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target/i386: Enable TARGET_TB_PCREL

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Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-27-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Richard Henderson 2022-10-01 07:09:35 -07:00 committed by Paolo Bonzini
parent 7db973bece
commit e3a79e0e87
3 changed files with 113 additions and 29 deletions
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4
target/i386/cpu-param.h
View File

@ -25,4 +25,8 @@
#define TARGET_PAGE_BITS 12
#define NB_MMU_MODES 3
#ifndef CONFIG_USER_ONLY
# define TARGET_TB_PCREL 1
#endif
#endif

8
target/i386/tcg/tcg-cpu.c
View File

@ -49,9 +49,11 @@ static void x86_cpu_exec_exit(CPUState *cs)
static void x86_cpu_synchronize_from_tb(CPUState *cs,
const TranslationBlock *tb)
{
X86CPU *cpu = X86_CPU(cs);
cpu->env.eip = tb_pc(tb) - tb->cs_base;
/* The instruction pointer is always up to date with TARGET_TB_PCREL. */
if (!TARGET_TB_PCREL) {
CPUX86State *env = cs->env_ptr;
env->eip = tb_pc(tb) - tb->cs_base;
}
}
#ifndef CONFIG_USER_ONLY

130
target/i386/tcg/translate.c
View File

@ -78,6 +78,7 @@ typedef struct DisasContext {
target_ulong pc; /* pc = eip + cs_base */
target_ulong cs_base; /* base of CS segment */
target_ulong pc_save;
MemOp aflag;
MemOp dflag;
@ -480,9 +481,10 @@ static void gen_add_A0_im(DisasContext *s, int val)
}
}
static inline void gen_op_jmp_v(TCGv dest)
static inline void gen_op_jmp_v(DisasContext *s, TCGv dest)
{
tcg_gen_mov_tl(cpu_eip, dest);
s->pc_save = -1;
}
static inline
@ -519,12 +521,24 @@ static inline void gen_op_st_rm_T0_A0(DisasContext *s, int idx, int d)
static void gen_update_eip_cur(DisasContext *s)
{
tcg_gen_movi_tl(cpu_eip, s->base.pc_next - s->cs_base);
assert(s->pc_save != -1);
if (TARGET_TB_PCREL) {
tcg_gen_addi_tl(cpu_eip, cpu_eip, s->base.pc_next - s->pc_save);
} else {
tcg_gen_movi_tl(cpu_eip, s->base.pc_next - s->cs_base);
}
s->pc_save = s->base.pc_next;
}
static void gen_update_eip_next(DisasContext *s)
{
tcg_gen_movi_tl(cpu_eip, s->pc - s->cs_base);
assert(s->pc_save != -1);
if (TARGET_TB_PCREL) {
tcg_gen_addi_tl(cpu_eip, cpu_eip, s->pc - s->pc_save);
} else {
tcg_gen_movi_tl(cpu_eip, s->pc - s->cs_base);
}
s->pc_save = s->pc;
}
static int cur_insn_len(DisasContext *s)
@ -539,6 +553,7 @@ static TCGv_i32 cur_insn_len_i32(DisasContext *s)
static TCGv_i32 eip_next_i32(DisasContext *s)
{
assert(s->pc_save != -1);
/*
* This function has two users: lcall_real (always 16-bit mode), and
* iret_protected (16, 32, or 64-bit mode). IRET only uses the value
@ -550,17 +565,38 @@ static TCGv_i32 eip_next_i32(DisasContext *s)
if (CODE64(s)) {
return tcg_constant_i32(-1);
}
return tcg_constant_i32(s->pc - s->cs_base);
if (TARGET_TB_PCREL) {
TCGv_i32 ret = tcg_temp_new_i32();
