Re: [Xen-devel] Xen crash on HVM shutdown [PATCH]

[Christoph Egger <Christoph.Egger@xxxxxxx>]

On Thursday 26 June 2008 12:32:11 Gianluca Guida wrote:
> Hello,
>
> Sorry for the late reply. Sending emails is sometimes more
> complicated than what you expect.
>
> On Jun 25, 2008, at 3:17 PM, Christoph Egger wrote:
> > It looks to me, the recent L1 shadow changesets introduced a bug.
>
> Yes. This bug is triggered when the guest shuts down with pages still
> OOS (e.g., paging still enabled and  recently touched L1s pagetables,
> or supposedly so). I unfortunately could not reproduce it, but the
> inline patch should fix this.

I can confirm this patch fixes the crash. Tnx.
Keir: Please apply the patch.

Christoph

>
> Thanks!
> Gianluca
>
> Signed-off-by: Gianluca Guida <gianluca.guida@xxxxxxxxxxxxx>
>
> diff -r 2be3c309e446 xen/arch/x86/mm/shadow/common.c
> --- a/xen/arch/x86/mm/shadow/common.c Wed Jun 25 13:39:14 2008 -0400
> +++ b/xen/arch/x86/mm/shadow/common.c Wed Jun 25 14:54:34 2008 -0400
> @@ -630,6 +630,11 @@
>       struct domain *d = v->domain;
>
>       perfc_incr(shadow_oos_fixup_remove);
> +
> +    /* If the domain is dying we might get called when deallocating
> +     * the shadows. Fixup tables are already freed so exit now. */
> +    if (d->is_dying)
> +        return;
>
>       idx = mfn_x(gmfn) % SHADOW_OOS_FT_HASH;
>       for_each_vcpu(d, v)
> @@ -3168,6 +3173,7 @@
>           {
>               free_xenheap_pages(v->arch.paging.shadow.oos_fixups,
>                                  SHADOW_OOS_FT_ORDER);
> +            v->arch.paging.shadow.oos_fixups = NULL;
>           }
>
>           {



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