { /* C.FSW (RV32) */
1426                     xinsn = OPC_RISC_FSW;
1427                     xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
1428                     access_rs1 = GET_C_RS1S(insn);
1429                     access_imm = GET_C_SW_IMM(insn);
1430                     access_size = 4;
1431                 } else { /* C.SD (RV64/RV128) */
1432                     xinsn = OPC_RISC_SD;
1433                     xinsn = SET_RS2(xinsn, GET_C_RS2S(insn));
1434                     access_rs1 = GET_C_RS1S(insn);
1435                     access_imm = GET_C_SD_IMM(insn);
1436                     access_size = 8;
1437                 }
1438                 break;
1439             default:
1440                 break;
1441             }
1442             break;
1443         case OPC_RISC_C_OP_QUAD2: /* Quadrant 2 */
1444             switch (GET_C_FUNC(insn)) {
1445             case OPC_RISC_C_FUNC_FLDSP_LQSP:
1446                 if (riscv_cpu_xlen(env) != 128) { /* C.FLDSP (RV32/64) */
1447                     xinsn = OPC_RISC_FLD;
1448                     xinsn = SET_RD(xinsn, GET_C_RD(insn));
1449                     access_rs1 = 2;
1450                     access_imm = GET_C_LDSP_IMM(insn);
1451                     access_size = 8;
1452                 }
1453                 break;
1454             case OPC_RISC_C_FUNC_LWSP: /* C.LWSP */
1455                 xinsn = OPC_RISC_LW;
1456                 xinsn = SET_RD(xinsn, GET_C_RD(insn));
1457                 access_rs1 = 2;
1458                 access_imm = GET_C_LWSP_IMM(insn);
1459                 access_size = 4;
1460                 break;
1461             case OPC_RISC_C_FUNC_FLWSP_LDSP:
1462                 if (riscv_cpu_xlen(env) == 32) { /* C.FLWSP (RV32) */
1463                     xinsn = OPC_RISC_FLW;
1464                     xinsn = SET_RD(xinsn, GET_C_RD(insn));
1465                     access_rs1 = 2;
1466                     access_imm = GET_C_LWSP_IMM(insn);
1467                     access_size = 4;
1468                 } else { /* C.LDSP (RV64/RV128) */
1469                     xinsn = OPC_RISC_LD;
1470                     xinsn = SET_RD(xinsn, GET_C_RD(insn));
1471                     access_rs1 = 2;
1472                     access_imm = GET_C_LDSP_IMM(insn);
1473                     access_size = 8;
1474                 }
1475                 break;
1476             case OPC_RISC_C_FUNC_FSDSP_SQSP:
1477                 if (riscv_cpu_xlen(env) != 128) { /* C.FSDSP (RV32/64) */
1478                     xinsn = OPC_RISC_FSD;
1479                     xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
1480                     access_rs1 = 2;
1481                     access_imm = GET_C_SDSP_IMM(insn);
1482                     access_size = 8;
1483                 }
1484                 break;
1485             case OPC_RISC_C_FUNC_SWSP: /* C.SWSP */
1486                 xinsn = OPC_RISC_SW;
1487                 xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
1488                 access_rs1 = 2;
1489                 access_imm = GET_C_SWSP_IMM(insn);
1490                 access_size = 4;
1491                 break;
1492             case 7:
1493                 if (riscv_cpu_xlen(env) == 32) { /* C.FSWSP (RV32) */
1494                     xinsn = OPC_RISC_FSW;
1495                     xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
1496                     access_rs1 = 2;
1497                     access_imm = GET_C_SWSP_IMM(insn);
1498                     access_size = 4;
1499                 } else { /* C.SDSP (RV64/RV128) */
1500                     xinsn = OPC_RISC_SD;
1501                     xinsn = SET_RS2(xinsn, GET_C_RS2(insn));
1502                     access_rs1 = 2;
1503                     access_imm = GET_C_SDSP_IMM(insn);
1504                     access_size = 8;
1505                 }
1506                 break;
1507             default:
1508                 break;
1509             }
1510             break;
1511         default:
1512             break;
1513         }
1514 
1515         /*
1516          * Clear Bit1 of transformed instruction to indicate that
1517          * original insruction was a 16bit instruction
1518          */
1519         xinsn &= ~((target_ulong)0x2);
1520     } else {
1521         /* Transform 32bit (or wider) instructions */
