linux-kernel - Re: [Xen-devel] Re: [PATCH 2/8] xen/mmu: Add the notion of identity (1-1) mapping.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 4 Jan 2011 17:20:23 +0000
From:	Ian Campbell <Ian.Campbell@...rix.com>
To:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	"xen-devel@...ts.xensource.com" <xen-devel@...ts.xensource.com>,
	Stefano Stabellini <Stefano.Stabellini@...citrix.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Jn Beulich <JBeulich@...ell.com>,
	"Konrad Rzeszutek Wilk" <konrad@...nel.org>,
	"hpa@...or.com" <hpa@...or.com>
Subject: Re: [Xen-devel] Re: [PATCH 2/8] xen/mmu: Add the notion of
 identity (1-1) mapping.

On Tue, 2011-01-04 at 16:59 +0000, Ian Campbell wrote:
> On Tue, 2011-01-04 at 16:53 +0000, Ian Campbell wrote:
> > 
> > If I do "__set_phys_to_machine(X, X)" where X happens to currently
> > correspond to p2m_mid_missing won't that cause all pfn entries in the
> > range covered by p2m_top[topidx] (i.e. quite a few, like 512^2 pages
> > or
> > something) to switch from missing to identity? Similarly for
> > p2m_top[topidx][mididx]?
> > 
> > Perhaps ranges of identity bits are often well aligned with the
> > boundaries in the p2m 3-level tree but wouldn't that just be
> > coincidence? 
> 
> I wonder if it would make sense to have a debugfs file which exports the
> p2m, for the purposes of eye-balling it for this sort of issue?
> comparing to the e820 etc...
> 
> Maybe the whole thing in raw form would be overkill but spitting out a
> list of ranges of identity, invalid, normal pages, plus annotation
> regarding whether those come from a p2m_mid_identity style page or a
> leaf node, might be occasionally useful.

I should have read patch 5/8 first...

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/