Re: [Qemu-devel] Re: KVM call agenda for July 27

[Kevin Wolf]

Am 28.07.2010 13:22, schrieb Markus Armbruster:
> Anthony Liguori <address@hidden> writes:
> 
>> On 07/27/2010 10:22 AM, Markus Armbruster wrote:
>>> Kevin Wolf<address@hidden>  writes:
>>>
>>>    
>>>> Am 27.07.2010 15:00, schrieb Anthony Liguori:
>>>>      
>>>>> On 07/27/2010 02:19 AM, Markus Armbruster wrote:
>>>>>        
>>>>>> Anthony Liguori<address@hidden>   writes:
>>>>>>
>>>>>>
>>>>>>          
>>>>>>> - any additional input on probed_raw?
>>>>>>>
>>>>>>>            
>>>>>> Isn't it a fait accompli?  I stopped providing input when commit
>>>>>> 79368c81 appeared.
>>>>>>
>>>>>>          
>>>>> No.  79368c81 was to close the security hole (and I do consider it a
>>>>> security hole).  But as I mentioned on the list, I'm also not satisfied
>>>>> with it and that's why I proposed probed_raw.  I was hoping to get a
>>>>> little more input from those that objected to 79368c81 as to whether
>>>>> probed_raw was more agreeable.
>>>>>        
>>>> Actually I believe qraw is less agreeable. It just too much magic. You
>>>> wouldn't expect that your raw images are turned into some other format
>>>> that you can't mount or use with any other program any more.
>>>>      
>>> I also dislike probed_raw, for the same reasons.
>>>
>>> Raw can't be probed safely, by its very nature.  For historical reasons,
>>> we try anyway.  I think we should stop doing that, even though that
>>> breaks existing use relying on the misfeature.  Announce it now, spit
>>> out scary warnings, kill it for good 1-2 releases later.
>>>
>>> If we're unwilling to do that, then I'd *strongly* prefer doing nothing
>>> over silently messing with the raw writes to sector 0 (so does
>>> Christoph, and he explained why).
>>
>> If we add docs/deprecated-features.txt, schedule removal for at least
>> 1 year in the future, and put a warning in the code that prints
>> whenever raw is probed, I think I could warm up to this.
>>
>> Since libvirt should be insulating users from this today, I think the
>> fall out might not be terrible.
> 
> Okay, I'll prepare a patch.

This kills -hda and friends for raw images. I'm not sure this is a good
idea.

Kevin