Re: [PATCH v2 01/22] block: add eMMC block device type

[Philippe Mathieu-Daudé]

On 2/22/21 2:16 PM, Dr. David Alan Gilbert wrote:
> * Markus Armbruster (armbru@redhat.com) wrote:
>> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
>>
>>> On 2/22/21 9:20 AM, Sai Pavan Boddu wrote:
>>>> From: Vincent Palatin <vpalatin@chromium.org>
>>>>
>>>> Add new block device type.
>>>>
>>>> Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
>>>> [SPB: Rebased over 5.1 version]
>>>> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
>>>> Signed-off-by: Joel Stanley <joel@jms.id.au>
>>>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>>>> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
>>>> ---
>>>>  include/sysemu/blockdev.h | 1 +
>>>>  blockdev.c                | 1 +
>>>>  2 files changed, 2 insertions(+)
>>>>
>>>> diff --git a/include/sysemu/blockdev.h b/include/sysemu/blockdev.h
>>>> index 3b5fcda..eefae9f 100644
>>>> --- a/include/sysemu/blockdev.h
>>>> +++ b/include/sysemu/blockdev.h
>>>> @@ -24,6 +24,7 @@ typedef enum {
>>>>       */
>>>>      IF_NONE = 0,
>>>>      IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO, 
>>>> IF_XEN,
>>>> +    IF_EMMC,
>>>>      IF_COUNT
>>>>  } BlockInterfaceType;
>>>>  
>>>> diff --git a/blockdev.c b/blockdev.c
>>>> index cd438e6..390d43c 100644
>>>> --- a/blockdev.c
>>>> +++ b/blockdev.c
>>>> @@ -83,6 +83,7 @@ static const char *const if_name[IF_COUNT] = {
>>>>      [IF_SD] = "sd",
>>>>      [IF_VIRTIO] = "virtio",
>>>>      [IF_XEN] = "xen",
>>>> +    [IF_EMMC] = "emmc",
>>>>  };
>>>
>>> We don't need to introduce support for the legacy -drive magic.
>>>
>>> -device should be enough for this device, right?
>>
>> External interface extensions need rationale: why do we want / need it?
>> The commit message neglects to provide one.
>>
>> Even more so when the interface in question is in a state like -drive
>> is.
> 
> I wouldn't be too nasty about -drive;  for me I still find it the
> easiest way to start a VM.

But eMMC isn't a bus where you can plug drives, it is soldered
on-board and is mmio mapped to a fixed address. I don't see the
point of having a drive interface for it...