cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

cpu_helper.c (38058B)


      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
     29int 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
     39static 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
     79bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
     80{
     81    if (interrupt_request & CPU_INTERRUPT_HARD) {
     82        RISCVCPU *cpu = RISCV_CPU(cs);
     83        CPURISCVState *env = &cpu->env;
     84        int interruptno = riscv_cpu_local_irq_pending(env);
     85        if (interruptno >= 0) {
     86            cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
     87            riscv_cpu_do_interrupt(cs);
     88            return true;
     89        }
     90    }
     91    return false;
     92}
     93
     94/* Return true is floating point support is currently enabled */
     95bool riscv_cpu_fp_enabled(CPURISCVState *env)
     96{
     97    if (env->mstatus & MSTATUS_FS) {
     98        if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
     99            return false;
    100        }
    101        return true;
    102    }
    103
    104    return false;
    105}
    106
    107void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
    108{
    109    uint64_t sd = riscv_cpu_is_32bit(env) ? MSTATUS32_SD : MSTATUS64_SD;
    110    uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
    111                            MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
    112                            MSTATUS64_UXL | sd;
    113    bool current_virt = riscv_cpu_virt_enabled(env);
    114
    115    g_assert(riscv_has_ext(env, RVH));
    116
    117    if (current_virt) {
    118        /* Current V=1 and we are about to change to V=0 */
    119        env->vsstatus = env->mstatus & mstatus_mask;
    120        env->mstatus &= ~mstatus_mask;
    121        env->mstatus |= env->mstatus_hs;
    122
    123        env->vstvec = env->stvec;
    124        env->stvec = env->stvec_hs;
    125
    126        env->vsscratch = env->sscratch;
    127        env->sscratch = env->sscratch_hs;
    128
    129        env->vsepc = env->sepc;
    130        env->sepc = env->sepc_hs;
    131
    132        env->vscause = env->scause;
    133        env->scause = env->scause_hs;
    134
    135        env->vstval = env->stval;
    136        env->stval = env->stval_hs;
    137
    138        env->vsatp = env->satp;
    139        env->satp = env->satp_hs;
    140    } else {
    141        /* Current V=0 and we are about to change to V=1 */
    142        env->mstatus_hs = env->mstatus & mstatus_mask;
    143        env->mstatus &= ~mstatus_mask;
    144        env->mstatus |= env->vsstatus;
    145
    146        env->stvec_hs = env->stvec;
    147        env->stvec = env->vstvec;
    148
    149        env->sscratch_hs = env->sscratch;
    150        env->sscratch = env->vsscratch;
    151
    152        env->sepc_hs = env->sepc;
    153        env->sepc = env->vsepc;
    154
    155        env->scause_hs = env->scause;
    156        env->scause = env->vscause;
    157
    158        env->stval_hs = env->stval;
    159        env->stval = env->vstval;
    160
    161        env->satp_hs = env->satp;
    162        env->satp = env->vsatp;
    163    }
    164}
    165
    166bool riscv_cpu_virt_enabled(CPURISCVState *env)
    167{
    168    if (!riscv_has_ext(env, RVH)) {
    169        return false;
    170    }
    171
    172    return get_field(env->virt, VIRT_ONOFF);
    173}
    174
    175void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
    176{
    177    if (!riscv_has_ext(env, RVH)) {
    178        return;
    179    }
    180
    181    /* Flush the TLB on all virt mode changes. */
    182    if (get_field(env->virt, VIRT_ONOFF) != enable) {
    183        tlb_flush(env_cpu(env));
    184    }
    185
    186    env->virt = set_field(env->virt, VIRT_ONOFF, enable);
    187}
    188
    189bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
    190{
    191    if (!riscv_has_ext(env, RVH)) {
    192        return false;
    193    }
    194
    195    return get_field(env->virt, FORCE_HS_EXCEP);
    196}
    197
    198void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
    199{
    200    if (!riscv_has_ext(env, RVH)) {
    201        return;
    202    }
    203
    204    env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
    205}
    206
    207bool riscv_cpu_two_stage_lookup(int mmu_idx)
    208{
    209    return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
    210}
    211
    212int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
    213{
    214    CPURISCVState *env = &cpu->env;
    215    if (env->miclaim & interrupts) {
    216        return -1;
    217    } else {
    218        env->miclaim |= interrupts;
