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qemu/cpu-exec.c
bellard 93a40ea926 fixed mmu fault priviledge logic 
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@406 c046a42c-6fe2-441c-8c8c-71466251a162
2003-10-27 21:13:06 +00:00

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/*
* i386 emulator main execution loop
*
* 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 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include "exec.h"
#include "disas.h"
//#define DEBUG_EXEC
//#define DEBUG_SIGNAL
#if defined(TARGET_ARM) || defined(TARGET_SPARC)
/* XXX: unify with i386 target */
void cpu_loop_exit(void)
{
longjmp(env->jmp_env, 1);
}
#endif
/* main execution loop */
int cpu_exec(CPUState *env1)
{
int saved_T0, saved_T1, saved_T2;
CPUState *saved_env;
#ifdef reg_EAX
int saved_EAX;
#endif
#ifdef reg_ECX
int saved_ECX;
#endif
#ifdef reg_EDX
int saved_EDX;
#endif
#ifdef reg_EBX
int saved_EBX;
#endif
#ifdef reg_ESP
int saved_ESP;
#endif
#ifdef reg_EBP
int saved_EBP;
#endif
#ifdef reg_ESI
int saved_ESI;
#endif
#ifdef reg_EDI
int saved_EDI;
#endif
#ifdef __sparc__
int saved_i7, tmp_T0;
#endif
int code_gen_size, ret, interrupt_request;
void (*gen_func)(void);
TranslationBlock *tb, **ptb;
uint8_t *tc_ptr, *cs_base, *pc;
unsigned int flags;
/* first we save global registers */
saved_T0 = T0;
saved_T1 = T1;
saved_T2 = T2;
saved_env = env;
env = env1;
#ifdef __sparc__
/* we also save i7 because longjmp may not restore it */
asm volatile ("mov %%i7, %0" : "=r" (saved_i7));
#endif
#if defined(TARGET_I386)
#ifdef reg_EAX
saved_EAX = EAX;
EAX = env->regs[R_EAX];
#endif
#ifdef reg_ECX
saved_ECX = ECX;
ECX = env->regs[R_ECX];
#endif
#ifdef reg_EDX
saved_EDX = EDX;
EDX = env->regs[R_EDX];
#endif
#ifdef reg_EBX
saved_EBX = EBX;
EBX = env->regs[R_EBX];
#endif
#ifdef reg_ESP
saved_ESP = ESP;
ESP = env->regs[R_ESP];
#endif
#ifdef reg_EBP
saved_EBP = EBP;
EBP = env->regs[R_EBP];
#endif
#ifdef reg_ESI
saved_ESI = ESI;
ESI = env->regs[R_ESI];
#endif
#ifdef reg_EDI
saved_EDI = EDI;
EDI = env->regs[R_EDI];
#endif
/* put eflags in CPU temporary format */
CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
DF = 1 - (2 * ((env->eflags >> 10) & 1));
CC_OP = CC_OP_EFLAGS;
env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
#elif defined(TARGET_ARM)
{
unsigned int psr;
psr = env->cpsr;
env->CF = (psr >> 29) & 1;
env->NZF = (psr & 0xc0000000) ^ 0x40000000;
env->VF = (psr << 3) & 0x80000000;
env->cpsr = psr & ~0xf0000000;
}
#elif defined(TARGET_SPARC)
#else
#error unsupported target CPU
#endif
env->exception_index = -1;
/* prepare setjmp context for exception handling */
for(;;) {
if (setjmp(env->jmp_env) == 0) {
/* if an exception is pending, we execute it here */
if (env->exception_index >= 0) {
if (env->exception_index >= EXCP_INTERRUPT) {
/* exit request from the cpu execution loop */
ret = env->exception_index;
break;
} else if (env->user_mode_only) {
/* if user mode only, we simulate a fake exception
which will be hanlded outside the cpu execution
loop */
#if defined(TARGET_I386)
do_interrupt_user(env->exception_index,
env->exception_is_int,
env->error_code,
env->exception_next_eip);
#endif
ret = env->exception_index;
break;
} else {
#if defined(TARGET_I386)
/* simulate a real cpu exception. On i386, it can
trigger new exceptions, but we do not handle
double or triple faults yet. */
do_interrupt(env->exception_index,
env->exception_is_int,
env->error_code,
env->exception_next_eip, 0);
#endif
}
