xref: /openbmc/qemu/target/riscv/cpu_helper.c (revision cbc183d2)
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 "hw/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 #ifndef CONFIG_USER_ONLY
39 static int riscv_cpu_local_irq_pending(CPURISCVState *env)
40 {
41     target_ulong irqs;
42 
43     target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
44     target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
45     target_ulong hs_mstatus_sie = get_field(env->mstatus_hs, MSTATUS_SIE);
46 
47     target_ulong pending = env->mip & env->mie &
48                                ~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
49     target_ulong vspending = (env->mip & env->mie &
50                               (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP));
51 
52     target_ulong mie    = env->priv < PRV_M ||
53                           (env->priv == PRV_M && mstatus_mie);
54     target_ulong sie    = env->priv < PRV_S ||
55                           (env->priv == PRV_S && mstatus_sie);
56     target_ulong hs_sie = env->priv < PRV_S ||
57                           (env->priv == PRV_S && hs_mstatus_sie);
58 
59     if (riscv_cpu_virt_enabled(env)) {
60         target_ulong pending_hs_irq = pending & -hs_sie;
61 
62         if (pending_hs_irq) {
63             riscv_cpu_set_force_hs_excep(env, FORCE_HS_EXCEP);
64             return ctz64(pending_hs_irq);
65         }
66 
67         pending = vspending;
68     }
69 
70     irqs = (pending & ~env->mideleg & -mie) | (pending &  env->mideleg & -sie);
71 
72     if (irqs) {
73         return ctz64(irqs); /* since non-zero */
74     } else {
75         return EXCP_NONE; /* indicates no pending interrupt */
76     }
77 }
78 #endif
79 
80 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
81 {
82 #if !defined(CONFIG_USER_ONLY)
83     if (interrupt_request & CPU_INTERRUPT_HARD) {
84         RISCVCPU *cpu = RISCV_CPU(cs);
85         CPURISCVState *env = &cpu->env;
86         int interruptno = riscv_cpu_local_irq_pending(env);
87         if (interruptno >= 0) {
88             cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
89             riscv_cpu_do_interrupt(cs);
90             return true;
91         }
92     }
93 #endif
94     return false;
95 }
96 
97 #if !defined(CONFIG_USER_ONLY)
98 
99 /* Return true is floating point support is currently enabled */
100 bool riscv_cpu_fp_enabled(CPURISCVState *env)
101 {
102     if (env->mstatus & MSTATUS_FS) {
103         if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
104             return false;
105         }
106         return true;
107     }
108 
109     return false;
110 }
111 
112 void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
113 {
114     uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
115                             MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
116                             MSTATUS64_UXL;
117     bool current_virt = riscv_cpu_virt_enabled(env);
118 
119     g_assert(riscv_has_ext(env, RVH));
120 
121     if (current_virt) {
122         /* Current V=1 and we are about to change to V=0 */
123         env->vsstatus = env->mstatus & mstatus_mask;
124         env->mstatus &= ~mstatus_mask;
125         env->mstatus |= env->mstatus_hs;
126 
127         env->vstvec = env->stvec;
128         env->stvec = env->stvec_hs;
129 
130         env->vsscratch = env->sscratch;
131         env->sscratch = env->sscratch_hs;
132 
133         env->vsepc = env->sepc;
134         env->sepc = env->sepc_hs;
135 
136         env->vscause = env->scause;
137         env->scause = env->scause_hs;
138 
139         env->vstval = env->sbadaddr;
140         env->sbadaddr = env->stval_hs;
141 
142         env->vsatp = env->satp;
143         env->satp = env->satp_hs;
144     } else {
145         /* Current V=0 and we are about to change to V=1 */
146         env->mstatus_hs = env->mstatus & mstatus_mask;
147         env->mstatus &= ~mstatus_mask;
148         env->mstatus |= env->vsstatus;
149 
150         env->stvec_hs = env->stvec;
151         env->stvec = env->vstvec;
152 
153         env->sscratch_hs = env->sscratch;
154         env->sscratch = env->vsscratch;
155 
156         env->sepc_hs = env->sepc;
157         env->sepc = env->vsepc;