    219        return 0;
    220    }
    221}
    222
    223uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
    224{
    225    CPURISCVState *env = &cpu->env;
    226    CPUState *cs = CPU(cpu);
    227    uint32_t old = env->mip;
    228    bool locked = false;
    229
    230    if (!qemu_mutex_iothread_locked()) {
    231        locked = true;
    232        qemu_mutex_lock_iothread();
    233    }
    234
    235    env->mip = (env->mip & ~mask) | (value & mask);
    236
    237    if (env->mip) {
    238        cpu_interrupt(cs, CPU_INTERRUPT_HARD);
    239    } else {
    240        cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
    241    }
    242
    243    if (locked) {
    244        qemu_mutex_unlock_iothread();
    245    }
    246
    247    return old;
    248}
    249
    250void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
    251                             uint32_t arg)
    252{
    253    env->rdtime_fn = fn;
    254    env->rdtime_fn_arg = arg;
    255}
    256
    257void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
    258{
    259    if (newpriv > PRV_M) {
    260        g_assert_not_reached();
    261    }
    262    if (newpriv == PRV_H) {
    263        newpriv = PRV_U;
    264    }
    265    /* tlb_flush is unnecessary as mode is contained in mmu_idx */
    266    env->priv = newpriv;
    267
    268    /*
    269     * Clear the load reservation - otherwise a reservation placed in one
    270     * context/process can be used by another, resulting in an SC succeeding
    271     * incorrectly. Version 2.2 of the ISA specification explicitly requires
    272     * this behaviour, while later revisions say that the kernel "should" use
    273     * an SC instruction to force the yielding of a load reservation on a
    274     * preemptive context switch. As a result, do both.
    275     */
    276    env->load_res = -1;
    277}
    278
    279/*
    280 * get_physical_address_pmp - check PMP permission for this physical address
    281 *
    282 * Match the PMP region and check permission for this physical address and it's
    283 * TLB page. Returns 0 if the permission checking was successful
    284 *
    285 * @env: CPURISCVState
    286 * @prot: The returned protection attributes
    287 * @tlb_size: TLB page size containing addr. It could be modified after PMP
    288 *            permission checking. NULL if not set TLB page for addr.
    289 * @addr: The physical address to be checked permission
    290 * @access_type: The type of MMU access
    291 * @mode: Indicates current privilege level.
    292 */
    293static int get_physical_address_pmp(CPURISCVState *env, int *prot,
    294                                    target_ulong *tlb_size, hwaddr addr,
    295                                    int size, MMUAccessType access_type,
    296                                    int mode)
    297{
    298    pmp_priv_t pmp_priv;
    299    target_ulong tlb_size_pmp = 0;
    300
    301    if (!riscv_feature(env, RISCV_FEATURE_PMP)) {
    302        *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
    303        return TRANSLATE_SUCCESS;
    304    }
    305
    306    if (!pmp_hart_has_privs(env, addr, size, 1 << access_type, &pmp_priv,
    307                            mode)) {
    308        *prot = 0;
    309        return TRANSLATE_PMP_FAIL;
    310    }
    311
    312    *prot = pmp_priv_to_page_prot(pmp_priv);
    313    if (tlb_size != NULL) {
    314        if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1), &tlb_size_pmp)) {
    315            *tlb_size = tlb_size_pmp;
    316        }
    317    }
    318
    319    return TRANSLATE_SUCCESS;
    320}
    321
    322/* get_physical_address - get the physical address for this virtual address
    323 *
    324 * Do a page table walk to obtain the physical address corresponding to a
    325 * virtual address. Returns 0 if the translation was successful
    326 *
    327 * Adapted from Spike's mmu_t::translate and mmu_t::walk
    328 *
    329 * @env: CPURISCVState
    330 * @physical: This will be set to the calculated physical address
    331 * @prot: The returned protection attributes
    332 * @addr: The virtual address to be translated
    333 * @fault_pte_addr: If not NULL, this will be set to fault pte address
    334 *                  when a error occurs on pte address translation.
    335 *                  This will already be shifted to match htval.
    336 * @access_type: The type of MMU access
    337 * @mmu_idx: Indicates current privilege level
    338 * @first_stage: Are we in first stage translation?
    339 *               Second stage is used for hypervisor guest translation
    340 * @two_stage: Are we going to perform two stage translation
    341 * @is_debug: Is this access from a debugger or the monitor?
