From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tommaso Cucinotta Subject: Asynchronous interruption of a compute-intensive guest Date: Wed, 13 Apr 2011 02:09:02 +0200 Message-ID: <4DA4E99E.1030200@sssup.it> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from ms01.sssup.it ([193.205.80.99]:45599 "EHLO sssup.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754870Ab1DMBJH (ORCPT ); Tue, 12 Apr 2011 21:09:07 -0400 Received: from [79.36.200.98] (account t.cucinotta@sssup.it HELO [192.168.1.5]) by sssup.it (CommuniGate Pro SMTP 5.3.10) with ESMTPSA id 68414286 for kvm@vger.kernel.org; Wed, 13 Apr 2011 02:09:03 +0200 Sender: kvm-owner@vger.kernel.org List-ID: Hi, I'd like to "intercept" from the host the exact times at which an incoming network packet directed to a guest VM: a) is delivered from the host OS to the KVM process; b) is delivered to the "CPU thread" of the KVM process. Specifically, I don't have a clean idea of how b) happens when the CPU thread is doing compute-intensive activities within the VM. How is the flow of control of such thread asynchronously interrupted so as to hand over control to the proper network driver in kvm ? Any pointer to the exact points to look at, in the KVM code, are also very well appreciated. Just in case you're interested, we need this for playing with some custom CPU scheduling policy we have at our lab, for the purpose of facing with the problem of responsiveness of VMs while doing CPU-intensive activities (i.e., a mixed batch/interactive guest). Thanks very much for your kind help. Regards, T. -- Tommaso Cucinotta, Computer Engineering PhD, Researcher ReTiS Lab, Scuola Superiore Sant'Anna, Pisa, Italy Tel +39 050 882 024, Fax +39 050 882 003 http://retis.sssup.it/people/tommaso