linux-kernel - Re: [RFC] Unify KVM kernel-space and user-space code into a single project

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: <4BA7C96D.2020702@redhat.com>
Date:	Mon, 22 Mar 2010 21:47:57 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Anthony Liguori <anthony@...emonkey.ws>,
	Pekka Enberg <penberg@...helsinki.fi>,
	"Zhang, Yanmin" <yanmin_zhang@...ux.intel.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Sheng Yang <sheng@...ux.intel.com>,
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
	Marcelo Tosatti <mtosatti@...hat.com>,
	oerg Roedel <joro@...tes.org>,
	Jes Sorensen <Jes.Sorensen@...hat.com>,
	Gleb Natapov <gleb@...hat.com>,
	Zachary Amsden <zamsden@...hat.com>, ziteng.huang@...el.com,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Fr?d?ric Weisbecker <fweisbec@...il.com>,
	Gregory Haskins <ghaskins@...ell.com>
Subject: Re: [RFC] Unify KVM kernel-space and user-space code into a single
 project

On 03/22/2010 09:27 PM, Ingo Molnar wrote:
>
>> If your position basically boils down to, we can't trust userspace
>> and we can always trust the kernel, I want to eliminate any
>> userspace path, then I can't really help you out.
>>      
> Why would you want to 'help me out'? I can tell a good solution from a bad one
> just fine.
>    

You are basically making a kernel implementation a requirement, instead 
of something that follows from the requirement.

> You should instead read the long list of disadvantages above, invert them and
> list then as advantages for the kernel-based vcpu enumeration solution, apply
> common sense and go admit to yourself that indeed in this situation a kernel
> provided enumeration of vcpu contexts is the most robust solution.
>    

Having qemu enumerate guests one way or another is not a good idea IMO 
since it is focused on one guest and doesn't have a system-wide entity.  
A userspace system-wide entity will work just as well as kernel 
implementation, without its disadvantages.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

--
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/