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

[John Snow]

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 <address@hidden>
> Cc: Markus Armbruster <address@hidden>
> 
> Signed-off-by: Mao Zhongyi <address@hidden>
> ---
>  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 ? "/address@hidden" : "/address@hidden");
> -
> -    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.

>  {
> -    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 <address@hidden>