Re: [PATCH 1/3] acpi/ged: Implement S3 and S4 sleep

[Igor Mammedov]

On Thu, 13 Jun 2024 18:30:15 +0100
Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:

> Implement S3 and S4 sleep with ACPI_GED_REG_SLEEP_CTL.SLP_TYP
> writes.
> 
> Implement wakeup callback and WAK_STS register to inform guest
> about current states.
> 
> All new functions are gated by "slp-typs" property, it is defaulted
> to S5 only and machines can opt-in for S3 and S4.

subject says S3 + S4 and don't mention S5
the same happens throughout the series, please fix it up

PS:
please reference relevant ACPI portions in the patch below,
so reader could easily find and understand what code does.

> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  hw/acpi/generic_event_device.c         | 70 
> ++++++++++++++++++++++++++++++----
>  include/hw/acpi/generic_event_device.h | 12 +++++-
>  2 files changed, 73 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 2d6e91b124e5..f1fc99c04011 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -11,6 +11,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "qapi/error.h"
> +#include "qapi/qapi-events-run-state.h"
>  #include "hw/acpi/acpi.h"
>  #include "hw/acpi/generic_event_device.h"
>  #include "hw/irq.h"
> @@ -186,24 +187,53 @@ static const MemoryRegionOps ged_evt_ops = {
>  
>  static uint64_t ged_regs_read(void *opaque, hwaddr addr, unsigned size)
>  {
> +    GEDState *ged_st = opaque;
> +
> +    switch (addr) {
> +    case ACPI_GED_REG_SLEEP_STS:
> +        return ged_st->sleep_sts;
> +    default:
> +        break;
> +    }
> +
>      return 0;
>  }
>  
>  static void ged_regs_write(void *opaque, hwaddr addr, uint64_t data,
>                             unsigned int size)
>  {
> -    bool slp_en;
> -    int slp_typ;
> +    GEDState *ged_st = opaque;
> +    AcpiGedState *s = container_of(ged_st, AcpiGedState, ged_state);
>  
>      switch (addr) {
>      case ACPI_GED_REG_SLEEP_CTL:
> -        slp_typ = (data >> 2) & 0x07;
> -        slp_en  = (data >> 5) & 0x01;
maybe use defines instead of magic numbers, it's also good to add
coments here referring to concrete chapter in APCI spec that describe
what these numbers are.

> -        if (slp_en && slp_typ == 5) {
                                    ^^^
ditto

> -            qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
> +        if (data & ACPI_GED_SLP_EN) {
> +            switch (extract8(data, 2, 3)) {
> +            case ACPI_GED_SLP_TYP_S3:
> +                if (s->slp_typs_bitmap & (1 << ACPI_GED_SLP_TYP_S3)) {

why not use existing helpers like test_bit()
the same applies to following bit checks

> +                    qemu_system_suspend_request();
> +                }
> +                break;
> +            case ACPI_GED_SLP_TYP_S4:
> +                if (s->slp_typs_bitmap & (1 << ACPI_GED_SLP_TYP_S4)) {
> +                    qapi_event_send_suspend_disk();
> +                    
> qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
> +                }
> +                break;
> +            case ACPI_GED_SLP_TYP_S5:
> +                if (s->slp_typs_bitmap & (1 << ACPI_GED_SLP_TYP_S5)) {
> +                    
> qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
> +                }
> +                break;
> +            default:
> +                break;
> +            }
>          }
>          return;
>      case ACPI_GED_REG_SLEEP_STS:
> +        if (data & ACPI_GED_WAK_STS) {
> +            ged_st->sleep_sts &= ~ACPI_GED_WAK_STS;
> +        }
>          return;
>      case ACPI_GED_REG_RESET:
>          if (data == ACPI_GED_RESET_VALUE) {
> @@ -223,6 +253,14 @@ static const MemoryRegionOps ged_regs_ops = {
>      },
>  };
>  
> +static void acpi_ged_notify_wakeup(Notifier *notifier, void *data)
> +{
> +    GEDState *ged_st = container_of(notifier, GEDState, wakeup);
> +
> +    ged_st->sleep_sts |= ACPI_GED_WAK_STS;

describe somewhere workflow how it is supposed to work 
(commit message or add ged specific doc in docs/specs/
as the 1st patch)

> +}
> +
> +
>  static void acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,
>                                      DeviceState *dev, Error **errp)
>  {
> @@ -305,6 +343,8 @@ static void acpi_ged_send_event(AcpiDeviceIf *adev, 
> AcpiEventStatusBits ev)
>  
>  static Property acpi_ged_properties[] = {
>      DEFINE_PROP_UINT32("ged-event", AcpiGedState, ged_event_bitmap, 0),
> +    DEFINE_PROP_UINT32("slp-typs", AcpiGedState, slp_typs_bitmap,
> +                        (1 << ACPI_GED_SLP_TYP_S5)),

I'd default to everything enabled, and use compat mechanism
to disable it on older machine types.

