Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757423AbcLTJ1X (ORCPT ); Tue, 20 Dec 2016 04:27:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51118 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbcLTJ1S (ORCPT ); Tue, 20 Dec 2016 04:27:18 -0500 Subject: Re: Questions on the task isolation patches To: Chris Metcalf , yunhong jiang References: <20161201142812.369f23f8@jnakajim-build> <5dd4cbf7-d0c0-074a-c5bc-e2e09ec3dc75@mellanox.com> <20161206134355.193c752b@jnakajim-build> Cc: "linux-kernel@vger.kernel.org" From: Paolo Bonzini Message-ID: <050e5bb5-b5d3-86a4-f7ff-5f633a4bd2bc@redhat.com> Date: Tue, 20 Dec 2016 10:27:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 20 Dec 2016 09:27:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 709 Lines: 17 On 16/12/2016 22:00, Chris Metcalf wrote: > > Sorry, I think I wasn't clear. Normally when you are running task > isolated and you enter the kernel, you will get a fatal signal. The > exception is if you call prctl itself (or exit), the kernel tolerates > it without a signal, since obviously that's how you need to cleanly > tell the kernel you are done with task isolation. Running in a guest is pretty much the same as running in userspace. Would it be possible to exclude the KVM_RUN ioctl as well? QEMU would still have to run prctl when a CPU goes to sleep, and KVM_RUN would have to enable/disable isolated mode when a VM executes HLT (which should never happen anyway in NFV scenarios). Paolo