Re: [Qemu-devel] [PATCH v7 4/6] s390x/cpu: Add CPU property links

[Igor Mammedov <imammedo@redhat.com>]

On Tue,  1 Mar 2016 16:13:24 -0500
Matthew Rosato <mjrosato@linux.vnet.ibm.com> wrote:

> Link each CPUState as property machine/cpu[n] during initialization.
> Add a hotplug handler to s390-virtio-ccw machine and set the
> state during plug.
> Additionally, maintain an array of state pointers indexed by CPU
> id for fast lookup during interrupt handling.
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
> ---
>  hw/s390x/s390-virtio-ccw.c | 33 +++++++++++++++++++++++++++++++++
>  hw/s390x/s390-virtio.c     | 26 +++++++++++++++++---------
>  2 files changed, 50 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index b05ed8b..3090e76 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -156,10 +156,40 @@ static void ccw_init(MachineState *machine)
>                      gtod_save, gtod_load, kvm_state);
>  }
>  
> +static void s390_cpu_plug(HotplugHandler *hotplug_dev,
> +                        DeviceState *dev, Error **errp)
> +{
> +    gchar *name;
> +    S390CPU *cpu = S390_CPU(dev);
> +    CPUState *cs = CPU(dev);
> +
> +    name = g_strdup_printf("cpu[%i]", cpu->env.cpu_num);
> +    object_property_set_link(OBJECT(qdev_get_machine()), OBJECT(cs), name,
hotplug_dev is machine, just do cast here instead of qdev_get_machine()

> +                             errp);

looks like 'name' is being leaked

> +}
> +
> +static void s390_machine_device_plug(HotplugHandler *hotplug_dev,
> +                                     DeviceState *dev, Error **errp)
> +{
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> +        s390_cpu_plug(hotplug_dev, dev, errp);
> +    }
> +}
> +
> +static HotplugHandler *s390_get_hotplug_handler(MachineState *machine,
> +                                                DeviceState *dev)
> +{
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> +        return HOTPLUG_HANDLER(machine);
> +    }
> +    return NULL;
> +}
> +
>  static void ccw_machine_class_init(ObjectClass *oc, void *data)
>  {
>      MachineClass *mc = MACHINE_CLASS(oc);
>      NMIClass *nc = NMI_CLASS(oc);
> +    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
>  
>      mc->init = ccw_init;
>      mc->reset = s390_machine_reset;
> @@ -171,6 +201,8 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>      mc->no_sdcard = 1;
>      mc->use_sclp = 1;
>      mc->max_cpus = 255;
> +    mc->get_hotplug_handler = s390_get_hotplug_handler;
> +    hc->plug = s390_machine_device_plug;
>      nc->nmi_monitor_handler = s390_nmi;
>  }
>  
> @@ -232,6 +264,7 @@ static const TypeInfo ccw_machine_info = {
>      .class_init    = ccw_machine_class_init,
>      .interfaces = (InterfaceInfo[]) {
>          { TYPE_NMI },
> +        { TYPE_HOTPLUG_HANDLER},
>          { }
>      },
>  };
> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
> index b3707f4..6bd9803 100644
> --- a/hw/s390x/s390-virtio.c
> +++ b/hw/s390x/s390-virtio.c
> @@ -60,15 +60,16 @@
>  #define S390_TOD_CLOCK_VALUE_MISSING    0x00
>  #define S390_TOD_CLOCK_VALUE_PRESENT    0x01
>  
> -static S390CPU **ipi_states;
> +static S390CPU **cpu_states;
>  
>  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>  {
> -    if (cpu_addr >= smp_cpus) {
> +    if (cpu_addr >= max_cpus) {
>          return NULL;
>      }
>  
> -    return ipi_states[cpu_addr];
> +    /* Fast lookup via CPU ID */
> +    return cpu_states[cpu_addr];
>  }
this hunk seems to be unrelated to this patch,
it probably belongs somewhere else

>  void s390_init_ipl_dev(const char *kernel_filename,
> @@ -98,19 +99,26 @@ void s390_init_ipl_dev(const char *kernel_filename,
>  void s390_init_cpus(MachineState *machine)
>  {
>      int i;
> +    gchar *name;
>  
>      if (machine->cpu_model == NULL) {
>          machine->cpu_model = "host";
>      }
>  
> -    ipi_states = g_malloc(sizeof(S390CPU *) * smp_cpus);
> +    cpu_states = g_malloc0(sizeof(S390CPU *) * max_cpus);
>  
> -    for (i = 0; i < smp_cpus; i++) {
> -        S390CPU *cpu;
> -
> -        cpu = cpu_s390x_init(machine->cpu_model);
> +    for (i = 0; i < max_cpus; i++) {
> +        name = g_strdup_printf("cpu[%i]", i);
> +        object_property_add_link(OBJECT(machine), name, TYPE_S390_CPU,
> +                                 (Object **) &cpu_states[i],
> +                                 object_property_allow_set_link,
> +                                 OBJ_PROP_LINK_UNREF_ON_RELEASE,
> +                                 &error_abort);
> +        g_free(name);
> +    }
>  
> -        ipi_states[i] = cpu;
> +    for (i = 0; i < smp_cpus; i++) {
> +        cpu_s390x_init(machine->cpu_model);
>      }
>  }
>