Re: [Qemu-devel] [PATCH v3 11/14] piix: APIs for pc guest info

["Andreas Färber" <afaerber@suse.de>]

Am 28.07.2013 09:30, schrieb Michael S. Tsirkin:
> On Sun, Jul 28, 2013 at 02:12:49AM +0200, Andreas Färber wrote:
>> Am 25.07.2013 11:32, schrieb Michael S. Tsirkin:
>>> This adds APIs that will be used to fill in guest info table,
>>> implemented using QOM, to various piix components.
>>>
>>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>>> ---
>>>
>>> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
>>> index c885690..2128f13 100644
>>> --- a/hw/acpi/piix4.c
>>> +++ b/hw/acpi/piix4.c
>>> @@ -29,6 +29,7 @@
>>>  #include "exec/ioport.h"
>>>  #include "hw/nvram/fw_cfg.h"
>>>  #include "exec/address-spaces.h"
>>> +#include "hw/acpi/piix4.h"
>>>  
>>>  //#define DEBUG
>>>  
>>> @@ -63,7 +64,7 @@ typedef struct CPUStatus {
>>>      uint8_t sts[PIIX4_PROC_LEN];
>>>  } CPUStatus;
>>>  
>>> -typedef struct PIIX4PMState {
>>> +struct PIIX4PMState {
>>>      /*< private >*/
>>>      PCIDevice parent_obj;
>>>      /*< public >*/
>>> @@ -96,7 +97,7 @@ typedef struct PIIX4PMState {
>>>  
>>>      CPUStatus gpe_cpu;
>>>      Notifier cpu_added_notifier;
>>> -} PIIX4PMState;
>>> +};
>>>  
>>>  #define TYPE_PIIX4_PM "PIIX4_PM"
>>>  
>>
>> Here add
>>
>> #define PIIX4_PM(obj) OBJECT_CHECK(PIIX4PMState, obj, TYPE_PIIX4_PM)
>>
>> for the general public ...
>>
>>> @@ -458,6 +459,30 @@ static int piix4_pm_initfn(PCIDevice *dev)
>>>      return 0;
>>>  }
>>>  
>>> +PIIX4PMState *piix4_pm_find(void)
>>> +{
>>> +    bool ambig;
>>> +    Object *o = object_resolve_path_type("", "PIIX4_PM", &ambig);
>>> +
>>> +    if (ambig || !o) {
>>> +        return NULL;
>>> +    }
>>> +    return OBJECT_CHECK(PIIX4PMState, o, "PIIX4_PM");
>>
>> ... instead of open-coding it where only you use it, please.
> 
> I don't really understand in which direction you want to take this.
> On the one hand, you are saying "there's one caller of
> this function so please open-code it".
> On the other hand, you are saying "it does not matter that
> there's one user of this macro put it in the header".
> 
> Is the point that macros are somehow better than functions so they
> should be used where possible?

No, the point is reuse: For QOM realize we will very likely need the
same thing. It was not my decision to make these macros, I'm just making
Anthony's QOM pattern consistent.

