xref: /openbmc/qemu/target/riscv/cpu_helper.c (revision 994b6bb2)
1 /*
2  * RISC-V CPU helpers for qemu.
3  *
4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
5  * Copyright (c) 2017-2018 SiFive, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/log.h"
22 #include "qemu/main-loop.h"
23 #include "cpu.h"
24 #include "exec/exec-all.h"
25 #include "tcg/tcg-op.h"
26 #include "trace.h"
27 #include "semihosting/common-semi.h"
28 
29 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
30 {
31 #ifdef CONFIG_USER_ONLY
32     return 0;
33 #else
34     return env->priv;
35 #endif
36 }
37 
38 #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 RISCV_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->stval;
140         env->stval = 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->stval;
163         env->stval = 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 /*
284  * get_physical_address_pmp - check PMP permission for this physical address
285  *
286  * Match the PMP region and check permission for this physical address and it's
287  * TLB page. Returns 0 if the permission checking was successful
288  *
289  * @env: CPURISCVState
290  * @prot: The returned protection attributes
291  * @tlb_size: TLB page size containing addr. It could be modified after PMP
292  *            permission checking. NULL if not set TLB page for addr.
293  * @addr: The physical address to be checked permission
294  * @access_type: The type of MMU access
295  * @mode: Indicates current privilege level.
296  */
297 static int get_physical_address_pmp(CPURISCVState *env, int *prot,
298                                     target_ulong *tlb_size, hwaddr addr,
299                                     int size, MMUAccessType access_type,
300                                     int mode)
301 {
302     pmp_priv_t pmp_priv;
303     target_ulong tlb_size_pmp = 0;
304 
305     if (!riscv_feature(env, RISCV_FEATURE_PMP)) {
306         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
307         return TRANSLATE_SUCCESS;
308     }
309 
310     if (!pmp_hart_has_privs(env, addr, size, 1 << access_type, &pmp_priv,
311                             mode)) {
312         *prot = 0;
313         return TRANSLATE_PMP_FAIL;
314     }
315 
316     *prot = pmp_priv_to_page_prot(pmp_priv);
317     if (tlb_size != NULL) {
318         if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1), &tlb_size_pmp)) {
319             *tlb_size = tlb_size_pmp;
320         }
321     }
322 
323     return TRANSLATE_SUCCESS;
324 }
325 
326 /* get_physical_address - get the physical address for this virtual address
327  *
328  * Do a page table walk to obtain the physical address corresponding to a
329  * virtual address. Returns 0 if the translation was successful
330  *
331  * Adapted from Spike's mmu_t::translate and mmu_t::walk
332  *
333  * @env: CPURISCVState
334  * @physical: This will be set to the calculated physical address
335  * @prot: The returned protection attributes
336  * @addr: The virtual address to be translated
337  * @fault_pte_addr: If not NULL, this will be set to fault pte address
338  *                  when a error occurs on pte address translation.
339  *                  This will already be shifted to match htval.
340  * @access_type: The type of MMU access
341  * @mmu_idx: Indicates current privilege level
342  * @first_stage: Are we in first stage translation?
343  *               Second stage is used for hypervisor guest translation
344  * @two_stage: Are we going to perform two stage translation
345  * @is_debug: Is this access from a debugger or the monitor?
346  */
347 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
348                                 int *prot, target_ulong addr,
349                                 target_ulong *fault_pte_addr,
350                                 int access_type, int mmu_idx,
351                                 bool first_stage, bool two_stage,
352                                 bool is_debug)
353 {
354     /* NOTE: the env->pc value visible here will not be
355      * correct, but the value visible to the exception handler
356      * (riscv_cpu_do_interrupt) is correct */
357     MemTxResult res;
358     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
359     int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
360     bool use_background = false;
361 
362     /*
363      * Check if we should use the background registers for the two
364      * stage translation. We don't need to check if we actually need
365      * two stage translation as that happened before this function
366      * was called. Background registers will be used if the guest has
367      * forced a two stage translation to be on (in HS or M mode).
