Re: [Qemu-devel] [PATCH 03/10] S390: Check Bootdevice Type

[Christian Borntraeger]

On 26/04/13 18:05, Alexander Graf wrote:
> 
> On 26.04.2013, at 18:01, Christian Borntraeger wrote:
> 
>> On 26/04/13 17:48, Alexander Graf wrote:
>>
>>>> So I suggest to go with this patch and implement later on what we
>>>> agree upon?
>>>
>>> I don't see how having "first device we find" is any better than a 
>>> rushed interface we need to agree on right before 1.5 hard freeze. 
>>
>> Exactly, find first device isnt better ;-)
>> See, the current code chooses the first subchannel that matches. This
>> boils down to "a random disk" as soon as you have more than one.
>>
>> With this patch the user can at least specify the devno of the disk.It
>> even works out of the box with libvirt.
>>
>> Let's just release 1.5 with the very simple one and then go for something 
>> awesome in the next version.
>>
>> Exactly - and having a list is more in the awesome area. Beiing able to
>> specify the first disk and pass that in a register to the bios is of
>> course not a full-features interface, but it works and can be changed.
> 
> My main concern is backwards compatibility. If we introduce a command line 
> interface now, we have to support it forever. I'd rather only support one 
> interface, rather than 2 out of which one is only legacy for 1.5 
> compatibility.

The cool thing is, that we dont introduce a command line interface in this 
patch.
We just use the existing bootindex.