>>> +}
>>> +
>>> +void piix4_pm_get_acpi_pm_info(PIIX4PMState *s, AcpiPmInfo *info)
>>> +{
>>> +        info->s3_disabled = s->disable_s3;
>>> +        info->s4_disabled = s->disable_s4;
>>> +        info->s4_val = s->s4_val;
>>
>> These three are accessible as qdev/QOM properties.
>>
>>> +
>>> +        info->acpi_enable_cmd = ACPI_ENABLE;
>>> +        info->acpi_disable_cmd = ACPI_DISABLE;
>>> +        info->gpe0_blk = GPE_BASE;
>>> +        info->gpe0_blk_len = GPE_LEN;
>>
>> So here the issue is that values are constant?
> 
> Yes.
> 
>>> +        info->sci_int = 9;
>>
>> Magic number - use a define to share it with wherever it is used?
>>
>>> +}
>>> +
>>>  i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
>>>                         qemu_irq sci_irq, qemu_irq smi_irq,
>>>                         int kvm_enabled, FWCfgState *fw_cfg)
>>> diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
>>> index de87241..14573ab 100644
>>> --- a/hw/mips/mips_malta.c
>>> +++ b/hw/mips/mips_malta.c
>>> @@ -965,7 +965,7 @@ void mips_malta_init(QEMUMachineInitArgs *args)
>>>      pci_piix4_ide_init(pci_bus, hd, piix4_devfn + 1);
>>>      pci_create_simple(pci_bus, piix4_devfn + 2, "piix4-usb-uhci");
>>>      smbus = piix4_pm_init(pci_bus, piix4_devfn + 3, 0x1100,
>>> -                          isa_get_irq(NULL, 9), NULL, 0, NULL);
>>> +                          isa_get_irq(NULL, 9), NULL, 0, NULL, NULL);
>>
>> This looks fishy. Might belong into a different patch? Implementation
>> didn't change above.
>>
>>>      /* TODO: Populate SPD eeprom data.  */
>>>      smbus_eeprom_init(smbus, 8, NULL, 0);
>>>      pit = pit_init(isa_bus, 0x40, 0, NULL);
>>> diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
>>> index 3908860..daefdfb 100644
>>> --- a/hw/pci-host/piix.c
>>> +++ b/hw/pci-host/piix.c
>>> @@ -349,6 +349,14 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix3_devfn,
>>>      return b;
>>>  }
>>>  
>>> +PCIBus *find_i440fx(void)
>>> +{
>>> +    PCIHostState *s = OBJECT_CHECK(PCIHostState,
>>> +                                   object_resolve_path("/machine/i440fx", NULL),
>>> +                                   TYPE_PCI_HOST_BRIDGE);
>>
>> Open-coded OBJECT_CHECK() - should use existing PCI_HOST_BRIDGE(...).
>>
>>> +    return s ? s->bus : NULL;
>>> +}
>>
>> Is this function really necessary? /machine/i440fx/pci.0 is a trivial
>> addition to the path that's already being used here. You can do:
>> PCIBus *bus = PCI_BUS(object_resolve_path("/machine/i440fx/pci.0"));
>> where you actually need to access it.
> 
> 
> I don't mind but I would like to avoid callers hard-coding
> paths, in this case "i440fx".
> Why the aversion to functions?

Simply because QMP cannot call functions. It has to work with qom-list
and qom-get, so this is a test case showing what is missing and can IMO
easily be addressed for both parties.

The suggested cast to PCI_BUS() lets you use regular qdev functions btw
as a shortcut, QMP users would need to iterate children of that node.

The suggested "pci.0" is considered stable for -device ...,bus=pci.0
according to review feedback the Xen people have received for libxl.

Andreas

> 
>>> +
>>>  /* PIIX3 PCI to ISA bridge */
>>>  static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq)
>>>  {
>>> diff --git a/include/hw/acpi/piix4.h b/include/hw/acpi/piix4.h
>>> new file mode 100644
>>> index 0000000..2876428
>>> --- /dev/null
>>> +++ b/include/hw/acpi/piix4.h
>>> @@ -0,0 +1,10 @@
>>> +#ifndef HW_ACPI_PIIX4_H
>>> +#define HW_ACPI_PIIX4_H
>>> +
>>> +#include "qemu/typedefs.h"
>>> +
>>> +PIIX4PMState *piix4_pm_find(void);
>>> +
>>> +void piix4_pm_get_acpi_pm_info(PIIX4PMState *, AcpiPmInfo *);
>>> +
>>> +#endif
>>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>>> index 7c0bd50..76af5cd 100644
>>> --- a/include/hw/i386/pc.h
>>> +++ b/include/hw/i386/pc.h
>>> @@ -186,6 +186,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
>>>                      MemoryRegion *pci_memory,
>>>                      MemoryRegion *ram_memory);
>>>  
>>> +PCIBus *find_i440fx(void);
>>>  /* piix4.c */
>>>  extern PCIDevice *piix4_dev;
>>>  int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn);
>>> diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
>>> index cb66e19..7d42693 100644
>>> --- a/include/qemu/typedefs.h
>>> +++ b/include/qemu/typedefs.h
>>> @@ -65,6 +65,7 @@ typedef struct QEMUSGList QEMUSGList;
>>>  typedef struct SHPCDevice SHPCDevice;
>>>  typedef struct FWCfgState FWCfgState;
>>>  typedef struct PcGuestInfo PcGuestInfo;
>>> +typedef struct PIIX4PMState PIIX4PMState;
>>>  typedef struct AcpiPmInfo AcpiPmInfo;
>>>  
>>>  #endif /* QEMU_TYPEDEFS_H */
>>>
>>
>>
>> -- 
>> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
>> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg