Re: [PATCH 03/18] hw/southbridge/ich9: Remove ICH9_LPC_SMI_F_BROADCAST_BIT definition

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 24 Feb 2026 16:24:10 +0100
Thomas Huth <thuth@redhat.com> wrote:

> On 01/05/2025 23.04, Philippe Mathieu-Daudé wrote:
> > 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>
> > ---
> >   include/hw/southbridge/ich9.h |  1 -
> >   hw/acpi/ich9.c                |  6 ++----
> >   hw/isa/lpc_ich9.c             | 22 +++-------------------
> >   3 files changed, 5 insertions(+), 24 deletions(-)  
> 
> FWIW, this patch seems to break tests/qtest/cpu-plug-test ... I get the 
> error message "cpu hotplug with SMI wasn't enabled by firmware".
> Sounds like the guest has the enable this feature, too, so I assume we 
> cannot simply assume that it is always available now?

I'll post fixed up patch as reply to your latest respin of this series

> 
>   Thomas
> 
> 
> 
> > diff --git a/include/hw/southbridge/ich9.h b/include/hw/southbridge/ich9.h
> > index 1e231e89c92..4764c03ac2d 100644
> > --- a/include/hw/southbridge/ich9.h
> > +++ b/include/hw/southbridge/ich9.h
> > @@ -244,7 +244,6 @@ struct ICH9LPCState {
> >   #define ICH9_LPC_SMI_NEGOTIATED_FEAT_PROP "x-smi-negotiated-features"
> >   
> >   /* bit positions used in fw_cfg SMI feature negotiation */
> > -#define ICH9_LPC_SMI_F_BROADCAST_BIT            0
> >   #define ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT          1
> >   #define ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT       2
> >   
> > diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
> > index c7a735bf642..40564605735 100644
> > --- a/hw/acpi/ich9.c
> > +++ b/hw/acpi/ich9.c
> > @@ -477,8 +477,7 @@ 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) &&
> > -            !(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT))) {
> > +        if (!(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 "
> >                   "and firmware that suppors CPU hotplug with SMM");
> > @@ -526,8 +525,7 @@ void ich9_pm_device_unplug_request_cb(HotplugHandler *hotplug_dev,
> >                  !lpc->pm.cpu_hotplug_legacy) {
> >           uint64_t negotiated = lpc->smi_negotiated_features;
> >   
> > -        if (negotiated & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT) &&
> > -            !(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) {
> > +        if (!(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) {
> >               error_setg(errp, "cpu hot-unplug with SMI wasn't enabled "
> >                                "by firmware");
> >               error_append_hint(errp, "update machine type to a version having "
> > diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> > index 71afb45b631..c57a06e0dde 100644
> > --- a/hw/isa/lpc_ich9.c
> > +++ b/hw/isa/lpc_ich9.c
> > @@ -400,15 +400,6 @@ 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 */
> > @@ -470,14 +461,9 @@ 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);
> >           }
> >       }
> >   }
> > @@ -830,8 +816,6 @@ 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,  
>