| /* |
| * x86 exception helpers - sysemu code |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "cpu.h" |
| #include "exec/cpu_ldst.h" |
| #include "exec/exec-all.h" |
| #include "exec/page-protection.h" |
| #include "tcg/helper-tcg.h" |
| |
| typedef struct TranslateParams { |
| target_ulong addr; |
| target_ulong cr3; |
| int pg_mode; |
| int mmu_idx; |
| int ptw_idx; |
| MMUAccessType access_type; |
| } TranslateParams; |
| |
| typedef struct TranslateResult { |
| hwaddr paddr; |
| int prot; |
| int page_size; |
| } TranslateResult; |
| |
| typedef enum TranslateFaultStage2 { |
| S2_NONE, |
| S2_GPA, |
| S2_GPT, |
| } TranslateFaultStage2; |
| |
| typedef struct TranslateFault { |
| int exception_index; |
| int error_code; |
| target_ulong cr2; |
| TranslateFaultStage2 stage2; |
| } TranslateFault; |
| |
| typedef struct PTETranslate { |
| CPUX86State *env; |
| TranslateFault *err; |
| int ptw_idx; |
| void *haddr; |
| hwaddr gaddr; |
| } PTETranslate; |
| |
| static bool ptw_translate(PTETranslate *inout, hwaddr addr) |
| { |
| int flags; |
| |
| inout->gaddr = addr; |
| flags = probe_access_full_mmu(inout->env, addr, 0, MMU_DATA_STORE, |
| inout->ptw_idx, &inout->haddr, NULL); |
| |
| if (unlikely(flags & TLB_INVALID_MASK)) { |
| TranslateFault *err = inout->err; |
| |
| assert(inout->ptw_idx == MMU_NESTED_IDX); |
| *err = (TranslateFault){ |
| .error_code = inout->env->error_code, |
| .cr2 = addr, |
| .stage2 = S2_GPT, |
| }; |
| return false; |
| } |
| return true; |
| } |
| |
| static inline uint32_t ptw_ldl(const PTETranslate *in, uint64_t ra) |
| { |
| if (likely(in->haddr)) { |
| return ldl_p(in->haddr); |
| } |
| return cpu_ldl_mmuidx_ra(in->env, in->gaddr, in->ptw_idx, ra); |
| } |
| |
| static inline uint64_t ptw_ldq(const PTETranslate *in, uint64_t ra) |
| { |
| if (likely(in->haddr)) { |
| return ldq_p(in->haddr); |
| } |
| return cpu_ldq_mmuidx_ra(in->env, in->gaddr, in->ptw_idx, ra); |
| } |
| |
| /* |
| * Note that we can use a 32-bit cmpxchg for all page table entries, |
| * even 64-bit ones, because PG_PRESENT_MASK, PG_ACCESSED_MASK and |
| * PG_DIRTY_MASK are all in the low 32 bits. |
| */ |
| static bool ptw_setl_slow(const PTETranslate *in, uint32_t old, uint32_t new) |
| { |
| uint32_t cmp; |
| |
| /* Does x86 really perform a rmw cycle on mmio for ptw? */ |
| start_exclusive(); |
| cmp = cpu_ldl_mmuidx_ra(in->env, in->gaddr, in->ptw_idx, 0); |
| if (cmp == old) { |
| cpu_stl_mmuidx_ra(in->env, in->gaddr, new, in->ptw_idx, 0); |
| } |
| end_exclusive(); |
| return cmp == old; |
| } |
| |
| static inline bool ptw_setl(const PTETranslate *in, uint32_t old, uint32_t set) |
| { |
| if (set & ~old) { |
| uint32_t new = old | set; |
| if (likely(in->haddr)) { |
| old = cpu_to_le32(old); |
| new = cpu_to_le32(new); |
| return qatomic_cmpxchg((uint32_t *)in->haddr, old, new) == old; |
| } |
| return ptw_setl_slow(in, old, new); |
| } |
| return true; |
| } |
| |
| static bool mmu_translate(CPUX86State *env, const TranslateParams *in, |
| TranslateResult *out, TranslateFault *err, |
| uint64_t ra) |
| { |
| const target_ulong addr = in->addr; |
| const int pg_mode = in->pg_mode; |
| const bool is_user = is_mmu_index_user(in->mmu_idx); |
