From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 1/3] KVM: x86 emulator: Fix task switch privilege checks Date: Tue, 24 Jan 2012 15:03:16 +0100 Message-ID: <20120124140316.GD19255@amd.com> References: <1327335048-31925-1-git-send-email-kwolf@redhat.com> <1327335048-31925-2-git-send-email-kwolf@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: , , , , To: Kevin Wolf Return-path: Received: from va3ehsobe006.messaging.microsoft.com ([216.32.180.16]:27190 "EHLO VA3EHSOBE007.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751809Ab2AXOD3 (ORCPT ); Tue, 24 Jan 2012 09:03:29 -0500 Content-Disposition: inline In-Reply-To: <1327335048-31925-2-git-send-email-kwolf@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Jan 23, 2012 at 05:10:46PM +0100, Kevin Wolf wrote: > This patch fixes the problem for VMX. For SVM, the logic used to > determine the source of the task switch is buggy, so we can't pass > useful information to the emulator there and just disable the check in > all cases. Actually, SVM isn't buggy :) For SVM you do not need to do any priviledge checks in software because the hardware already takes care of that. In other words, KVM only gets a task-switch intercept if the priviledges are all checked and correct. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632