Re: [PATCH 17/16] hw/southbridge/ich9: Remove ICH9_LPC_SMI_F_BROADCAST_BIT definition

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 4 Mar 2026 18:20:27 +0100
Thomas Huth <thuth@redhat.com> wrote:

> On 03/03/2026 15.00, Igor Mammedov wrote:
> > From: Philippe Mathieu-Daudé <philmd@linaro.org>
> > 
> > v2:
> >     - do not check for SMI features if hotplug happens when
> >       SMI is not enabled. (matters for qtest and possibly seabios)
> >     - removing property also removes default ICH9_LPC_SMI_F_BROADCAST_BIT
> >       put default back in place only set it initfn() instead
> > 
> > The ICH9_LPC_SMI_F_BROADCAST_BIT feature bit was only set
> > in the pc_compat_2_8[] array, via the 'x-smi-broadcast=off'
> > property. We removed all machines using that array, lets remove
> > that property and all the code around it.
> > 
> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >   hw/acpi/ich9.c    |  4 ++--
> >   hw/isa/lpc_ich9.c | 23 ++++-------------------
> >   2 files changed, 6 insertions(+), 21 deletions(-)
> > 
> > diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
> > index bbb1bd60a2..87afe86bcc 100644
> > --- a/hw/acpi/ich9.c
> > +++ b/hw/acpi/ich9.c
> > @@ -432,7 +432,7 @@ void ich9_pm_device_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
> >       if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> >           uint64_t negotiated = lpc->smi_negotiated_features;
> >   
> > -        if (negotiated & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT) &&
> > +        if (lpc->pm.smi_en & ICH9_PMIO_SMI_EN_APMC_EN &&
> >               !(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT))) {
> >               error_setg(errp, "cpu hotplug with SMI wasn't enabled by firmware");
> >               error_append_hint(errp, "update machine type to newer than 5.1 "
> > @@ -476,7 +476,7 @@ void ich9_pm_device_unplug_request_cb(HotplugHandler *hotplug_dev,
> >       } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> >           uint64_t negotiated = lpc->smi_negotiated_features;
> >   
> > -        if (negotiated & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT) &&
> > +        if (lpc->pm.smi_en & ICH9_PMIO_SMI_EN_APMC_EN &&
> >               !(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) {
> >               error_setg(errp, "cpu hot-unplug with SMI wasn't enabled "
> >                                "by firmware");
> > diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> > index 51dc680029..04169ffa24 100644
> > --- a/hw/isa/lpc_ich9.c
> > +++ b/hw/isa/lpc_ich9.c
> > @@ -404,15 +404,6 @@ static void smi_features_ok_callback(void *opaque)
> >       guest_cpu_hotplug_features = guest_features &
> >                                    (BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT) |
> >                                     BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT));
> > -    if (!(guest_features & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT)) &&
> > -        guest_cpu_hotplug_features) {
> > -        /*
> > -         * cpu hot-[un]plug with SMI requires SMI broadcast,
> > -         * leave @features_ok at zero
> > -         */
> > -        return;
> > -    }
> > -
> >       if (guest_cpu_hotplug_features ==
> >           BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT)) {
> >           /* cpu hot-unplug is unsupported without cpu-hotplug */
> > @@ -474,14 +465,9 @@ static void ich9_apm_ctrl_changed(uint32_t val, void *arg)
> >   
> >       /* SMI_EN = PMBASE + 30. SMI control and enable register */
> >       if (lpc->pm.smi_en & ICH9_PMIO_SMI_EN_APMC_EN) {
> > -        if (lpc->smi_negotiated_features &
> > -            (UINT64_C(1) << ICH9_LPC_SMI_F_BROADCAST_BIT)) {
> > -            CPUState *cs;
> > -            CPU_FOREACH(cs) {
> > -                cpu_interrupt(cs, CPU_INTERRUPT_SMI);
> > -            }
> > -        } else {
> > -            cpu_interrupt(current_cpu, CPU_INTERRUPT_SMI);
> > +        CPUState *cs;
> > +        CPU_FOREACH(cs) {
> > +            cpu_interrupt(cs, CPU_INTERRUPT_SMI);
> >           }
> >       }
> >   }
> > @@ -685,6 +671,7 @@ static void ich9_lpc_initfn(Object *obj)
> >   
> >       static const uint8_t acpi_enable_cmd = ICH9_APM_ACPI_ENABLE;
> >       static const uint8_t acpi_disable_cmd = ICH9_APM_ACPI_DISABLE;
> > +    lpc->smi_host_features = BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT);  
> 
> Shouldn't that rather be a "|=" instead of the "=" so that we don't lose the 
> other bits?

Indeed it should be '|=',
can you fix it up on merge or should I better send fixed up version?

 
>   Thomas
> 
> 
> 
> >       object_initialize_child(obj, "rtc", &lpc->rtc, TYPE_MC146818_RTC);
> >   
> > @@ -834,8 +821,6 @@ static const Property ich9_lpc_properties[] = {
> >       DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, false),
> >       DEFINE_PROP_BOOL("smm-compat", ICH9LPCState, pm.smm_compat, false),
> >       DEFINE_PROP_BOOL("smm-enabled", ICH9LPCState, pm.smm_enabled, false),
> > -    DEFINE_PROP_BIT64("x-smi-broadcast", ICH9LPCState, smi_host_features,
> > -                      ICH9_LPC_SMI_F_BROADCAST_BIT, true),
> >       DEFINE_PROP_BIT64("x-smi-cpu-hotplug", ICH9LPCState, smi_host_features,
> >                         ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT, true),
> >       DEFINE_PROP_BIT64("x-smi-cpu-hotunplug", ICH9LPCState, smi_host_features,  
>