From 2e255c6b9f05f78a7effc4d1246c8a420680b810 Mon Sep 17 00:00:00 2001 From: bellard Date: Thu, 21 Aug 2003 23:25:21 +0000 Subject: [PATCH] faster and more accurate segment handling git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@373 c046a42c-6fe2-441c-8c8c-71466251a162 --- cpu-exec.c | 20 ++----- cpu-i386.h | 45 ++++++++++++++-- helper-i386.c | 155 ++++++++++++++++++++++++++++++++---------------------- linux-user/main.c | 2 + op-i386.c | 1 + translate-i386.c | 3 +- vl.c | 24 ++++----- 7 files changed, 153 insertions(+), 97 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index 7899a90..e3d2391 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -182,7 +182,7 @@ int cpu_exec(CPUState *env1) tmp_T0 = T0; #endif interrupt_request = env->interrupt_request; - if (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) && @@ -238,15 +238,7 @@ int cpu_exec(CPUState *env1) always be the same before a given translated block is executed. */ #if defined(TARGET_I386) - flags = (env->segs[R_CS].flags & DESC_B_MASK) - >> (DESC_B_SHIFT - HF_CS32_SHIFT); - flags |= (env->segs[R_SS].flags & DESC_B_MASK) - >> (DESC_B_SHIFT - HF_SS32_SHIFT); - flags |= (((unsigned long)env->segs[R_DS].base | - (unsigned long)env->segs[R_ES].base | - (unsigned long)env->segs[R_SS].base) != 0) << - HF_ADDSEG_SHIFT; - flags |= env->hflags; + flags = env->hflags; flags |= (env->eflags & (IOPL_MASK | TF_MASK | VM_MASK)); cs_base = env->segs[R_CS].base; pc = cs_base + env->eip; @@ -402,13 +394,9 @@ void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector) saved_env = env; env = s; if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) { - SegmentCache *sc; selector &= 0xffff; - sc = &env->segs[seg_reg]; - sc->base = (void *)(selector << 4); - sc->limit = 0xffff; - sc->flags = 0; - sc->selector = selector; + cpu_x86_load_seg_cache(env, seg_reg, selector, + (uint8_t *)(selector << 4), 0xffff, 0); } else { load_seg(seg_reg, selector, 0); } diff --git a/cpu-i386.h b/cpu-i386.h index ad3a6b8..ffc4654 100644 --- a/cpu-i386.h +++ b/cpu-i386.h @@ -109,7 +109,7 @@ #define HF_SOFTMMU_MASK (1 << HF_SOFTMMU_SHIFT) #define HF_INHIBIT_IRQ_MASK (1 << HF_INHIBIT_IRQ_SHIFT) #define HF_CS32_MASK (1 << HF_CS32_SHIFT) -#define HF_SS32_MASK (1 << HF_CS32_SHIFT) +#define HF_SS32_MASK (1 << HF_SS32_SHIFT) #define HF_ADDSEG_MASK (1 << HF_ADDSEG_SHIFT) #define CR0_PE_MASK (1 << 0) @@ -323,8 +323,43 @@ int cpu_x86_exec(CPUX86State *s); void cpu_x86_close(CPUX86State *s); int cpu_x86_get_pic_interrupt(CPUX86State *s); -/* needed to load some predefinied segment registers */ -void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector); +/* this function must always be used to load data in the segment + cache: it synchronizes the hflags with the segment cache values */ +static inline void cpu_x86_load_seg_cache(CPUX86State *env, + int seg_reg, unsigned int selector, + uint8_t *base, unsigned int limit, + unsigned int flags) +{ + SegmentCache *sc; + unsigned int new_hflags; + + sc = &env->segs[seg_reg]; + sc->selector = selector; + sc->base = base; + sc->limit = limit; + sc->flags = flags; + + /* update the hidden flags */ + new_hflags = (env->segs[R_CS].flags & DESC_B_MASK) + >> (DESC_B_SHIFT - HF_CS32_SHIFT); + new_hflags |= (env->segs[R_SS].flags & DESC_B_MASK) + >> (DESC_B_SHIFT - HF_SS32_SHIFT); + if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) { + /* XXX: