/* * x86 exception helpers * * 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 . */ #include "qemu/osdep.h" #include "cpu.h" #include "exec/exec-all.h" #include "qemu/log.h" #include "sysemu/runstate.h" #include "exec/helper-proto.h" #include "helper-tcg.h" void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend) { raise_interrupt(env, intno, 1, 0, next_eip_addend); } void helper_raise_exception(CPUX86State *env, int exception_index) { raise_exception(env, exception_index); } /* * Check nested exceptions and change to double or triple fault if * needed. It should only be called, if this is not an interrupt. * Returns the new exception number. */ static int check_exception(CPUX86State *env, int intno, int *error_code, uintptr_t retaddr) { int first_contributory = env->old_exception == 0 || (env->old_exception >= 10 && env->old_exception <= 13); int second_contributory = intno == 0 || (intno >= 10 && intno <= 13); qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n", env->old_exception, intno); #if !defined(CONFIG_USER_ONLY) if (env->old_exception == EXCP08_DBLE) { if (env->hflags & HF_GUEST_MASK) { cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0, retaddr); /* does not return */ } qemu_log_mask(CPU_LOG_RESET, "Triple fault\n"); qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); return EXCP_HLT; } #endif if ((first_contributory && second_contributory) || (env->old_exception == EXCP0E_PAGE && (second_contributory || (intno == EXCP0E_PAGE)))) { intno = EXCP08_DBLE; *error_code = 0; } if (second_contributory || (intno == EXCP0E_PAGE) || (intno == EXCP08_DBLE)) { env->old_exception = intno; } return intno; } /* * Signal an interruption. It is executed in the main CPU loop. * is_int is TRUE if coming from the int instruction. next_eip is the * env->eip value AFTER the interrupt instruction. It is only relevant if * is_int is TRUE. */ static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno, int is_int, int error_code, int next_eip_addend, uintptr_t retaddr) { CPUState *cs = env_cpu(env); if (!is_int) { cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno, error_code, retaddr); intno = check_exception(env, intno, &error_code, retaddr); } else { cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0, retaddr); } cs->exception_index = intno; env->error_code = error_code; env->exception_is_int = is_int; env->exception_next_eip = env->eip + next_eip_addend; cpu_loop_exit_restore(cs, retaddr); } /* shortcuts to generate exceptions */ void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int, int error_code, int next_eip_addend) { raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0); } void raise_exception_err(CPUX86State *env, int exception_index, int error_code) { raise_interrupt2(env, exception_index, 0, error_code, 0, 0); } void raise_exception_err_ra(CPUX86State *env, int exception_index, int error_code, uintptr_t retaddr) { raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr); } void raise_exception(CPUX86State *env, int exception_index) { raise_interrupt2(env, exception_index, 0, 0, 0, 0); } void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr) { raise_interrupt2(env, exception_index, 0, 0, 0, retaddr); } #if !defined(CONFIG_USER_ONLY) static hwaddr get_hphys(CPUState *cs, hwaddr gphys, MMUAccessType access_type, int *prot) { CPUX86State *env = &X86_CPU(cs)->env; uint64_t rsvd_mask = PG_HI_RSVD_MASK; uint64_t ptep, pte; uint64_t exit_info_1 = 0; target_ulong pde_addr, pte_addr; uint32_t page_offset; int page_size; if (likely(!(env->hflags2 & HF2_NPT_MASK))) { return gphys; } if (!(env->nested_pg_mode & SVM_NPT_NXE)) { rsvd_mask |= PG_NX_MASK; } if (env->nested_pg_mode & SVM_NPT_PAE) { uint64_t pde, pdpe; target_ulong pdpe_addr; #ifdef TARGET_X86_64 if (env->nested_pg_mode & SVM_NPT_LMA) { uint64_t pml5e; uint64_t pml4e_addr, pml4e; pml5e = env->nested_cr3; ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; pml4e_addr = (pml5e & PG_ADDRESS_MASK) + (((gphys >> 39) & 0x1ff) << 3); pml4e = x86_ldq_phys(cs, pml4e_addr); if (!