xref: /openbmc/qemu/linux-user/i386/cpu_loop.c (revision 3d9569b8)
1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu-common.h"
22 #include "qemu.h"
23 #include "cpu_loop-common.h"
24 
25 /***********************************************************/
26 /* CPUX86 core interface */
27 
28 uint64_t cpu_get_tsc(CPUX86State *env)
29 {
30     return cpu_get_host_ticks();
31 }
32 
33 static void write_dt(void *ptr, unsigned long addr, unsigned long limit,
34               int flags)
35 {
36     unsigned int e1, e2;
37     uint32_t *p;
38     e1 = (addr << 16) | (limit & 0xffff);
39     e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
40     e2 |= flags;
41     p = ptr;
42     p[0] = tswap32(e1);
43     p[1] = tswap32(e2);
44 }
45 
46 static uint64_t *idt_table;
47 #ifdef TARGET_X86_64
48 static void set_gate64(void *ptr, unsigned int type, unsigned int dpl,
49                        uint64_t addr, unsigned int sel)
50 {
51     uint32_t *p, e1, e2;
52     e1 = (addr & 0xffff) | (sel << 16);
53     e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
54     p = ptr;
55     p[0] = tswap32(e1);
56     p[1] = tswap32(e2);
57     p[2] = tswap32(addr >> 32);
58     p[3] = 0;
59 }
60 /* only dpl matters as we do only user space emulation */
61 static void set_idt(int n, unsigned int dpl)
62 {
63     set_gate64(idt_table + n * 2, 0, dpl, 0, 0);
64 }
65 #else
66 static void set_gate(void *ptr, unsigned int type, unsigned int dpl,
67                      uint32_t addr, unsigned int sel)
68 {
69     uint32_t *p, e1, e2;
70     e1 = (addr & 0xffff) | (sel << 16);
71     e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
72     p = ptr;
73     p[0] = tswap32(e1);
74     p[1] = tswap32(e2);
75 }
76 
77 /* only dpl matters as we do only user space emulation */
78 static void set_idt(int n, unsigned int dpl)
79 {
80     set_gate(idt_table + n, 0, dpl, 0, 0);
81 }
82 #endif
83 
84 void cpu_loop(CPUX86State *env)
85 {
86     CPUState *cs = env_cpu(env);
87     int trapnr;
88     abi_ulong pc;
89     abi_ulong ret;
90     target_siginfo_t info;
91 
92     for(;;) {
93         cpu_exec_start(cs);
94         trapnr = cpu_exec(cs);
95         cpu_exec_end(cs);
96         process_queued_cpu_work(cs);
97 
98         switch(trapnr) {
99         case 0x80:
100             /* linux syscall from int $0x80 */
101             ret = do_syscall(env,
102                              env->regs[R_EAX],
103                              env->regs[R_EBX],
104                              env->regs[R_ECX],
105                              env->regs[R_EDX],
106                              env->regs[R_ESI],
107                              env->regs[R_EDI],
108                              env->regs[R_EBP],
109                              0, 0);
110             if (ret == -TARGET_ERESTARTSYS) {
111                 env->eip -= 2;
112             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
113                 env->regs[R_EAX] = ret;
114             }
115             break;
116 #ifndef TARGET_ABI32
117         case EXCP_SYSCALL:
118             /* linux syscall from syscall instruction */
119             ret = do_syscall(env,
120                              env->regs[R_EAX],
121                              env->regs[R_EDI],
122                              env->regs[R_ESI],
123                              env->regs[R_EDX],
124                              env->regs[10],
125                              env->regs[8],
126                              env->regs[9],
127                              0, 0);
128             if (ret == -TARGET_ERESTARTSYS) {
129                 env->eip -= 2;
130             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
131                 env->regs[R_EAX] = ret;
132             }
133             break;
134 #endif
135         case EXCP0B_NOSEG:
136         case EXCP0C_STACK:
137             info.si_signo = TARGET_SIGBUS;
138             info.si_errno = 0;
139             info.si_code = TARGET_SI_KERNEL;
140             info._sifields._sigfault._addr = 0;
141             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
142             break;
143         case EXCP0D_GPF:
