Re: [Qemu-devel] [PATCH v2 1/6] hw/ide: Convert DeviceClass init to realize

[Mao Zhongyi <maozy.fnst@cn.fujitsu.com>]

On 09/16/2017 05:35 AM, John Snow wrote:
>
>
> On 08/04/2017 06:26 AM, Mao Zhongyi wrote:
>> Replace init with realize in IDEDeviceClass, which has errp
>> as a parameter. So all the implementations now use error_setg
>> instead of error_report for reporting error.
>>
>> Cc: John Snow <jsnow@redhat.com>
>> Cc: Markus Armbruster <armbru@redhat.com>
>>
>> Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
>> ---
>>  hw/ide/core.c             |  7 ++--
>>  hw/ide/qdev.c             | 86 +++++++++++++++++++++++------------------------
>>  include/hw/ide/internal.h |  5 +--
>>  3 files changed, 49 insertions(+), 49 deletions(-)
>>
>> diff --git a/hw/ide/core.c b/hw/ide/core.c
>> index 0b48b64..7c86fc7 100644
>> --- a/hw/ide/core.c
>> +++ b/hw/ide/core.c
>> @@ -34,6 +34,7 @@
>>  #include "hw/block/block.h"
>>  #include "sysemu/block-backend.h"
>>  #include "qemu/cutils.h"
>> +#include "qemu/error-report.h"
>>
>>  #include "hw/ide/internal.h"
>>
>> @@ -2398,7 +2399,7 @@ int ide_init_drive(IDEState *s, BlockBackend *blk, IDEDriveKind kind,
>>                     const char *version, const char *serial, const char *model,
>>                     uint64_t wwn,
>>                     uint32_t cylinders, uint32_t heads, uint32_t secs,
>> -                   int chs_trans)
>> +                   int chs_trans, Error **errp)
>
> this function now requires an additional invariant, which is that we
> must return -1 AND set errp. Probably wisest to just get rid of the
> return code so that we don't accidentally goof this up in the future.
>
> I think Markus has had some guidance on this in the past, but admittedly
> I can't remember his preference.
>
>>  {
>>      uint64_t nb_sectors;
>>
>> @@ -2423,11 +2424,11 @@ int ide_init_drive(IDEState *s, BlockBackend *blk, IDEDriveKind kind,
>>          blk_set_guest_block_size(blk, 2048);
>>      } else {
>>          if (!blk_is_inserted(s->blk)) {
>> -            error_report("Device needs media, but drive is empty");
>> +            error_setg(errp, "Device needs media, but drive is empty");
>>              return -1;
>>          }
>>          if (blk_is_read_only(blk)) {
>> -            error_report("Can't use a read-only drive");
>> +            error_setg(errp, "Can't use a read-only drive");
>>              return -1;
>>          }
>>          blk_set_dev_ops(blk, &ide_hd_block_ops, s);
>> diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
>> index cc2f5bd..d60ac25 100644
>> --- a/hw/ide/qdev.c
>> +++ b/hw/ide/qdev.c
>> @@ -80,7 +80,7 @@ static char *idebus_get_fw_dev_path(DeviceState *dev)
>>      return g_strdup(path);
>>  }
>>
>> -static int ide_qdev_init(DeviceState *qdev)
>> +static void ide_qdev_realize(DeviceState *qdev, Error **errp)
>>  {
>>      IDEDevice *dev = IDE_DEVICE(qdev);
>>      IDEDeviceClass *dc = IDE_DEVICE_GET_CLASS(dev);
>> @@ -91,34 +91,31 @@ static int ide_qdev_init(DeviceState *qdev)
>>      }
>>
>>      if (dev->unit >= bus->max_units) {
>> -        error_report("Can't create IDE unit %d, bus supports only %d units",
>> +        error_setg(errp, "Can't create IDE unit %d, bus supports only %d units",
>>                       dev->unit, bus->max_units);
>> -        goto err;
>> +        return;
>>      }
>>
>>      switch (dev->unit) {
>>      case 0:
>>          if (bus->master) {
>> -            error_report("IDE unit %d is in use", dev->unit);
>> -            goto err;
>> +            error_setg(errp, "IDE unit %d is in use", dev->unit);
>> +            return;
>>          }
>>          bus->master = dev;
>>          break;
>>      case 1:
>>          if (bus->slave) {
>> -            error_report("IDE unit %d is in use", dev->unit);
