Re: [Qemu-devel] [PATCH V4 5/8] pc: Update rtc_cmos in pc_cpu_plug

[Gu Zheng <guz.fnst@cn.fujitsu.com>]

On 10/08/2014 08:25 PM, Igor Mammedov wrote:

> On Wed, 8 Oct 2014 09:12:11 +0800
> Gu Zheng <guz.fnst@cn.fujitsu.com> wrote:
> 
>> Hi Igor,
>>
>> On 10/07/2014 09:01 PM, Igor Mammedov wrote:
>>
>>> On Mon, 29 Sep 2014 18:52:34 +0800
>>> Gu Zheng <guz.fnst@cn.fujitsu.com> wrote:
>>>
>>>> Update rtc_cmos in pc_cpu_plug directly instead of the notifier.
>>>>
>>>> v4:
>>>>  -Make link<rtc> property in PCMachine rather than the global
>>>>   variables.
>>>>  -Split out the removal of unused notifier into separate patch.
>>>>
>>>> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
>>>> ---
>>>>  hw/i386/pc.c         |   37 ++++++++++++++++---------------------
>>>>  hw/i386/pc_piix.c    |    2 +-
>>>>  hw/i386/pc_q35.c     |    2 +-
>>>>  include/hw/i386/pc.h |    3 ++-
>>>>  qom/cpu.c            |    1 -
>>>>  5 files changed, 20 insertions(+), 25 deletions(-)
>>>>
>>>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>>>> index dcb9332..301e704 100644
>>>> --- a/hw/i386/pc.c
>>>> +++ b/hw/i386/pc.c
>>>> @@ -355,30 +355,15 @@ static void pc_cmos_init_late(void *opaque)
>>>>      qemu_unregister_reset(pc_cmos_init_late, opaque);
>>>>  }
>>>>  
>>>> -typedef struct RTCCPUHotplugArg {
>>>> -    Notifier cpu_added_notifier;
>>>> -    ISADevice *rtc_state;
>>>> -} RTCCPUHotplugArg;
>>>> -
>>>> -static void rtc_notify_cpu_added(Notifier *notifier, void *data)
>>>> -{
>>>> -    RTCCPUHotplugArg *arg = container_of(notifier, RTCCPUHotplugArg,
>>>> -                                         cpu_added_notifier);
>>>> -    ISADevice *s = arg->rtc_state;
>>>> -
>>>> -    /* increment the number of CPUs */
>>>> -    rtc_set_memory(s, 0x5f, rtc_get_memory(s, 0x5f) + 1);
>>>> -}
>>>> -
>>>>  void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
>>>> -                  const char *boot_device,
>>>> +                  const char *boot_device, MachineState *machine,
>>>>                    ISADevice *floppy, BusState *idebus0, BusState *idebus1,
>>>>                    ISADevice *s)
>>>>  {
>>>>      int val, nb, i;
>>>>      FDriveType fd_type[2] = { FDRIVE_DRV_NONE, FDRIVE_DRV_NONE };
>>>>      static pc_cmos_init_late_arg arg;
>>>> -    static RTCCPUHotplugArg cpu_hotplug_cb;
>>>> +    PCMachineState *pc_machine = PC_MACHINE(machine);
>>>>  
>>>>      /* various important CMOS locations needed by PC/Bochs bios */
>>>>  
>>>> @@ -417,10 +402,14 @@ void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
>>>>  
>>>>      /* set the number of CPU */
>>>>      rtc_set_memory(s, 0x5f, smp_cpus - 1);
>>>> -    /* init CPU hotplug notifier */
>>>> -    cpu_hotplug_cb.rtc_state = s;
>>>> -    cpu_hotplug_cb.cpu_added_notifier.notify = rtc_notify_cpu_added;
>>>> -    qemu_register_cpu_added_notifier(&cpu_hotplug_cb.cpu_added_notifier);
>>>> +
>>>> +    object_property_add_link(OBJECT(machine), "rtc_state",
>>>> +                             TYPE_ISA_DEVICE,
>>>> +                             (Object **)&pc_machine->rtc,
>>>> +                             object_property_allow_set_link,
>>>> +                             OBJ_PROP_LINK_UNREF_ON_RELEASE, &error_abort);
>>>> +    object_property_set_link(OBJECT(machine), OBJECT(s),
>>>> +                             "rtc_state", &error_abort);
>>>>  
>>>>      if (set_boot_dev(s, boot_device)) {
>>>>          exit(1);
>>>> @@ -1633,6 +1622,12 @@ static void pc_cpu_plug(HotplugHandler *hotplug_dev,
>>>>  
