Re: [PATCH 02/10] loongarch: add virt feature avecintc support

[Bibo Mao]

On 2025/6/9 下午6:48, Song Gao wrote:
> LoongArchVirtMachinState add  avecintc features, and
> it use to check whether virt machine support advance interrupt controller
> and default is on.
>
> Signed-off-by: Song Gao <gaosong@loongson.cn>
> ---
>   hw/loongarch/virt.c         | 31 +++++++++++++++++++++++++++----
>   include/hw/loongarch/virt.h |  9 +++++++++
>   2 files changed, 36 insertions(+), 4 deletions(-)
>
> diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
> index 90d4643721..35643a4e0b 100644
> --- a/hw/loongarch/virt.c
> +++ b/hw/loongarch/virt.c
> @@ -47,6 +47,23 @@
>   #include "hw/virtio/virtio-iommu.h"
>   #include "qemu/error-report.h"
>   
> +static void virt_get_avecintc(Object *obj, Visitor *v, const char *name,
> +                             void *opaque, Error **errp)
> +{
> +    LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(obj);
> +    OnOffAuto avecintc = lvms->avecintc;
> +
> +    visit_type_OnOffAuto(v, name, &avecintc, errp);
> +
> +}
> +static void virt_set_avecintc(Object *obj, Visitor *v, const char *name,
> +                              void *opaque, Error **errp)
> +{
> +    LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(obj);
> +
> +    visit_type_OnOffAuto(v, name, &lvms->avecintc, errp);
> +}
> +
>   static void virt_get_veiointc(Object *obj, Visitor *v, const char *name,
>                                 void *opaque, Error **errp)
>   {
> @@ -548,8 +565,9 @@ static MemTxResult virt_iocsr_misc_read(void *opaque, 
> hwaddr addr,
>           break;
>       case FEATURE_REG:
>           ret = BIT(IOCSRF_MSI) | BIT(IOCSRF_EXTIOI) | BIT(IOCSRF_CSRIPI);
> -        /*TODO: check bit IOCSRF_AVEC with virt_is_avec_enabled */
> -        ret |= BIT(IOCSRF_AVEC);
> +        if (virt_is_avecintc_enabled(lvms)) {
> +            ret |= BIT(IOCSRF_AVEC);
> +        }
>           if (kvm_enabled()) {
>               ret |= BIT(IOCSRF_VM);
>           }
> @@ -575,8 +593,9 @@ static MemTxResult virt_iocsr_misc_read(void *opaque, 
> hwaddr addr,
>           if (features & BIT(EXTIOI_ENABLE_INT_ENCODE)) {
>               ret |= BIT_ULL(IOCSRM_EXTIOI_INT_ENCODE);
>           }
> -        /* enable avec default */
> -        ret |= BIT_ULL(IOCSRM_AVEC_EN);
> +        if (virt_is_avecintc_enabled(lvms)) {
> +            ret |= BIT_ULL(IOCSRM_AVEC_EN);
> +        }
Is it really that reading of MISC_FUNC_REG will return 
BIT_ULL(IOCSRM_AVEC_EN) if there is avec?

Where is the write operation with register MISC_FUNC_REG?

Regard
Bibo Mao
>           break;
>       default:
>           g_assert_not_reached();
> @@ -1212,6 +1231,10 @@ static void virt_class_init(ObjectClass *oc, const void 
> *data)
>           NULL, NULL);
>       object_class_property_set_description(oc, "v-eiointc",
>                               "Enable Virt Extend I/O Interrupt Controller.");
> +    object_class_property_add(oc, "avecintc", "OnOffAuto",
> +        virt_get_avecintc, virt_set_avecintc, NULL, NULL);
> +    object_class_property_set_description(oc, "avecintc",
> +                            "Enable Advance Interrupt Controller.");
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_UEFI_VARS_SYSBUS);
>   #ifdef CONFIG_TPM
> diff --git a/include/hw/loongarch/virt.h b/include/hw/loongarch/virt.h
> index 2b7d19953f..3a81f048e8 100644
> --- a/include/hw/loongarch/virt.h
> +++ b/include/hw/loongarch/virt.h
> @@ -50,6 +50,7 @@ struct LoongArchVirtMachineState {
>       Notifier     powerdown_notifier;
>       OnOffAuto    acpi;
>       OnOffAuto    veiointc;
> +    OnOffAuto    avecintc;
>       char         *oem_id;
>       char         *oem_table_id;
>       DeviceState  *acpi_ged;
> @@ -70,6 +71,14 @@ OBJECT_DECLARE_SIMPLE_TYPE(LoongArchVirtMachineState, 
> LOONGARCH_VIRT_MACHINE)
>   void virt_acpi_setup(LoongArchVirtMachineState *lvms);
>   void virt_fdt_setup(LoongArchVirtMachineState *lvms);
>   
> +static inline bool virt_is_avecintc_enabled(LoongArchVirtMachineState *lvms)
> +{
> +    if (lvms->avecintc == ON_OFF_AUTO_OFF) {
> +        return false;
> +    }
> +    return true;
> +}
> +
>   static inline bool virt_is_veiointc_enabled(LoongArchVirtMachineState *lvms)
>   {
>       if (lvms->veiointc == ON_OFF_AUTO_OFF) {