| /* |
| * vm86 linux syscall support |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| #include "qemu/osdep.h" |
| |
| #include "qemu.h" |
| #include "user-internals.h" |
| |
| //#define DEBUG_VM86 |
| |
| #ifdef DEBUG_VM86 |
| # define LOG_VM86(...) qemu_log(__VA_ARGS__); |
| #else |
| # define LOG_VM86(...) do { } while (0) |
| #endif |
| |
| |
| #define set_flags(X,new,mask) \ |
| ((X) = ((X) & ~(mask)) | ((new) & (mask))) |
| |
| #define SAFE_MASK (0xDD5) |
| #define RETURN_MASK (0xDFF) |
| |
| static inline int is_revectored(int nr, struct target_revectored_struct *bitmap) |
| { |
| return (((uint8_t *)bitmap)[nr >> 3] >> (nr & 7)) & 1; |
| } |
| |
| static inline void vm_putw(CPUX86State *env, uint32_t segptr, |
| unsigned int reg16, unsigned int val) |
| { |
| cpu_stw_data(env, segptr + (reg16 & 0xffff), val); |
| } |
| |
| static inline void vm_putl(CPUX86State *env, uint32_t segptr, |
| unsigned int reg16, unsigned int val) |
| { |
| cpu_stl_data(env, segptr + (reg16 & 0xffff), val); |
| } |
| |
| static inline unsigned int vm_getb(CPUX86State *env, |
| uint32_t segptr, unsigned int reg16) |
| { |
| return cpu_ldub_data(env, segptr + (reg16 & 0xffff)); |
| } |
| |
| static inline unsigned int vm_getw(CPUX86State *env, |
| uint32_t segptr, unsigned int reg16) |
| { |
| return cpu_lduw_data(env, segptr + (reg16 & 0xffff)); |
| } |
| |
| static inline unsigned int vm_getl(CPUX86State *env, |
| uint32_t segptr, unsigned int reg16) |
| { |
| return cpu_ldl_data(env, segptr + (reg16 & 0xffff)); |
| } |
| |
| void save_v86_state(CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| struct target_vm86plus_struct * target_v86; |
| |
| if (!lock_user_struct(VERIFY_WRITE, target_v86, ts->target_v86, 0)) |
| /* FIXME - should return an error */ |
| return; |
| /* put the VM86 registers in the userspace register structure */ |
| target_v86->regs.eax = tswap32(env->regs[R_EAX]); |
| target_v86->regs.ebx = tswap32(env->regs[R_EBX]); |
| target_v86->regs.ecx = tswap32(env->regs[R_ECX]); |
| target_v86->regs.edx = tswap32(env->regs[R_EDX]); |
| target_v86->regs.esi = tswap32(env->regs[R_ESI]); |
| target_v86->regs.edi = tswap32(env->regs[R_EDI]); |
| target_v86->regs.ebp = tswap32(env->regs[R_EBP]); |
| target_v86->regs.esp = tswap32(env->regs[R_ESP]); |
| target_v86->regs.eip = tswap32(env->eip); |
| target_v86->regs.cs = tswap16(env->segs[R_CS].selector); |
| target_v86->regs.ss = tswap16(env->segs[R_SS].selector); |
| target_v86->regs.ds = tswap16(env->segs[R_DS].selector); |
| target_v86->regs.es = tswap16(env->segs[R_ES].selector); |
| target_v86->regs.fs = tswap16(env->segs[R_FS].selector); |
| target_v86->regs.gs = tswap16(env->segs[R_GS].selector); |
| set_flags(env->eflags, ts->v86flags, VIF_MASK | ts->v86mask); |
| target_v86->regs.eflags = tswap32(env->eflags); |
| unlock_user_struct(target_v86, ts->target_v86, 1); |
| LOG_VM86("save_v86_state: eflags=%08x cs:ip=%04x:%04x\n", |
