On 5/24/24 08:33, Paolo Bonzini wrote:
Using DISAS_NORETURN does not process any of HF_INHIBIT_IRQ_MASK,
HF_RF_MASK or HF_TF_MASK. Never use it, instead there is
DISAS_EOB_ONLY.
Cc: qemu-sta...@nongnu.org
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
target/i386/tcg/translate.c | 18 ++++++++++++------
target/i386/tcg/emit.c.inc | 4 ++--
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index ebcff8766cf..df10e7d8a6a 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -1406,7 +1406,7 @@ static void gen_exception(DisasContext *s, int trapno)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_raise_exception(tcg_env, tcg_constant_i32(trapno));
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
This is wrong, because we exit via exception, right here.
Anything you add afterward is unreachable.
}
/* Generate #UD for the current instruction. The assumption here is that
@@ -2191,7 +2191,7 @@ static void gen_interrupt(DisasContext *s, uint8_t intno)
gen_update_eip_cur(s);
gen_helper_raise_interrupt(tcg_env, tcg_constant_i32(intno),
cur_insn_len_i32(s));
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
Likewise.
}
static void gen_set_hflag(DisasContext *s, uint32_t mask)
@@ -2354,7 +2354,7 @@ static void gen_jmp_rel(DisasContext *s, MemOp ot, int
diff, int tb_num)
tcg_gen_movi_tl(cpu_eip, new_eip);
}
tcg_gen_exit_tb(s->base.tb, tb_num);
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
This is wrong because exit_tb exits, and anything you add after is unreachable.
I think you simply want to remove the exit_tb call as well, but there may be more cleanup
possible in the wider context; I haven't checked.
} else {
if (!(tb_cflags(s->base.tb) & CF_PCREL)) {
tcg_gen_movi_tl(cpu_eip, new_eip);
@@ -3520,7 +3520,7 @@ static void disas_insn_old(DisasContext *s, CPUState
*cpu, int b)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_rdpmc(tcg_env);
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
This is wrong because helper_rdpmc is noreturn, always raising an exception.
@@ -3690,7 +3690,7 @@ static void disas_insn_old(DisasContext *s, CPUState
*cpu, int b)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_mwait(tcg_env, cur_insn_len_i32(s));
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
Likewise.
@@ -3769,7 +3769,7 @@ static void disas_insn_old(DisasContext *s, CPUState
*cpu, int b)
gen_helper_vmrun(tcg_env, tcg_constant_i32(s->aflag - 1),
cur_insn_len_i32(s));
tcg_gen_exit_tb(NULL, 0);
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
Calls exit_tb, which is probably bogus here and EOB_ONLY is correct.
But I'd need to look deeper into what vmrun does.
switch (dc->base.is_jmp) {
case DISAS_NORETURN:
+ /*
+ * Nothing to do, gen_eob*() was already called. DISAS_NORETURN is
+ * never set explicitly except in gen_eob_worker(), because that is
+ * where HF_INHIBIT_IRQ_MASK, HF_RF_MASK and HF_TF_MASK are handled.
+ */
Comment is wrong because exceptions *should* set NORETURN.
All of the masks are irrelevant to #gp or #ud etc.
@@ -1642,7 +1642,7 @@ static void gen_HLT(DisasContext *s, CPUX86State *env,
X86DecodedInsn *decode)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_hlt(tcg_env, cur_insn_len_i32(s));
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
noreturn.
@@ -4022,7 +4022,7 @@ static void gen_XCHG(DisasContext *s, CPUX86State *env,
X86DecodedInsn *decode)
gen_update_cc_op(s);
gen_update_eip_cur(s);
gen_helper_pause(tcg_env, cur_insn_len_i32(s));
- s->base.is_jmp = DISAS_NORETURN;
+ s->base.is_jmp = DISAS_EOB_ONLY;
noreturn.
r~