| const MMUAccessType access_type = in->access_type; |
| uint64_t ptep, pte, rsvd_mask; |
| PTETranslate pte_trans = { |
| .env = env, |
| .err = err, |
| .ptw_idx = in->ptw_idx, |
| }; |
| hwaddr pte_addr, paddr; |
| uint32_t pkr; |
| int page_size; |
| int error_code; |
| int prot; |
| |
| restart_all: |
| rsvd_mask = ~MAKE_64BIT_MASK(0, env_archcpu(env)->phys_bits); |
| rsvd_mask &= PG_ADDRESS_MASK; |
| if (!(pg_mode & PG_MODE_NXE)) { |
| rsvd_mask |= PG_NX_MASK; |
| } |
| |
| if (pg_mode & PG_MODE_PAE) { |
| #ifdef TARGET_X86_64 |
| if (pg_mode & PG_MODE_LMA) { |
| if (pg_mode & PG_MODE_LA57) { |
| /* |
| * Page table level 5 |
| */ |
| pte_addr = (in->cr3 & ~0xfff) + (((addr >> 48) & 0x1ff) << 3); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| restart_5: |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & (rsvd_mask | PG_PSE_MASK)) { |
| goto do_fault_rsvd; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_5; |
| } |
| ptep = pte ^ PG_NX_MASK; |
| } else { |
| pte = in->cr3; |
| ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; |
| } |
| |
| /* |
| * Page table level 4 |
| */ |
| pte_addr = (pte & PG_ADDRESS_MASK) + (((addr >> 39) & 0x1ff) << 3); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| restart_4: |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & (rsvd_mask | PG_PSE_MASK)) { |
| goto do_fault_rsvd; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_4; |
| } |
| ptep &= pte ^ PG_NX_MASK; |
| |
| /* |
| * Page table level 3 |
| */ |
| pte_addr = (pte & PG_ADDRESS_MASK) + (((addr >> 30) & 0x1ff) << 3); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| restart_3_lma: |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & rsvd_mask) { |
| goto do_fault_rsvd; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_3_lma; |
| } |
| ptep &= pte ^ PG_NX_MASK; |
| if (pte & PG_PSE_MASK) { |
| /* 1 GB page */ |
| page_size = 1024 * 1024 * 1024; |
| goto do_check_protect; |
| } |
| } else |
| #endif |
| { |
| /* |
| * Page table level 3 |
| */ |
| pte_addr = (in->cr3 & 0xffffffe0ULL) + ((addr >> 27) & 0x18); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| rsvd_mask |= PG_HI_USER_MASK; |
| restart_3_nolma: |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & (rsvd_mask | PG_NX_MASK)) { |
| goto do_fault_rsvd; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_3_nolma; |
| } |
| ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; |
| } |
| |
| /* |
| * Page table level 2 |
| */ |
| pte_addr = (pte & PG_ADDRESS_MASK) + (((addr >> 21) & 0x1ff) << 3); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| restart_2_pae: |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & rsvd_mask) { |
| goto do_fault_rsvd; |
| } |
| if (pte & PG_PSE_MASK) { |
| /* 2 MB page */ |
| page_size = 2048 * 1024; |
| ptep &= pte ^ PG_NX_MASK; |
| goto do_check_protect; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_2_pae; |
| } |
| ptep &= pte ^ PG_NX_MASK; |
| |
| /* |
| * Page table level 1 |
| */ |
| pte_addr = (pte & PG_ADDRESS_MASK) + (((addr >> 12) & 0x1ff) << 3); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| pte = ptw_ldq(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| if (pte & rsvd_mask) { |
