From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: I/O port permission bit inheritance between threads Date: Tue, 21 May 2013 11:50:30 +0200 Message-ID: <20130521095030.GC7424@8bytes.org> References: <20130520142431.5221e2d0@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Stephen Hemminger Return-path: Received: from 8bytes.org ([85.214.48.195]:47678 "EHLO mail.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751303Ab3EUJuc (ORCPT ); Tue, 21 May 2013 05:50:32 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.8bytes.org (Postfix) with SMTP id 02E9F12AF2A for ; Tue, 21 May 2013 11:50:30 +0200 (CEST) Content-Disposition: inline In-Reply-To: <20130520142431.5221e2d0@nehalam.linuxnetplumber.net> Sender: kvm-owner@vger.kernel.org List-ID: Hey Stephen, On Mon, May 20, 2013 at 02:24:31PM -0700, Stephen Hemminger wrote: > ioperm() inheritance across threads is different in KVM then when run > on physical hardware. The following program runs on physical hardware > but get SEGV under KVM. > > It appears that the I/O permission bits are not shared between threads > in the same way. Is this specific to SVM or do you see it on VMX too? My first guess would be that the KVM instruction emulator does not check to IO-permissions correctly, but that would affect VMX and SVM. Joerg