    342 */
    343static int get_physical_address(CPURISCVState *env, hwaddr *physical,
    344                                int *prot, target_ulong addr,
    345                                target_ulong *fault_pte_addr,
    346                                int access_type, int mmu_idx,
    347                                bool first_stage, bool two_stage,
    348                                bool is_debug)
    349{
    350    /* NOTE: the env->pc value visible here will not be
    351     * correct, but the value visible to the exception handler
    352     * (riscv_cpu_do_interrupt) is correct */
    353    MemTxResult res;
    354    MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
    355    int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
    356    bool use_background = false;
    357
    358    /*
    359     * Check if we should use the background registers for the two
    360     * stage translation. We don't need to check if we actually need
    361     * two stage translation as that happened before this function
    362     * was called. Background registers will be used if the guest has
    363     * forced a two stage translation to be on (in HS or M mode).
    364     */
    365    if (!riscv_cpu_virt_enabled(env) && two_stage) {
    366        use_background = true;
    367    }
    368
    369    /* MPRV does not affect the virtual-machine load/store
    370       instructions, HLV, HLVX, and HSV. */
    371    if (riscv_cpu_two_stage_lookup(mmu_idx)) {
    372        mode = get_field(env->hstatus, HSTATUS_SPVP);
    373    } else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
    374        if (get_field(env->mstatus, MSTATUS_MPRV)) {
    375            mode = get_field(env->mstatus, MSTATUS_MPP);
    376        }
    377    }
    378
    379    if (first_stage == false) {
    380        /* We are in stage 2 translation, this is similar to stage 1. */
    381        /* Stage 2 is always taken as U-mode */
    382        mode = PRV_U;
    383    }
    384
    385    if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
    386        *physical = addr;
    387        *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
    388        return TRANSLATE_SUCCESS;
    389    }
    390
    391    *prot = 0;
    392
    393    hwaddr base;
    394    int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
    395
    396    if (first_stage == true) {
    397        mxr = get_field(env->mstatus, MSTATUS_MXR);
    398    } else {
    399        mxr = get_field(env->vsstatus, MSTATUS_MXR);
    400    }
    401
    402    if (first_stage == true) {
    403        if (use_background) {
    404            if (riscv_cpu_is_32bit(env)) {
    405                base = (hwaddr)get_field(env->vsatp, SATP32_PPN) << PGSHIFT;
    406                vm = get_field(env->vsatp, SATP32_MODE);
    407            } else {
    408                base = (hwaddr)get_field(env->vsatp, SATP64_PPN) << PGSHIFT;
    409                vm = get_field(env->vsatp, SATP64_MODE);
    410            }
    411        } else {
    412            if (riscv_cpu_is_32bit(env)) {
    413                base = (hwaddr)get_field(env->satp, SATP32_PPN) << PGSHIFT;
    414                vm = get_field(env->satp, SATP32_MODE);
    415            } else {
    416                base = (hwaddr)get_field(env->satp, SATP64_PPN) << PGSHIFT;
    417                vm = get_field(env->satp, SATP64_MODE);
    418            }
    419        }
    420        widened = 0;
    421    } else {
    422        if (riscv_cpu_is_32bit(env)) {
    423            base = (hwaddr)get_field(env->hgatp, SATP32_PPN) << PGSHIFT;
    424            vm = get_field(env->hgatp, SATP32_MODE);
    425        } else {
    426            base = (hwaddr)get_field(env->hgatp, SATP64_PPN) << PGSHIFT;
    427            vm = get_field(env->hgatp, SATP64_MODE);
    428        }
    429        widened = 2;
    430    }
    431    /* status.SUM will be ignored if execute on background */
    432    sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
    433    switch (vm) {
    434    case VM_1_10_SV32:
    435      levels = 2; ptidxbits = 10; ptesize = 4; break;
    436    case VM_1_10_SV39:
    437      levels = 3; ptidxbits = 9; ptesize = 8; break;
    438    case VM_1_10_SV48:
    439      levels = 4; ptidxbits = 9; ptesize = 8; break;
    440    case VM_1_10_SV57:
    441      levels = 5; ptidxbits = 9; ptesize = 8; break;
    442    case VM_1_10_MBARE:
    443        *physical = addr;
    444        *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
    445        return TRANSLATE_SUCCESS;
    446    default:
    447      g_assert_not_reached();
    448    }
    449
    450    CPUState *cs = env_cpu(env);
    451    int va_bits = PGSHIFT + levels * ptidxbits + widened;
    452    target_ulong mask, masked_msbs;
    453
    454    if (TARGET_LONG_BITS > (va_bits - 1)) {
    455        mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
    456    } else {
    457        mask = 0;
    458    }
    459    masked_msbs = (addr >> (va_bits - 1)) & mask;
    460
    461    if (masked_msbs != 0 && masked_msbs != mask) {
