Re: [Qemu-devel] [PATCH 10/23] qdev: remove baked in notion of aliases

[Paolo Bonzini <pbonzini@redhat.com>]

On 01/30/2012 10:08 PM, Anthony Liguori wrote:
> +/*
> + * Aliases were a bad idea from the start.  Let's keep them
> + * from spreading further.
> + */
> +static const char *qdev_class_get_alias(DeviceClass *dc)
> +{
> +    const char *typename = object_class_get_name(OBJECT_CLASS(dc));
> +
> +    if (strcmp(typename, "virtio-blk-pci") == 0) {
> +        return "virtio-blk";
> +    } else if (strcmp(typename, "virtio-net-pci") == 0) {
> +        return "virtio-net";
> +    } else if (strcmp(typename, "virtio-serial-pci") == 0) {
> +        return "virtio-serial";
> +    } else if (strcmp(typename, "virtio-balloon-pci") == 0) {
> +        return "virtio-balloon";
> +    } else if (strcmp(typename, "virtio-blk-s390") == 0) {
> +        return "virtio-blk";
> +    } else if (strcmp(typename, "virtio-net-s390") == 0) {
> +        return "virtio-net";
> +    } else if (strcmp(typename, "virtio-serial-s390") == 0) {
> +        return "virtio-serial";
> +    } else if (strcmp(typename, "lsi53c895a") == 0) {
> +        return "lsi";
> +    } else if (strcmp(typename, "ich9-ahci") == 0) {
> +        return "ahci";
> +    }
> +
> +    return NULL;
> +}
> +
> +static bool qdev_class_has_alias(DeviceClass *dc)
> +{
> +    return (qdev_class_get_alias(dc) != NULL);
> +}
> +
>   const char *qdev_fw_name(DeviceState *dev)
>   {
>       DeviceClass *dc = DEVICE_GET_CLASS(dev);
>
>       if (dc->fw_name) {
>           return dc->fw_name;
> -    } else if (dc->alias) {
> -        return dc->alias;
> +    } else if (qdev_class_has_alias(dc)) {
> +        return qdev_class_get_alias(dc);
>       }
>
>       return object_get_typename(OBJECT(dev));
> @@ -161,8 +197,8 @@ static void qdev_print_devinfo(ObjectClass *klass, void *opaque)
>       if (dc->bus_info) {
>           error_printf(", bus %s", dc->bus_info->name);
>       }
> -    if (dc->alias) {
> -        error_printf(", alias \"%s\"", dc->alias);
> +    if (qdev_class_has_alias(dc)) {
> +        error_printf(", alias \"%s\"", qdev_class_get_alias(dc));
>       }
>       if (dc->desc) {
>           error_printf(", desc \"%s\"", dc->desc);
> @@ -188,6 +224,27 @@ static int set_property(const char *name, const char *value, void *opaque)
>       return 0;
>   }
>
> +static const char *find_typename_by_alias(const char *alias)
> +{
> +    /* I don't think s390 aliasing could have ever worked... */

Yes, because s390 doesn't have PCI.

> +    if (strcmp(alias, "virtio-blk") == 0) {
> +        return "virtio-blk-pci";
> +    } else if (strcmp(alias, "virtio-net") == 0) {
> +        return "virtio-net-pci";
> +    } else if (strcmp(alias, "virtio-serial") == 0) {
> +        return "virtio-serial-pci";
> +    } else if (strcmp(alias, "virtio-balloon") == 0) {
> +        return "virtio-balloon-pci";
> +    } else if (strcmp(alias, "lsi") == 0) {
> +        return "lsi53c895a";
> +    } else if (strcmp(alias, "ahci") == 0) {
> +        return "ich9-ahci";
> +    }
> +
> +    return NULL;
> +}
> +


Please change this to a table so that you can have:

     if (object_class_by_name(table[i].name) &&
         strcmp(alias, table[i].alias) == 0) {
         return table[i].name;
     }

and for the other direction

     if (object_class_by_name(table[i].name) &&
         strcmp(name, table[i].name) == 0) {
         return table[i].alias;
     }

Paolo