linux-kernel - Re: [PATCH 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE

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:	Mon, 1 Oct 2012 15:01:51 +0200
From:	Daniel Kiper <daniel.kiper@...cle.com>
To:	Jan Beulich <JBeulich@...e.com>
Cc:	andrew.cooper3@...rix.com, xen-devel <xen-devel@...ts.xen.org>,
	konrad.wilk@...cle.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 02/11] x86/kexec: Add extra pointers to transition page
 table PGD, PUD, PMD and PTE

On Fri, Sep 28, 2012 at 08:56:50AM +0100, Jan Beulich wrote:
> >>> On 27.09.12 at 20:06, Daniel Kiper <daniel.kiper@...cle.com> wrote:
> > Some implementations (e.g. Xen PVOPS) could not use part of identity page
> > table to construct transition page table. It means that they require separate
> > PUDs, PMDs and PTEs for virtual and physical (identity) mapping. To satisfy that
> > requirement add extra pointer to PGD, PUD, PMD and PTE and align existing
> > code.
>
> I'm puzzled by this - why would you need to reintroduce what had
> been dropped a long time ago, when the forward ported kernels
> don't need it? Xen itself doesn't need the extra entries, their
> presence is purely a requirement of the specific kernel
> implementation afaict.

Hmmm... I will try to optimize that a bit.

Daniel
--
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/