    462        return TRANSLATE_FAIL;
    463    }
    464
    465    int ptshift = (levels - 1) * ptidxbits;
    466    int i;
    467
    468#if !TCG_OVERSIZED_GUEST
    469restart:
    470#endif
    471    for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
    472        target_ulong idx;
    473        if (i == 0) {
    474            idx = (addr >> (PGSHIFT + ptshift)) &
    475                           ((1 << (ptidxbits + widened)) - 1);
    476        } else {
    477            idx = (addr >> (PGSHIFT + ptshift)) &
    478                           ((1 << ptidxbits) - 1);
    479        }
    480
    481        /* check that physical address of PTE is legal */
    482        hwaddr pte_addr;
    483
    484        if (two_stage && first_stage) {
    485            int vbase_prot;
    486            hwaddr vbase;
    487
    488            /* Do the second stage translation on the base PTE address. */
    489            int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
    490                                                 base, NULL, MMU_DATA_LOAD,
    491                                                 mmu_idx, false, true,
    492                                                 is_debug);
    493
    494            if (vbase_ret != TRANSLATE_SUCCESS) {
    495                if (fault_pte_addr) {
    496                    *fault_pte_addr = (base + idx * ptesize) >> 2;
    497                }
    498                return TRANSLATE_G_STAGE_FAIL;
    499            }
    500
    501            pte_addr = vbase + idx * ptesize;
    502        } else {
    503            pte_addr = base + idx * ptesize;
    504        }
    505
    506        int pmp_prot;
    507        int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
    508                                               sizeof(target_ulong),
    509                                               MMU_DATA_LOAD, PRV_S);
    510        if (pmp_ret != TRANSLATE_SUCCESS) {
    511            return TRANSLATE_PMP_FAIL;
    512        }
    513
    514        target_ulong pte;
    515        if (riscv_cpu_is_32bit(env)) {
    516            pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
    517        } else {
    518            pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
    519        }
    520
    521        if (res != MEMTX_OK) {
    522            return TRANSLATE_FAIL;
    523        }
    524
    525        hwaddr ppn = pte >> PTE_PPN_SHIFT;
    526
    527        if (!(pte & PTE_V)) {
    528            /* Invalid PTE */
    529            return TRANSLATE_FAIL;
    530        } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
    531            /* Inner PTE, continue walking */
    532            base = ppn << PGSHIFT;
    533        } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
    534            /* Reserved leaf PTE flags: PTE_W */
    535            return TRANSLATE_FAIL;
    536        } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
    537            /* Reserved leaf PTE flags: PTE_W + PTE_X */
    538            return TRANSLATE_FAIL;
    539        } else if ((pte & PTE_U) && ((mode != PRV_U) &&
    540                   (!sum || access_type == MMU_INST_FETCH))) {
    541            /* User PTE flags when not U mode and mstatus.SUM is not set,
    542               or the access type is an instruction fetch */
    543            return TRANSLATE_FAIL;
    544        } else if (!(pte & PTE_U) && (mode != PRV_S)) {
    545            /* Supervisor PTE flags when not S mode */
    546            return TRANSLATE_FAIL;
    547        } else if (ppn & ((1ULL << ptshift) - 1)) {
    548            /* Misaligned PPN */
    549            return TRANSLATE_FAIL;
    550        } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
    551                   ((pte & PTE_X) && mxr))) {
    552            /* Read access check failed */
    553            return TRANSLATE_FAIL;
    554        } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
    555            /* Write access check failed */
    556            return TRANSLATE_FAIL;
    557        } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
    558            /* Fetch access check failed */
    559            return TRANSLATE_FAIL;
    560        } else {
    561            /* if necessary, set accessed and dirty bits. */
    562            target_ulong updated_pte = pte | PTE_A |
    563                (access_type == MMU_DATA_STORE ? PTE_D : 0);
    564
    565            /* Page table updates need to be atomic with MTTCG enabled */
    566            if (updated_pte != pte) {
    567                /*
    568                 * - if accessed or dirty bits need updating, and the PTE is
    569                 *   in RAM, then we do so atomically with a compare and swap.
    570                 * - if the PTE is in IO space or ROM, then it can't be updated
    571                 *   and we return TRANSLATE_FAIL.
    572                 * - if the PTE changed by the time we went to update it, then
    573                 *   it is no longer valid and we must re-walk the page table.
