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RE: [Xen-devel] passing hypercall parameters by pointer

To: "Sharma, Arun" <arun.sharma@xxxxxxxxx>, "Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] passing hypercall parameters by pointer
From: "Ling, Xiaofeng" <xiaofeng.ling@xxxxxxxxx>
Date: Thu, 18 Aug 2005 08:47:54 +0800
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, "Yu, Ke" <ke.yu@xxxxxxxxx>
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Thread-topic: [Xen-devel] passing hypercall parameters by pointer

Arun Sharma <mailto:arun.sharma@xxxxxxxxx> wrote:
> Ian Pratt wrote:
> The other alternative (which we talked about at OLS) is to use a
> couple of pinned pages for parameter passing - but it doesn't work
> very well for:  
> a) Multiple levels of structures/pointers
A good example is do_multicall.
A complete implementation need to enum all the hypercall and 
try to deal with each hypercall if it uses points.

> b) Arguments which may be bigger than a couple of pages
> (xc_get_pfn_list() for a bigmem domain for example).
>       -Arun

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