(pml4e & PG_PRESENT_MASK)) { goto do_fault; } if (pml4e & (rsvd_mask | PG_PSE_MASK)) { goto do_fault_rsvd; } if (!(pml4e & PG_ACCESSED_MASK)) { pml4e |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pml4e_addr, pml4e); } ptep &= pml4e ^ PG_NX_MASK; pdpe_addr = (pml4e & PG_ADDRESS_MASK) + (((gphys >> 30) & 0x1ff) << 3); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; } if (pdpe & rsvd_mask) { goto do_fault_rsvd; } ptep &= pdpe ^ PG_NX_MASK; if (!(pdpe & PG_ACCESSED_MASK)) { pdpe |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pdpe_addr, pdpe); } if (pdpe & PG_PSE_MASK) { /* 1 GB page */ page_size = 1024 * 1024 * 1024; pte_addr = pdpe_addr; pte = pdpe; goto do_check_protect; } } else #endif { pdpe_addr = (env->nested_cr3 & ~0x1f) + ((gphys >> 27) & 0x18); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; } rsvd_mask |= PG_HI_USER_MASK; if (pdpe & (rsvd_mask | PG_NX_MASK)) { goto do_fault_rsvd; } ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; } pde_addr = (pdpe & PG_ADDRESS_MASK) + (((gphys >> 21) & 0x1ff) << 3); pde = x86_ldq_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; } if (pde & rsvd_mask) { goto do_fault_rsvd; } ptep &= pde ^ PG_NX_MASK; if (pde & PG_PSE_MASK) { /* 2 MB page */ page_size = 2048 * 1024; pte_addr = pde_addr; pte = pde; goto do_check_protect; } /* 4 KB page */ if (!(pde & PG_ACCESSED_MASK)) { pde |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pde_addr, pde); } pte_addr = (pde & PG_ADDRESS_MASK) + (((gphys >> 12) & 0x1ff) << 3); pte = x86_ldq_phys(cs, pte_addr); 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 { uint32_t pde; /* page directory entry */ pde_addr = (env->nested_cr3 & ~0xfff) + ((gphys >> 20) & 0xffc); pde = x86_ldl_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; } ptep = pde | PG_NX_MASK; /* if host cr4 PSE bit is set, then we use a 4MB page */ if ((pde & PG_PSE_MASK) && (env->nested_pg_mode & SVM_NPT_PSE)) { page_size = 4096 * 1024; pte_addr = pde_addr; /* 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 = pde | ((pde & 0x1fe000LL) << (32 - 13)); rsvd_mask = 0x200000; goto do_check_protect_pse36; } if (!(pde & PG_ACCESSED_MASK)) { pde |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pde_addr, pde); } /* page directory entry */ pte_addr = (pde & ~0xfff) + ((gphys >> 10) & 0xffc); pte = x86_ldl_phys(cs, pte_addr); 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; } 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; if (!(ptep & PG_USER_MASK)) { goto do_fault_protect; } if (ptep & PG_NX_MASK) { if (access_type == MMU_INST_FETCH) { goto do_fault_protect; } *prot &= ~PAGE_EXEC; } if (!(ptep & PG_RW_MASK)) { if (access_type == MMU_DATA_STORE) { goto do_fault_protect; } *prot &= ~PAGE_WRITE; } pte &= PG_ADDRESS_MASK & ~(page_size - 1); page_offset = gphys & (page_size - 1); return pte + page_offset; do_fault_rsvd: exit_info_1 |= SVM_NPTEXIT_RSVD; do_fault_protect: exit_info_1 |= SVM_NPTEXIT_P; do_fault: x86_stq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2), gphys); exit_info_1 |= SVM_NPTEXIT_US; if (access_type == MMU_DATA_STORE) { exit_info_1 |= SVM_NPTEXIT_RW; } else if (access_type == MMU_INST_FETCH) { exit_info_1 |= SVM_NPTEXIT_ID; } if (prot) { exit_info_1 |= SVM_NPTEXIT_GPA; } else { /* page table access */ exit_info_1 |= SVM_NPTEXIT_GPT; } cpu_vmexit(env, SVM_EXIT_NPF, exit_info_1, env->retaddr); } /* return value: * -1 = cannot handle fault * 0 = nothing more to do * 1 = generate PF fault */ static int handle_mmu_fault(CPUState *cs, vaddr addr, int size, int is_write1, int mmu_idx) { X86CPU *cpu = X86_CPU(cs); CPUX86State *env = &cpu->env; uint64_t ptep, pte; int32_t a20_mask; target_ulong pde_addr, pte_addr; int error_code = 0; int is_dirty, prot, page_size, is_write, is_user; hwaddr paddr; uint64_t rsvd_mask = PG_HI_RSVD_MASK; uint32_t page_offset; target_ulong vaddr; uint32_t pkr; is_user = mmu_idx == MMU_USER_IDX; #if defined(DEBUG_MMU) printf("MMU fault: addr=%" VADDR_PRIx " w=%d u=%d eip=" TARGET_FMT_lx "\n", addr, is_write1, is_user, env->eip); #endif is_write = is_write1 & 1; a20_mask = x86_get_a20_mask(env); if (!