Re: [Qemu-devel] [PATCH] honor IDE_DMA_BUF_SECTORS

[Avi Kivity]

Samuel Thibault wrote:
> Nothing in Linux makes filesystems and devices systematically read/write
> the amount of data that was requested.
>
>   

We're talking about the qemu block layer, not Linux.  You're proposing 
to take the posix API rules and apply them to the qemu block layer.  But 
posix read/write does not fit how DMA works.  A request should either 
complete fully, or fail, leaving the destination (disk or memory) in an 
undefined state.  Partial completions are impossible to implement 
efficiently, and are a needless complication.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.