368      */
369     if (!riscv_cpu_virt_enabled(env) && two_stage) {
370         use_background = true;
371     }
372 
373     /* MPRV does not affect the virtual-machine load/store
374        instructions, HLV, HLVX, and HSV. */
375     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
376         mode = get_field(env->hstatus, HSTATUS_SPVP);
377     } else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
378         if (get_field(env->mstatus, MSTATUS_MPRV)) {
379             mode = get_field(env->mstatus, MSTATUS_MPP);
380         }
381     }
382 
383     if (first_stage == false) {
384         /* We are in stage 2 translation, this is similar to stage 1. */
385         /* Stage 2 is always taken as U-mode */
386         mode = PRV_U;
387     }
388 
389     if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
390         *physical = addr;
391         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
392         return TRANSLATE_SUCCESS;
393     }
394 
395     *prot = 0;
396 
397     hwaddr base;
398     int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
399 
400     if (first_stage == true) {
401         mxr = get_field(env->mstatus, MSTATUS_MXR);
402     } else {
403         mxr = get_field(env->vsstatus, MSTATUS_MXR);
404     }
405 
406     if (first_stage == true) {
407         if (use_background) {
408             base = (hwaddr)get_field(env->vsatp, SATP_PPN) << PGSHIFT;
409             vm = get_field(env->vsatp, SATP_MODE);
410         } else {
411             base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
412             vm = get_field(env->satp, SATP_MODE);
413         }
414         widened = 0;
415     } else {
416         if (riscv_cpu_is_32bit(env)) {
417             base = (hwaddr)get_field(env->hgatp, SATP32_PPN) << PGSHIFT;
418             vm = get_field(env->hgatp, SATP32_MODE);
419         } else {
420             base = (hwaddr)get_field(env->hgatp, SATP64_PPN) << PGSHIFT;
421             vm = get_field(env->hgatp, SATP64_MODE);
422         }
423         widened = 2;
424     }
425     /* status.SUM will be ignored if execute on background */
426     sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
427     switch (vm) {
428     case VM_1_10_SV32:
429       levels = 2; ptidxbits = 10; ptesize = 4; break;
430     case VM_1_10_SV39:
431       levels = 3; ptidxbits = 9; ptesize = 8; break;
432     case VM_1_10_SV48:
433       levels = 4; ptidxbits = 9; ptesize = 8; break;
434     case VM_1_10_SV57:
435       levels = 5; ptidxbits = 9; ptesize = 8; break;
436     case VM_1_10_MBARE:
437         *physical = addr;
438         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
439         return TRANSLATE_SUCCESS;
440     default:
441       g_assert_not_reached();
442     }
443 
444     CPUState *cs = env_cpu(env);
445     int va_bits = PGSHIFT + levels * ptidxbits + widened;
446     target_ulong mask, masked_msbs;
447 
448     if (TARGET_LONG_BITS > (va_bits - 1)) {
449         mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
450     } else {
451         mask = 0;
452     }
453     masked_msbs = (addr >> (va_bits - 1)) & mask;
454 
455     if (masked_msbs != 0 && masked_msbs != mask) {
456         return TRANSLATE_FAIL;
457     }
458 
459     int ptshift = (levels - 1) * ptidxbits;
460     int i;
461 
462 #if !TCG_OVERSIZED_GUEST
463 restart:
464 #endif
465     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
466         target_ulong idx;
467         if (i == 0) {
468             idx = (addr >> (PGSHIFT + ptshift)) &
469                            ((1 << (ptidxbits + widened)) - 1);
470         } else {
471             idx = (addr >> (PGSHIFT + ptshift)) &
472                            ((1 << ptidxbits) - 1);
473         }
474 
475         /* check that physical address of PTE is legal */
476         hwaddr pte_addr;
477 
478         if (two_stage && first_stage) {
479             int vbase_prot;
480             hwaddr vbase;
481 
482             /* Do the second stage translation on the base PTE address. */