    574                 */
    575                MemoryRegion *mr;
    576                hwaddr l = sizeof(target_ulong), addr1;
    577                mr = address_space_translate(cs->as, pte_addr,
    578                    &addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
    579                if (memory_region_is_ram(mr)) {
    580                    target_ulong *pte_pa =
    581                        qemu_map_ram_ptr(mr->ram_block, addr1);
    582#if TCG_OVERSIZED_GUEST
    583                    /* MTTCG is not enabled on oversized TCG guests so
    584                     * page table updates do not need to be atomic */
    585                    *pte_pa = pte = updated_pte;
    586#else
    587                    target_ulong old_pte =
    588                        qatomic_cmpxchg(pte_pa, pte, updated_pte);
    589                    if (old_pte != pte) {
    590                        goto restart;
    591                    } else {
    592                        pte = updated_pte;
    593                    }
    594#endif
    595                } else {
    596                    /* misconfigured PTE in ROM (AD bits are not preset) or
    597                     * PTE is in IO space and can't be updated atomically */
    598                    return TRANSLATE_FAIL;
    599                }
    600            }
    601
    602            /* for superpage mappings, make a fake leaf PTE for the TLB's
    603               benefit. */
    604            target_ulong vpn = addr >> PGSHIFT;
    605            *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
    606                        (addr & ~TARGET_PAGE_MASK);
    607
    608            /* set permissions on the TLB entry */
    609            if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
    610                *prot |= PAGE_READ;
    611            }
    612            if ((pte & PTE_X)) {
    613                *prot |= PAGE_EXEC;
    614            }
    615            /* add write permission on stores or if the page is already dirty,
    616               so that we TLB miss on later writes to update the dirty bit */
    617            if ((pte & PTE_W) &&
    618                    (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
    619                *prot |= PAGE_WRITE;
    620            }
    621            return TRANSLATE_SUCCESS;
    622        }
    623    }
    624    return TRANSLATE_FAIL;
    625}
    626
    627static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
    628                                MMUAccessType access_type, bool pmp_violation,
    629                                bool first_stage, bool two_stage)
    630{
    631    CPUState *cs = env_cpu(env);
    632    int page_fault_exceptions, vm;
    633    uint64_t stap_mode;
    634
    635    if (riscv_cpu_is_32bit(env)) {
    636        stap_mode = SATP32_MODE;
    637    } else {
    638        stap_mode = SATP64_MODE;
    639    }
    640
    641    if (first_stage) {
    642        vm = get_field(env->satp, stap_mode);
    643    } else {
    644        vm = get_field(env->hgatp, stap_mode);
    645    }
    646
    647    page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
    648
    649    switch (access_type) {
    650    case MMU_INST_FETCH:
    651        if (riscv_cpu_virt_enabled(env) && !first_stage) {
    652            cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
    653        } else {
    654            cs->exception_index = page_fault_exceptions ?
    655                RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
    656        }
    657        break;
    658    case MMU_DATA_LOAD:
    659        if (two_stage && !first_stage) {
    660            cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
    661        } else {
    662            cs->exception_index = page_fault_exceptions ?
    663                RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
    664        }
    665        break;
    666    case MMU_DATA_STORE:
    667        if (two_stage && !first_stage) {
    668            cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
    669        } else {
    670            cs->exception_index = page_fault_exceptions ?
    671                RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
    672        }
    673        break;
    674    default:
    675        g_assert_not_reached();
    676    }
    677    env->badaddr = address;
    678    env->two_stage_lookup = two_stage;
    679}
    680
    681hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
    682{
    683    RISCVCPU *cpu = RISCV_CPU(cs);
    684    CPURISCVState *env = &cpu->env;
    685    hwaddr phys_addr;
    686    int prot;
    687    int mmu_idx = cpu_mmu_index(&cpu->env, false);
    688
    689    if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
    690                             true, riscv_cpu_virt_enabled(env), true)) {
    691        return -1;
    692    }
    693
    694    if (riscv_cpu_virt_enabled(env)) {
    695        if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
    696                                 0, mmu_idx, false, true, true)) {
    697            return -1;
    698        }
    699    }
    700
    701    return phys_addr & TARGET_PAGE_MASK;
    702}
    703
    704void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
    705                                     vaddr addr, unsigned size,
    706                                     MMUAccessType access_type,
    707                                     int mmu_idx, MemTxAttrs attrs,
    708                                     MemTxResult response, uintptr_t retaddr)
    709{
    710    RISCVCPU *cpu = RISCV_CPU(cs);
    711    CPURISCVState *env = &cpu->env;
    712
    713    if (access_type == MMU_DATA_STORE) {
    714        cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
    715    } else if (access_type == MMU_DATA_LOAD) {
    716        cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
    717    } else {