tcg_gen_trunc_tl_i32(ret, cpu_eip);
tcg_gen_addi_i32(ret, ret, s->pc - s->pc_save);
return ret;
} else {
return tcg_constant_i32(s->pc - s->cs_base);
}
}
static TCGv eip_next_tl(DisasContext *s)
{
return tcg_constant_tl(s->pc - s->cs_base);
assert(s->pc_save != -1);
if (TARGET_TB_PCREL) {
TCGv ret = tcg_temp_new();
tcg_gen_addi_tl(ret, cpu_eip, s->pc - s->pc_save);
return ret;
} else {
return tcg_constant_tl(s->pc - s->cs_base);
}
}
static TCGv eip_cur_tl(DisasContext *s)
{
return tcg_constant_tl(s->base.pc_next - s->cs_base);
assert(s->pc_save != -1);
if (TARGET_TB_PCREL) {
TCGv ret = tcg_temp_new();
tcg_gen_addi_tl(ret, cpu_eip, s->base.pc_next - s->pc_save);
return ret;
} else {
return tcg_constant_tl(s->base.pc_next - s->cs_base);
}
}
/* Compute SEG:REG into A0. SEG is selected from the override segment
@ -2260,7 +2296,12 @@ static TCGv gen_lea_modrm_1(DisasContext *s, AddressParts a)
ea = cpu_regs[a.base];
}
if (!ea) {
tcg_gen_movi_tl(s->A0, a.disp);
if (TARGET_TB_PCREL && a.base == -2) {
/* With cpu_eip ~= pc_save, the expression is pc-relative. */
tcg_gen_addi_tl(s->A0, cpu_eip, a.disp - s->pc_save);
} else {
tcg_gen_movi_tl(s->A0, a.disp);
}
ea = s->A0;
} else if (a.disp != 0) {
tcg_gen_addi_tl(s->A0, ea, a.disp);
@ -2748,32 +2789,58 @@ static void gen_jr(DisasContext *s)
/* Jump to eip+diff, truncating the result to OT. */
static void gen_jmp_rel(DisasContext *s, MemOp ot, int diff, int tb_num)
{
target_ulong dest = s->pc - s->cs_base + diff;
bool use_goto_tb = s->jmp_opt;
target_ulong mask = -1;
target_ulong new_pc = s->pc + diff;
target_ulong new_eip = new_pc - s->cs_base;
/* In 64-bit mode, operand size is fixed at 64 bits. */
if (!CODE64(s)) {
if (ot == MO_16) {
dest &= 0xffff;
mask = 0xffff;
if (TARGET_TB_PCREL && CODE32(s)) {
use_goto_tb = false;
}
} else {
dest &= 0xffffffff;
mask = 0xffffffff;
}
}
new_eip &= mask;
gen_update_cc_op(s);
set_cc_op(s, CC_OP_DYNAMIC);
if (!s->jmp_opt) {
tcg_gen_movi_tl(cpu_eip, dest);
gen_eob(s);
} else if (translator_use_goto_tb(&s->base, dest)) {
if (TARGET_TB_PCREL) {
tcg_gen_addi_tl(cpu_eip, cpu_eip, new_pc - s->pc_save);
/*
* If we can prove the branch does not leave the page and we have
* no extra masking to apply (data16 branch in code32, see above),
* then we have also proven that the addition does not wrap.
*/
if (!use_goto_tb || !is_same_page(&s->base, new_pc)) {
tcg_gen_andi_tl(cpu_eip, cpu_eip, mask);
use_goto_tb = false;
}
}
if (use_goto_tb &&
translator_use_goto_tb(&s->base, new_eip + s->cs_base)) {
/* jump to same page: we can use a direct jump */
tcg_gen_goto_tb(tb_num);
tcg_gen_movi_tl(cpu_eip, dest);
if (!TARGET_TB_PCREL) {
tcg_gen_movi_tl(cpu_eip, new_eip);
}
tcg_gen_exit_tb(s->base.tb, tb_num);
s->base.is_jmp = DISAS_NORETURN;
} else {
/* jump to another page */
tcg_gen_movi_tl(cpu_eip, dest);
gen_jr(s);
