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Date: Wed, 24 Mar 2010 08:38:54 +0100
From: Andi Kleen <andi@firstfloor.org>
To: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>, Joerg Roedel <joro@8bytes.org>,
       Anthony Liguori <anthony@codemonkey.ws>, Ingo Molnar <mingo@elte.hu>,
       Pekka Enberg <penberg@cs.helsinki.fi>,
       "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Sheng Yang <sheng@linux.intel.com>, linux-kernel@vger.kernel.org,
       kvm@vger.kernel.org, Marcelo Tosatti <mtosatti@redhat.com>,
       Jes Sorensen <Jes.Sorensen@redhat.com>, Gleb Natapov <gleb@redhat.com>,
       Zachary Amsden <zamsden@redhat.com>, ziteng.huang@intel.com,
       Arnaldo Carvalho de Melo <acme@redhat.com>,
       Fr?d?ric Weisbecker <fweisbec@gmail.com>,
       Gregory Haskins <ghaskins@novell.com>
Subject: Re: [RFC] Unify KVM kernel-space and user-space code into a single project
Message-ID: <20100324073854.GD20695@one.firstfloor.org>
References: <20100322173400.GB15795@elte.hu> <4BA7B9E0.5080009@codemonkey.ws> <20100322192739.GE21919@elte.hu> <4BA7C96D.2020702@redhat.com> <4BA7E9D9.5060800@codemonkey.ws> <20100323140608.GJ1940@8bytes.org> <4BA8EEDE.8070309@redhat.com> <20100323182153.GA14800@8bytes.org> <87hbo6fgpy.fsf@basil.nowhere.org> <4BA9B454.5090908@redhat.com>
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> If you're profiling a single guest it makes more sense to do this from 
> inside the guest - you can profile userspace as well as the kernel.

I'm interested in debugging the guest without guest cooperation.

In many cases qemu's new gdb stub works for that, but in some cases
I would prefer instruction/branch traces over standard gdb style
debugging.

I used to use that very successfully with simulators in the past
for some hard bugs.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.