Re: [Qemu-devel] [PATCH 13/22] acpi_piix4: add infrastructure to send CPU hot-plug GPE to guest

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 08 Apr 2013 10:24:50 +0800
li guang <lig.fnst@cn.fujitsu.com> wrote:

> 在 2013-04-05五的 16:37 +0200，Igor Mammedov写道：
> > * introduce processor status bitmask visible to guest at 0xaf00 addr,
> >   where Seabios expects it
> > * set bit corresponding to APIC ID in processor status bitmask on
> >   receiving CPU hot-plug notification
> > * trigger CPU hot-plug SCI, expected by Seabios on receiving CPU
> >   hot-plug notification
> 
> expected by seabios?
> IMHO, seems you are saying ACPI's asl code which
> just wrapped in seabios.
Yep, that's what ACPI asl code there expects. With current effort to move
ACPI tables into it might be better to s/Seabios/ACPI/ here.

> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> > v2:
> >   * use CPUClass.get_firmware_id() to make code target independent
> >   * bump up vmstate_acpi version
> > ---
> >  hw/acpi_piix4.c | 114
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed,
> > 111 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
> > index 48a32b5..ccfc028 100644
> > --- a/hw/acpi_piix4.c
> > +++ b/hw/acpi_piix4.c
> > @@ -48,19 +48,28 @@
> >  #define PCI_EJ_BASE 0xae08
> >  #define PCI_RMV_BASE 0xae0c
> >  
> > +#define PROC_BASE 0xaf00
> > +#define PROC_LEN 32
> > +
> >  #define PIIX4_PCI_HOTPLUG_STATUS 2
> > +#define PIIX4_CPU_HOTPLUG_STATUS 4
> >  
> >  struct pci_status {
> >      uint32_t up; /* deprecated, maintained for migration compatibility */
> >      uint32_t down;
> >  };
> >  
> > +struct cpu_status {
> > +    uint8_t sts[PROC_LEN];
> > +};
> > +
> >  typedef struct PIIX4PMState {
> >      PCIDevice dev;
> >  
> >      MemoryRegion io;
> >      MemoryRegion io_gpe;
> >      MemoryRegion io_pci;
> > +    MemoryRegion io_cpu;
> >      ACPIREGS ar;
> >  
> >      APMState apm;
> > @@ -82,6 +91,9 @@ typedef struct PIIX4PMState {
> >      uint8_t disable_s3;
> >      uint8_t disable_s4;
> >      uint8_t s4_val;
> > +
> > +    struct cpu_status gpe_cpu;
> > +    Notifier cpu_add_notifier;
> 
> seems you named cpu_added_notifier at [PATCH 10/22],
> should the notifer's name be unified?
I'll fix it on next respin, thanks.

