From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xensource.com>
Subject: Re: [PATCH 0 of 3] Enable domain checkpointing via xm
	save --checkpoint
Date: Tue, 27 Feb 2007 16:10:55 +0000
Message-ID: <C20A088F.A3C3%keir@xensource.com>
References: <patchbomb.1172543793@ventoux.cs.ubc.ca>
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To: Brendan Cully <brendan@cs.ubc.ca>, xen-devel@lists.xensource.com
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Basically okay, but please create a new elfnote rather than adding a
feature. The feature stuff has kind of got a bit confused, but is meant to
indicate features provided by Xen to a particular guest. The feature maps in
the guest header indicate which Xen features it requires and/or supports.
This new flag has nothing to do with the hypervisor itself so I think it
belongs in its own elfnote (XEN_ELFNOTE_SUSPEND_CANCEL?). This can either be
a boolean (so no elfnote description bytes) or perhaps we should map it to a
long with value 1 for now (so we can add further save/restore revisions
later if we like).

Oh, also remember to add the elfnote to the x86/64 head-xen.S.

 -- Keir

On 27/2/07 02:36, "Brendan Cully" <brendan@cs.ubc.ca> wrote:

> The attached patches create a --checkpoint flag for xm save:
> 
> xc_domain_resume lets the caller alert the guest that it is being
> resumed. Callers should not do this unless they know the guest
> supports the operation.
> 
> When xend wants to resume a domain, it checks for the suspend_cancel
> feature in the elfnotes it has recorded from domain build or
> resume. If the flag is present, it simply lets the guest handle
> resuming, otherwise it tears down and rebuilds the domain and lets the
> guest act as if it is resuming in a new domain.
> 
> A new suspend_cancel feature is added to the kernel 'features'
> elfnote.
> 
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