From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [PATCH v2 28/30] KVM: x86 emulator: restart string instruction
 without going back to a guest.
Date: Mon, 15 Mar 2010 12:19:56 +0200
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To: Avi Kivity <avi@redhat.com>
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On Mon, Mar 15, 2010 at 12:15:22PM +0200, Avi Kivity wrote:
> On 03/15/2010 12:07 PM, Gleb Natapov wrote:
> >
> >>Or we can make the buffer larger for everyone (outside this patchset
> >>though).
> >>
> >I am not sure what do you mean here. INS read ahead and MMIO read cache are
> >different beasts. Former is needed to speed-up string pio reads, later
> >(not yet implemented) is needed to reread previous MMIO read results in
> >case instruction emulation is restarted due to need to exit to userspace.
> >MMIO read cache need to be invalidated on each iteration of string
> >instruction.
> 
> Instructions with multiple reads or writes need an mmio read/write
> buffer that can be replayed on re-execution.
> 
> buffer != cache!  A cache can be dropped (perhaps after flushing it
> to a backing store), but a buffer in general cannot.
> 
That is just naming. Call it "buffer" if you want.

I still don't understand what do you mean by "Or we can make the buffer
larger for everyone". Who is this "everyone"? Different instruction need
different kind of buffers.

--
			Gleb.