try to avoid this test. The problem comes from the + fact that is real mode or vm86 mode we only modify the + 'base' and 'selector' fields of the segment cache to go + faster. A solution may be to force addseg to one in + translate-i386.c. */ + new_hflags |= HF_ADDSEG_MASK; + } else { + new_hflags |= (((unsigned long)env->segs[R_DS].base | + (unsigned long)env->segs[R_ES].base | + (unsigned long)env->segs[R_SS].base) != 0) << + HF_ADDSEG_SHIFT; + } + env->hflags = (env->hflags & + ~(HF_CS32_MASK | HF_SS32_MASK | HF_ADDSEG_MASK)) | new_hflags; +} /* wrapper, just in case memory mappings must be changed */ static inline void cpu_x86_set_cpl(CPUX86State *s, int cpl) @@ -336,7 +371,9 @@ static inline void cpu_x86_set_cpl(CPUX86State *s, int cpl) #endif } -/* simulate fsave/frstor */ +/* the following helpers are only usable in user mode simulation as + they can trigger unexpected exceptions */ +void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector); void cpu_x86_fsave(CPUX86State *s, uint8_t *ptr, int data32); void cpu_x86_frstor(CPUX86State *s, uint8_t *ptr, int data32); diff --git a/helper-i386.c b/helper-i386.c index 0d128ea..67c3aec 100644 --- a/helper-i386.c +++ b/helper-i386.c @@ -182,6 +182,34 @@ static inline int load_segment(uint32_t *e1_ptr, uint32_t *e2_ptr, return 0; } +static inline unsigned int get_seg_limit(uint32_t e1, uint32_t e2) +{ + unsigned int limit; + limit = (e1 & 0xffff) | (e2 & 0x000f0000); + if (e2 & DESC_G_MASK) + limit = (limit << 12) | 0xfff; + return limit; +} + +static inline uint8_t *get_seg_base(uint32_t e1, uint32_t e2) +{ + return (uint8_t *)((e1 >> 16) | ((e2 & 0xff) << 16) | (e2 & 0xff000000)); +} + +static inline void load_seg_cache_raw_dt(SegmentCache *sc, uint32_t e1, uint32_t e2) +{ + sc->base = get_seg_base(e1, e2); + sc->limit = get_seg_limit(e1, e2); + sc->flags = e2; +} + +/* init the segment cache in vm86 mode. */ +static inline void load_seg_vm(int seg, int selector) +{ + selector &= 0xffff; + cpu_x86_load_seg_cache(env, seg, selector, + (uint8_t *)(selector << 4), 0xffff, 0); +} /* protected mode interrupt */ static void do_interrupt_protected(int intno, int is_int, int error_code, @@ -288,7 +316,11 @@ static void do_interrupt_protected(int intno, int is_int, int error_code, if (new_stack) { old_esp = ESP; old_ss = env->segs[R_SS].selector; - load_seg(R_SS, ss, env->eip); + ss = (ss & ~3) | dpl; + cpu_x86_load_seg_cache(env, R_SS, ss, + get_seg_base(ss_e1, ss_e2), + get_seg_limit(ss_e1, ss_e2), + ss_e2); } else { old_esp = 0; old_ss = 0; @@ -299,7 +331,12 @@ static void do_interrupt_protected(int intno, int is_int, int error_code, else old_eip = env->eip; old_cs = env->segs[R_CS].selector; - load_seg(R_CS, selector, env->eip); + selector = (selector & ~3) | dpl; + cpu_x86_load_seg_cache(env, R_CS, selector, + get_seg_base(e1, e2), + get_seg_limit(e1, e2), + e2); + cpu_x86_set_cpl(env, dpl); env->eip = offset; ESP = esp - push_size; ssp = env->segs[R_SS].base + esp; @@ -593,15 +630,6 @@ void helper_cpuid(void) } } -static inline void load_seg_cache(SegmentCache *sc, uint32_t e1, uint32_t e2) -{ - sc->base = (void *)((e1 >> 16) | ((e2 & 0xff) << 16) | (e2 & 0xff000000)); - sc->limit = (e1 & 0xffff) | (e2 & 0x000f0000); - if (e2 & DESC_G_MASK) - sc->limit = (sc->limit << 12) | 0xfff; - sc->flags = e2; -} - void helper_lldt_T0(void) { int selector; @@ -629,7 +657,7 @@ void helper_lldt_T0(void) raise_exception_err(EXCP0D_GPF, selector & 0xfffc); if (!