env->exception_index = -1;
}
T0 = 0; /* force lookup of first TB */
for(;;) {
#ifdef __sparc__
/* g1 can be modified by some libc? functions */
tmp_T0 = T0;
#endif
interrupt_request = env->interrupt_request;
if (__builtin_expect(interrupt_request, 0)) {
#if defined(TARGET_I386)
/* if hardware interrupt pending, we execute it */
if ((interrupt_request & CPU_INTERRUPT_HARD) &&
(env->eflags & IF_MASK) &&
!(env->hflags & HF_INHIBIT_IRQ_MASK)) {
int intno;
intno = cpu_x86_get_pic_interrupt(env);
if (loglevel) {
fprintf(logfile, "Servicing hardware INT=0x%02x\n", intno);
}
do_interrupt(intno, 0, 0, 0, 1);
env->interrupt_request &= ~CPU_INTERRUPT_HARD;
/* ensure that no TB jump will be modified as
the program flow was changed */
#ifdef __sparc__
tmp_T0 = 0;
#else
T0 = 0;
#endif
}
#endif
if (interrupt_request & CPU_INTERRUPT_EXIT) {
env->interrupt_request &= ~CPU_INTERRUPT_EXIT;
env->exception_index = EXCP_INTERRUPT;
cpu_loop_exit();
}
}
#ifdef DEBUG_EXEC
if (loglevel) {
#if defined(TARGET_I386)
/* restore flags in standard format */
env->regs[R_EAX] = EAX;
env->regs[R_EBX] = EBX;
env->regs[R_ECX] = ECX;
env->regs[R_EDX] = EDX;
env->regs[R_ESI] = ESI;
env->regs[R_EDI] = EDI;
env->regs[R_EBP] = EBP;
env->regs[R_ESP] = ESP;
env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);
cpu_x86_dump_state(env, logfile, X86_DUMP_CCOP);
env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
#elif defined(TARGET_ARM)
env->cpsr = compute_cpsr();
cpu_arm_dump_state(env, logfile, 0);
env->cpsr &= ~0xf0000000;
#elif defined(TARGET_SPARC)
cpu_sparc_dump_state (env, logfile, 0);
#else
#error unsupported target CPU
#endif
}
#endif
/* we record a subset of the CPU state. It will
always be the same before a given translated block
is executed. */
#if defined(TARGET_I386)
flags = env->hflags;
flags |= (env->eflags & (IOPL_MASK | TF_MASK | VM_MASK));
cs_base = env->segs[R_CS].base;
pc = cs_base + env->eip;
#elif defined(TARGET_ARM)
flags = 0;
cs_base = 0;
pc = (uint8_t *)env->regs[15];
#elif defined(TARGET_SPARC)
flags = 0;
cs_base = 0;
if (env->npc) {
env->pc = env->npc;
env->npc = 0;
}
pc = (uint8_t *) env->pc;
#else
#error unsupported CPU
#endif
tb = tb_find(&ptb, (unsigned long)pc, (unsigned long)cs_base,
flags);
if (!tb) {
spin_lock(&tb_lock);
/* if no translated code available, then translate it now */
tb = tb_alloc((unsigned long)pc);
if (!tb) {
/* flush must be done */
tb_flush();
/* cannot fail at this point */
tb = tb_alloc((unsigned long)pc);
/* don't forget to invalidate previous TB info */
ptb = &tb_hash[tb_hash_func((unsigned long)pc)];
T0 = 0;
}
tc_ptr = code_gen_ptr;
tb->tc_ptr = tc_ptr;
tb->cs_base = (unsigned long)cs_base;
tb->flags = flags;
/* XXX: an MMU exception can occur here */
cpu_gen_code(env, tb, CODE_GEN_MAX_SIZE, &code_gen_size);
*ptb = tb;
tb->hash_next = NULL;
tb_link(tb);
code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1));
spin_unlock(&tb_lock);
}
#ifdef DEBUG_EXEC
if (loglevel) {
fprintf(logfile, "Trace 0x%08lx [0x%08lx] %s\n",
(long)tb->tc_ptr, (long)tb->pc,
lookup_symbol((void *)tb->pc));
}
#endif
#ifdef __sparc__
T0 = tmp_T0;
#endif
/* see if we can patch the calling TB. */
if (T0 != 0) {
spin_lock(&tb_lock);
tb_add_jump((TranslationBlock *)(T0 & ~3), T0 & 3, tb);
spin_unlock(&tb_lock);
}
tc_ptr = tb->tc_ptr;
env->current_tb = tb;
/* execute the generated code */
gen_func = (void *)tc_ptr;
#if defined(__sparc__)
__asm__ __volatile__("call %0\n\t"
"mov %%o7,%%i0"
: /* no outputs */