| goto do_fault_rsvd; |
| } |
| /* combine pde and pte nx, user and rw protections */ |
| ptep &= pte ^ PG_NX_MASK; |
| page_size = 4096; |
| } else if (pg_mode) { |
| /* |
| * Page table level 2 |
| */ |
| pte_addr = (in->cr3 & 0xfffff000ULL) + ((addr >> 20) & 0xffc); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| restart_2_nopae: |
| pte = ptw_ldl(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| ptep = pte | PG_NX_MASK; |
| |
| /* if PSE bit is set, then we use a 4MB page */ |
| if ((pte & PG_PSE_MASK) && (pg_mode & PG_MODE_PSE)) { |
| page_size = 4096 * 1024; |
| /* |
| * Bits 20-13 provide bits 39-32 of the address, bit 21 is reserved. |
| * Leave bits 20-13 in place for setting accessed/dirty bits below. |
| */ |
| pte = (uint32_t)pte | ((pte & 0x1fe000LL) << (32 - 13)); |
| rsvd_mask = 0x200000; |
| goto do_check_protect_pse36; |
| } |
| if (!ptw_setl(&pte_trans, pte, PG_ACCESSED_MASK)) { |
| goto restart_2_nopae; |
| } |
| |
| /* |
| * Page table level 1 |
| */ |
| pte_addr = (pte & ~0xfffu) + ((addr >> 10) & 0xffc); |
| if (!ptw_translate(&pte_trans, pte_addr)) { |
| return false; |
| } |
| pte = ptw_ldl(&pte_trans, ra); |
| if (!(pte & PG_PRESENT_MASK)) { |
| goto do_fault; |
| } |
| /* combine pde and pte user and rw protections */ |
| ptep &= pte | PG_NX_MASK; |
| page_size = 4096; |
| rsvd_mask = 0; |
| } else { |
| /* |
| * No paging (real mode), let's tentatively resolve the address as 1:1 |
| * here, but conditionally still perform an NPT walk on it later. |
| */ |
| page_size = 0x40000000; |
| paddr = in->addr; |
| prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; |
| goto stage2; |
| } |
| |
| do_check_protect: |
| rsvd_mask |= (page_size - 1) & PG_ADDRESS_MASK & ~PG_PSE_PAT_MASK; |
| do_check_protect_pse36: |
| if (pte & rsvd_mask) { |
| goto do_fault_rsvd; |
| } |
| ptep ^= PG_NX_MASK; |
| |
| /* can the page can be put in the TLB? prot will tell us */ |
| if (is_user && !(ptep & PG_USER_MASK)) { |
| goto do_fault_protect; |
| } |
| |
| prot = 0; |
| if (!is_mmu_index_smap(in->mmu_idx) || !(ptep & PG_USER_MASK)) { |
| prot |= PAGE_READ; |
| if ((ptep & PG_RW_MASK) || !(is_user || (pg_mode & PG_MODE_WP))) { |
| prot |= PAGE_WRITE; |
| } |
| } |
| if (!(ptep & PG_NX_MASK) && |
| (is_user || |
| !((pg_mode & PG_MODE_SMEP) && (ptep & PG_USER_MASK)))) { |
| prot |= PAGE_EXEC; |
| } |
| |
| if (ptep & PG_USER_MASK) { |
| pkr = pg_mode & PG_MODE_PKE ? env->pkru : 0; |
| } else { |
| pkr = pg_mode & PG_MODE_PKS ? env->pkrs : 0; |
| } |
| if (pkr) { |
| uint32_t pk = (pte & PG_PKRU_MASK) >> PG_PKRU_BIT; |
| uint32_t pkr_ad = (pkr >> pk * 2) & 1; |
| uint32_t pkr_wd = (pkr >> pk * 2) & 2; |
| uint32_t pkr_prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; |
| |
| if (pkr_ad) { |
| pkr_prot &= ~(PAGE_READ | PAGE_WRITE); |
| } else if (pkr_wd && (is_user || (pg_mode & PG_MODE_WP))) { |
| pkr_prot &= ~PAGE_WRITE; |
| } |
| if ((pkr_prot & (1 << access_type)) == 0) { |
| goto do_fault_pk_protect; |
| } |
| prot &= pkr_prot; |
| } |
| |
| if ((prot & (1 << access_type)) == 0) { |
| goto do_fault_protect; |
| } |
| |
| /* yes, it can! */ |
| { |
| uint32_t set = PG_ACCESSED_MASK; |
