Re: [Qemu-block] [PATCH] pflash: Only read non-zero parts of backend image

[Xiang Zheng]

On 2019/5/5 23:37, Peter Maydell wrote:
> On Sun, 5 May 2019 at 08:02, Xiang Zheng <address@hidden> wrote:
>>
>> Currently we fill the memory space with two 64MB NOR images when
>> using persistent UEFI variables on virt board. Actually we only use
>> a very small(non-zero) part of the memory while the rest significant
>> large(zero) part of memory is wasted.
>>
>> So this patch checks the block status and only writes the non-zero part
>> into memory. This requires pflash devices to use sparse files for
>> backends.
> 
> Do you mean "pflash devices will no longer work if the file
> that is backing them is not sparse", or just "if the file that
> is backing them is not sparse then you won't get the benefit
> of using less memory" ?
> 

I mean the latter, if the file is not sparse, nothing would change.
I will improve this commit message in the next version.

-- 

Thanks,
Xiang