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Date: Wed, 25 Mar 2009 18:45:19 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] honor IDE_DMA_BUF_SECTORS
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To: qemu-devel@nongnu.org

Stefano Stabellini wrote:
> Avi Kivity wrote:
>
>   
>> Stefano Stabellini wrote:
>>     
>>> Hi all,
>>> after the recent introduction of dma_buf_prepare we stopped honoring
>>> IDE_DMA_BUF_SECTORS (the guest can issue dma requests with a greater
>>> total length than IDE_DMA_BUF_SECTORS).
>>> This patch adds the IDE_DMA_BUF_SECTORS limit back in place.
>>>
>>> Comments are welcome.
>>>   
>>>       
>> Aren't 64K sector requests legal?
>>
>> Looking at ide_cmd_lba48_transform().
>>
>>     
>
>
> I am not sure about that, but I would think not since we define MAX_MULT_SECTORS 16
> If I change MAX_MULT_SECTORS, am I supposed to see smaller dma requests?
>   

I think that's for pio, or maybe older DMA?  Certainly you wouldn't 
expect to be limited to 16 sectors DMA.

Anyway I think IDE_DMA_BUF_SECTORS was a qemu limitation and did not 
model real hardware behaviour.

-- 
error compiling committee.c: too many arguments to function