(e2 & DESC_P_MASK)) raise_exception_err(EXCP0B_NOSEG, selector & 0xfffc); - load_seg_cache(&env->ldt, e1, e2); + load_seg_cache_raw_dt(&env->ldt, e1, e2); } env->ldt.selector = selector; } @@ -664,30 +692,26 @@ void helper_ltr_T0(void) raise_exception_err(EXCP0D_GPF, selector & 0xfffc); if (!(e2 & DESC_P_MASK)) raise_exception_err(EXCP0B_NOSEG, selector & 0xfffc); - load_seg_cache(&env->tr, e1, e2); + load_seg_cache_raw_dt(&env->tr, e1, e2); e2 |= 0x00000200; /* set the busy bit */ stl(ptr + 4, e2); } env->tr.selector = selector; } -/* only works if protected mode and not VM86 */ +/* only works if protected mode and not VM86. Calling load_seg with + seg_reg == R_CS is discouraged */ void load_seg(int seg_reg, int selector, unsigned int cur_eip) { - SegmentCache *sc; uint32_t e1, e2; - sc = &env->segs[seg_reg]; if ((selector & 0xfffc) == 0) { /* null selector case */ if (seg_reg == R_SS) { EIP = cur_eip; raise_exception_err(EXCP0D_GPF, 0); } else { - /* XXX: each access should trigger an exception */ - sc->base = NULL; - sc->limit = 0; - sc->flags = 0; + cpu_x86_load_seg_cache(env, seg_reg, selector, NULL, 0, 0); } } else { if (load_segment(&e1, &e2, selector) != 0) { @@ -719,24 +743,22 @@ void load_seg(int seg_reg, int selector, unsigned int cur_eip) else raise_exception_err(EXCP0B_NOSEG, selector & 0xfffc); } - load_seg_cache(sc, e1, e2); + cpu_x86_load_seg_cache(env, seg_reg, selector, + get_seg_base(e1, e2), + get_seg_limit(e1, e2), + e2); #if 0 fprintf(logfile, "load_seg: sel=0x%04x base=0x%08lx limit=0x%08lx flags=%08x\n", selector, (unsigned long)sc->base, sc->limit, sc->flags); #endif } - if (seg_reg == R_CS) { - cpu_x86_set_cpl(env, selector & 3); - } - sc->selector = selector; } /* protected mode jump */ void helper_ljmp_protected_T0_T1(void) { int new_cs, new_eip; - SegmentCache sc1; - uint32_t e1, e2, cpl, dpl, rpl; + uint32_t e1, e2, cpl, dpl, rpl, limit; new_cs = T0; new_eip = T1; @@ -763,13 +785,11 @@ void helper_ljmp_protected_T0_T1(void) } if (!(e2 & DESC_P_MASK)) raise_exception_err(EXCP0B_NOSEG, new_cs & 0xfffc); - load_seg_cache(&sc1, e1, e2); - if (new_eip > sc1.limit) + limit = get_seg_limit(e1, e2); + if (new_eip > limit) raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc); - env->segs[R_CS].base = sc1.base; - env->segs[R_CS].limit = sc1.limit; - env->segs[R_CS].flags = sc1.flags; - env->segs[R_CS].selector = (new_cs & 0xfffc) | cpl; + cpu_x86_load_seg_cache(env, R_CS, (new_cs & 0xfffc) | cpl, + get_seg_base(e1, e2), limit, e2); EIP = new_eip; } else { cpu_abort(env, "jmp to call/task gate not supported 0x%04x:0x%08x", @@ -816,10 +836,9 @@ void helper_lcall_real_T0_T1(int shift, int next_eip) void helper_lcall_protected_T0_T1(int shift, int next_eip) { int new_cs, new_eip; - SegmentCache sc1; uint32_t e1, e2, cpl, dpl, rpl, selector, offset, param_count; uint32_t ss, ss_e1, ss_e2, push_size, sp, type, ss_dpl; - uint32_t old_ss, old_esp, val, i; + uint32_t old_ss, old_esp, val, i, limit; uint8_t *ssp, *old_ssp; new_cs = T0; @@ -865,18 +884,16 @@ void helper_lcall_protected_T0_T1(int shift, int next_eip) } sp -= (4 << shift); - load_seg_cache(&sc1, e1, e2); - if (new_eip > sc1.limit) + limit = get_seg_limit(e1, e2); + if (new_eip > limit) raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc); /* from this point, not restartable */ if (!