158 
159         env->scause_hs = env->scause;
160         env->scause = env->vscause;
161 
162         env->stval_hs = env->sbadaddr;
163         env->sbadaddr = env->vstval;
164 
165         env->satp_hs = env->satp;
166         env->satp = env->vsatp;
167     }
168 }
169 
170 bool riscv_cpu_virt_enabled(CPURISCVState *env)
171 {
172     if (!riscv_has_ext(env, RVH)) {
173         return false;
174     }
175 
176     return get_field(env->virt, VIRT_ONOFF);
177 }
178 
179 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
180 {
181     if (!riscv_has_ext(env, RVH)) {
182         return;
183     }
184 
185     /* Flush the TLB on all virt mode changes. */
186     if (get_field(env->virt, VIRT_ONOFF) != enable) {
187         tlb_flush(env_cpu(env));
188     }
189 
190     env->virt = set_field(env->virt, VIRT_ONOFF, enable);
191 }
192 
193 bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
194 {
195     if (!riscv_has_ext(env, RVH)) {
196         return false;
197     }
198 
199     return get_field(env->virt, FORCE_HS_EXCEP);
200 }
201 
202 void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
203 {
204     if (!riscv_has_ext(env, RVH)) {
205         return;
206     }
207 
208     env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
209 }
210 
211 bool riscv_cpu_two_stage_lookup(int mmu_idx)
212 {
213     return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
214 }
215 
216 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
217 {
218     CPURISCVState *env = &cpu->env;
219     if (env->miclaim & interrupts) {
220         return -1;
221     } else {
222         env->miclaim |= interrupts;
223         return 0;
224     }
225 }
226 
227 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
228 {
229     CPURISCVState *env = &cpu->env;
230     CPUState *cs = CPU(cpu);
231     uint32_t old = env->mip;
232     bool locked = false;
233 
234     if (!qemu_mutex_iothread_locked()) {
235         locked = true;
236         qemu_mutex_lock_iothread();
237     }
238 
239     env->mip = (env->mip & ~mask) | (value & mask);
240 
241     if (env->mip) {
242         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
243     } else {
244         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
245     }
246 
247     if (locked) {
248         qemu_mutex_unlock_iothread();
249     }
250 
251     return old;
252 }
253 
254 void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
255                              uint32_t arg)
256 {
257     env->rdtime_fn = fn;
258     env->rdtime_fn_arg = arg;
259 }
260 
261 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
262 {
263     if (newpriv > PRV_M) {
264         g_assert_not_reached();
265     }
266     if (newpriv == PRV_H) {
267         newpriv = PRV_U;
268     }
269     /* tlb_flush is unnecessary as mode is contained in mmu_idx */
270     env->priv = newpriv;
271 
272     /*
273      * Clear the load reservation - otherwise a reservation placed in one
274      * context/process can be used by another, resulting in an SC succeeding
275      * incorrectly. Version 2.2 of the ISA specification explicitly requires
276      * this behaviour, while later revisions say that the kernel "should" use
277      * an SC instruction to force the yielding of a load reservation on a
278      * preemptive context switch. As a result, do both.
279      */
280     env->load_res = -1;
281 }
282 
283 /* get_physical_address - get the physical address for this virtual address
284  *
285  * Do a page table walk to obtain the physical address corresponding to a
286  * virtual address. Returns 0 if the translation was successful
287  *
288  * Adapted from Spike's mmu_t::translate and mmu_t::walk
289  *
290  * @env: CPURISCVState
291  * @physical: This will be set to the calculated physical address
292  * @prot: The returned protection attributes
293  * @addr: The virtual address to be translated
294  * @fault_pte_addr: If not NULL, this will be set to fault pte address
295  *                  when a error occurs on pte address translation.
296  *                  This will already be shifted to match htval.
297  * @access_type: The type of MMU access
298  * @mmu_idx: Indicates current privilege level
299  * @first_stage: Are we in first stage translation?