| env->eflags, env->segs[R_CS].selector, env->eip); |
| |
| /* restore 32 bit registers */ |
| env->regs[R_EAX] = ts->vm86_saved_regs.eax; |
| env->regs[R_EBX] = ts->vm86_saved_regs.ebx; |
| env->regs[R_ECX] = ts->vm86_saved_regs.ecx; |
| env->regs[R_EDX] = ts->vm86_saved_regs.edx; |
| env->regs[R_ESI] = ts->vm86_saved_regs.esi; |
| env->regs[R_EDI] = ts->vm86_saved_regs.edi; |
| env->regs[R_EBP] = ts->vm86_saved_regs.ebp; |
| env->regs[R_ESP] = ts->vm86_saved_regs.esp; |
| env->eflags = ts->vm86_saved_regs.eflags; |
| env->eip = ts->vm86_saved_regs.eip; |
| |
| cpu_x86_load_seg(env, R_CS, ts->vm86_saved_regs.cs); |
| cpu_x86_load_seg(env, R_SS, ts->vm86_saved_regs.ss); |
| cpu_x86_load_seg(env, R_DS, ts->vm86_saved_regs.ds); |
| cpu_x86_load_seg(env, R_ES, ts->vm86_saved_regs.es); |
| cpu_x86_load_seg(env, R_FS, ts->vm86_saved_regs.fs); |
| cpu_x86_load_seg(env, R_GS, ts->vm86_saved_regs.gs); |
| } |
| |
| /* return from vm86 mode to 32 bit. The vm86() syscall will return |
| 'retval' */ |
| static inline void return_to_32bit(CPUX86State *env, int retval) |
| { |
| LOG_VM86("return_to_32bit: ret=0x%x\n", retval); |
| save_v86_state(env); |
| env->regs[R_EAX] = retval; |
| } |
| |
| static inline int set_IF(CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| |
| ts->v86flags |= VIF_MASK; |
| if (ts->v86flags & VIP_MASK) { |
| return_to_32bit(env, TARGET_VM86_STI); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static inline void clear_IF(CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| |
| ts->v86flags &= ~VIF_MASK; |
| } |
| |
| static inline void clear_TF(CPUX86State *env) |
| { |
| env->eflags &= ~TF_MASK; |
| } |
| |
| static inline void clear_AC(CPUX86State *env) |
| { |
| env->eflags &= ~AC_MASK; |
| } |
| |
| static inline int set_vflags_long(unsigned long eflags, CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| |
| set_flags(ts->v86flags, eflags, ts->v86mask); |
| set_flags(env->eflags, eflags, SAFE_MASK); |
| if (eflags & IF_MASK) |
| return set_IF(env); |
| else |
| clear_IF(env); |
| return 0; |
| } |
| |
| static inline int set_vflags_short(unsigned short flags, CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| |
| set_flags(ts->v86flags, flags, ts->v86mask & 0xffff); |
| set_flags(env->eflags, flags, SAFE_MASK); |
| if (flags & IF_MASK) |
| return set_IF(env); |
| else |
| clear_IF(env); |
| return 0; |
| } |
| |
| static inline unsigned int get_vflags(CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| unsigned int flags; |
| |
| flags = env->eflags & RETURN_MASK; |
| if (ts->v86flags & VIF_MASK) |
| flags |= IF_MASK; |
| flags |= IOPL_MASK; |
| return flags | (ts->v86flags & ts->v86mask); |
| } |
| |
| #define ADD16(reg, val) reg = (reg & ~0xffff) | ((reg + (val)) & 0xffff) |
| |
| /* handle VM86 interrupt (NOTE: the CPU core currently does not |
| support TSS interrupt revectoring, so this code is always executed) */ |