483             int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
484                                                  base, NULL, MMU_DATA_LOAD,
485                                                  mmu_idx, false, true,
486                                                  is_debug);
487 
488             if (vbase_ret != TRANSLATE_SUCCESS) {
489                 if (fault_pte_addr) {
490                     *fault_pte_addr = (base + idx * ptesize) >> 2;
491                 }
492                 return TRANSLATE_G_STAGE_FAIL;
493             }
494 
495             pte_addr = vbase + idx * ptesize;
496         } else {
497             pte_addr = base + idx * ptesize;
498         }
499 
500         int pmp_prot;
501         int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
502                                                sizeof(target_ulong),
503                                                MMU_DATA_LOAD, PRV_S);
504         if (pmp_ret != TRANSLATE_SUCCESS) {
505             return TRANSLATE_PMP_FAIL;
506         }
507 
508         target_ulong pte;
509         if (riscv_cpu_is_32bit(env)) {
510             pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
511         } else {
512             pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
513         }
514 
515         if (res != MEMTX_OK) {
516             return TRANSLATE_FAIL;
517         }
518 
519         hwaddr ppn = pte >> PTE_PPN_SHIFT;
520 
521         if (!(pte & PTE_V)) {
522             /* Invalid PTE */
523             return TRANSLATE_FAIL;
524         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
525             /* Inner PTE, continue walking */
526             base = ppn << PGSHIFT;
527         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
528             /* Reserved leaf PTE flags: PTE_W */
529             return TRANSLATE_FAIL;
530         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
531             /* Reserved leaf PTE flags: PTE_W + PTE_X */
532             return TRANSLATE_FAIL;
533         } else if ((pte & PTE_U) && ((mode != PRV_U) &&
534                    (!sum || access_type == MMU_INST_FETCH))) {
535             /* User PTE flags when not U mode and mstatus.SUM is not set,
536                or the access type is an instruction fetch */
537             return TRANSLATE_FAIL;
538         } else if (!(pte & PTE_U) && (mode != PRV_S)) {
539             /* Supervisor PTE flags when not S mode */
540             return TRANSLATE_FAIL;
541         } else if (ppn & ((1ULL << ptshift) - 1)) {
542             /* Misaligned PPN */
543             return TRANSLATE_FAIL;
544         } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
545                    ((pte & PTE_X) && mxr))) {
546             /* Read access check failed */
547             return TRANSLATE_FAIL;
548         } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
549             /* Write access check failed */
550             return TRANSLATE_FAIL;
551         } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
552             /* Fetch access check failed */
553             return TRANSLATE_FAIL;
554         } else {
555             /* if necessary, set accessed and dirty bits. */
556             target_ulong updated_pte = pte | PTE_A |
557                 (access_type == MMU_DATA_STORE ? PTE_D : 0);
558 
559             /* Page table updates need to be atomic with MTTCG enabled */
560             if (updated_pte != pte) {
561                 /*
562                  * - if accessed or dirty bits need updating, and the PTE is
563                  *   in RAM, then we do so atomically with a compare and swap.
564                  * - if the PTE is in IO space or ROM, then it can't be updated
565                  *   and we return TRANSLATE_FAIL.
566                  * - if the PTE changed by the time we went to update it, then
567                  *   it is no longer valid and we must re-walk the page table.