300  *               Second stage is used for hypervisor guest translation
301  * @two_stage: Are we going to perform two stage translation
302  */
303 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
304                                 int *prot, target_ulong addr,
305                                 target_ulong *fault_pte_addr,
306                                 int access_type, int mmu_idx,
307                                 bool first_stage, bool two_stage)
308 {
309     /* NOTE: the env->pc value visible here will not be
310      * correct, but the value visible to the exception handler
311      * (riscv_cpu_do_interrupt) is correct */
312     MemTxResult res;
313     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
314     int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
315     bool use_background = false;
316 
317     /*
318      * Check if we should use the background registers for the two
319      * stage translation. We don't need to check if we actually need
320      * two stage translation as that happened before this function
321      * was called. Background registers will be used if the guest has
322      * forced a two stage translation to be on (in HS or M mode).
323      */
324     if (!riscv_cpu_virt_enabled(env) && riscv_cpu_two_stage_lookup(mmu_idx)) {
325         use_background = true;
326     }
327 
328     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
329         if (get_field(env->mstatus, MSTATUS_MPRV)) {
330             mode = get_field(env->mstatus, MSTATUS_MPP);
331         }
332     }
333 
334     if (first_stage == false) {
335         /* We are in stage 2 translation, this is similar to stage 1. */
336         /* Stage 2 is always taken as U-mode */
337         mode = PRV_U;
338     }
339 
340     if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
341         *physical = addr;
342         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
343         return TRANSLATE_SUCCESS;
344     }
345 
346     *prot = 0;
347 
348     hwaddr base;
349     int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
350 
351     if (first_stage == true) {
352         mxr = get_field(env->mstatus, MSTATUS_MXR);
353     } else {
354         mxr = get_field(env->vsstatus, MSTATUS_MXR);
355     }
356 
357     if (first_stage == true) {
358         if (use_background) {
359             base = (hwaddr)get_field(env->vsatp, SATP_PPN) << PGSHIFT;
360             vm = get_field(env->vsatp, SATP_MODE);
361         } else {
362             base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
363             vm = get_field(env->satp, SATP_MODE);
364         }
365         widened = 0;
366     } else {
367         base = (hwaddr)get_field(env->hgatp, HGATP_PPN) << PGSHIFT;
368         vm = get_field(env->hgatp, HGATP_MODE);
369         widened = 2;
370     }
371     /* status.SUM will be ignored if execute on background */
372     sum = get_field(env->mstatus, MSTATUS_SUM) || use_background;
373     switch (vm) {
374     case VM_1_10_SV32:
375       levels = 2; ptidxbits = 10; ptesize = 4; break;
376     case VM_1_10_SV39:
377       levels = 3; ptidxbits = 9; ptesize = 8; break;
378     case VM_1_10_SV48:
379       levels = 4; ptidxbits = 9; ptesize = 8; break;
380     case VM_1_10_SV57:
381       levels = 5; ptidxbits = 9; ptesize = 8; break;
382     case VM_1_10_MBARE:
383         *physical = addr;
384         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
385         return TRANSLATE_SUCCESS;
386     default:
387       g_assert_not_reached();
388     }
389 
390     CPUState *cs = env_cpu(env);
391     int va_bits = PGSHIFT + levels * ptidxbits + widened;
392     target_ulong mask, masked_msbs;
393 
394     if (TARGET_LONG_BITS > (va_bits - 1)) {
395         mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
396     } else {
397         mask = 0;
398     }
399     masked_msbs = (addr >> (va_bits - 1)) & mask;
400 
401     if (masked_msbs != 0 && masked_msbs != mask) {
402         return TRANSLATE_FAIL;
403     }
404 
405     int ptshift = (levels - 1) * ptidxbits;
406     int i;
407 
408 #if !TCG_OVERSIZED_GUEST
409 restart:
410 #endif
411     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
412         target_ulong idx;
413         if (i == 0) {
414             idx = (addr >> (PGSHIFT + ptshift)) &