| static void do_int(CPUX86State *env, int intno) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| uint32_t int_addr, segoffs, ssp; |
| unsigned int sp; |
| |
| if (env->segs[R_CS].selector == TARGET_BIOSSEG) |
| goto cannot_handle; |
| if (is_revectored(intno, &ts->vm86plus.int_revectored)) |
| goto cannot_handle; |
| if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff, |
| &ts->vm86plus.int21_revectored)) |
| goto cannot_handle; |
| int_addr = (intno << 2); |
| segoffs = cpu_ldl_data(env, int_addr); |
| if ((segoffs >> 16) == TARGET_BIOSSEG) |
| goto cannot_handle; |
| LOG_VM86("VM86: emulating int 0x%x. CS:IP=%04x:%04x\n", |
| intno, segoffs >> 16, segoffs & 0xffff); |
| /* save old state */ |
| ssp = env->segs[R_SS].selector << 4; |
| sp = env->regs[R_ESP] & 0xffff; |
| vm_putw(env, ssp, sp - 2, get_vflags(env)); |
| vm_putw(env, ssp, sp - 4, env->segs[R_CS].selector); |
| vm_putw(env, ssp, sp - 6, env->eip); |
| ADD16(env->regs[R_ESP], -6); |
| /* goto interrupt handler */ |
| env->eip = segoffs & 0xffff; |
| cpu_x86_load_seg(env, R_CS, segoffs >> 16); |
| clear_TF(env); |
| clear_IF(env); |
| clear_AC(env); |
| return; |
| cannot_handle: |
| LOG_VM86("VM86: return to 32 bits int 0x%x\n", intno); |
| return_to_32bit(env, TARGET_VM86_INTx | (intno << 8)); |
| } |
| |
| void handle_vm86_trap(CPUX86State *env, int trapno) |
| { |
| if (trapno == 1 || trapno == 3) { |
| return_to_32bit(env, TARGET_VM86_TRAP + (trapno << 8)); |
| } else { |
| do_int(env, trapno); |
| } |
| } |
| |
| #define CHECK_IF_IN_TRAP() \ |
| if ((ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) && \ |
| (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_TFpendig)) \ |
| newflags |= TF_MASK |
| |
| #define VM86_FAULT_RETURN \ |
| if ((ts->vm86plus.vm86plus.flags & TARGET_force_return_for_pic) && \ |
| (ts->v86flags & (IF_MASK | VIF_MASK))) \ |
| return_to_32bit(env, TARGET_VM86_PICRETURN); \ |
| return |
| |
| void handle_vm86_fault(CPUX86State *env) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| uint32_t csp, ssp; |
| unsigned int ip, sp, newflags, newip, newcs, opcode, intno; |
| int data32, pref_done; |
| |
| csp = env->segs[R_CS].selector << 4; |
| ip = env->eip & 0xffff; |
| |
| ssp = env->segs[R_SS].selector << 4; |
| sp = env->regs[R_ESP] & 0xffff; |
| |
| LOG_VM86("VM86 exception %04x:%08x\n", |
| env->segs[R_CS].selector, env->eip); |
| |
| data32 = 0; |
| pref_done = 0; |
| do { |
| opcode = vm_getb(env, csp, ip); |
| ADD16(ip, 1); |
| switch (opcode) { |
| case 0x66: /* 32-bit data */ data32=1; break; |
| case 0x67: /* 32-bit address */ break; |
| case 0x2e: /* CS */ break; |
| case 0x3e: /* DS */ break; |
| case 0x26: /* ES */ break; |
| case 0x36: /* SS */ break; |
| case 0x65: /* GS */ break; |
| case 0x64: /* FS */ break; |
| case 0xf2: /* repnz */ break; |
| case 0xf3: /* rep */ break; |
| default: pref_done = 1; |
| } |
| } while (!pref_done); |
| |
| /* VM86 mode */ |
