RF must be set on traps and interrupts from a string instruction, except if they occur after the last iteration. Ensure it is set before giving the main loop a chance to execute.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> Link: https://lore.kernel.org/r/20241215090613.89588-8-pbonz...@redhat.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- target/i386/tcg/translate.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 6347de446a4..141295742ae 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -1337,6 +1337,14 @@ static void do_gen_rep(DisasContext *s, MemOp ot, bool is_repz_nz) { TCGLabel *done = gen_new_label(); + bool had_rf = s->flags & HF_RF_MASK; + + /* + * Even if EFLAGS.RF was set on entry (such as if we're on the second or + * later iteration and an exception or interrupt happened), force gen_eob() + * not to clear the flag. We do that ourselves after the last iteration. + */ + s->flags &= ~HF_RF_MASK; gen_update_cc_op(s); gen_op_jz_ecx(s, done); @@ -1348,12 +1356,24 @@ static void do_gen_rep(DisasContext *s, MemOp ot, gen_jcc(s, (JCC_Z << 1) | (nz ^ 1), done); } + /* + * Traps or interrupts set RF_MASK if they happen after any iteration + * but the last. Set it here before giving the main loop a chance to + * execute. (For faults, seg_helper.c sets the flag as usual). + */ + if (!had_rf) { + gen_set_eflags(s, RF_MASK); + } + /* Go to the main loop but reenter the same instruction. */ gen_jmp_rel_csize(s, -cur_insn_len(s), 0); /* CX/ECX/RCX is zero, or REPZ/REPNZ broke the repetition. */ gen_set_label(done); set_cc_op(s, CC_OP_DYNAMIC); + if (had_rf) { + gen_reset_eflags(s, RF_MASK); + } gen_jmp_rel_csize(s, 0, 1); } @@ -2158,7 +2178,7 @@ gen_eob(DisasContext *s, int mode) gen_set_hflag(s, HF_INHIBIT_IRQ_MASK); } - if (s->base.tb->flags & HF_RF_MASK) { + if (s->flags & HF_RF_MASK) { gen_reset_eflags(s, RF_MASK); } if (mode == DISAS_EOB_RECHECK_TF) { -- 2.48.1