415                            ((1 << (ptidxbits + widened)) - 1);
416         } else {
417             idx = (addr >> (PGSHIFT + ptshift)) &
418                            ((1 << ptidxbits) - 1);
419         }
420 
421         /* check that physical address of PTE is legal */
422         hwaddr pte_addr;
423 
424         if (two_stage && first_stage) {
425             int vbase_prot;
426             hwaddr vbase;
427 
428             /* Do the second stage translation on the base PTE address. */
429             int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
430                                                  base, NULL, MMU_DATA_LOAD,
431                                                  mmu_idx, false, true);
432 
433             if (vbase_ret != TRANSLATE_SUCCESS) {
434                 if (fault_pte_addr) {
435                     *fault_pte_addr = (base + idx * ptesize) >> 2;
436                 }
437                 return TRANSLATE_G_STAGE_FAIL;
438             }
439 
440             pte_addr = vbase + idx * ptesize;
441         } else {
442             pte_addr = base + idx * ptesize;
443         }
444 
445         if (riscv_feature(env, RISCV_FEATURE_PMP) &&
446             !pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
447             1 << MMU_DATA_LOAD, PRV_S)) {
448             return TRANSLATE_PMP_FAIL;
449         }
450 
451         target_ulong pte;
452         if (riscv_cpu_is_32bit(env)) {
453             pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
454         } else {
455             pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
456         }
457 
458         if (res != MEMTX_OK) {
459             return TRANSLATE_FAIL;
460         }
461 
462         hwaddr ppn = pte >> PTE_PPN_SHIFT;
463 
464         if (!(pte & PTE_V)) {
465             /* Invalid PTE */
466             return TRANSLATE_FAIL;
467         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
468             /* Inner PTE, continue walking */
469             base = ppn << PGSHIFT;
470         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
471             /* Reserved leaf PTE flags: PTE_W */
472             return TRANSLATE_FAIL;
473         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
474             /* Reserved leaf PTE flags: PTE_W + PTE_X */
475             return TRANSLATE_FAIL;
476         } else if ((pte & PTE_U) && ((mode != PRV_U) &&
477                    (!sum || access_type == MMU_INST_FETCH))) {
478             /* User PTE flags when not U mode and mstatus.SUM is not set,
479                or the access type is an instruction fetch */
480             return TRANSLATE_FAIL;
481         } else if (!(pte & PTE_U) && (mode != PRV_S)) {
482             /* Supervisor PTE flags when not S mode */
483             return TRANSLATE_FAIL;
484         } else if (ppn & ((1ULL << ptshift) - 1)) {
485             /* Misaligned PPN */
486             return TRANSLATE_FAIL;
487         } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
488                    ((pte & PTE_X) && mxr))) {
489             /* Read access check failed */
490             return TRANSLATE_FAIL;
491         } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
492             /* Write access check failed */
493             return TRANSLATE_FAIL;
494         } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
495             /* Fetch access check failed */
496             return TRANSLATE_FAIL;
497         } else {
498             /* if necessary, set accessed and dirty bits. */
499             target_ulong updated_pte = pte | PTE_A |
500                 (access_type == MMU_DATA_STORE ? PTE_D : 0);
501 
502             /* Page table updates need to be atomic with MTTCG enabled */
503             if (updated_pte != pte) {
504                 /*
505                  * - if accessed or dirty bits need updating, and the PTE is
506                  *   in RAM, then we do so atomically with a compare and swap.
507                  * - if the PTE is in IO space or ROM, then it can't be updated
508                  *   and we return TRANSLATE_FAIL.
509                  * - if the PTE changed by the time we went to update it, then
510                  *   it is no longer valid and we must re-walk the page table.