> 
> >  } PIIX4PMState;
> >  
> >  static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
> > @@ -100,8 +112,8 @@ static void pm_update_sci(PIIX4PMState *s)
> >                     ACPI_BITMASK_POWER_BUTTON_ENABLE |
> >                     ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
> >                     ACPI_BITMASK_TIMER_ENABLE)) != 0) ||
> > -        (((s->ar.gpe.sts[0] & s->ar.gpe.en[0])
> > -          & PIIX4_PCI_HOTPLUG_STATUS) != 0);
> > +        (((s->ar.gpe.sts[0] & s->ar.gpe.en[0]) &
> > +          (PIIX4_PCI_HOTPLUG_STATUS | PIIX4_CPU_HOTPLUG_STATUS)) != 0);
> >  
> >      qemu_set_irq(s->irq, sci_level);
> >      /* schedule a timer interruption if needed */
> > @@ -257,6 +269,17 @@ static int acpi_load_old(QEMUFile *f, void *opaque,
> > int version_id) return ret;
> >  }
> >  
> > +#define VMSTATE_CPU_STATUS_ARRAY(_field,
> > _state)                             \
> > +
> > {                                                                           \
> > +     .name       =
> > (stringify(_field)),                                      \
> > +     .version_id =
> > 0,                                                        \
> > +     .num        =
> > PROC_LEN,                                                 \
> > +     .info       =
> > &vmstate_info_uint8,                                      \
> > +     .size       =
> > sizeof(uint8_t),                                          \
> > +     .flags      =
> > VMS_ARRAY,                                                \
> > +     .offset     = vmstate_offset_array(_state, _field, uint8_t,
> > PROC_LEN),  \
> > + }
> > +
> >  /* qemu-kvm 1.2 uses version 3 but advertised as 2
> >   * To support incoming qemu-kvm 1.2 migration, change version_id
> >   * and minimum_version_id to 2 below (which breaks migration from
> > @@ -265,7 +288,7 @@ static int acpi_load_old(QEMUFile *f, void *opaque,
> > int version_id) */
> >  static const VMStateDescription vmstate_acpi = {
> >      .name = "piix4_pm",
> > -    .version_id = 3,
> > +    .version_id = 4,
> >      .minimum_version_id = 3,
> >      .minimum_version_id_old = 1,
> >      .load_state_old = acpi_load_old,
> > @@ -281,6 +304,7 @@ static const VMStateDescription vmstate_acpi = {
> >          VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
> >          VMSTATE_STRUCT(pci0_status, PIIX4PMState, 2, vmstate_pci_status,
> >                         struct pci_status),
> > +        VMSTATE_CPU_STATUS_ARRAY(gpe_cpu.sts, PIIX4PMState),
> >          VMSTATE_END_OF_LIST()
> >      }
> >  };
> > @@ -585,6 +609,83 @@ static const MemoryRegionOps piix4_pci_ops = {
> >      },
> >  };
> >  
> > +static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned
> > width) +{
> > +    PIIX4PMState *s = opaque;
> > +    struct cpu_status *cpus = &s->gpe_cpu;
> > +    uint64_t val = cpus->sts[addr];
> > +    return val;
> > +}
> > +
> > +static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
> > +                             unsigned int size)
> > +{
> > +    /* TODO: implement VCPU removal on guest signal that CPU can be
> > removed */ +}
> > +
> > +static const MemoryRegionOps cpu_hotplug_ops = {
> > +    .read = cpu_status_read,
> > +    .write = cpu_status_write,
> > +    .endianness = DEVICE_LITTLE_ENDIAN,
> > +    .valid = {
> > +        .min_access_size = 1,
> > +        .max_access_size = 1,
> > +    },
> > +};
> > +
> > +typedef enum {
> > +    PLUG,
> > +    UNPLUG,
> > +} HotplugEventType;
> > +
> > +static void piix4_cpu_hotplug_req(PIIX4PMState *s, CPUState *cpu,
> > +                                  HotplugEventType action)
> > +{
> > +    struct cpu_status *g = &s->gpe_cpu;
> > +    ACPIGPE *gpe = &s->ar.gpe;
> > +    CPUClass *k = CPU_GET_CLASS(cpu);
> > +    int64_t cpu_id;
> > +
> > +    assert(s != NULL);
> > +
> > +    *gpe->sts = *gpe->sts | PIIX4_CPU_HOTPLUG_STATUS;
> > +    cpu_id = k->get_firmware_id(CPU(cpu));
> > +    if (action == PLUG) {
> > +        g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
> > +    } else {
> > +        g->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
> > +    }
> > +    pm_update_sci(s);
> > +}
> > +
> > +static void piix4_cpu_add_req(Notifier *n, void *opaque)
> > +{
> > +    PIIX4PMState *s = container_of(n, PIIX4PMState, cpu_add_notifier);
> > +    piix4_cpu_hotplug_req(s, CPU(opaque), PLUG);
> > +}
> > +
> > +static int piix4_init_cpu_status(Object *obj, void *opaque)
> > +{
> > +    struct cpu_status *g = (struct cpu_status *)opaque;
> > +    Object *cpu_obj = object_dynamic_cast(obj, TYPE_CPU);
> > +
> > +    if (cpu_obj) {
> > +        struct Error *error = NULL;
> > +        CPUClass *k = CPU_GET_CLASS(cpu_obj);
> > +        int64_t id = k->get_firmware_id(CPU(cpu_obj));
> > +
> > +        if (error) {
> > +            fprintf(stderr, "failed to initilize CPU status for ACPI:
> > %s\n",
> > +                    error_get_pretty(error));
> > +            error_free(error);
> > +            abort();
> > +        }
> > +        g_assert((id / 8) < PROC_LEN);
> > +        g->sts[id / 8] |= (1 << (id % 8));
> > +    }
> > +    return object_child_foreach(obj, piix4_init_cpu_status, opaque);
> > +}
> > +
> >  static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
> >                                  PCIHotplugState state);
> >  
> > @@ -600,6 +701,13 @@ static void
> > piix4_acpi_system_hot_add_init(MemoryRegion *parent,
> > memory_region_add_subregion(parent, PCI_HOTPLUG_ADDR, &s->io_pci);
> >      pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
> > +
> > +    piix4_init_cpu_status(qdev_get_machine(), &s->gpe_cpu);
> > +    memory_region_init_io(&s->io_cpu, &cpu_hotplug_ops, s,
> > "apci-cpu-hotplug",
> > +                          PROC_LEN);
> > +    memory_region_add_subregion(parent, PROC_BASE, &s->io_cpu);
> > +    s->cpu_add_notifier.notify = piix4_cpu_add_req;
> > +    qemu_register_cpu_added_notifier(&s->cpu_add_notifier);
> >  }
> >  
> >  static void enable_device(PIIX4PMState *s, int slot)
> 
>