linux-kernel - Re: [PATCH] Enhance perf to collect KVM guest os statistics from host side

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: <20100316163537.GA17537@elte.hu>
Date:	Tue, 16 Mar 2010 17:35:37 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	"Frank Ch. Eigler" <fche@...hat.com>
Cc:	Avi Kivity <avi@...hat.com>,
	"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
Subject: Re: [PATCH] Enhance perf to collect KVM guest os statistics from
 host side


* Frank Ch. Eigler <fche@...hat.com> wrote:

> Hi -
> 
> On Tue, Mar 16, 2010 at 04:52:21PM +0100, Ingo Molnar wrote:
> > [...]
> > > Perhaps the fact that kvm happens to deal with an interesting application 
> > > area (virtualization) is misleading here.  As far as the host kernel or 
> > > other host userspace is concerned, qemu is just some random unprivileged 
> > > userspace program [...]
> 
> > You are quite mistaken: KVM isnt really a 'random unprivileged
> > application' in this context, it is clearly an extension of
> > system/kernel services.
> 
> I don't know what "extension of system/kernel services" means in this 
> context, beyond something running on the system/kernel, like every other 
> process. [...]

It means something like my example of 'extended to guest space' 
/proc/kallsyms:

> > [...]
> >
> > ( Which can be seen from the simple fact that what started the
> >   discussion was 'how do we get /proc/kallsyms from the guest'. I.e. an 
> >   extension of the existing host-space /proc/kallsyms was desired. )
> 
> (Sorry, that smacks of circular reasoning.)

To me it sounds like an example supporting my point. /proc/kallsyms is a 
service by the kernel, and 'perf kvm' desires this to be extended to guest 
space as well.

Thanks,

	Ingo
--
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/