511                  */
512                 MemoryRegion *mr;
513                 hwaddr l = sizeof(target_ulong), addr1;
514                 mr = address_space_translate(cs->as, pte_addr,
515                     &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
516                 if (memory_region_is_ram(mr)) {
517                     target_ulong *pte_pa =
518                         qemu_map_ram_ptr(mr->ram_block, addr1);
519 #if TCG_OVERSIZED_GUEST
520                     /* MTTCG is not enabled on oversized TCG guests so
521                      * page table updates do not need to be atomic */
522                     *pte_pa = pte = updated_pte;
523 #else
524                     target_ulong old_pte =
525                         qatomic_cmpxchg(pte_pa, pte, updated_pte);
526                     if (old_pte != pte) {
527                         goto restart;
528                     } else {
529                         pte = updated_pte;
530                     }
531 #endif
532                 } else {
533                     /* misconfigured PTE in ROM (AD bits are not preset) or
534                      * PTE is in IO space and can't be updated atomically */
535                     return TRANSLATE_FAIL;
536                 }
537             }
538 
539             /* for superpage mappings, make a fake leaf PTE for the TLB's
540                benefit. */
541             target_ulong vpn = addr >> PGSHIFT;
542             *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
543                         (addr & ~TARGET_PAGE_MASK);
544 
545             /* set permissions on the TLB entry */
546             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
547                 *prot |= PAGE_READ;
548             }
549             if ((pte & PTE_X)) {
550                 *prot |= PAGE_EXEC;
551             }
552             /* add write permission on stores or if the page is already dirty,
553                so that we TLB miss on later writes to update the dirty bit */
554             if ((pte & PTE_W) &&
555                     (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
556                 *prot |= PAGE_WRITE;
557             }
558             return TRANSLATE_SUCCESS;
559         }
560     }
561     return TRANSLATE_FAIL;
562 }
563 
564 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
565                                 MMUAccessType access_type, bool pmp_violation,
566                                 bool first_stage, bool two_stage)
567 {
568     CPUState *cs = env_cpu(env);
569     int page_fault_exceptions;
570     if (first_stage) {
571         page_fault_exceptions =
572             get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
573             !pmp_violation;
574     } else {
575         page_fault_exceptions =
576             get_field(env->hgatp, HGATP_MODE) != VM_1_10_MBARE &&
577             !pmp_violation;
578     }
579     switch (access_type) {
580     case MMU_INST_FETCH:
581         if (riscv_cpu_virt_enabled(env) && !first_stage) {
582             cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
583         } else {
584             cs->exception_index = page_fault_exceptions ?
585                 RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
586         }
587         break;
588     case MMU_DATA_LOAD:
589         if (two_stage && !first_stage) {
590             cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
591         } else {
592             cs->exception_index = page_fault_exceptions ?
593                 RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
594         }
595         break;
596     case MMU_DATA_STORE:
597         if (two_stage && !first_stage) {
598             cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
599         } else {
600             cs->exception_index = page_fault_exceptions ?
601                 RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
602         }
603         break;
604     default:
605         g_assert_not_reached();
606     }
607     env->badaddr = address;
608 }
609 
610 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
611 {
612     RISCVCPU *cpu = RISCV_CPU(cs);
613     CPURISCVState *env = &cpu->env;
614     hwaddr phys_addr;
615     int prot;
616     int mmu_idx = cpu_mmu_index(&cpu->env, false);
617 
618     if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
619                              true, riscv_cpu_virt_enabled(env))) {
620         return -1;
621     }
622 
623     if (riscv_cpu_virt_enabled(env)) {
624         if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
625                                  0, mmu_idx, false, true)) {
626             return -1;
627         }
628     }
629 
630     return phys_addr & TARGET_PAGE_MASK;
631 }
632 
633 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
634                                      vaddr addr, unsigned size,
635                                      MMUAccessType access_type,
636                                      int mmu_idx, MemTxAttrs attrs,
637                                      MemTxResult response, uintptr_t retaddr)
638 {
639     RISCVCPU *cpu = RISCV_CPU(cs);
640     CPURISCVState *env = &cpu->env;
641 
642     if (access_type == MMU_DATA_STORE) {
643         cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
644     } else {
645         cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
646     }
647 