144             /* XXX: potential problem if ABI32 */
145 #ifndef TARGET_X86_64
146             if (env->eflags & VM_MASK) {
147                 handle_vm86_fault(env);
148             } else
149 #endif
150             {
151                 info.si_signo = TARGET_SIGSEGV;
152                 info.si_errno = 0;
153                 info.si_code = TARGET_SI_KERNEL;
154                 info._sifields._sigfault._addr = 0;
155                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
156             }
157             break;
158         case EXCP0E_PAGE:
159             info.si_signo = TARGET_SIGSEGV;
160             info.si_errno = 0;
161             if (!(env->error_code & 1))
162                 info.si_code = TARGET_SEGV_MAPERR;
163             else
164                 info.si_code = TARGET_SEGV_ACCERR;
165             info._sifields._sigfault._addr = env->cr[2];
166             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
167             break;
168         case EXCP00_DIVZ:
169 #ifndef TARGET_X86_64
170             if (env->eflags & VM_MASK) {
171                 handle_vm86_trap(env, trapnr);
172             } else
173 #endif
174             {
175                 /* division by zero */
176                 info.si_signo = TARGET_SIGFPE;
177                 info.si_errno = 0;
178                 info.si_code = TARGET_FPE_INTDIV;
179                 info._sifields._sigfault._addr = env->eip;
180                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
181             }
182             break;
183         case EXCP01_DB:
184         case EXCP03_INT3:
185 #ifndef TARGET_X86_64
186             if (env->eflags & VM_MASK) {
187                 handle_vm86_trap(env, trapnr);
188             } else
189 #endif
190             {
191                 info.si_signo = TARGET_SIGTRAP;
192                 info.si_errno = 0;
193                 if (trapnr == EXCP01_DB) {
194                     info.si_code = TARGET_TRAP_BRKPT;
195                     info._sifields._sigfault._addr = env->eip;
196                 } else {
197                     info.si_code = TARGET_SI_KERNEL;
198                     info._sifields._sigfault._addr = 0;
199                 }
200                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
201             }
202             break;
203         case EXCP04_INTO:
204         case EXCP05_BOUND:
205 #ifndef TARGET_X86_64
206             if (env->eflags & VM_MASK) {
207                 handle_vm86_trap(env, trapnr);
208             } else
209 #endif
210             {
211                 info.si_signo = TARGET_SIGSEGV;
212                 info.si_errno = 0;
213                 info.si_code = TARGET_SI_KERNEL;
214                 info._sifields._sigfault._addr = 0;
215                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
216             }
217             break;
218         case EXCP06_ILLOP:
219             info.si_signo = TARGET_SIGILL;
220             info.si_errno = 0;
221             info.si_code = TARGET_ILL_ILLOPN;
222             info._sifields._sigfault._addr = env->eip;
223             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
224             break;
225         case EXCP_INTERRUPT:
226             /* just indicate that signals should be handled asap */
227             break;
228         case EXCP_DEBUG:
229             info.si_signo = TARGET_SIGTRAP;
230             info.si_errno = 0;
231             info.si_code = TARGET_TRAP_BRKPT;
232             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
233             break;
234         case EXCP_ATOMIC:
235             cpu_exec_step_atomic(cs);
236             break;
237         default:
238             pc = env->segs[R_CS].base + env->eip;
239             EXCP_DUMP(env, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n",
240                       (long)pc, trapnr);
241             abort();
242         }
243         process_pending_signals(env);
244     }
245 }
246 
247 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
248 {
249     env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
250     env->hflags |= HF_PE_MASK | HF_CPL_MASK;