(env->segs[R_SS].flags & DESC_B_MASK)) ESP = (ESP & 0xffff0000) | (sp & 0xffff); else ESP = sp; - env->segs[R_CS].base = sc1.base; - env->segs[R_CS].limit = sc1.limit; - env->segs[R_CS].flags = sc1.flags; - env->segs[R_CS].selector = (new_cs & 0xfffc) | cpl; + cpu_x86_load_seg_cache(env, R_CS, (new_cs & 0xfffc) | cpl, + get_seg_base(e1, e2), limit, e2); EIP = new_eip; } else { /* check gate type */ @@ -947,7 +964,11 @@ void helper_lcall_protected_T0_T1(int shift, int next_eip) old_ssp = env->segs[R_SS].base + old_esp; /* XXX: from this point not restartable */ - load_seg(R_SS, ss, env->eip); + ss = (ss & ~3) | dpl; + cpu_x86_load_seg_cache(env, R_SS, ss, + get_seg_base(ss_e1, ss_e2), + get_seg_limit(ss_e1, ss_e2), + ss_e2); if (!(env->segs[R_SS].flags & DESC_B_MASK)) sp &= 0xffff; @@ -994,7 +1015,13 @@ void helper_lcall_protected_T0_T1(int shift, int next_eip) } sp -= push_size; - load_seg(R_CS, selector, env->eip); + selector = (selector & ~3) | dpl; + cpu_x86_load_seg_cache(env, R_CS, selector, + get_seg_base(e1, e2), + get_seg_limit(e1, e2), + e2); + cpu_x86_set_cpl(env, dpl); + /* from this point, not restartable if same priviledge */ if (!(env->segs[R_SS].flags & DESC_B_MASK)) ESP = (ESP & 0xffff0000) | (sp & 0xffff); @@ -1004,17 +1031,6 @@ void helper_lcall_protected_T0_T1(int shift, int next_eip) } } -/* init the segment cache in vm86 mode */ -static inline void load_seg_vm(int seg, int selector) -{ - SegmentCache *sc = &env->segs[seg]; - selector &= 0xffff; - sc->base = (uint8_t *)(selector << 4); - sc->selector = selector; - sc->flags = 0; - sc->limit = 0xffff; -} - /* real mode iret */ void helper_iret_real(int shift) { @@ -1051,7 +1067,7 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend) { uint32_t sp, new_cs, new_eip, new_eflags, new_esp, new_ss; uint32_t new_es, new_ds, new_fs, new_gs; - uint32_t e1, e2; + uint32_t e1, e2, ss_e1, ss_e2; int cpl, dpl, rpl, eflags_mask; uint8_t *ssp; @@ -1098,7 +1114,10 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend) if (rpl == cpl) { /* return to same priledge level */ - load_seg(R_CS, new_cs, env->eip); + cpu_x86_load_seg_cache(env, R_CS, new_cs, + get_seg_base(e1, e2), + get_seg_limit(e1, e2), + e2); new_esp = sp + (4 << shift) + ((2 * is_iret) << shift) + addend; } else { /* return to different priviledge level */ @@ -1115,20 +1134,27 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend) if ((new_ss & 3) != rpl) raise_exception_err(EXCP0D_GPF, new_ss & 0xfffc); - if (load_segment(&e1, &e2, new_ss) != 0) + if (load_segment(&ss_e1, &ss_e2, new_ss) != 0) raise_exception_err(EXCP0D_GPF, new_ss & 0xfffc); - if (!(e2 & DESC_S_MASK) || - (e2 & DESC_CS_MASK) || - !(e2 & DESC_W_MASK)) + if (!(ss_e2 & DESC_S_MASK) || + (ss_e2 & DESC_CS_MASK) || + !(ss_e2 & DESC_W_MASK)) raise_exception_err(EXCP0D_GPF, new_ss & 0xfffc); - dpl = (e2 >> DESC_DPL_SHIFT) & 3; + dpl = (ss_e2 >> DESC_DPL_SHIFT) & 3; if (dpl != rpl) raise_exception_err(EXCP0D_GPF, new_ss & 0xfffc); - if (!(e2 & DESC_P_MASK)) + if (!