1522         switch (MASK_OP_MAJOR(insn)) {
1523         case OPC_RISC_ATOMIC:
1524             xinsn = insn;
1525             access_rs1 = GET_RS1(insn);
1526             access_size = 1 << GET_FUNCT3(insn);
1527             break;
1528         case OPC_RISC_LOAD:
1529         case OPC_RISC_FP_LOAD:
1530             xinsn = SET_I_IMM(insn, 0);
1531             access_rs1 = GET_RS1(insn);
1532             access_imm = GET_IMM(insn);
1533             access_size = 1 << GET_FUNCT3(insn);
1534             break;
1535         case OPC_RISC_STORE:
1536         case OPC_RISC_FP_STORE:
1537             xinsn = SET_S_IMM(insn, 0);
1538             access_rs1 = GET_RS1(insn);
1539             access_imm = GET_STORE_IMM(insn);
1540             access_size = 1 << GET_FUNCT3(insn);
1541             break;
1542         case OPC_RISC_SYSTEM:
1543             if (MASK_OP_SYSTEM(insn) == OPC_RISC_HLVHSV) {
1544                 xinsn = insn;
1545                 access_rs1 = GET_RS1(insn);
1546                 access_size = 1 << ((GET_FUNCT7(insn) >> 1) & 0x3);
1547                 access_size = 1 << access_size;
1548             }
1549             break;
1550         default:
1551             break;
1552         }
1553     }
1554 
1555     if (access_size) {
1556         xinsn = SET_RS1(xinsn, (taddr - (env->gpr[access_rs1] + access_imm)) &
1557                                (access_size - 1));
1558     }
1559 
1560     return xinsn;
1561 }
1562 #endif /* !CONFIG_USER_ONLY */
1563 
1564 /*
1565  * Handle Traps
1566  *
1567  * Adapted from Spike's processor_t::take_trap.
1568  *
1569  */
1570 void riscv_cpu_do_interrupt(CPUState *cs)
1571 {
1572 #if !defined(CONFIG_USER_ONLY)
1573 
1574     RISCVCPU *cpu = RISCV_CPU(cs);
1575     CPURISCVState *env = &cpu->env;
1576     bool write_gva = false;
1577     uint64_t s;
1578 
1579     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
1580      * so we mask off the MSB and separate into trap type and cause.
1581      */
1582     bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
1583     target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
1584     uint64_t deleg = async ? env->mideleg : env->medeleg;
1585     target_ulong tval = 0;
1586     target_ulong tinst = 0;
1587     target_ulong htval = 0;
1588     target_ulong mtval2 = 0;
1589 
1590     if  (cause == RISCV_EXCP_SEMIHOST) {
1591         do_common_semihosting(cs);
1592         env->pc += 4;
1593         return;
1594     }
1595 
1596     if (!async) {
1597         /* set tval to badaddr for traps with address information */
1598         switch (cause) {
1599         case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
1600         case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
1601         case RISCV_EXCP_LOAD_ADDR_MIS:
1602         case RISCV_EXCP_STORE_AMO_ADDR_MIS:
1603         case RISCV_EXCP_LOAD_ACCESS_FAULT:
1604         case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
1605         case RISCV_EXCP_LOAD_PAGE_FAULT:
1606         case RISCV_EXCP_STORE_PAGE_FAULT:
1607             write_gva = env->two_stage_lookup;
1608             tval = env->badaddr;
1609             if (env->two_stage_indirect_lookup) {
1610                 /*
1611                  * special pseudoinstruction for G-stage fault taken while
1612                  * doing VS-stage page table walk.
1613                  */
1614                 tinst = (riscv_cpu_xlen(env) == 32) ? 0x00002000 : 0x00003000;
1615             } else {
1616                 /*
1617                  * The "Addr. Offset" field in transformed instruction is
1618                  * non-zero only for misaligned access.
1619                  */
1620                 tinst = riscv_transformed_insn(env, env->bins, tval);
1621             }
1622             break;
1623         case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
1624         case RISCV_EXCP_INST_ADDR_MIS:
1625         case RISCV_EXCP_INST_ACCESS_FAULT:
1626         case RISCV_EXCP_INST_PAGE_FAULT:
1627             write_gva = env->two_stage_lookup;
1628             tval = env->badaddr;
1629             if (env->two_stage_indirect_lookup) {
1630                 /*
1631                  * special pseudoinstruction for G-stage fault taken while
1632                  * doing VS-stage page table walk.