    718        cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT;
    719    }
    720
    721    env->badaddr = addr;
    722    env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
    723                            riscv_cpu_two_stage_lookup(mmu_idx);
    724    riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
    725}
    726
    727void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
    728                                   MMUAccessType access_type, int mmu_idx,
    729                                   uintptr_t retaddr)
    730{
    731    RISCVCPU *cpu = RISCV_CPU(cs);
    732    CPURISCVState *env = &cpu->env;
    733    switch (access_type) {
    734    case MMU_INST_FETCH:
    735        cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
    736        break;
    737    case MMU_DATA_LOAD:
    738        cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
    739        break;
    740    case MMU_DATA_STORE:
    741        cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
    742        break;
    743    default:
    744        g_assert_not_reached();
    745    }
    746    env->badaddr = addr;
    747    env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
    748                            riscv_cpu_two_stage_lookup(mmu_idx);
    749    riscv_raise_exception(env, cs->exception_index, retaddr);
    750}
    751#endif /* !CONFIG_USER_ONLY */
    752
    753bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
    754                        MMUAccessType access_type, int mmu_idx,
    755                        bool probe, uintptr_t retaddr)
    756{
    757    RISCVCPU *cpu = RISCV_CPU(cs);
    758    CPURISCVState *env = &cpu->env;
    759#ifndef CONFIG_USER_ONLY
    760    vaddr im_address;
    761    hwaddr pa = 0;
    762    int prot, prot2, prot_pmp;
    763    bool pmp_violation = false;
    764    bool first_stage_error = true;
    765    bool two_stage_lookup = false;
    766    int ret = TRANSLATE_FAIL;
    767    int mode = mmu_idx;
    768    /* default TLB page size */
    769    target_ulong tlb_size = TARGET_PAGE_SIZE;
    770
    771    env->guest_phys_fault_addr = 0;
    772
    773    qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
    774                  __func__, address, access_type, mmu_idx);
    775
    776    /* MPRV does not affect the virtual-machine load/store
    777       instructions, HLV, HLVX, and HSV. */
    778    if (riscv_cpu_two_stage_lookup(mmu_idx)) {
    779        mode = get_field(env->hstatus, HSTATUS_SPVP);
    780    } else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
    781               get_field(env->mstatus, MSTATUS_MPRV)) {
    782        mode = get_field(env->mstatus, MSTATUS_MPP);
    783        if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
    784            two_stage_lookup = true;
    785        }
    786    }
    787
    788    if (riscv_cpu_virt_enabled(env) ||
    789        ((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
    790         access_type != MMU_INST_FETCH)) {
    791        /* Two stage lookup */
    792        ret = get_physical_address(env, &pa, &prot, address,
    793                                   &env->guest_phys_fault_addr, access_type,
    794                                   mmu_idx, true, true, false);
    795
    796        /*
    797         * A G-stage exception may be triggered during two state lookup.
    798         * And the env->guest_phys_fault_addr has already been set in
    799         * get_physical_address().
    800         */
    801        if (ret == TRANSLATE_G_STAGE_FAIL) {
    802            first_stage_error = false;
    803            access_type = MMU_DATA_LOAD;
    804        }
    805
    806        qemu_log_mask(CPU_LOG_MMU,
    807                      "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
    808                      TARGET_FMT_plx " prot %d\n",
    809                      __func__, address, ret, pa, prot);
    810
    811        if (ret == TRANSLATE_SUCCESS) {
    812            /* Second stage lookup */
    813            im_address = pa;
    814
    815            ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
    816                                       access_type, mmu_idx, false, true,
    817                                       false);
    818
    819            qemu_log_mask(CPU_LOG_MMU,
    820                    "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
    821                    TARGET_FMT_plx " prot %d\n",
    822                    __func__, im_address, ret, pa, prot2);
    823
    824            prot &= prot2;
    825
    826            if (ret == TRANSLATE_SUCCESS) {
    827                ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
    828                                               size, access_type, mode);
    829
    830                qemu_log_mask(CPU_LOG_MMU,
    831                              "%s PMP address=" TARGET_FMT_plx " ret %d prot"
    832                              " %d tlb_size " TARGET_FMT_lu "\n",
    833                              __func__, pa, ret, prot_pmp, tlb_size);
    834
    835                prot &= prot_pmp;
    836            }
    837
    838            if (ret != TRANSLATE_SUCCESS) {
    839                /*
    840                 * Guest physical address translation failed, this is a HS
    841                 * level exception
    842                 */
    843                first_stage_error = false;
    844                env->guest_phys_fault_addr = (im_address |
    845                                              (address &
    846                                               (TARGET_PAGE_SIZE - 1))) >> 2;
    847            }
    848        }
    849    } else {
    850        /* Single stage lookup */
    851        ret = get_physical_address(env, &pa, &prot, address, NULL,
    852                                   access_type, mmu_idx, true, false, false);
    853
    854        qemu_log_mask(CPU_LOG_MMU,
    855                      "%s address=%" VADDR_PRIx " ret %d physical "