568                  */
569                 MemoryRegion *mr;
570                 hwaddr l = sizeof(target_ulong), addr1;
571                 mr = address_space_translate(cs->as, pte_addr,
572                     &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
573                 if (memory_region_is_ram(mr)) {
574                     target_ulong *pte_pa =
575                         qemu_map_ram_ptr(mr->ram_block, addr1);
576 #if TCG_OVERSIZED_GUEST
577                     /* MTTCG is not enabled on oversized TCG guests so
578                      * page table updates do not need to be atomic */
579                     *pte_pa = pte = updated_pte;
580 #else
581                     target_ulong old_pte =
582                         qatomic_cmpxchg(pte_pa, pte, updated_pte);
583                     if (old_pte != pte) {
584                         goto restart;
585                     } else {
586                         pte = updated_pte;
587                     }
588 #endif
589                 } else {
590                     /* misconfigured PTE in ROM (AD bits are not preset) or
591                      * PTE is in IO space and can't be updated atomically */
592                     return TRANSLATE_FAIL;
593                 }
594             }
595 
596             /* for superpage mappings, make a fake leaf PTE for the TLB's
597                benefit. */
598             target_ulong vpn = addr >> PGSHIFT;
599             *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
600                         (addr & ~TARGET_PAGE_MASK);
601 
602             /* set permissions on the TLB entry */
603             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
604                 *prot |= PAGE_READ;
605             }
606             if ((pte & PTE_X)) {
607                 *prot |= PAGE_EXEC;
608             }
609             /* add write permission on stores or if the page is already dirty,
610                so that we TLB miss on later writes to update the dirty bit */
611             if ((pte & PTE_W) &&
612                     (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
613                 *prot |= PAGE_WRITE;
614             }
615             return TRANSLATE_SUCCESS;
616         }
617     }
618     return TRANSLATE_FAIL;
619 }
620 
621 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
622                                 MMUAccessType access_type, bool pmp_violation,
623                                 bool first_stage, bool two_stage)
624 {
625     CPUState *cs = env_cpu(env);
626     int page_fault_exceptions, vm;
627 
628     if (first_stage) {
629         vm = get_field(env->satp, SATP_MODE);
630     } else if (riscv_cpu_is_32bit(env)) {
631         vm = get_field(env->hgatp, SATP32_MODE);
632     } else {
633         vm = get_field(env->hgatp, SATP64_MODE);
634     }
635     page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
636 
637     switch (access_type) {
638     case MMU_INST_FETCH:
639         if (riscv_cpu_virt_enabled(env) && !first_stage) {
640             cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
641         } else {
642             cs->exception_index = page_fault_exceptions ?
643                 RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
644         }
645         break;
646     case MMU_DATA_LOAD:
647         if (two_stage && !first_stage) {
648             cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
649         } else {
650             cs->exception_index = page_fault_exceptions ?
651                 RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
652         }
653         break;
654     case MMU_DATA_STORE:
655         if (two_stage && !first_stage) {
656             cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
657         } else {
658             cs->exception_index = page_fault_exceptions ?
659                 RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
660         }
661         break;
662     default:
663         g_assert_not_reached();
664     }
665     env->badaddr = address;
666     env->two_stage_lookup = two_stage;
667 }
668 
669 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
670 {
671     RISCVCPU *cpu = RISCV_CPU(cs);
672     CPURISCVState *env = &cpu->env;
673     hwaddr phys_addr;
674     int prot;
675     int mmu_idx = cpu_mmu_index(&cpu->env, false);
676 
677     if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
678                              true, riscv_cpu_virt_enabled(env), true)) {
679         return -1;
680     }
681 
682     if (riscv_cpu_virt_enabled(env)) {
683         if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
684                                  0, mmu_idx, false, true, true)) {
685             return -1;
686         }
687     }
688 
689     return phys_addr & TARGET_PAGE_MASK;
690 }
691 
692 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
693                                      vaddr addr, unsigned size,
694                                      MMUAccessType access_type,
695                                      int mmu_idx, MemTxAttrs attrs,
696                                      MemTxResult response, uintptr_t retaddr)
697 {
698     RISCVCPU *cpu = RISCV_CPU(cs);
699     CPURISCVState *env = &cpu->env;
700 
701     if (access_type == MMU_DATA_STORE) {
702         cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
703     } else if (access_type == MMU_DATA_LOAD) {
704         cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
705     } else {
706         cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT;
707     }
708 