: "r" (gen_func)
: "i0", "i1", "i2", "i3", "i4", "i5");
#elif defined(__arm__)
asm volatile ("mov pc, %0\n\t"
".global exec_loop\n\t"
"exec_loop:\n\t"
: /* no outputs */
: "r" (gen_func)
: "r1", "r2", "r3", "r8", "r9", "r10", "r12", "r14");
#else
gen_func();
#endif
env->current_tb = NULL;
/* reset soft MMU for next block (it can currently
only be set by a memory fault) */
#if defined(TARGET_I386) && !defined(CONFIG_SOFTMMU)
if (env->hflags & HF_SOFTMMU_MASK) {
env->hflags &= ~HF_SOFTMMU_MASK;
/* do not allow linking to another block */
T0 = 0;
}
#endif
}
} else {
}
} /* for(;;) */
#if defined(TARGET_I386)
/* restore flags in standard format */
env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK);
/* restore global registers */
#ifdef reg_EAX
EAX = saved_EAX;
#endif
#ifdef reg_ECX
ECX = saved_ECX;
#endif
#ifdef reg_EDX
EDX = saved_EDX;
#endif
#ifdef reg_EBX
EBX = saved_EBX;
#endif
#ifdef reg_ESP
ESP = saved_ESP;
#endif
#ifdef reg_EBP
EBP = saved_EBP;
#endif
#ifdef reg_ESI
ESI = saved_ESI;
#endif
#ifdef reg_EDI
EDI = saved_EDI;
#endif
#elif defined(TARGET_ARM)
env->cpsr = compute_cpsr();
#elif defined(TARGET_SPARC)
#else
#error unsupported target CPU
#endif
#ifdef __sparc__
asm volatile ("mov %0, %%i7" : : "r" (saved_i7));
#endif
T0 = saved_T0;
T1 = saved_T1;
T2 = saved_T2;
env = saved_env;
return ret;
}
#if defined(TARGET_I386)
void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector)
{
CPUX86State *saved_env;
saved_env = env;
env = s;
if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {
selector &= 0xffff;
cpu_x86_load_seg_cache(env, seg_reg, selector,
(uint8_t *)(selector << 4), 0xffff, 0);
} else {
load_seg(seg_reg, selector, 0);
}
env = saved_env;
}
void cpu_x86_fsave(CPUX86State *s, uint8_t *ptr, int data32)
{
CPUX86State *saved_env;
saved_env = env;
env = s;
helper_fsave(ptr, data32);
env = saved_env;
}
void cpu_x86_frstor(CPUX86State *s, uint8_t *ptr, int data32)
{
CPUX86State *saved_env;
saved_env = env;
env = s;
helper_frstor(ptr, data32);
env = saved_env;
}
#endif /* TARGET_I386 */
#undef EAX
#undef ECX
#undef EDX
#undef EBX
#undef ESP
#undef EBP
#undef ESI
#undef EDI
#undef EIP
#include <signal.h>
#include <sys/ucontext.h>
#if defined(TARGET_I386)
/* 'pc' is the host PC at which the exception was raised. 'address' is
the effective address of the memory exception. 'is_write' is 1 if a
write caused the exception and otherwise 0'. 'old_set' is the
signal set which should be restored */
static inline int handle_cpu_signal(unsigned long pc, unsigned long address,
int is_write, sigset_t *old_set)
{
TranslationBlock *tb;
int ret;
if (cpu_single_env)
env = cpu_single_env; /* XXX: find a correct solution for multithread */
#if defined(DEBUG_SIGNAL)
printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
pc, address, is_write, *(unsigned long *)old_set);
#endif
/* XXX: locking issue */
if (is_write && page_unprotect(address)) {
return 1;
}
/* see if it is an MMU fault */
ret = cpu_x86_handle_mmu_fault(env, address, is_write,
((env->hflags & HF_CPL_MASK) == 3), 0);
if (ret < 0)
return 0; /* not an MMU fault */
if (ret == 0)
return 1; /* the MMU fault was handled without causing real CPU fault */
/* now we have a real cpu fault */
tb = tb_find_pc(pc);
if (tb) {
/* the PC is inside the translated code. It means that we have
a virtual CPU fault */
cpu_restore_state(tb, env, pc);
}
if (ret == 1) {
#if 0
printf("PF exception: EIP=0x%08x CR2=0x%08x error=0x%x\n",
env->eip, env->cr[2], env->error_code);