| switch(opcode) { |
| case 0x9c: /* pushf */ |
| if (data32) { |
| vm_putl(env, ssp, sp - 4, get_vflags(env)); |
| ADD16(env->regs[R_ESP], -4); |
| } else { |
| vm_putw(env, ssp, sp - 2, get_vflags(env)); |
| ADD16(env->regs[R_ESP], -2); |
| } |
| env->eip = ip; |
| VM86_FAULT_RETURN; |
| |
| case 0x9d: /* popf */ |
| if (data32) { |
| newflags = vm_getl(env, ssp, sp); |
| ADD16(env->regs[R_ESP], 4); |
| } else { |
| newflags = vm_getw(env, ssp, sp); |
| ADD16(env->regs[R_ESP], 2); |
| } |
| env->eip = ip; |
| CHECK_IF_IN_TRAP(); |
| if (data32) { |
| if (set_vflags_long(newflags, env)) |
| return; |
| } else { |
| if (set_vflags_short(newflags, env)) |
| return; |
| } |
| VM86_FAULT_RETURN; |
| |
| case 0xcd: /* int */ |
| intno = vm_getb(env, csp, ip); |
| ADD16(ip, 1); |
| env->eip = ip; |
| if (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) { |
| if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >> |
| (intno &7)) & 1) { |
| return_to_32bit(env, TARGET_VM86_INTx + (intno << 8)); |
| return; |
| } |
| } |
| do_int(env, intno); |
| break; |
| |
| case 0xcf: /* iret */ |
| if (data32) { |
| newip = vm_getl(env, ssp, sp) & 0xffff; |
| newcs = vm_getl(env, ssp, sp + 4) & 0xffff; |
| newflags = vm_getl(env, ssp, sp + 8); |
| ADD16(env->regs[R_ESP], 12); |
| } else { |
| newip = vm_getw(env, ssp, sp); |
| newcs = vm_getw(env, ssp, sp + 2); |
| newflags = vm_getw(env, ssp, sp + 4); |
| ADD16(env->regs[R_ESP], 6); |
| } |
| env->eip = newip; |
| cpu_x86_load_seg(env, R_CS, newcs); |
| CHECK_IF_IN_TRAP(); |
| if (data32) { |
| if (set_vflags_long(newflags, env)) |
| return; |
| } else { |
| if (set_vflags_short(newflags, env)) |
| return; |
| } |
| VM86_FAULT_RETURN; |
| |
| case 0xfa: /* cli */ |
| env->eip = ip; |
| clear_IF(env); |
| VM86_FAULT_RETURN; |
| |
| case 0xfb: /* sti */ |
| env->eip = ip; |
| if (set_IF(env)) |
| return; |
| VM86_FAULT_RETURN; |
| |
| default: |
| /* real VM86 GPF exception */ |
| return_to_32bit(env, TARGET_VM86_UNKNOWN); |
| break; |
| } |
| } |
| |
| int do_vm86(CPUX86State *env, long subfunction, abi_ulong vm86_addr) |
| { |
| CPUState *cs = env_cpu(env); |
| TaskState *ts = get_task_state(cs); |
| struct target_vm86plus_struct * target_v86; |
| int ret; |
| |
| switch (subfunction) { |
| case TARGET_VM86_REQUEST_IRQ: |
| case TARGET_VM86_FREE_IRQ: |
| case TARGET_VM86_GET_IRQ_BITS: |
| case TARGET_VM86_GET_AND_RESET_IRQ: |
| qemu_log_mask(LOG_UNIMP, "qemu: unsupported vm86 subfunction (%ld)\n", |
| subfunction); |
| ret = -TARGET_EINVAL; |
| goto out; |
| case TARGET_VM86_PLUS_INSTALL_CHECK: |
| /* NOTE: on old vm86 stuff this will return the error |
| from verify_area(), because the subfunction is |
| interpreted as (invalid) address to vm86_struct. |
| So the installation check works. |
| */ |
| ret = 0; |
| goto out; |
| } |
| |
| /* save current CPU regs */ |
| ts->vm86_saved_regs.eax = 0; /* default vm86 syscall return code */ |