709     env->badaddr = addr;
710     env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
711                             riscv_cpu_two_stage_lookup(mmu_idx);
712     riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
713 }
714 
715 void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
716                                    MMUAccessType access_type, int mmu_idx,
717                                    uintptr_t retaddr)
718 {
719     RISCVCPU *cpu = RISCV_CPU(cs);
720     CPURISCVState *env = &cpu->env;
721     switch (access_type) {
722     case MMU_INST_FETCH:
723         cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
724         break;
725     case MMU_DATA_LOAD:
726         cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
727         break;
728     case MMU_DATA_STORE:
729         cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
730         break;
731     default:
732         g_assert_not_reached();
733     }
734     env->badaddr = addr;
735     env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
736                             riscv_cpu_two_stage_lookup(mmu_idx);
737     riscv_raise_exception(env, cs->exception_index, retaddr);
738 }
739 #endif /* !CONFIG_USER_ONLY */
740 
741 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
742                         MMUAccessType access_type, int mmu_idx,
743                         bool probe, uintptr_t retaddr)
744 {
745     RISCVCPU *cpu = RISCV_CPU(cs);
746     CPURISCVState *env = &cpu->env;
747 #ifndef CONFIG_USER_ONLY
748     vaddr im_address;
749     hwaddr pa = 0;
750     int prot, prot2, prot_pmp;
751     bool pmp_violation = false;
752     bool first_stage_error = true;
753     bool two_stage_lookup = false;
754     int ret = TRANSLATE_FAIL;
755     int mode = mmu_idx;
756     /* default TLB page size */
757     target_ulong tlb_size = TARGET_PAGE_SIZE;
758 
759     env->guest_phys_fault_addr = 0;
760 
761     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
762                   __func__, address, access_type, mmu_idx);
763 
764     /* MPRV does not affect the virtual-machine load/store
765        instructions, HLV, HLVX, and HSV. */
766     if (riscv_cpu_two_stage_lookup(mmu_idx)) {
767         mode = get_field(env->hstatus, HSTATUS_SPVP);
768     } else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
769                get_field(env->mstatus, MSTATUS_MPRV)) {
770         mode = get_field(env->mstatus, MSTATUS_MPP);
771         if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
772             two_stage_lookup = true;
773         }
774     }
775 
776     if (riscv_cpu_virt_enabled(env) ||
777         ((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
778          access_type != MMU_INST_FETCH)) {
779         /* Two stage lookup */
780         ret = get_physical_address(env, &pa, &prot, address,
781                                    &env->guest_phys_fault_addr, access_type,
782                                    mmu_idx, true, true, false);
783 
784         /*
785          * A G-stage exception may be triggered during two state lookup.
786          * And the env->guest_phys_fault_addr has already been set in
787          * get_physical_address().
788          */
789         if (ret == TRANSLATE_G_STAGE_FAIL) {
790             first_stage_error = false;
791             access_type = MMU_DATA_LOAD;
792         }
793 
794         qemu_log_mask(CPU_LOG_MMU,
795                       "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
796                       TARGET_FMT_plx " prot %d\n",
797                       __func__, address, ret, pa, prot);
798 
799         if (ret == TRANSLATE_SUCCESS) {
800             /* Second stage lookup */
801             im_address = pa;
802 
803             ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
804                                        access_type, mmu_idx, false, true,
805                                        false);
806 
807             qemu_log_mask(CPU_LOG_MMU,
808                     "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
809                     TARGET_FMT_plx " prot %d\n",
810                     __func__, im_address, ret, pa, prot2);
811 
812             prot &= prot2;
813 
814             if (ret == TRANSLATE_SUCCESS) {
815                 ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
816                                                size, access_type, mode);
817 
818                 qemu_log_mask(CPU_LOG_MMU,
819                               "%s PMP address=" TARGET_FMT_plx " ret %d prot"
820                               " %d tlb_size " TARGET_FMT_lu "\n",
821                               __func__, pa, ret, prot_pmp, tlb_size);
822 
823                 prot &= prot_pmp;
824             }
825 
826             if (ret != TRANSLATE_SUCCESS) {
827                 /*
828                  * Guest physical address translation failed, this is a HS
829                  * level exception
830                  */
831                 first_stage_error = false;
832                 env->guest_phys_fault_addr = (im_address |
833                                               (address &
834                                                (TARGET_PAGE_SIZE - 1))) >> 2;
835             }
836         }
837     } else {
838         /* Single stage lookup */
839         ret = get_physical_address(env, &pa, &prot, address, NULL,
840                                    access_type, mmu_idx, true, false, false);
841 
842         qemu_log_mask(CPU_LOG_MMU,
843                       "%s address=%" VADDR_PRIx " ret %d physical "
844                       TARGET_FMT_plx " prot %d\n",