| if (access_type == MMU_DATA_STORE) { |
| set |= PG_DIRTY_MASK; |
| } else if (!(pte & PG_DIRTY_MASK)) { |
| /* |
| * Only set write access if already dirty... |
| * otherwise wait for dirty access. |
| */ |
| prot &= ~PAGE_WRITE; |
| } |
| if (!ptw_setl(&pte_trans, pte, set)) { |
| /* |
| * We can arrive here from any of 3 levels and 2 formats. |
| * The only safe thing is to restart the entire lookup. |
| */ |
| goto restart_all; |
| } |
| } |
| |
| /* merge offset within page */ |
| paddr = (pte & PG_ADDRESS_MASK & ~(page_size - 1)) | (addr & (page_size - 1)); |
| stage2: |
| |
| /* |
| * Note that NPT is walked (for both paging structures and final guest |
| * addresses) using the address with the A20 bit set. |
| */ |
| if (in->ptw_idx == MMU_NESTED_IDX) { |
| CPUTLBEntryFull *full; |
| int flags, nested_page_size; |
| |
| flags = probe_access_full_mmu(env, paddr, 0, access_type, |
| MMU_NESTED_IDX, &pte_trans.haddr, &full); |
| if (unlikely(flags & TLB_INVALID_MASK)) { |
| *err = (TranslateFault){ |
| .error_code = env->error_code, |
| .cr2 = paddr, |
| .stage2 = S2_GPA, |
| }; |
| return false; |
| } |
| |
| /* Merge stage1 & stage2 protection bits. */ |
| prot &= full->prot; |
| |
| /* Re-verify resulting protection. */ |
| if ((prot & (1 << access_type)) == 0) { |
| goto do_fault_protect; |
| } |
| |
| /* Merge stage1 & stage2 addresses to final physical address. */ |
| nested_page_size = 1 << full->lg_page_size; |
| paddr = (full->phys_addr & ~(nested_page_size - 1)) |
| | (paddr & (nested_page_size - 1)); |
| |
| /* |
| * Use the larger of stage1 & stage2 page sizes, so that |
| * invalidation works. |
| */ |
| if (nested_page_size > page_size) { |
| page_size = nested_page_size; |
| } |
| } |
| |
| out->paddr = paddr & x86_get_a20_mask(env); |
| out->prot = prot; |
| out->page_size = page_size; |
| return true; |
| |
| do_fault_rsvd: |
| error_code = PG_ERROR_RSVD_MASK; |
| goto do_fault_cont; |
| do_fault_protect: |
| error_code = PG_ERROR_P_MASK; |
| goto do_fault_cont; |
| do_fault_pk_protect: |
| assert(access_type != MMU_INST_FETCH); |
| error_code = PG_ERROR_PK_MASK | PG_ERROR_P_MASK; |
| goto do_fault_cont; |
| do_fault: |
| error_code = 0; |
| do_fault_cont: |
| if (is_user) { |
| error_code |= PG_ERROR_U_MASK; |
| } |
| switch (access_type) { |
| case MMU_DATA_LOAD: |
| break; |
| case MMU_DATA_STORE: |
| error_code |= PG_ERROR_W_MASK; |
| break; |
| case MMU_INST_FETCH: |
| if (pg_mode & (PG_MODE_NXE | PG_MODE_SMEP)) { |
| error_code |= PG_ERROR_I_D_MASK; |
| } |
| break; |
| } |
| *err = (TranslateFault){ |
| .exception_index = EXCP0E_PAGE, |
| .error_code = error_code, |
| .cr2 = addr, |
| }; |
| return false; |
| } |
| |
| static G_NORETURN void raise_stage2(CPUX86State *env, TranslateFault *err, |
| uintptr_t retaddr) |
| { |
| uint64_t exit_info_1 = err->error_code; |
| |
| switch (err->stage2) { |
| case S2_GPT: |
| exit_info_1 |= SVM_NPTEXIT_GPT; |
| break; |
| case S2_GPA: |
| exit_info_1 |= SVM_NPTEXIT_GPA; |
| break; |
| default: |
| g_assert_not_reached(); |
| } |
| |
| x86_stq_phys(env_cpu(env), |
| env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2), |
| err->cr2); |
| cpu_vmexit(env, SVM_EXIT_NPF, exit_info_1, retaddr); |