648     env->badaddr = addr;
649     riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
650 }
651 
652 void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
653                                    MMUAccessType access_type, int mmu_idx,
654                                    uintptr_t retaddr)
655 {
656     RISCVCPU *cpu = RISCV_CPU(cs);
657     CPURISCVState *env = &cpu->env;
658     switch (access_type) {
659     case MMU_INST_FETCH:
660         cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
661         break;
662     case MMU_DATA_LOAD:
663         cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
664         break;
665     case MMU_DATA_STORE:
666         cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
667         break;
668     default:
669         g_assert_not_reached();
670     }
671     env->badaddr = addr;
672     riscv_raise_exception(env, cs->exception_index, retaddr);
673 }
674 #endif /* !CONFIG_USER_ONLY */
675 
676 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
677                         MMUAccessType access_type, int mmu_idx,
678                         bool probe, uintptr_t retaddr)
679 {
680     RISCVCPU *cpu = RISCV_CPU(cs);
681     CPURISCVState *env = &cpu->env;
682 #ifndef CONFIG_USER_ONLY
683     vaddr im_address;
684     hwaddr pa = 0;
685     int prot, prot2;
686     bool pmp_violation = false;
687     bool first_stage_error = true;
688     bool two_stage_lookup = false;
689     int ret = TRANSLATE_FAIL;
690     int mode = mmu_idx;
691     target_ulong tlb_size = 0;
692 
693     env->guest_phys_fault_addr = 0;
694 
695     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
696                   __func__, address, access_type, mmu_idx);
697 
698     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
699         if (get_field(env->mstatus, MSTATUS_MPRV)) {
700             mode = get_field(env->mstatus, MSTATUS_MPP);
701         }
702     }
703 
704     if (riscv_has_ext(env, RVH) && env->priv == PRV_M &&
705         access_type != MMU_INST_FETCH &&
706         get_field(env->mstatus, MSTATUS_MPRV) &&
707         get_field(env->mstatus, MSTATUS_MPV)) {
708         two_stage_lookup = true;
709     }
710 
711     if (riscv_cpu_virt_enabled(env) ||
712         ((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
713          access_type != MMU_INST_FETCH)) {
714         /* Two stage lookup */
715         ret = get_physical_address(env, &pa, &prot, address,
716                                    &env->guest_phys_fault_addr, access_type,
717                                    mmu_idx, true, true);
718 
719         /*
720          * A G-stage exception may be triggered during two state lookup.
721          * And the env->guest_phys_fault_addr has already been set in
722          * get_physical_address().
723          */
724         if (ret == TRANSLATE_G_STAGE_FAIL) {
725             first_stage_error = false;
726             access_type = MMU_DATA_LOAD;
727         }
728 
729         qemu_log_mask(CPU_LOG_MMU,
730                       "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
731                       TARGET_FMT_plx " prot %d\n",
732                       __func__, address, ret, pa, prot);
733 
734         if (ret == TRANSLATE_SUCCESS) {
735             /* Second stage lookup */
736             im_address = pa;
737 
738             ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
739                                        access_type, mmu_idx, false, true);
740 
741             qemu_log_mask(CPU_LOG_MMU,
742                     "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
743                     TARGET_FMT_plx " prot %d\n",
744                     __func__, im_address, ret, pa, prot2);
745 
746             prot &= prot2;
747 
748             if (riscv_feature(env, RISCV_FEATURE_PMP) &&
749                 (ret == TRANSLATE_SUCCESS) &&
750                 !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
751                 ret = TRANSLATE_PMP_FAIL;
752             }
753 
754             if (ret != TRANSLATE_SUCCESS) {
755                 /*
756                  * Guest physical address translation failed, this is a HS
757                  * level exception
758                  */
759                 first_stage_error = false;
760                 env->guest_phys_fault_addr = (im_address |
761                                               (address &
762                                                (TARGET_PAGE_SIZE - 1))) >> 2;
763             }
764         }
765     } else {
766         /* Single stage lookup */
767         ret = get_physical_address(env, &pa, &prot, address, NULL,
768                                    access_type, mmu_idx, true, false);
769 
770         qemu_log_mask(CPU_LOG_MMU,
771                       "%s address=%" VADDR_PRIx " ret %d physical "
772                       TARGET_FMT_plx " prot %d\n",
773                       __func__, address, ret, pa, prot);
774     }
775 
776     if (riscv_feature(env, RISCV_FEATURE_PMP) &&
777         (ret == TRANSLATE_SUCCESS) &&
778         !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
779         ret = TRANSLATE_PMP_FAIL;
780     }
781     if (ret == TRANSLATE_PMP_FAIL) {
782         pmp_violation = true;
783     }
784 
785     if (ret == TRANSLATE_SUCCESS) {
786         if (pmp_is_range_in_tlb(env, pa & TARGET_PAGE_MASK, &tlb_size)) {
