On Mon, Jan 28, 2019 at 10:46:14AM +0100, Cédric Le Goater wrote: > From: Benjamin Herrenschmidt <b...@kernel.crashing.org> > > Those instructions currently raise an exception from within > the helper. This tends to result in a bogus nip value in > the env context (typically the beginning of the TB). Such > a helper needs a gen_update_nip() first. > > This fixes it with a different approach which is to throw > the exception from translate.c instead of the helper using > gen_exception_nip() which does the right thing. > > Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Signed-off-by: Cédric Le Goater <c...@kaod.org> > --- > target/ppc/excp_helper.c | 1 - > target/ppc/translate.c | 12 ++++++++---- > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c > index 751d759fcc1d..8407e0ade938 100644 > --- a/target/ppc/excp_helper.c > +++ b/target/ppc/excp_helper.c > @@ -958,7 +958,6 @@ void helper_pminsn(CPUPPCState *env, powerpc_pm_insn_t > insn) > * but this doesn't seem to be a problem. > */ > env->msr |= (1ull << MSR_EE); > - raise_exception(env, EXCP_HLT); > } > #endif /* defined(TARGET_PPC64) */ > > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > index 7d40a1fbe6bd..55281a8975e0 100644 > --- a/target/ppc/translate.c > +++ b/target/ppc/translate.c > @@ -3571,7 +3571,8 @@ static void gen_doze(DisasContext *ctx) > t = tcg_const_i32(PPC_PM_DOZE); > gen_helper_pminsn(cpu_env, t); > tcg_temp_free_i32(t); > - gen_stop_exception(ctx); > + /* Stop translation, as the CPU is supposed to sleep from now */ > + gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next);
IIUC this also changes from EXCP_STOP to EXCP_HLT, is that intentional?
> #endif /* defined(CONFIG_USER_ONLY) */
> }
>
> @@ -3586,7 +3587,8 @@ static void gen_nap(DisasContext *ctx)
> t = tcg_const_i32(PPC_PM_NAP);
> gen_helper_pminsn(cpu_env, t);
> tcg_temp_free_i32(t);
> - gen_stop_exception(ctx);
> + /* Stop translation, as the CPU is supposed to sleep from now */
> + gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next);
> #endif /* defined(CONFIG_USER_ONLY) */
> }
>
> @@ -3606,7 +3608,8 @@ static void gen_sleep(DisasContext *ctx)
> t = tcg_const_i32(PPC_PM_SLEEP);
> gen_helper_pminsn(cpu_env, t);
> tcg_temp_free_i32(t);
> - gen_stop_exception(ctx);
> + /* Stop translation, as the CPU is supposed to sleep from now */
> + gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next);
> #endif /* defined(CONFIG_USER_ONLY) */
> }
>
> @@ -3621,7 +3624,8 @@ static void gen_rvwinkle(DisasContext *ctx)
> t = tcg_const_i32(PPC_PM_RVWINKLE);
> gen_helper_pminsn(cpu_env, t);
> tcg_temp_free_i32(t);
> - gen_stop_exception(ctx);
> + /* Stop translation, as the CPU is supposed to sleep from now */
> + gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next);
> #endif /* defined(CONFIG_USER_ONLY) */
> }
> #endif /* #if defined(TARGET_PPC64) */
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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