#endif
/* we restore the process signal mask as the sigreturn should
do it (XXX: use sigsetjmp) */
sigprocmask(SIG_SETMASK, old_set, NULL);
raise_exception_err(EXCP0E_PAGE, env->error_code);
} else {
/* activate soft MMU for this block */
env->hflags |= HF_SOFTMMU_MASK;
sigprocmask(SIG_SETMASK, old_set, NULL);
cpu_loop_exit();
}
/* never comes here */
return 1;
}
#elif defined(TARGET_ARM)
static inline int handle_cpu_signal(unsigned long pc, unsigned long address,
int is_write, sigset_t *old_set)
{
/* XXX: do more */
return 0;
}
#elif defined(TARGET_SPARC)
static inline int handle_cpu_signal(unsigned long pc, unsigned long address,
int is_write, sigset_t *old_set)
{
return 0;
}
#else
#error unsupported target CPU
#endif
#if defined(__i386__)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
struct ucontext *uc = puc;
unsigned long pc;
#ifndef REG_EIP
/* for glibc 2.1 */
#define REG_EIP EIP
#define REG_ERR ERR
#define REG_TRAPNO TRAPNO
#endif
pc = uc->uc_mcontext.gregs[REG_EIP];
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
uc->uc_mcontext.gregs[REG_TRAPNO] == 0xe ?
(uc->uc_mcontext.gregs[REG_ERR] >> 1) & 1 : 0,
&uc->uc_sigmask);
}
#elif defined(__powerpc)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
struct ucontext *uc = puc;
struct pt_regs *regs = uc->uc_mcontext.regs;
unsigned long pc;
int is_write;
pc = regs->nip;
is_write = 0;
#if 0
/* ppc 4xx case */
if (regs->dsisr & 0x00800000)
is_write = 1;
#else
if (regs->trap != 0x400 && (regs->dsisr & 0x02000000))
is_write = 1;
#endif
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask);
}
#elif defined(__alpha__)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
struct ucontext *uc = puc;
uint32_t *pc = uc->uc_mcontext.sc_pc;
uint32_t insn = *pc;
int is_write = 0;
/* XXX: need kernel patch to get write flag faster */
switch (insn >> 26) {
case 0x0d: // stw
case 0x0e: // stb
case 0x0f: // stq_u
case 0x24: // stf
case 0x25: // stg
case 0x26: // sts
case 0x27: // stt
case 0x2c: // stl
case 0x2d: // stq
case 0x2e: // stl_c
case 0x2f: // stq_c
is_write = 1;
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask);
}
#elif defined(__sparc__)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
uint32_t *regs = (uint32_t *)(info + 1);
void *sigmask = (regs + 20);
unsigned long pc;
int is_write;
uint32_t insn;
/* XXX: is there a standard glibc define ? */
pc = regs[1];
/* XXX: need kernel patch to get write flag faster */
is_write = 0;
insn = *(uint32_t *)pc;
if ((insn >> 30) == 3) {
switch((insn >> 19) & 0x3f) {
case 0x05: // stb
case 0x06: // sth
case 0x04: // st
case 0x07: // std
case 0x24: // stf
case 0x27: // stdf
case 0x25: // stfsr
is_write = 1;
break;
}
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, sigmask);
}
#elif defined(__arm__)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
struct ucontext *uc = puc;
unsigned long pc;
int is_write;
pc = uc->uc_mcontext.gregs[R15];
/* XXX: compute is_write */
is_write = 0;
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write,
&uc->uc_sigmask);
}
#elif defined(__mc68000)
int cpu_signal_handler(int host_signum, struct siginfo *info,
void *puc)
{
struct ucontext *uc = puc;
unsigned long pc;
int is_write;
pc = uc->uc_mcontext.gregs[16];
/* XXX: compute is_write */
is_write = 0;
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write,
&uc->uc_sigmask);
}
#else
#error host CPU specific signal handler needed
#endif
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