You have to do this as ged is also used by versioned arm/virt machine

>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -320,10 +360,11 @@ static const VMStateDescription vmstate_memhp_state = {
>  
>  static const VMStateDescription vmstate_ged_state = {
>      .name = "acpi-ged-state",
> -    .version_id = 1,
> -    .minimum_version_id = 1,
> +    .version_id = 2,
> +    .minimum_version_id = 2,
>      .fields = (const VMStateField[]) {
>          VMSTATE_UINT32(sel, GEDState),
> +        VMSTATE_UINT8(sleep_sts, GEDState),
>          VMSTATE_END_OF_LIST()
>      }
>  };

see for example
commit 829600a519386c7b188d5d813e78ba69bf0bd323
    hpet: recover timer offset correctly



> @@ -371,6 +412,18 @@ static const VMStateDescription vmstate_acpi_ged = {
>      }
>  };
>  
> +static void acpi_ged_realize(DeviceState *dev, Error **errp)
> +{
> +    AcpiGedState *s = ACPI_GED(dev);
> +    GEDState *ged_st = &s->ged_state;
> +
> +    if (s->slp_typs_bitmap & (1 << ACPI_GED_SLP_TYP_S3)) {
> +        ged_st->wakeup.notify = acpi_ged_notify_wakeup;
> +        qemu_register_wakeup_notifier(&ged_st->wakeup);
> +        qemu_register_wakeup_support();
> +    }
> +}
> +
>  static void acpi_ged_initfn(Object *obj)
>  {
>      DeviceState *dev = DEVICE(obj);
> @@ -409,6 +462,7 @@ static void acpi_ged_class_init(ObjectClass *class, void 
> *data)
>      AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_CLASS(class);
>  
>      dc->desc = "ACPI Generic Event Device";
> +    dc->realize = acpi_ged_realize;

realize was added recently (currently in master),
please rebase on top of current master tree

>      device_class_set_props(dc, acpi_ged_properties);
>      dc->vmsd = &vmstate_acpi_ged;
>  
> diff --git a/include/hw/acpi/generic_event_device.h 
> b/include/hw/acpi/generic_event_device.h
> index ba84ce021477..1ea3cb848679 100644
> --- a/include/hw/acpi/generic_event_device.h
> +++ b/include/hw/acpi/generic_event_device.h
> @@ -80,9 +80,16 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
>  /* ACPI_GED_REG_RESET value for reset*/
>  #define ACPI_GED_RESET_VALUE       0x42
>  
> -/* ACPI_GED_REG_SLEEP_CTL.SLP_TYP value for S5 (aka poweroff) */
> +/* ACPI_GED_REG_SLEEP_CTL.SLP_EN bit */
> +#define ACPI_GED_SLP_EN            (1 << 5)
> +
> +/* ACPI_GED_REG_SLEEP_CTL.SLP_TYP values */
> +#define ACPI_GED_SLP_TYP_S3        0x03
> +#define ACPI_GED_SLP_TYP_S4        0x04
>  #define ACPI_GED_SLP_TYP_S5        0x05
>  
> +#define ACPI_GED_WAK_STS           (1 << 7)
> +
>  #define GED_DEVICE      "GED"
>  #define AML_GED_EVT_REG "EREG"
>  #define AML_GED_EVT_SEL "ESEL"
> @@ -99,7 +106,9 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
>  typedef struct GEDState {
>      MemoryRegion evt;
>      MemoryRegion regs;
> +    Notifier     wakeup;
>      uint32_t     sel;
> +    uint8_t      sleep_sts;
>  } GEDState;
>  
>  struct AcpiGedState {
> @@ -108,6 +117,7 @@ struct AcpiGedState {
>      MemoryRegion container_memhp;
>      GEDState ged_state;
>      uint32_t ged_event_bitmap;
> +    uint32_t slp_typs_bitmap;
>      qemu_irq irq;
>      AcpiGhesState ghes_state;
>  };
>