>>>>      hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
>>>>      hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
>>>> +    if (local_err) {
>>>> +        goto out;
>>>> +    }
>>>> +
>>>> +    /* increment the number of CPUs */
>>>> +    rtc_set_memory(pcms->rtc, 0x5f, rtc_get_memory(pcms->rtc, 0x5f) + 1);
>>>>  out:
>>>>      error_propagate(errp, local_err);
>>>>  }
>>>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>>>> index 103d756..2c8d4dc 100644
>>>> --- a/hw/i386/pc_piix.c
>>>> +++ b/hw/i386/pc_piix.c
>>>> @@ -266,7 +266,7 @@ static void pc_init1(MachineState *machine,
>>>>      }
>>>>  
>>>>      pc_cmos_init(below_4g_mem_size, above_4g_mem_size, machine->boot_order,
>>>> -                 floppy, idebus[0], idebus[1], rtc_state);
>>>> +                 machine, floppy, idebus[0], idebus[1], rtc_state);
>>>>  
>>>>      if (pci_enabled && usb_enabled(false)) {
>>>>          pci_create_simple(pci_bus, piix3_devfn + 2, "piix3-usb-uhci");
>>>> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
>>>> index d4a907c..94ba98d 100644
>>>> --- a/hw/i386/pc_q35.c
>>>> +++ b/hw/i386/pc_q35.c
>>>> @@ -266,7 +266,7 @@ static void pc_q35_init(MachineState *machine)
>>>>                        8, NULL, 0);
>>>>  
>>>>      pc_cmos_init(below_4g_mem_size, above_4g_mem_size, machine->boot_order,
>>>> -                 floppy, idebus[0], idebus[1], rtc_state);
>>>> +                 machine, floppy, idebus[0], idebus[1], rtc_state);
>>>>  
>>>>      /* the rest devices to which pci devfn is automatically assigned */
>>>>      pc_vga_init(isa_bus, host_bus);
>>>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>>>> index 77316d5..7a4bff4 100644
>>>> --- a/include/hw/i386/pc.h
>>>> +++ b/include/hw/i386/pc.h
>>>> @@ -33,6 +33,7 @@ struct PCMachineState {
>>>>      MemoryRegion hotplug_memory;
>>>>  
>>>>      HotplugHandler *acpi_dev;
>>>> +    ISADevice *rtc;
>>>>  
>>>>      uint64_t max_ram_below_4g;
>>>>  };
>>>> @@ -210,7 +211,7 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
>>>>                            uint32 hpet_irqs);
>>>>  void pc_init_ne2k_isa(ISABus *bus, NICInfo *nd);
>>>>  void pc_cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
>>>> -                  const char *boot_device,
>>>> +                  const char *boot_device, MachineState *machine,
>>>>                    ISADevice *floppy, BusState *ide0, BusState *ide1,
>>>>                    ISADevice *s);
>>>>  void pc_nic_init(ISABus *isa_bus, PCIBus *pci_bus);
>>>> diff --git a/qom/cpu.c b/qom/cpu.c
>>>> index ba8b402..09c7e41 100644
>>>> --- a/qom/cpu.c
>>>> +++ b/qom/cpu.c
>>>> @@ -307,7 +307,6 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>>>>  
>>>>      if (dev->hotplugged) {
>>>>          cpu_synchronize_post_init(cpu);
>>>> -        notifier_list_notify(&cpu_added_notifiers, dev);
>>> this hunk belongs to the next patch
>>
>> This notifier was only used to update rtc state, and after we dropped
>> rtc state update into pc_cpu_plug, this line will be dead code, so I
>> think deleting it here is more reasonable.
> Well the same reasoning would apply to CPU hot-plug notifier as well.
> But above hunk is not related to RTC but it's a part of notifier itself.
> RTC related part is refactoring RTC callback but not mechanism that
> called it (i.e. CPU hot-plug notifier).

Got it, thanks.

Best regards,
Gu

> 
>> And in the next patch, just removing the unused CPU hot-plug notifier.
> 
>>
>> Thanks,
>> Gu
>>
>>>
>>>>          cpu_resume(cpu);
>>>>      }
>>>>  }
>>>
>>> .
>>>
>>
>>
>>
> 
> .
>