(ss_e2 & DESC_P_MASK)) raise_exception_err(EXCP0B_NOSEG, new_ss & 0xfffc); - load_seg(R_CS, new_cs, env->eip); - load_seg(R_SS, new_ss, env->eip); + cpu_x86_load_seg_cache(env, R_CS, new_cs, + get_seg_base(e1, e2), + get_seg_limit(e1, e2), + e2); + cpu_x86_load_seg_cache(env, R_SS, new_ss, + get_seg_base(ss_e1, ss_e2), + get_seg_limit(ss_e1, ss_e2), + ss_e2); + cpu_x86_set_cpl(env, rpl); } if (env->segs[R_SS].flags & DESC_B_MASK) ESP = new_esp; @@ -1137,6 +1163,7 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend) (new_esp & 0xffff); env->eip = new_eip; if (is_iret) { + /* NOTE: 'cpl' can be different from the current CPL */ if (cpl == 0) eflags_mask = FL_UPDATE_CPL0_MASK; else diff --git a/linux-user/main.c b/linux-user/main.c index b85637f..f4c936c 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -433,6 +433,8 @@ int main(int argc, char **argv) env->user_mode_only = 1; #if defined(TARGET_I386) + cpu_x86_set_cpl(env, 3); + env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK; /* linux register setup */ diff --git a/op-i386.c b/op-i386.c index 7b0c391..2f84e15 100644 --- a/op-i386.c +++ b/op-i386.c @@ -890,6 +890,7 @@ void OPPROTO op_das(void) /* segment handling */ +/* never use it with R_CS */ void OPPROTO op_movl_seg_T0(void) { load_seg(PARAM1, T0 & 0xffff, PARAM2); diff --git a/translate-i386.c b/translate-i386.c index 0e72acf..fd13adb 100644 --- a/translate-i386.c +++ b/translate-i386.c @@ -1544,7 +1544,8 @@ static void gen_setcc(DisasContext *s, int b) } } -/* move T0 to seg_reg and compute if the CPU state may change */ +/* move T0 to seg_reg and compute if the CPU state may change. Never + call this function with seg_reg == R_CS */ static void gen_movl_seg_T0(DisasContext *s, int seg_reg, unsigned int cur_eip) { if (s->pe && !s->vm86) diff --git a/vl.c b/vl.c index 97c3be8..d517eee 100644 --- a/vl.c +++ b/vl.c @@ -3590,12 +3590,12 @@ int main(int argc, char **argv) env->gdt.base = (void *)params->gdt_table; env->gdt.limit = sizeof(params->gdt_table) - 1; - cpu_x86_load_seg(env, R_CS, KERNEL_CS); - cpu_x86_load_seg(env, R_DS, KERNEL_DS); - cpu_x86_load_seg(env, R_ES, KERNEL_DS); - cpu_x86_load_seg(env, R_SS, KERNEL_DS); - cpu_x86_load_seg(env, R_FS, KERNEL_DS); - cpu_x86_load_seg(env, R_GS, KERNEL_DS); + cpu_x86_load_seg_cache(env, R_CS, KERNEL_CS, NULL, 0xffffffff, 0x00cf9a00); + cpu_x86_load_seg_cache(env, R_DS, KERNEL_DS, NULL, 0xffffffff, 0x00cf9200); + cpu_x86_load_seg_cache(env, R_ES, KERNEL_DS, NULL, 0xffffffff, 0x00cf9200); + cpu_x86_load_seg_cache(env, R_SS, KERNEL_DS, NULL, 0xffffffff, 0x00cf9200); + cpu_x86_load_seg_cache(env, R_FS, KERNEL_DS, NULL, 0xffffffff, 0x00cf9200); + cpu_x86_load_seg_cache(env, R_GS, KERNEL_DS, NULL, 0xffffffff, 0x00cf9200); env->eip = KERNEL_LOAD_ADDR; env->regs[R_ESI] = KERNEL_PARAMS_ADDR; @@ -3627,12 +3627,12 @@ int main(int argc, char **argv) env->ldt.limit = 0xffff; /* not correct (CS base=0xffff0000) */ - cpu_x86_load_seg(env, R_CS, 0xf000); - cpu_x86_load_seg(env, R_DS, 0); - cpu_x86_load_seg(env, R_ES, 0); - cpu_x86_load_seg(env, R_SS, 0); - cpu_x86_load_seg(env, R_FS, 0); - cpu_x86_load_seg(env, R_GS, 0); + cpu_x86_load_seg_cache(env, R_CS, 0xf000, (uint8_t *)0x000f0000, 0xffff, 0); + cpu_x86_load_seg_cache(env, R_DS, 0, NULL, 0xffff, 0); + cpu_x86_load_seg_cache(env, R_ES, 0, NULL, 0xffff, 0); + cpu_x86_load_seg_cache(env, R_SS, 0, NULL, 0xffff, 0); + cpu_x86_load_seg_cache(env, R_FS, 0, NULL, 0xffff, 0); + cpu_x86_load_seg_cache(env, R_GS, 0, NULL, 0xffff, 0); env->eip = 0xfff0; env->regs[R_EDX] = 0x600; /* indicate P6 processor */ -- 2.7.4