845                       __func__, address, ret, pa, prot);
846 
847         if (ret == TRANSLATE_SUCCESS) {
848             ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
849                                            size, access_type, mode);
850 
851             qemu_log_mask(CPU_LOG_MMU,
852                           "%s PMP address=" TARGET_FMT_plx " ret %d prot"
853                           " %d tlb_size " TARGET_FMT_lu "\n",
854                           __func__, pa, ret, prot_pmp, tlb_size);
855 
856             prot &= prot_pmp;
857         }
858     }
859 
860     if (ret == TRANSLATE_PMP_FAIL) {
861         pmp_violation = true;
862     }
863 
864     if (ret == TRANSLATE_SUCCESS) {
865         tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
866                      prot, mmu_idx, tlb_size);
867         return true;
868     } else if (probe) {
869         return false;
870     } else {
871         raise_mmu_exception(env, address, access_type, pmp_violation,
872                             first_stage_error,
873                             riscv_cpu_virt_enabled(env) ||
874                                 riscv_cpu_two_stage_lookup(mmu_idx));
875         riscv_raise_exception(env, cs->exception_index, retaddr);
876     }
877 
878     return true;
879 
880 #else
881     switch (access_type) {
882     case MMU_INST_FETCH:
883         cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
884         break;
885     case MMU_DATA_LOAD:
886         cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
887         break;
888     case MMU_DATA_STORE:
889         cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
890         break;
891     default:
892         g_assert_not_reached();
893     }
894     env->badaddr = address;
895     cpu_loop_exit_restore(cs, retaddr);
896 #endif
897 }
898 
899 /*
900  * Handle Traps
901  *
902  * Adapted from Spike's processor_t::take_trap.
903  *
904  */
905 void riscv_cpu_do_interrupt(CPUState *cs)
906 {
907 #if !defined(CONFIG_USER_ONLY)
908 
909     RISCVCPU *cpu = RISCV_CPU(cs);
910     CPURISCVState *env = &cpu->env;
911     bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
912     uint64_t s;
913 
914     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
915      * so we mask off the MSB and separate into trap type and cause.
916      */
917     bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
918     target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
919     target_ulong deleg = async ? env->mideleg : env->medeleg;
920     bool write_tval = false;
921     target_ulong tval = 0;
922     target_ulong htval = 0;
923     target_ulong mtval2 = 0;
924 
925     if  (cause == RISCV_EXCP_SEMIHOST) {
926         if (env->priv >= PRV_S) {
927             env->gpr[xA0] = do_common_semihosting(cs);
928             env->pc += 4;
929             return;
930         }
931         cause = RISCV_EXCP_BREAKPOINT;
932     }
933 
934     if (!async) {
935         /* set tval to badaddr for traps with address information */
936         switch (cause) {
937         case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
938         case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
939         case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
940             force_hs_execp = true;
941             /* fallthrough */
942         case RISCV_EXCP_INST_ADDR_MIS:
943         case RISCV_EXCP_INST_ACCESS_FAULT:
944         case RISCV_EXCP_LOAD_ADDR_MIS:
945         case RISCV_EXCP_STORE_AMO_ADDR_MIS:
946         case RISCV_EXCP_LOAD_ACCESS_FAULT:
947         case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
948         case RISCV_EXCP_INST_PAGE_FAULT:
949         case RISCV_EXCP_LOAD_PAGE_FAULT:
950         case RISCV_EXCP_STORE_PAGE_FAULT:
951             write_tval  = true;
952             tval = env->badaddr;
953             break;
954         default:
955             break;
956         }
957         /* ecall is dispatched as one cause so translate based on mode */
958         if (cause == RISCV_EXCP_U_ECALL) {
959             assert(env->priv <= 3);
960 
961             if (env->priv == PRV_M) {
962                 cause = RISCV_EXCP_M_ECALL;
963             } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
964                 cause = RISCV_EXCP_VS_ECALL;
965             } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
966                 cause = RISCV_EXCP_S_ECALL;
967             } else if (env->priv == PRV_U) {
968                 cause = RISCV_EXCP_U_ECALL;
969             }
970         }
971     }
972 
973     trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
974                      riscv_cpu_get_trap_name(cause, async));
975 
976     qemu_log_mask(CPU_LOG_INT,
977                   "%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
978                   "epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
979                   __func__, env->mhartid, async, cause, env->pc, tval,
980                   riscv_cpu_get_trap_name(cause, async));
981 
982     if (env->priv <= PRV_S &&
983             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
984         /* handle the trap in S-mode */
985         if (riscv_has_ext(env, RVH)) {
986             target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
987 
988             if (env->two_stage_lookup && write_tval) {
989                 /*
990                  * If we are writing a guest virtual address to stval, set
991                  * this to 1. If we are trapping to VS we will set this to 0
992                  * later.