787             tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
788                          prot, mmu_idx, tlb_size);
789         } else {
790             tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
791                          prot, mmu_idx, TARGET_PAGE_SIZE);
792         }
793         return true;
794     } else if (probe) {
795         return false;
796     } else {
797         raise_mmu_exception(env, address, access_type, pmp_violation,
798                             first_stage_error,
799                             riscv_cpu_virt_enabled(env) ||
800                                 riscv_cpu_two_stage_lookup(mmu_idx));
801         riscv_raise_exception(env, cs->exception_index, retaddr);
802     }
803 
804     return true;
805 
806 #else
807     switch (access_type) {
808     case MMU_INST_FETCH:
809         cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
810         break;
811     case MMU_DATA_LOAD:
812         cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
813         break;
814     case MMU_DATA_STORE:
815         cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
816         break;
817     default:
818         g_assert_not_reached();
819     }
820     env->badaddr = address;
821     cpu_loop_exit_restore(cs, retaddr);
822 #endif
823 }
824 
825 /*
826  * Handle Traps
827  *
828  * Adapted from Spike's processor_t::take_trap.
829  *
830  */
831 void riscv_cpu_do_interrupt(CPUState *cs)
832 {
833 #if !defined(CONFIG_USER_ONLY)
834 
835     RISCVCPU *cpu = RISCV_CPU(cs);
836     CPURISCVState *env = &cpu->env;
837     bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
838     uint64_t s;
839 
840     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
841      * so we mask off the MSB and separate into trap type and cause.
842      */
843     bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
844     target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
845     target_ulong deleg = async ? env->mideleg : env->medeleg;
846     bool write_tval = false;
847     target_ulong tval = 0;
848     target_ulong htval = 0;
849     target_ulong mtval2 = 0;
850 
851     if  (cause == RISCV_EXCP_SEMIHOST) {
852         if (env->priv >= PRV_S) {
853             env->gpr[xA0] = do_common_semihosting(cs);
854             env->pc += 4;
855             return;
856         }
857         cause = RISCV_EXCP_BREAKPOINT;
858     }
859 
860     if (!async) {
861         /* set tval to badaddr for traps with address information */
862         switch (cause) {
863         case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
864         case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
865         case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
866             force_hs_execp = true;
867             /* fallthrough */
868         case RISCV_EXCP_INST_ADDR_MIS:
869         case RISCV_EXCP_INST_ACCESS_FAULT:
870         case RISCV_EXCP_LOAD_ADDR_MIS:
871         case RISCV_EXCP_STORE_AMO_ADDR_MIS:
872         case RISCV_EXCP_LOAD_ACCESS_FAULT:
873         case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
874         case RISCV_EXCP_INST_PAGE_FAULT:
875         case RISCV_EXCP_LOAD_PAGE_FAULT:
876         case RISCV_EXCP_STORE_PAGE_FAULT:
877             write_tval  = true;
878             tval = env->badaddr;
879             break;
880         default:
881             break;
882         }
883         /* ecall is dispatched as one cause so translate based on mode */
884         if (cause == RISCV_EXCP_U_ECALL) {
885             assert(env->priv <= 3);
886 
887             if (env->priv == PRV_M) {
888                 cause = RISCV_EXCP_M_ECALL;
889             } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
890                 cause = RISCV_EXCP_VS_ECALL;
891             } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
892                 cause = RISCV_EXCP_S_ECALL;
893             } else if (env->priv == PRV_U) {
894                 cause = RISCV_EXCP_U_ECALL;
895             }
896         }
897     }
898 
899     trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
900                      riscv_cpu_get_trap_name(cause, async));
901 
902     qemu_log_mask(CPU_LOG_INT,
903                   "%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
904                   "epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
905                   __func__, env->mhartid, async, cause, env->pc, tval,
906                   riscv_cpu_get_trap_name(cause, async));
907 
908     if (env->priv <= PRV_S &&
909             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
910         /* handle the trap in S-mode */
911         if (riscv_has_ext(env, RVH)) {
912             target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
913             bool two_stage_lookup = false;
914 
915             if (env->priv == PRV_M ||
916                 (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
917                 (env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
918                     get_field(env->hstatus, HSTATUS_HU))) {
919                     two_stage_lookup = true;
920             }
921 
922             if ((riscv_cpu_virt_enabled(env) || two_stage_lookup) && write_tval) {
923                 /*
924                  * If we are writing a guest virtual address to stval, set
925                  * this to 1. If we are trapping to VS we will set this to 0
926                  * later.