>> -            goto err;
>> +            error_setg(errp, "IDE unit %d is in use", dev->unit);
>> +            return;
>>          }
>>          bus->slave = dev;
>>          break;
>>      default:
>> -        error_report("Invalid IDE unit %d", dev->unit);
>> -        goto err;
>> +        error_setg(errp, "Invalid IDE unit %d", dev->unit);
>> +        return;
>>      }
>> -    return dc->init(dev);
>> -
>> -err:
>> -    return -1;
>> +    dc->realize(dev, errp);
>>  }
>>
>>  IDEDevice *ide_create_drive(IDEBus *bus, int unit, DriveInfo *drive)
>> @@ -159,7 +156,7 @@ typedef struct IDEDrive {
>>      IDEDevice dev;
>>  } IDEDrive;
>>
>> -static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
>> +static void ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind, Error **errp)
>>  {
>>      IDEBus *bus = DO_UPCAST(IDEBus, qbus, dev->qdev.parent_bus);
>>      IDEState *s = bus->ifs + dev->unit;
>> @@ -168,8 +165,8 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
>>
>>      if (!dev->conf.blk) {
>>          if (kind != IDE_CD) {
>> -            error_report("No drive specified");
>> -            return -1;
>> +            error_setg(errp, "No drive specified");
>> +            return;
>>          } else {
>>              /* Anonymous BlockBackend for an empty drive */
>>              dev->conf.blk = blk_new(0, BLK_PERM_ALL);
>> @@ -182,36 +179,36 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
>>          dev->conf.discard_granularity = 512;
>>      } else if (dev->conf.discard_granularity &&
>>                 dev->conf.discard_granularity != 512) {
>> -        error_report("discard_granularity must be 512 for ide");
>> -        return -1;
>> +        error_setg(errp, "discard_granularity must be 512 for ide");
>> +        return;
>>      }
>>
>>      blkconf_blocksizes(&dev->conf);
>>      if (dev->conf.logical_block_size != 512) {
>> -        error_report("logical_block_size must be 512 for IDE");
>> -        return -1;
>> +        error_setg(errp, "logical_block_size must be 512 for IDE");
>> +        return;
>>      }
>>
>>      blkconf_serial(&dev->conf, &dev->serial);
>>      if (kind != IDE_CD) {
>>          blkconf_geometry(&dev->conf, &dev->chs_trans, 65535, 16, 255, &err);
>>          if (err) {
>> -            error_report_err(err);
>> -            return -1;
>> +            error_propagate(errp, err);
>> +            return;
>>          }
>>      }
>>      blkconf_apply_backend_options(&dev->conf, kind == IDE_CD, kind != IDE_CD,
>>                                    &err);
>>      if (err) {
>> -        error_report_err(err);
>> -        return -1;
>> +        error_propagate(errp, err);
>> +        return;
>>      }
>>
>>      if (ide_init_drive(s, dev->conf.blk, kind,
>>                         dev->version, dev->serial, dev->model, dev->wwn,
>>                         dev->conf.cyls, dev->conf.heads, dev->conf.secs,
>> -                       dev->chs_trans) < 0) {
>> -        return -1;
>> +                       dev->chs_trans, errp) < 0) {
>> +        return;
>>      }
>>
>>      if (!dev->version) {
>> @@ -223,8 +220,6 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
>>
>>      add_boot_device_path(dev->conf.bootindex, &dev->qdev,
>>                           dev->unit ? "/disk@1" : "/disk@0");
>> -
>> -    return 0;
>>  }
>>
>>  static void ide_dev_get_bootindex(Object *obj, Visitor *v, const char *name,
>> @@ -270,17 +265,17 @@ static void ide_dev_instance_init(Object *obj)
>>      object_property_set_int(obj, -1, "bootindex", NULL);
>>  }
>>
>> -static int ide_hd_initfn(IDEDevice *dev)
>> +static void ide_hd_realize(IDEDevice *dev, Error **errp)
>
> why rename these but not ide_dev_initfn ? I guess because it's not
> directly referenced as being a realize function.

