linux-kernel - Re: [PATCH] xen: core dom0 support

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]

Message-ID: <49ABA633.2050903@redhat.com>
Date:	Mon, 02 Mar 2009 10:26:11 +0100
From:	Gerd Hoffmann <kraxel@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	the arch/x86 maintainers <x86@...nel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Xen-devel <xen-devel@...ts.xensource.com>
Subject: Re: [PATCH] xen: core dom0 support

Ingo Molnar wrote:
>>> In three years time, will we regret having merged this?
>> Its a pretty minor amount of extra stuff on top of what's been 
>> added over the last 3 years, so I don't think it's going to 
>> tip the scales on its own.  I wouldn't be comfortable in 
>> trying to merge something that's very intrusive.
> 
> Hm, how can the same code that you call "massive out-of-tree 
> patches which doesn't make anyone happy" in an out of tree 
> context suddenly become non-intrusive "minor amount of extra 
> stuff" in an upstream context?

The current, out-of-tree xen kernel stuff is based on 2.6.18.  That
predates pv_ops and is quite intrusive stuff, with alot of cut+paste
programming and dirty hacks.

Alot has happened in x86 land since 2.6.18.  Being one of the x86 arch
maintainers you should know that very well.  Most notably:

  * pv_ops.  Point of adding these is to allow virtualization-friendly
    kernels *without* being intrusive as hell.
  * x86 arch merge, followed up by tons of cleanups and code
    reorganizations.  These changes also make it easier to merge xen
    support in a non-intrusive manner.

Also the xen support code in the linux kernel itself is basically a
rewrite from scratch, it hasn't much in common with the 2.6.18 code base.

> I wish the upstream kernel was able to do such magic, but i'm 
> afraid it is not.

It's no magic, it's alot of hard work.

cheers,
  Gerd


--
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/