From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757148AbbFQNU5 (ORCPT ); Wed, 17 Jun 2015 09:20:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50231 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754862AbbFQNUs (ORCPT ); Wed, 17 Jun 2015 09:20:48 -0400 Message-ID: <5581742C.9060100@redhat.com> Date: Wed, 17 Jun 2015 15:20:44 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: "Michael S. Tsirkin" , Igor Mammedov CC: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH 3/5] vhost: support upto 509 memory regions References: <20150617083202-mutt-send-email-mst@redhat.com> <20150617092802.5c8d8475@igors-macbook-pro.local> <20150617092910-mutt-send-email-mst@redhat.com> <20150617105421.71751f44@nial.brq.redhat.com> <20150617110711-mutt-send-email-mst@redhat.com> <20150617123742.5c3fec30@nial.brq.redhat.com> <20150617123842-mutt-send-email-mst@redhat.com> <20150617134803.5a03d04e@nial.brq.redhat.com> <20150617134848-mutt-send-email-mst@redhat.com> <20150617142339.6e6deb12@nial.brq.redhat.com> <20150617151030-mutt-send-email-mst@redhat.com> In-Reply-To: <20150617151030-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/06/2015 15:13, Michael S. Tsirkin wrote: > > > Considering userspace can be malicious, I guess yes. > > I don't think it's a valid concern in this case, > > setting limit back from 509 to 64 will not help here in any way, > > userspace still can create as many vhost instances as it needs > > to consume memory it desires. > > Not really since vhost char device isn't world-accessible. > It's typically opened by a priveledged tool, the fd is > then passed to an unpriveledged userspace, or permissions dropped. Then what's the concern anyway? Paolo