if (!TARGET_TB_PCREL) {
tcg_gen_movi_tl(cpu_eip, new_eip);
}
if (s->jmp_opt) {
gen_jr(s); /* jump to another page */
} else {
gen_eob(s); /* exit to main loop */
}
}
}
@ -5329,7 +5396,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
tcg_gen_ext16u_tl(s->T0, s->T0);
}
gen_push_v(s, eip_next_tl(s));
gen_op_jmp_v(s->T0);
gen_op_jmp_v(s, s->T0);
gen_bnd_jmp(s);
s->base.is_jmp = DISAS_JUMP;
break;
@ -5359,7 +5426,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
if (dflag == MO_16) {
tcg_gen_ext16u_tl(s->T0, s->T0);
}
gen_op_jmp_v(s->T0);
gen_op_jmp_v(s, s->T0);
gen_bnd_jmp(s);
s->base.is_jmp = DISAS_JUMP;
break;
@ -5377,7 +5444,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
eip_next_tl(s));
} else {
gen_op_movl_seg_T0_vm(s, R_CS);
gen_op_jmp_v(s->T1);
gen_op_jmp_v(s, s->T1);
}
s->base.is_jmp = DISAS_JUMP;
break;
@ -6792,7 +6859,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
ot = gen_pop_T0(s);
gen_stack_update(s, val + (1 << ot));
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(s->T0);
gen_op_jmp_v(s, s->T0);
gen_bnd_jmp(s);
s->base.is_jmp = DISAS_JUMP;
break;
@ -6800,7 +6867,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
ot = gen_pop_T0(s);
gen_pop_update(s, ot);
/* Note that gen_pop_T0 uses a zero-extending load. */
gen_op_jmp_v(s->T0);
gen_op_jmp_v(s, s->T0);
gen_bnd_jmp(s);
s->base.is_jmp = DISAS_JUMP;
break;
@ -6818,7 +6885,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
gen_op_ld_v(s, dflag, s->T0, s->A0);
/* NOTE: keeping EIP updated is not a problem in case of
exception */
gen_op_jmp_v(s->T0);
gen_op_jmp_v(s, s->T0);
/* pop selector */
gen_add_A0_im(s, 1 << dflag);
gen_op_ld_v(s, dflag, s->T0, s->A0);
@ -8680,6 +8747,7 @@ static void i386_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cpu)
int iopl = (flags >> IOPL_SHIFT) & 3;
dc->cs_base = dc->base.tb->cs_base;
dc->pc_save = dc->base.pc_next;
dc->flags = flags;
#ifndef CONFIG_USER_ONLY
dc->cpl = cpl;
@ -8743,9 +8811,14 @@ static void i386_tr_tb_start(DisasContextBase *db, CPUState *cpu)
static void i386_tr_insn_start(DisasContextBase *dcbase, CPUState *cpu)
{
DisasContext *dc = container_of(dcbase, DisasContext, base);
target_ulong pc_arg = dc->base.pc_next;
dc->prev_insn_end = tcg_last_op();
tcg_gen_insn_start(dc->base.pc_next, dc->cc_op);
if (TARGET_TB_PCREL) {
pc_arg -= dc->cs_base;
pc_arg &= ~TARGET_PAGE_MASK;
}
tcg_gen_insn_start(pc_arg, dc->cc_op);
}
static void i386_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
@ -8846,7 +8919,12 @@ void restore_state_to_opc(CPUX86State *env, TranslationBlock *tb,
target_ulong *data)
{
int cc_op = data[1];
env->eip = data[0] - tb->cs_base;
if (TARGET_TB_PCREL) {
env->eip = (env->eip & TARGET_PAGE_MASK) | data[0];
} else {
env->eip = data[0] - tb->cs_base;
}
if (cc_op != CC_OP_DYNAMIC) {
env->cc_op = cc_op;
}