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Re: [Xen-devel] [PATCH] libxc: failure to save/restore 32bit HVM guest

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] libxc: failure to save/restore 32bit HVM guest
From: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
Date: Tue, 24 Nov 2009 11:23:48 -0800
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On Tue, 24 Nov 2009 08:48:16 +0000
Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:

> On 23/11/2009 23:14, "Mukesh Rathor" <mukesh.rathor@xxxxxxxxxx> wrote:
> > Following appears to be an obvious bug. Save/restore of HVM guests
> > works fine after the following fix. Including the patch, please let
> > me know if you agree. I'll make parallel fix in our previous
> > versions here.
> Save/restore of HVM guests should work fine before this fix too, since
> nothing in xc_core.c is used for guest save/restore. It's used for
> core dumps, as the name implies, and which is a rather different
> thing.
> Furthermore I think the code in xc_core.c is correct as is.
>  -- Keir

Sorry, my bad, I meant dump core. I was simultaneously looking at
save/restore, and accidentally said that.

Anyways, since 32bit HVM returns 64bit contexts, it appears the way it
is, is buggy, since the sizeof(ctxt[0].c) will return 32bit context
size in 32 bit libxc. Infact, after making the fix, user is able to get
proper core of a Java HVM guest. Can you please quickly explain why you
think it's correct in such case?


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