(env->cr[0] & CR0_PG_MASK)) { pte = addr; #ifdef TARGET_X86_64 if (!(env->hflags & HF_LMA_MASK)) { /* Without long mode we can only address 32bits in real mode */ pte = (uint32_t)pte; } #endif prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; page_size = 4096; goto do_mapping; } if (!(env->efer & MSR_EFER_NXE)) { rsvd_mask |= PG_NX_MASK; } if (env->cr[4] & CR4_PAE_MASK) { uint64_t pde, pdpe; target_ulong pdpe_addr; #ifdef TARGET_X86_64 if (env->hflags & HF_LMA_MASK) { bool la57 = env->cr[4] & CR4_LA57_MASK; uint64_t pml5e_addr, pml5e; uint64_t pml4e_addr, pml4e; int32_t sext; /* test virtual address sign extension */ sext = la57 ? (int64_t)addr >> 56 : (int64_t)addr >> 47; if (sext != 0 && sext != -1) { env->error_code = 0; cs->exception_index = EXCP0D_GPF; return 1; } if (la57) { pml5e_addr = ((env->cr[3] & ~0xfff) + (((addr >> 48) & 0x1ff) << 3)) & a20_mask; pml5e_addr = get_hphys(cs, pml5e_addr, MMU_DATA_STORE, NULL); pml5e = x86_ldq_phys(cs, pml5e_addr); if (!(pml5e & PG_PRESENT_MASK)) { goto do_fault; } if (pml5e & (rsvd_mask | PG_PSE_MASK)) { goto do_fault_rsvd; } if (!(pml5e & PG_ACCESSED_MASK)) { pml5e |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pml5e_addr, pml5e); } ptep = pml5e ^ PG_NX_MASK; } else { pml5e = env->cr[3]; ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; } pml4e_addr = ((pml5e & PG_ADDRESS_MASK) + (((addr >> 39) & 0x1ff) << 3)) & a20_mask; pml4e_addr = get_hphys(cs, pml4e_addr, MMU_DATA_STORE, false); pml4e = x86_ldq_phys(cs, pml4e_addr); if (!(pml4e & PG_PRESENT_MASK)) { goto do_fault; } if (pml4e & (rsvd_mask | PG_PSE_MASK)) { goto do_fault_rsvd; } if (!(pml4e & PG_ACCESSED_MASK)) { pml4e |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pml4e_addr, pml4e); } ptep &= pml4e ^ PG_NX_MASK; pdpe_addr = ((pml4e & PG_ADDRESS_MASK) + (((addr >> 30) & 0x1ff) << 3)) & a20_mask; pdpe_addr = get_hphys(cs, pdpe_addr, MMU_DATA_STORE, NULL); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; } if (pdpe & rsvd_mask) { goto do_fault_rsvd; } ptep &= pdpe ^ PG_NX_MASK; if (!(pdpe & PG_ACCESSED_MASK)) { pdpe |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pdpe_addr, pdpe); } if (pdpe & PG_PSE_MASK) { /* 1 GB page */ page_size = 1024 * 1024 * 1024; pte_addr = pdpe_addr; pte = pdpe; goto do_check_protect; } } else #endif { /* XXX: load them when cr3 is loaded ? */ pdpe_addr = ((env->cr[3] & ~0x1f) + ((addr >> 27) & 0x18)) & a20_mask; pdpe_addr = get_hphys(cs, pdpe_addr, MMU_DATA_STORE, false); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; } rsvd_mask |= PG_HI_USER_MASK; if (pdpe & (rsvd_mask | PG_NX_MASK)) { goto do_fault_rsvd; } ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK; } pde_addr = ((pdpe & PG_ADDRESS_MASK) + (((addr >> 21) & 0x1ff) << 3)) & a20_mask; pde_addr = get_hphys(cs, pde_addr, MMU_DATA_STORE, NULL); pde = x86_ldq_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; } if (pde & rsvd_mask) { goto do_fault_rsvd; } ptep &= pde ^ PG_NX_MASK; if (pde & PG_PSE_MASK) { /* 2 MB page */ page_size = 2048 * 1024; pte_addr = pde_addr; pte = pde; goto do_check_protect; } /* 4 KB page */ if (!