1633                  */
1634                 tinst = (riscv_cpu_xlen(env) == 32) ? 0x00002000 : 0x00003000;
1635             }
1636             break;
1637         case RISCV_EXCP_ILLEGAL_INST:
1638         case RISCV_EXCP_VIRT_INSTRUCTION_FAULT:
1639             tval = env->bins;
1640             break;
1641         case RISCV_EXCP_BREAKPOINT:
1642             if (cs->watchpoint_hit) {
1643                 tval = cs->watchpoint_hit->hitaddr;
1644                 cs->watchpoint_hit = NULL;
1645             }
1646             break;
1647         default:
1648             break;
1649         }
1650         /* ecall is dispatched as one cause so translate based on mode */
1651         if (cause == RISCV_EXCP_U_ECALL) {
1652             assert(env->priv <= 3);
1653 
1654             if (env->priv == PRV_M) {
1655                 cause = RISCV_EXCP_M_ECALL;
1656             } else if (env->priv == PRV_S && env->virt_enabled) {
1657                 cause = RISCV_EXCP_VS_ECALL;
1658             } else if (env->priv == PRV_S && !env->virt_enabled) {
1659                 cause = RISCV_EXCP_S_ECALL;
1660             } else if (env->priv == PRV_U) {
1661                 cause = RISCV_EXCP_U_ECALL;
1662             }
1663         }
1664     }
1665 
1666     trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
1667                      riscv_cpu_get_trap_name(cause, async));
1668 
1669     qemu_log_mask(CPU_LOG_INT,
1670                   "%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
1671                   "epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
1672                   __func__, env->mhartid, async, cause, env->pc, tval,
1673                   riscv_cpu_get_trap_name(cause, async));
1674 
1675     if (env->priv <= PRV_S &&
1676             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
1677         /* handle the trap in S-mode */
1678         if (riscv_has_ext(env, RVH)) {
1679             uint64_t hdeleg = async ? env->hideleg : env->hedeleg;
1680 
1681             if (env->virt_enabled && ((hdeleg >> cause) & 1)) {
1682                 /* Trap to VS mode */
1683                 /*
1684                  * See if we need to adjust cause. Yes if its VS mode interrupt
1685                  * no if hypervisor has delegated one of hs mode's interrupt
1686                  */
1687                 if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
1688                     cause == IRQ_VS_EXT) {
1689                     cause = cause - 1;
1690                 }
1691                 write_gva = false;
1692             } else if (env->virt_enabled) {
1693                 /* Trap into HS mode, from virt */
1694                 riscv_cpu_swap_hypervisor_regs(env);
1695                 env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
1696                                          env->priv);
1697                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV, true);
1698 
1699                 htval = env->guest_phys_fault_addr;
1700 
1701                 riscv_cpu_set_virt_enabled(env, 0);
1702             } else {
1703                 /* Trap into HS mode */
1704                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
1705                 htval = env->guest_phys_fault_addr;
1706             }
1707             env->hstatus = set_field(env->hstatus, HSTATUS_GVA, write_gva);
1708         }
1709 
1710         s = env->mstatus;
1711         s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
1712         s = set_field(s, MSTATUS_SPP, env->priv);
1713         s = set_field(s, MSTATUS_SIE, 0);
1714         env->mstatus = s;
1715         env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
1716         env->sepc = env->pc;
1717         env->stval = tval;
1718         env->htval = htval;
1719         env->htinst = tinst;
1720         env->pc = (env->stvec >> 2 << 2) +
1721             ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
1722         riscv_cpu_set_mode(env, PRV_S);
1723     } else {
1724         /* handle the trap in M-mode */
1725         if (riscv_has_ext(env, RVH)) {
1726             if (env->virt_enabled) {
1727                 riscv_cpu_swap_hypervisor_regs(env);
1728             }
1729             env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
1730                                      env->virt_enabled);
1731             if (env->virt_enabled && tval) {
1732                 env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
1733             }
1734 
1735             mtval2 = env->guest_phys_fault_addr;
1736 
1737             /* Trapping to M mode, virt is disabled */
1738             riscv_cpu_set_virt_enabled(env, 0);
1739         }
1740 
1741         s = env->mstatus;
1742         s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
1743         s = set_field(s, MSTATUS_MPP, env->priv);
1744         s = set_field(s, MSTATUS_MIE, 0);
1745         env->mstatus = s;
1746         env->mcause = cause | ~(((target_ulong)-1) >> async);
1747         env->mepc = env->pc;
1748         env->mtval = tval;
1749         env->mtval2 = mtval2;
1750         env->mtinst = tinst;
1751         env->pc = (env->mtvec >> 2 << 2) +
1752             ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
1753         riscv_cpu_set_mode(env, PRV_M);
1754     }
1755 
1756     /* NOTE: it is not necessary to yield load reservations here. It is only
1757      * necessary for an SC from "another hart" to cause a load reservation
1758      * to be yielded. Refer to the memory consistency model section of the
1759      * RISC-V ISA Specification.
1760      */
1761 
1762     env->two_stage_lookup = false;
1763     env->two_stage_indirect_lookup = false;
1764 #endif
1765     cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
1766 }
1767