251     if (env->features[FEAT_1_EDX] & CPUID_SSE) {
252         env->cr[4] |= CR4_OSFXSR_MASK;
253         env->hflags |= HF_OSFXSR_MASK;
254     }
255 #ifndef TARGET_ABI32
256     /* enable 64 bit mode if possible */
257     if (!(env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM)) {
258         fprintf(stderr, "The selected x86 CPU does not support 64 bit mode\n");
259         exit(EXIT_FAILURE);
260     }
261     env->cr[4] |= CR4_PAE_MASK;
262     env->efer |= MSR_EFER_LMA | MSR_EFER_LME;
263     env->hflags |= HF_LMA_MASK;
264 #endif
265 
266     /* flags setup : we activate the IRQs by default as in user mode */
267     env->eflags |= IF_MASK;
268 
269     /* linux register setup */
270 #ifndef TARGET_ABI32
271     env->regs[R_EAX] = regs->rax;
272     env->regs[R_EBX] = regs->rbx;
273     env->regs[R_ECX] = regs->rcx;
274     env->regs[R_EDX] = regs->rdx;
275     env->regs[R_ESI] = regs->rsi;
276     env->regs[R_EDI] = regs->rdi;
277     env->regs[R_EBP] = regs->rbp;
278     env->regs[R_ESP] = regs->rsp;
279     env->eip = regs->rip;
280 #else
281     env->regs[R_EAX] = regs->eax;
282     env->regs[R_EBX] = regs->ebx;
283     env->regs[R_ECX] = regs->ecx;
284     env->regs[R_EDX] = regs->edx;
285     env->regs[R_ESI] = regs->esi;
286     env->regs[R_EDI] = regs->edi;
287     env->regs[R_EBP] = regs->ebp;
288     env->regs[R_ESP] = regs->esp;
289     env->eip = regs->eip;
290 #endif
291 
292     /* linux interrupt setup */
293 #ifndef TARGET_ABI32
294     env->idt.limit = 511;
295 #else
296     env->idt.limit = 255;
297 #endif
298     env->idt.base = target_mmap(0, sizeof(uint64_t) * (env->idt.limit + 1),
299                                 PROT_READ|PROT_WRITE,
300                                 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
301     idt_table = g2h(env->idt.base);
302     set_idt(0, 0);
303     set_idt(1, 0);
304     set_idt(2, 0);
305     set_idt(3, 3);
306     set_idt(4, 3);
307     set_idt(5, 0);
308     set_idt(6, 0);
309     set_idt(7, 0);
310     set_idt(8, 0);
311     set_idt(9, 0);
312     set_idt(10, 0);
313     set_idt(11, 0);
314     set_idt(12, 0);
315     set_idt(13, 0);
316     set_idt(14, 0);
317     set_idt(15, 0);
318     set_idt(16, 0);
319     set_idt(17, 0);
320     set_idt(18, 0);
321     set_idt(19, 0);
322     set_idt(0x80, 3);
323 
324     /* linux segment setup */
325     {
326         uint64_t *gdt_table;
327         env->gdt.base = target_mmap(0, sizeof(uint64_t) * TARGET_GDT_ENTRIES,
328                                     PROT_READ|PROT_WRITE,
329                                     MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
330         env->gdt.limit = sizeof(uint64_t) * TARGET_GDT_ENTRIES - 1;
331         gdt_table = g2h(env->gdt.base);
332 #ifdef TARGET_ABI32
333         write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
334                  DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
335                  (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
336 #else
337         /* 64 bit code segment */
338         write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
339                  DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
340                  DESC_L_MASK |
341                  (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
342 #endif
343         write_dt(&gdt_table[__USER_DS >> 3], 0, 0xfffff,
344                  DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
345                  (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
346     }
347     cpu_x86_load_seg(env, R_CS, __USER_CS);
348     cpu_x86_load_seg(env, R_SS, __USER_DS);
349 #ifdef TARGET_ABI32
350     cpu_x86_load_seg(env, R_DS, __USER_DS);
351     cpu_x86_load_seg(env, R_ES, __USER_DS);
352     cpu_x86_load_seg(env, R_FS, __USER_DS);
353     cpu_x86_load_seg(env, R_GS, __USER_DS);
354     /* This hack makes Wine work... */
355     env->segs[R_FS].selector = 0;
356 #else
357     cpu_x86_load_seg(env, R_DS, 0);
358     cpu_x86_load_seg(env, R_ES, 0);
359     cpu_x86_load_seg(env, R_FS, 0);
360     cpu_x86_load_seg(env, R_GS, 0);
361 #endif
362 }
363