| ts->vm86_saved_regs.ebx = env->regs[R_EBX]; |
| ts->vm86_saved_regs.ecx = env->regs[R_ECX]; |
| ts->vm86_saved_regs.edx = env->regs[R_EDX]; |
| ts->vm86_saved_regs.esi = env->regs[R_ESI]; |
| ts->vm86_saved_regs.edi = env->regs[R_EDI]; |
| ts->vm86_saved_regs.ebp = env->regs[R_EBP]; |
| ts->vm86_saved_regs.esp = env->regs[R_ESP]; |
| ts->vm86_saved_regs.eflags = env->eflags; |
| ts->vm86_saved_regs.eip = env->eip; |
| ts->vm86_saved_regs.cs = env->segs[R_CS].selector; |
| ts->vm86_saved_regs.ss = env->segs[R_SS].selector; |
| ts->vm86_saved_regs.ds = env->segs[R_DS].selector; |
| ts->vm86_saved_regs.es = env->segs[R_ES].selector; |
| ts->vm86_saved_regs.fs = env->segs[R_FS].selector; |
| ts->vm86_saved_regs.gs = env->segs[R_GS].selector; |
| |
| ts->target_v86 = vm86_addr; |
| if (!lock_user_struct(VERIFY_READ, target_v86, vm86_addr, 1)) |
| return -TARGET_EFAULT; |
| /* build vm86 CPU state */ |
| ts->v86flags = tswap32(target_v86->regs.eflags); |
| env->eflags = (env->eflags & ~SAFE_MASK) | |
| (tswap32(target_v86->regs.eflags) & SAFE_MASK) | VM_MASK; |
| |
| ts->vm86plus.cpu_type = tswapal(target_v86->cpu_type); |
| switch (ts->vm86plus.cpu_type) { |
| case TARGET_CPU_286: |
| ts->v86mask = 0; |
| break; |
| case TARGET_CPU_386: |
| ts->v86mask = NT_MASK | IOPL_MASK; |
| break; |
| case TARGET_CPU_486: |
| ts->v86mask = AC_MASK | NT_MASK | IOPL_MASK; |
| break; |
| default: |
| ts->v86mask = ID_MASK | AC_MASK | NT_MASK | IOPL_MASK; |
| break; |
| } |
| |
| env->regs[R_EBX] = tswap32(target_v86->regs.ebx); |
| env->regs[R_ECX] = tswap32(target_v86->regs.ecx); |
| env->regs[R_EDX] = tswap32(target_v86->regs.edx); |
| env->regs[R_ESI] = tswap32(target_v86->regs.esi); |
| env->regs[R_EDI] = tswap32(target_v86->regs.edi); |
| env->regs[R_EBP] = tswap32(target_v86->regs.ebp); |
| env->regs[R_ESP] = tswap32(target_v86->regs.esp); |
| env->eip = tswap32(target_v86->regs.eip); |
| cpu_x86_load_seg(env, R_CS, tswap16(target_v86->regs.cs)); |
| cpu_x86_load_seg(env, R_SS, tswap16(target_v86->regs.ss)); |
| cpu_x86_load_seg(env, R_DS, tswap16(target_v86->regs.ds)); |
| cpu_x86_load_seg(env, R_ES, tswap16(target_v86->regs.es)); |
| cpu_x86_load_seg(env, R_FS, tswap16(target_v86->regs.fs)); |
| cpu_x86_load_seg(env, R_GS, tswap16(target_v86->regs.gs)); |
| ret = tswap32(target_v86->regs.eax); /* eax will be restored at |
| the end of the syscall */ |
| memcpy(&ts->vm86plus.int_revectored, |
| &target_v86->int_revectored, 32); |
| memcpy(&ts->vm86plus.int21_revectored, |
| &target_v86->int21_revectored, 32); |
| ts->vm86plus.vm86plus.flags = tswapal(target_v86->vm86plus.flags); |
| memcpy(&ts->vm86plus.vm86plus.vm86dbg_intxxtab, |
| target_v86->vm86plus.vm86dbg_intxxtab, 32); |
| unlock_user_struct(target_v86, vm86_addr, 0); |
| |
| LOG_VM86("do_vm86: cs:ip=%04x:%04x\n", |
| env->segs[R_CS].selector, env->eip); |
| /* now the virtual CPU is ready for vm86 execution ! */ |
| out: |
| return ret; |
| } |