    856                      TARGET_FMT_plx " prot %d\n",
    857                      __func__, address, ret, pa, prot);
    858
    859        if (ret == TRANSLATE_SUCCESS) {
    860            ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
    861                                           size, access_type, mode);
    862
    863            qemu_log_mask(CPU_LOG_MMU,
    864                          "%s PMP address=" TARGET_FMT_plx " ret %d prot"
    865                          " %d tlb_size " TARGET_FMT_lu "\n",
    866                          __func__, pa, ret, prot_pmp, tlb_size);
    867
    868            prot &= prot_pmp;
    869        }
    870    }
    871
    872    if (ret == TRANSLATE_PMP_FAIL) {
    873        pmp_violation = true;
    874    }
    875
    876    if (ret == TRANSLATE_SUCCESS) {
    877        tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
    878                     prot, mmu_idx, tlb_size);
    879        return true;
    880    } else if (probe) {
    881        return false;
    882    } else {
    883        raise_mmu_exception(env, address, access_type, pmp_violation,
    884                            first_stage_error,
    885                            riscv_cpu_virt_enabled(env) ||
    886                                riscv_cpu_two_stage_lookup(mmu_idx));
    887        riscv_raise_exception(env, cs->exception_index, retaddr);
    888    }
    889
    890    return true;
    891
    892#else
    893    switch (access_type) {
    894    case MMU_INST_FETCH:
    895        cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
    896        break;
    897    case MMU_DATA_LOAD:
    898        cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
    899        break;
    900    case MMU_DATA_STORE:
    901        cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
    902        break;
    903    default:
    904        g_assert_not_reached();
    905    }
    906    env->badaddr = address;
    907    cpu_loop_exit_restore(cs, retaddr);
    908#endif
    909}
    910
    911/*
    912 * Handle Traps
    913 *
    914 * Adapted from Spike's processor_t::take_trap.
    915 *
    916 */
    917void riscv_cpu_do_interrupt(CPUState *cs)
    918{
    919#if !defined(CONFIG_USER_ONLY)
    920
    921    RISCVCPU *cpu = RISCV_CPU(cs);
    922    CPURISCVState *env = &cpu->env;
    923    bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
    924    uint64_t s;
    925
    926    /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
    927     * so we mask off the MSB and separate into trap type and cause.
    928     */
    929    bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
    930    target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
    931    target_ulong deleg = async ? env->mideleg : env->medeleg;
    932    bool write_tval = false;
    933    target_ulong tval = 0;
    934    target_ulong htval = 0;
    935    target_ulong mtval2 = 0;
    936
    937    if  (cause == RISCV_EXCP_SEMIHOST) {
    938        if (env->priv >= PRV_S) {
    939            env->gpr[xA0] = do_common_semihosting(cs);
    940            env->pc += 4;
    941            return;
    942        }
    943        cause = RISCV_EXCP_BREAKPOINT;
    944    }
    945
    946    if (!async) {
    947        /* set tval to badaddr for traps with address information */
    948        switch (cause) {
    949        case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
    950        case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
    951        case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
    952            force_hs_execp = true;
    953            /* fallthrough */
    954        case RISCV_EXCP_INST_ADDR_MIS:
    955        case RISCV_EXCP_INST_ACCESS_FAULT:
    956        case RISCV_EXCP_LOAD_ADDR_MIS:
    957        case RISCV_EXCP_STORE_AMO_ADDR_MIS:
    958        case RISCV_EXCP_LOAD_ACCESS_FAULT:
    959        case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
    960        case RISCV_EXCP_INST_PAGE_FAULT:
    961        case RISCV_EXCP_LOAD_PAGE_FAULT:
    962        case RISCV_EXCP_STORE_PAGE_FAULT:
    963            write_tval  = true;
    964            tval = env->badaddr;
    965            break;
    966        default:
    967            break;
    968        }
    969        /* ecall is dispatched as one cause so translate based on mode */
    970        if (cause == RISCV_EXCP_U_ECALL) {
    971            assert(env->priv <= 3);
    972
    973            if (env->priv == PRV_M) {
    974                cause = RISCV_EXCP_M_ECALL;
    975            } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
    976                cause = RISCV_EXCP_VS_ECALL;
    977            } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
    978                cause = RISCV_EXCP_S_ECALL;
    979            } else if (env->priv == PRV_U) {
    980                cause = RISCV_EXCP_U_ECALL;
    981            }
    982        }
    983    }
    984
    985    trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
    986                     riscv_cpu_get_trap_name(cause, async));
    987
    988    qemu_log_mask(CPU_LOG_INT,
    989                  "%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
    990                  "epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
    991                  __func__, env->mhartid, async, cause, env->pc, tval,
    992                  riscv_cpu_get_trap_name(cause, async));
    993
    994    if (env->priv <= PRV_S &&
    995            cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
    996        /* handle the trap in S-mode */
    997        if (riscv_has_ext(env, RVH)) {
    998            target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
    999
   1000            if (env->two_stage_lookup && write_tval) {
   1001                /*
   1002                 * If we are writing a guest virtual address to stval, set
   1003                 * this to 1. If we are trapping to VS we will set this to 0
   1004                 * later.