993                  */
994                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 1);
995             } else {
996                 /* For other HS-mode traps, we set this to 0. */
997                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
998             }
999 
1000             if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
1001                 !force_hs_execp) {
1002                 /* Trap to VS mode */
1003                 /*
1004                  * See if we need to adjust cause. Yes if its VS mode interrupt
1005                  * no if hypervisor has delegated one of hs mode's interrupt
1006                  */
1007                 if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
1008                     cause == IRQ_VS_EXT) {
1009                     cause = cause - 1;
1010                 }
1011                 env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
1012             } else if (riscv_cpu_virt_enabled(env)) {
1013                 /* Trap into HS mode, from virt */
1014                 riscv_cpu_swap_hypervisor_regs(env);
1015                 env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
1016                                          env->priv);
1017                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
1018                                          riscv_cpu_virt_enabled(env));
1019 
1020                 htval = env->guest_phys_fault_addr;
1021 
1022                 riscv_cpu_set_virt_enabled(env, 0);
1023                 riscv_cpu_set_force_hs_excep(env, 0);
1024             } else {
1025                 /* Trap into HS mode */
1026                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
1027                 htval = env->guest_phys_fault_addr;
1028             }
1029         }
1030 
1031         s = env->mstatus;
1032         s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
1033         s = set_field(s, MSTATUS_SPP, env->priv);
1034         s = set_field(s, MSTATUS_SIE, 0);
1035         env->mstatus = s;
1036         env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
1037         env->sepc = env->pc;
1038         env->stval = tval;
1039         env->htval = htval;
1040         env->pc = (env->stvec >> 2 << 2) +
1041             ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
1042         riscv_cpu_set_mode(env, PRV_S);
1043     } else {
1044         /* handle the trap in M-mode */
1045         if (riscv_has_ext(env, RVH)) {
1046             if (riscv_cpu_virt_enabled(env)) {
1047                 riscv_cpu_swap_hypervisor_regs(env);
1048             }
1049             env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
1050                                      riscv_cpu_virt_enabled(env));
1051             if (riscv_cpu_virt_enabled(env) && tval) {
1052                 env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
1053             }
1054 
1055             mtval2 = env->guest_phys_fault_addr;
1056 
1057             /* Trapping to M mode, virt is disabled */
1058             riscv_cpu_set_virt_enabled(env, 0);
1059             riscv_cpu_set_force_hs_excep(env, 0);
1060         }
1061 
1062         s = env->mstatus;
1063         s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
1064         s = set_field(s, MSTATUS_MPP, env->priv);
1065         s = set_field(s, MSTATUS_MIE, 0);
1066         env->mstatus = s;
1067         env->mcause = cause | ~(((target_ulong)-1) >> async);
1068         env->mepc = env->pc;
1069         env->mtval = tval;
1070         env->mtval2 = mtval2;
1071         env->pc = (env->mtvec >> 2 << 2) +
1072             ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
1073         riscv_cpu_set_mode(env, PRV_M);
1074     }
1075 
1076     /* NOTE: it is not necessary to yield load reservations here. It is only
1077      * necessary for an SC from "another hart" to cause a load reservation
1078      * to be yielded. Refer to the memory consistency model section of the
1079      * RISC-V ISA Specification.
1080      */
1081 
1082     env->two_stage_lookup = false;
1083 #endif
1084     cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
1085 }
1086