(pde & PG_ACCESSED_MASK)) { pde |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pde_addr, pde); } pte_addr = ((pde & PG_ADDRESS_MASK) + (((addr >> 12) & 0x1ff) << 3)) & a20_mask; pte_addr = get_hphys(cs, pte_addr, MMU_DATA_STORE, NULL); pte = x86_ldq_phys(cs, pte_addr); 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 { uint32_t pde; /* page directory entry */ pde_addr = ((env->cr[3] & ~0xfff) + ((addr >> 20) & 0xffc)) & a20_mask; pde_addr = get_hphys(cs, pde_addr, MMU_DATA_STORE, NULL); pde = x86_ldl_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; } ptep = pde | PG_NX_MASK; /* if PSE bit is set, then we use a 4MB page */ if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) { page_size = 4096 * 1024; pte_addr = pde_addr; /* 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 = pde | ((pde & 0x1fe000LL) << (32 - 13)); rsvd_mask = 0x200000; goto do_check_protect_pse36; } if (!(pde & PG_ACCESSED_MASK)) { pde |= PG_ACCESSED_MASK; x86_stl_phys_notdirty(cs, pde_addr, pde); } /* page directory entry */ pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & a20_mask; pte_addr = get_hphys(cs, pte_addr, MMU_DATA_STORE, NULL); pte = x86_ldl_phys(cs, pte_addr); 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; } 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 (mmu_idx != MMU_KSMAP_IDX || !(ptep & PG_USER_MASK)) { prot |= PAGE_READ; if ((ptep & PG_RW_MASK) || (!is_user && !(env->cr[0] & CR0_WP_MASK))) { prot |= PAGE_WRITE; } } if (!(ptep & PG_NX_MASK) && (mmu_idx == MMU_USER_IDX || !((env->cr[4] & CR4_SMEP_MASK) && (ptep & PG_USER_MASK)))) { prot |= PAGE_EXEC; } if (!(env->hflags & HF_LMA_MASK)) { pkr = 0; } else if (ptep & PG_USER_MASK) { pkr = env->cr[4] & CR4_PKE_MASK ? env->pkru : 0; } else { pkr = env->cr[4] & CR4_PKS_MASK ? 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 || env->cr[0] & CR0_WP_MASK)) { pkr_prot &= ~PAGE_WRITE; } prot &= pkr_prot; if ((pkr_prot & (1 << is_write1)) == 0) { assert(is_write1 != 2); error_code |= PG_ERROR_PK_MASK; goto do_fault_protect; } } if ((prot & (1 << is_write1)) == 0) { goto do_fault_protect; } /* yes, it can! */ is_dirty = is_write && !(pte & PG_DIRTY_MASK); if (!(pte & PG_ACCESSED_MASK) || is_dirty) { pte |= PG_ACCESSED_MASK; if (is_dirty) { pte |= PG_DIRTY_MASK; } x86_stl_phys_notdirty(cs, pte_addr, pte); } if (!(pte & PG_DIRTY_MASK)) { /* only set write access if already dirty... otherwise wait for dirty access */ assert(!is_write); prot &= ~PAGE_WRITE; } do_mapping: pte = pte & a20_mask; /* align to page_size */ pte &= PG_ADDRESS_MASK & ~(page_size - 1); page_offset = addr & (page_size - 1); paddr = get_hphys(cs, pte + page_offset, is_write1, &prot); /* Even if 4MB pages, we map only one 4KB page in the cache to avoid filling it too fast */ vaddr = addr & TARGET_PAGE_MASK; paddr &= TARGET_PAGE_MASK; assert(prot & (1 << is_write1)); tlb_set_page_with_attrs(cs, vaddr, paddr, cpu_get_mem_attrs(env), prot, mmu_idx, page_size); return 0; do_fault_rsvd: error_code |= PG_ERROR_RSVD_MASK; do_fault_protect: error_code |= PG_ERROR_P_MASK; do_fault: error_code |= (is_write << PG_ERROR_W_BIT); if (is_user) error_code |= PG_ERROR_U_MASK; if (is_write1 == 2 && (((env->efer & MSR_EFER_NXE) && (env->cr[4] & CR4_PAE_MASK)) || (env->cr[4] & CR4_SMEP_MASK))) error_code |= PG_ERROR_I_D_MASK; if (env->intercept_exceptions & (1 << EXCP0E_PAGE)) { /* cr2 is not modified in case of exceptions */ x86_stq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2), addr); } else { env->cr[2] = addr; } env->error_code = error_code; cs->exception_index = EXCP0E_PAGE; return 1; } #endif bool x86_cpu_tlb_fill(CPUState *cs, vaddr addr, int size, MMUAccessType access_type, int mmu_idx, bool probe, uintptr_t retaddr) { X86CPU *cpu = X86_CPU(cs); CPUX86State *env = &cpu->env; #ifdef CONFIG_USER_ONLY /* user mode only emulation */ env->cr[2] = addr; env->error_code = (access_type == MMU_DATA_STORE) << PG_ERROR_W_BIT; env->error_code |= PG_ERROR_U_MASK; cs->exception_index = EXCP0E_PAGE; env->exception_is_int = 0; env->exception_next_eip = -1; cpu_loop_exit_restore(cs, retaddr); #else env->retaddr = retaddr; if (handle_mmu_fault(cs, addr, size, access_type, mmu_idx)) { /* FIXME: On error in get_hphys we have already jumped out. */ g_assert(!probe); raise_exception_err_ra(env, cs->exception_index, env->error_code, retaddr); } return true; #endif }