Re: [Qemu-devel] [RFC v4 08/13] ide: enumerate_slots implementation

[John Snow <jsnow@redhat.com>]

On 08/14/2017 05:57 PM, Eduardo Habkost wrote:
> Example output when using "-machine q35":
> 
>   {
>     "available": true,
>     "count": 1,
>     "device-types": [
>       "ide-device"
>     ],
>     "hotpluggable": false,
>     "opts": [
>       { "option": "unit", "values": 0 },
>       { "option": "bus", "values": "ide.2" }
>     ],
>     "opts-complete": true
>   }
>   {
>     "available": false,
>     "count": 1,
>     "device": "/machine/unattached/device[19]",
>     "device-types": [
>       "ide-device"
>     ],
>     "hotpluggable": false,
>     "opts": [
>       { "option": "unit", "values": 1 },
>       { "option": "bus", "values": "ide.2" } ],
>     "opts-complete": true
>   }
>   {
>     "available": true,
>     "count": 10,
>     "device-types": [
>       "ide-device"
>     ],
>     "hotpluggable": false,
>     "opts": [
>       { "option": "unit", "values": [ [ 0, 1 ] ] },

Hm, these unit values aren't really correct -- we do not support
primary/secondary semantics for IDE buses on the AHCI device. I guess
they technically exist, but you cannot use them for anything.

Should I do something to "disable" or otherwise hide the unusable
secondary unit slots for AHCI devices?

--js

>       { "option": "bus", "values": [ "ide.4", "ide.3", "ide.5", "ide.0", "ide.1" ] }
>     ],
>     "opts-complete": true
>   }
> 
> Cc: John Snow <jsnow@redhat.com>
> Cc: qemu-block@nongnu.org
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  hw/ide/qdev.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
> index f17da1f..cc96f6f 100644
> --- a/hw/ide/qdev.c
> +++ b/hw/ide/qdev.c
> @@ -25,6 +25,7 @@
>  #include "sysemu/block-backend.h"
>  #include "sysemu/blockdev.h"
>  #include "hw/block/block.h"
> +#include "hw/qdev-slotinfo.h"
>  #include "sysemu/sysemu.h"
>  #include "qapi/visitor.h"
>  
> @@ -38,6 +39,30 @@ static Property ide_props[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> +static DeviceSlotInfoList *ide_bus_enumerate_slots(BusState *bus)
> +{
> +    int unit;
> +    DeviceSlotInfoList *r = NULL;
> +    IDEBus *ib = IDE_BUS(bus);
> +
> +    for (unit = 0; unit < 2; unit++) {
> +        DeviceSlotInfo *s = make_slot(bus);
> +        IDEDevice *dev = (unit ? ib->master : ib->slave);
> +        slot_add_opt_int(s, "unit", unit);
> +        s->opts_complete = true;
> +        s->has_count = true;
> +        s->count = 1;
> +        if (dev) {
> +            s->available = false;
> +            s->has_device = true;
> +            s->device = object_get_canonical_path(OBJECT(dev));
> +        }
> +        slot_list_add_slot(&r, s);
> +    }
> +
> +    return r;
> +}
> +
>  static void ide_bus_class_init(ObjectClass *klass, void *data)
>  {
>      BusClass *k = BUS_CLASS(klass);
> @@ -45,6 +70,7 @@ static void ide_bus_class_init(ObjectClass *klass, void *data)
>      k->get_fw_dev_path = idebus_get_fw_dev_path;
>      k->unrealize = idebus_unrealize;
>      k->device_type = TYPE_IDE_DEVICE;
> +    k->enumerate_slots = ide_bus_enumerate_slots;
>  }
>  
>  static void idebus_unrealize(BusState *bus, Error **errp)
>