| } |
| |
| static bool get_physical_address(CPUX86State *env, vaddr addr, |
| MMUAccessType access_type, int mmu_idx, |
| TranslateResult *out, TranslateFault *err, |
| uint64_t ra) |
| { |
| TranslateParams in; |
| bool use_stage2 = env->hflags2 & HF2_NPT_MASK; |
| |
| in.addr = addr; |
| in.access_type = access_type; |
| |
| switch (mmu_idx) { |
| case MMU_PHYS_IDX: |
| break; |
| |
| case MMU_NESTED_IDX: |
| if (likely(use_stage2)) { |
| in.cr3 = env->nested_cr3; |
| in.pg_mode = env->nested_pg_mode; |
| in.mmu_idx = |
| env->nested_pg_mode & PG_MODE_LMA ? MMU_USER64_IDX : MMU_USER32_IDX; |
| in.ptw_idx = MMU_PHYS_IDX; |
| |
| if (!mmu_translate(env, &in, out, err, ra)) { |
| err->stage2 = S2_GPA; |
| return false; |
| } |
| return true; |
| } |
| break; |
| |
| default: |
| if (is_mmu_index_32(mmu_idx)) { |
| addr = (uint32_t)addr; |
| } |
| |
| if (likely(env->cr[0] & CR0_PG_MASK || use_stage2)) { |
| in.cr3 = env->cr[3]; |
| in.mmu_idx = mmu_idx; |
| in.ptw_idx = use_stage2 ? MMU_NESTED_IDX : MMU_PHYS_IDX; |
| in.pg_mode = get_pg_mode(env); |
| |
| if (in.pg_mode & PG_MODE_LMA) { |
| /* test virtual address sign extension */ |
| int shift = in.pg_mode & PG_MODE_LA57 ? 56 : 47; |
| int64_t sext = (int64_t)addr >> shift; |
| if (sext != 0 && sext != -1) { |
| *err = (TranslateFault){ |
| .exception_index = EXCP0D_GPF, |
| .cr2 = addr, |
| }; |
| return false; |
| } |
| } |
| return mmu_translate(env, &in, out, err, ra); |
| } |
| break; |
| } |
| |
| /* No translation needed. */ |
| out->paddr = addr & x86_get_a20_mask(env); |
| out->prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; |
| out->page_size = TARGET_PAGE_SIZE; |
| return true; |
| } |
| |
| bool x86_cpu_tlb_fill(CPUState *cs, vaddr addr, int size, |
| MMUAccessType access_type, int mmu_idx, |
| bool probe, uintptr_t retaddr) |
| { |
| CPUX86State *env = cpu_env(cs); |
| TranslateResult out; |
| TranslateFault err; |
| |
| if (get_physical_address(env, addr, access_type, mmu_idx, &out, &err, |
| retaddr)) { |
| /* |
| * Even if 4MB pages, we map only one 4KB page in the cache to |
| * avoid filling it too fast. |
| */ |
| assert(out.prot & (1 << access_type)); |
| tlb_set_page_with_attrs(cs, addr & TARGET_PAGE_MASK, |
| out.paddr & TARGET_PAGE_MASK, |
| cpu_get_mem_attrs(env), |
| out.prot, mmu_idx, out.page_size); |
| return true; |
| } |
| |
| if (probe) { |
| /* This will be used if recursing for stage2 translation. */ |
| env->error_code = err.error_code; |
| return false; |
| } |
| |
| if (err.stage2 != S2_NONE) { |
| raise_stage2(env, &err, retaddr); |
| } |
| |
| if (env->intercept_exceptions & (1 << err.exception_index)) { |
| /* cr2 is not modified in case of exceptions */ |
| x86_stq_phys(cs, env->vm_vmcb + |
| offsetof(struct vmcb, control.exit_info_2), |
| err.cr2); |
| } else { |
| env->cr[2] = err.cr2; |
| } |
| raise_exception_err_ra(env, err.exception_index, err.error_code, retaddr); |
| } |
| |
| G_NORETURN void x86_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr, |
| MMUAccessType access_type, |
| int mmu_idx, uintptr_t retaddr) |
| { |
| X86CPU *cpu = X86_CPU(cs); |
| handle_unaligned_access(&cpu->env, vaddr, access_type, retaddr); |
| } |