927                  */
928                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 1);
929             } else {
930                 /* For other HS-mode traps, we set this to 0. */
931                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
932             }
933 
934             if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
935                 !force_hs_execp) {
936                 /* Trap to VS mode */
937                 /*
938                  * See if we need to adjust cause. Yes if its VS mode interrupt
939                  * no if hypervisor has delegated one of hs mode's interrupt
940                  */
941                 if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
942                     cause == IRQ_VS_EXT) {
943                     cause = cause - 1;
944                 }
945                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
946             } else if (riscv_cpu_virt_enabled(env)) {
947                 /* Trap into HS mode, from virt */
948                 riscv_cpu_swap_hypervisor_regs(env);
949                 env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
950                                          env->priv);
951                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
952                                          riscv_cpu_virt_enabled(env));
953 
954                 htval = env->guest_phys_fault_addr;
955 
956                 riscv_cpu_set_virt_enabled(env, 0);
957                 riscv_cpu_set_force_hs_excep(env, 0);
958             } else {
959                 /* Trap into HS mode */
960                 if (!two_stage_lookup) {
961                     env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
962                                              riscv_cpu_virt_enabled(env));
963                 }
964                 htval = env->guest_phys_fault_addr;
965             }
966         }
967 
968         s = env->mstatus;
969         s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
970         s = set_field(s, MSTATUS_SPP, env->priv);
971         s = set_field(s, MSTATUS_SIE, 0);
972         env->mstatus = s;
973         env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
974         env->sepc = env->pc;
975         env->sbadaddr = tval;
976         env->htval = htval;
977         env->pc = (env->stvec >> 2 << 2) +
978             ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
979         riscv_cpu_set_mode(env, PRV_S);
980     } else {
981         /* handle the trap in M-mode */
982         if (riscv_has_ext(env, RVH)) {
983             if (riscv_cpu_virt_enabled(env)) {
984                 riscv_cpu_swap_hypervisor_regs(env);
985             }
986             env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
987                                      riscv_cpu_virt_enabled(env));
988             if (riscv_cpu_virt_enabled(env) && tval) {
989                 env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
990             }
991 
992             mtval2 = env->guest_phys_fault_addr;
993 
994             /* Trapping to M mode, virt is disabled */
995             riscv_cpu_set_virt_enabled(env, 0);
996             riscv_cpu_set_force_hs_excep(env, 0);
997         }
998 
999         s = env->mstatus;
1000         s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
1001         s = set_field(s, MSTATUS_MPP, env->priv);
1002         s = set_field(s, MSTATUS_MIE, 0);
1003         env->mstatus = s;
1004         env->mcause = cause | ~(((target_ulong)-1) >> async);
1005         env->mepc = env->pc;
1006         env->mbadaddr = tval;
1007         env->mtval2 = mtval2;
1008         env->pc = (env->mtvec >> 2 << 2) +
1009             ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
1010         riscv_cpu_set_mode(env, PRV_M);
1011     }
1012 
1013     /* NOTE: it is not necessary to yield load reservations here. It is only
1014      * necessary for an SC from "another hart" to cause a load reservation
1015      * to be yielded. Refer to the memory consistency model section of the
1016      * RISC-V ISA Specification.
1017      */
1018 
1019 #endif
1020     cs->exception_index = EXCP_NONE; /* mark handled to qemu */
1021 }
1022