   1005                 */
   1006                env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 1);
   1007            } else {
   1008                /* For other HS-mode traps, we set this to 0. */
   1009                env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
   1010            }
   1011
   1012            if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
   1013                !force_hs_execp) {
   1014                /* Trap to VS mode */
   1015                /*
   1016                 * See if we need to adjust cause. Yes if its VS mode interrupt
   1017                 * no if hypervisor has delegated one of hs mode's interrupt
   1018                 */
   1019                if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
   1020                    cause == IRQ_VS_EXT) {
   1021                    cause = cause - 1;
   1022                }
   1023                env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
   1024            } else if (riscv_cpu_virt_enabled(env)) {
   1025                /* Trap into HS mode, from virt */
   1026                riscv_cpu_swap_hypervisor_regs(env);
   1027                env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
   1028                                         env->priv);
   1029                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
   1030                                         riscv_cpu_virt_enabled(env));
   1031
   1032                htval = env->guest_phys_fault_addr;
   1033
   1034                riscv_cpu_set_virt_enabled(env, 0);
   1035                riscv_cpu_set_force_hs_excep(env, 0);
   1036            } else {
   1037                /* Trap into HS mode */
   1038                env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
   1039                htval = env->guest_phys_fault_addr;
   1040            }
   1041        }
   1042
   1043        s = env->mstatus;
   1044        s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
   1045        s = set_field(s, MSTATUS_SPP, env->priv);
   1046        s = set_field(s, MSTATUS_SIE, 0);
   1047        env->mstatus = s;
   1048        env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
   1049        env->sepc = env->pc;
   1050        env->stval = tval;
   1051        env->htval = htval;
   1052        env->pc = (env->stvec >> 2 << 2) +
   1053            ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
   1054        riscv_cpu_set_mode(env, PRV_S);
   1055    } else {
   1056        /* handle the trap in M-mode */
   1057        if (riscv_has_ext(env, RVH)) {
   1058            if (riscv_cpu_virt_enabled(env)) {
   1059                riscv_cpu_swap_hypervisor_regs(env);
   1060            }
   1061            env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
   1062                                     riscv_cpu_virt_enabled(env));
   1063            if (riscv_cpu_virt_enabled(env) && tval) {
   1064                env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
   1065            }
   1066
   1067            mtval2 = env->guest_phys_fault_addr;
   1068
   1069            /* Trapping to M mode, virt is disabled */
   1070            riscv_cpu_set_virt_enabled(env, 0);
   1071            riscv_cpu_set_force_hs_excep(env, 0);
   1072        }
   1073
   1074        s = env->mstatus;
   1075        s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
   1076        s = set_field(s, MSTATUS_MPP, env->priv);
   1077        s = set_field(s, MSTATUS_MIE, 0);
   1078        env->mstatus = s;
   1079        env->mcause = cause | ~(((target_ulong)-1) >> async);
   1080        env->mepc = env->pc;
   1081        env->mtval = tval;
   1082        env->mtval2 = mtval2;
   1083        env->pc = (env->mtvec >> 2 << 2) +
   1084            ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
   1085        riscv_cpu_set_mode(env, PRV_M);
   1086    }
   1087
   1088    /* NOTE: it is not necessary to yield load reservations here. It is only
   1089     * necessary for an SC from "another hart" to cause a load reservation
   1090     * to be yielded. Refer to the memory consistency model section of the
   1091     * RISC-V ISA Specification.
   1092     */
   1093
   1094    env->two_stage_lookup = false;
   1095#endif
   1096    cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
   1097}