[Xen-devel] Re: [PATCH 0/3][IA64] Accelerate IDE PIO on HVM/IA64

To:	Kouya SHIMURA <kouya@xxxxxxxxxxxxxx>, Alex Williamson <alex.williamson@xxxxxx>
Subject:	[Xen-devel] Re: [PATCH 0/3][IA64] Accelerate IDE PIO on HVM/IA64
From:	Keir Fraser <keir@xxxxxxxxxxxxx>
Date:	Tue, 27 Feb 2007 10:56:16 +0000
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On 27/2/07 09:34, "Kouya SHIMURA" <kouya@xxxxxxxxxxxxxx> wrote:

> The basic idea is to add a buffering mechanism in a hypervisor.
> I know this approach is not sophisticated. But there is no other
> good way in IA64 which has no string instructions like x86's.
> 
> This patchset is indispensable to support windows/ia64 on HVM
> since installing windows and crash dumping is terribly slow.

Can you explain how this new code works? As I understand it the problem is
that each PIO instruction decoded by Xen and propagated to qemu only
transfers a single word of data. How does this new buffering mechanism work
around this?

 -- Keir

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