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Re: [Xen-devel] [PATCH 5/5] changes of common files for xen/ia64 dom0 vp

To: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 5/5] changes of common files for xen/ia64 dom0 vp model: netback work around
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Fri, 28 Apr 2006 14:53:20 +0100
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On 28 Apr 2006, at 03:56, Isaku Yamahata wrote:

Work around for vnif support of xen/ia64 with dom0 vp model.
This is a temporal work around until figuring out how to place a new page
after grant table page transfer.

Does netback work *at all* for you with vp model? Looks like this patch may make it build but not actually work, which makes it seem a bit pointless.

Anyway, two possible solutions are apparent to me:
1. netback gathers 'transmitted' skbuffs and then, in one batch, does a populate_physmap() call to get new pages for all of them, the kfree_skb()s each one back to system pool. 2. change semantics of grant transfers for vp guests so that the operation automatically gets you a fresh page at the same pseudo-physical address.

Option (2) is maybe the better one? Then this patch would make more sense (except that the code would be made run-time dependent on autotranslate feature flag).

 -- Keir

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