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From: Ian Campbell <Ian.Campbell@citrix.com>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: xen-devel@lists.xensource.com, tim@xen.org
Subject: Re: [PATCH v5 2/4] xen/arm: introduce a generic p2m walker and use it in p2m_lookup
Date: Tue, 10 Sep 2013 19:38:55 +0100	[thread overview]
Message-ID: <1378838335.3057.43.camel@dagon.hellion.org.uk> (raw)
In-Reply-To: <alpine.DEB.2.02.1309101847080.32236@kaball.uk.xensource.com>

On Tue, 2013-09-10 at 19:00 +0100, Stefano Stabellini wrote:
> > > -    /* This bit must be one in the level 3 entry */
> > > -    if ( !pte.p2m.table )
> > > -        pte.bits = 0;
> > > +        if ( cur_first_offset != first_table_offset(paddr) )
> > > +        {
> > > +            if (second) unmap_domain_page(second);
> > > +            second = map_domain_page(first[first_table_offset(paddr)].p2m.base);
> > > +            cur_first_offset = first_table_offset(paddr);
> > > +        }
> > > +        level++;
> > > +        if ( !second ||
> > 
> > ASSERT(second) seems reasonable here, I think, since it would indicate
> > we had screwed up the p2m pretty badly.
> 
> I think it's possible: what if a memory range is simply missing from the
> p2m? The second level pagetable pages could be missing too.

Then the level above it shouldn't have the valid bit set.

Ian.

  reply	other threads:[~2013-09-10 18:38 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-09 16:04 [PATCH v5 0/4] introduce XENMEM_exchange_and_pin and XENMEM_unpin Stefano Stabellini
2013-09-09 16:06 ` [PATCH v5 1/4] xen: move steal_page and donate_page to common code Stefano Stabellini
2013-09-10  9:08   ` Ian Campbell
2013-09-10 10:39   ` Jan Beulich
2013-09-10 17:20     ` Stefano Stabellini
2013-09-10 18:06       ` Tim Deegan
2013-09-10 18:14         ` Stefano Stabellini
2013-09-11  6:31       ` Jan Beulich
2013-09-09 16:06 ` [PATCH v5 2/4] xen/arm: introduce a generic p2m walker and use it in p2m_lookup Stefano Stabellini
2013-09-10  9:26   ` Ian Campbell
2013-09-10 18:00     ` Stefano Stabellini
2013-09-10 18:38       ` Ian Campbell [this message]
2013-09-11 16:55         ` Stefano Stabellini
2013-09-09 16:06 ` [PATCH v5 3/4] xen: implement guest_physmap_pin_range and guest_physmap_unpin_range Stefano Stabellini
2013-09-10  9:30   ` Ian Campbell
2013-09-10 19:11     ` Stefano Stabellini
2013-09-10 19:42       ` Ian Campbell
2013-09-27 14:46         ` Stefano Stabellini
2013-09-10  9:33   ` Ian Campbell
2013-09-27 15:23     ` Stefano Stabellini
2013-09-27 15:27       ` Ian Campbell
2013-09-09 16:06 ` [PATCH v5 4/4] xen: introduce XENMEM_exchange_and_pin and XENMEM_unpin Stefano Stabellini
2013-09-10  9:47   ` Ian Campbell
2013-09-10 12:15   ` Jan Beulich
2013-09-10 12:50     ` Ian Campbell
2013-09-10 13:28       ` Jan Beulich
2013-09-10 18:32         ` Stefano Stabellini
2013-09-10 18:37           ` Tim Deegan
2013-09-10 18:40             ` Ian Campbell
2013-09-10 18:50               ` Tim Deegan
2013-09-11  6:33           ` Jan Beulich
2013-09-27 14:49     ` Stefano Stabellini

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