Re: [PATCH] kvm: Take into account the unaligned section size when preparing bitmap

[zhukeqian]

On 2020/12/10 10:08, Peter Xu wrote:
> Keqian,
> 
> On Thu, Dec 10, 2020 at 09:46:06AM +0800, zhukeqian wrote:
>> Hi,
>>
>> I see that if start or size is not PAGE aligned, it also clears areas
>> which beyond caller's expectation, so do we also need to consider this?
> 
> Could you elaborate?
> 
> If start_delta != 0, kvm_log_clear_one_slot() should already go the slow path.
> 
> Thanks,
> 

Hi Peter,

start_delta /= psize;

If start is not PAGE aligned, then start_delta is not PAGE aligned.
so I think the above code will implicitly extend our start to be PAGE aligned.

I suggest that we should shrink the start and (start + size) to be PAGE aligned
at beginning of this function.

Maybe I miss something?

Keqian.