Hi, John

Yes, but not exactly. Because the realize function used to initialize the device
can only accept two arguments, but ide_dev_initfn has three. If it is renamed to
realize, although it is not wrong, but it looks puzzled.

Thanks,
Mao

>
>>  {
>> -    return ide_dev_initfn(dev, IDE_HD);
>> +    ide_dev_initfn(dev, IDE_HD, errp);
>>  }
>>
>> -static int ide_cd_initfn(IDEDevice *dev)
>> +static void ide_cd_realize(IDEDevice *dev, Error **errp)
>>  {
>> -    return ide_dev_initfn(dev, IDE_CD);
>> +    ide_dev_initfn(dev, IDE_CD, errp);
>>  }
>>
>> -static int ide_drive_initfn(IDEDevice *dev)
>> +static void ide_drive_realize(IDEDevice *dev, Error **errp)
>>  {
>>      DriveInfo *dinfo = NULL;
>>
>> @@ -288,7 +283,7 @@ static int ide_drive_initfn(IDEDevice *dev)
>>          dinfo = blk_legacy_dinfo(dev->conf.blk);
>>      }
>>
>> -    return ide_dev_initfn(dev, dinfo && dinfo->media_cd ? IDE_CD : IDE_HD);
>> +    ide_dev_initfn(dev, dinfo && dinfo->media_cd ? IDE_CD : IDE_HD, errp);
>>  }
>>
>>  #define DEFINE_IDE_DEV_PROPERTIES()                     \
>> @@ -311,10 +306,11 @@ static void ide_hd_class_init(ObjectClass *klass, void *data)
>>  {
>>      DeviceClass *dc = DEVICE_CLASS(klass);
>>      IDEDeviceClass *k = IDE_DEVICE_CLASS(klass);
>> -    k->init = ide_hd_initfn;
>> +
>> +    k->realize  = ide_hd_realize;
>>      dc->fw_name = "drive";
>> -    dc->desc = "virtual IDE disk";
>> -    dc->props = ide_hd_properties;
>> +    dc->desc    = "virtual IDE disk";
>> +    dc->props   = ide_hd_properties;
>>  }
>>
>>  static const TypeInfo ide_hd_info = {
>> @@ -333,10 +329,11 @@ static void ide_cd_class_init(ObjectClass *klass, void *data)
>>  {
>>      DeviceClass *dc = DEVICE_CLASS(klass);
>>      IDEDeviceClass *k = IDE_DEVICE_CLASS(klass);
>> -    k->init = ide_cd_initfn;
>> +
>> +    k->realize  = ide_cd_realize;
>>      dc->fw_name = "drive";
>> -    dc->desc = "virtual IDE CD-ROM";
>> -    dc->props = ide_cd_properties;
>> +    dc->desc    = "virtual IDE CD-ROM";
>> +    dc->props   = ide_cd_properties;
>>  }
>>
>>  static const TypeInfo ide_cd_info = {
>> @@ -355,10 +352,11 @@ static void ide_drive_class_init(ObjectClass *klass, void *data)
>>  {
>>      DeviceClass *dc = DEVICE_CLASS(klass);
>>      IDEDeviceClass *k = IDE_DEVICE_CLASS(klass);
>> -    k->init = ide_drive_initfn;
>> +
>> +    k->realize  = ide_drive_realize;
>>      dc->fw_name = "drive";
>> -    dc->desc = "virtual IDE disk or CD-ROM (legacy)";
>> -    dc->props = ide_drive_properties;
>> +    dc->desc    = "virtual IDE disk or CD-ROM (legacy)";
>> +    dc->props   = ide_drive_properties;
>>  }
>>
>>  static const TypeInfo ide_drive_info = {
>> @@ -371,7 +369,7 @@ static const TypeInfo ide_drive_info = {
>>  static void ide_device_class_init(ObjectClass *klass, void *data)
>>  {
>>      DeviceClass *k = DEVICE_CLASS(klass);
>> -    k->init = ide_qdev_init;
>> +    k->realize = ide_qdev_realize;
>>      set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
>>      k->bus_type = TYPE_IDE_BUS;
>>      k->props = ide_props;
>> diff --git a/include/hw/ide/internal.h b/include/hw/ide/internal.h
>> index 482a951..5ebb4c9 100644
>> --- a/include/hw/ide/internal.h
>> +++ b/include/hw/ide/internal.h
>> @@ -12,6 +12,7 @@
>>  #include "sysemu/sysemu.h"
>>  #include "hw/block/block.h"
>>  #include "block/scsi.h"
>> +#include "qapi/error.h"
>>
>>  /* debug IDE devices */
>>  //#define DEBUG_IDE
>> @@ -495,7 +496,7 @@ struct IDEBus {
>>
>>  typedef struct IDEDeviceClass {
>>      DeviceClass parent_class;
>> -    int (*init)(IDEDevice *dev);
>> +    void (*realize)(IDEDevice *dev, Error **errp);
>>  } IDEDeviceClass;
>>
>>  struct IDEDevice {
>> @@ -605,7 +606,7 @@ int ide_init_drive(IDEState *s, BlockBackend *blk, IDEDriveKind kind,
>>                     const char *version, const char *serial, const char *model,
>>                     uint64_t wwn,
>>                     uint32_t cylinders, uint32_t heads, uint32_t secs,
>> -                   int chs_trans);
>> +                   int chs_trans, Error **errp);
>>  void ide_init2(IDEBus *bus, qemu_irq irq);
>>  void ide_exit(IDEState *s);
>>  void ide_init_ioport(IDEBus *bus, ISADevice *isa, int iobase, int iobase2);
>>
>
> Only matters of style; seems mechanically OK.
>
> Reviewed-by: John Snow <jsnow@redhat.com>
>
>
>