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target/i386: avoid calling gen_eob_syscall before tb_stop

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syscall and sysret only have one exit, so they do not need to
generate the end-of-translation code inline.  It can be
deferred to tb_stop.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-05-16 18:46:55 +02:00
parent 9594b59331
commit c8494cb8b1
1 changed files with 11 additions and 2 deletions
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13
target/i386/tcg/translate.c
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@ -168,6 +168,12 @@ typedef struct DisasContext {
*/
#define DISAS_JUMP DISAS_TARGET_3
/*
* EIP has already been updated. Use updated value of
* EFLAGS.TF to determine singlestep trap (SYSCALL/SYSRET).
*/
#define DISAS_EOB_RECHECK_TF DISAS_TARGET_4
/* The environment in which user-only runs is constrained. */
#ifdef CONFIG_USER_ONLY
#define PE(S) true
@ -3587,7 +3593,7 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
/* TF handling for the syscall insn is different. The TF bit is checked
after the syscall insn completes. This allows #DB to not be
generated after one has entered CPL0 if TF is set in FMASK. */
gen_eob_syscall(s);
s->base.is_jmp = DISAS_EOB_RECHECK_TF;
break;
case 0x107: /* sysret */
/* For Intel SYSRET is only valid in long mode */
@ -3606,7 +3612,7 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
checked after the sysret insn completes. This allows #DB to be
generated "as if" the syscall insn in userspace has just
completed. */
gen_eob_syscall(s);
s->base.is_jmp = DISAS_EOB_RECHECK_TF;
}
break;
case 0x1a2: /* cpuid */
@ -4810,6 +4816,9 @@ static void i386_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
case DISAS_EOB_ONLY:
gen_eob(dc);
break;
case DISAS_EOB_RECHECK_TF:
gen_eob_syscall(dc);
break;
case DISAS_EOB_INHIBIT_IRQ:
gen_update_eip_cur(dc);
gen_eob_inhibit_irq(dc);