Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934144AbZIDUTq (ORCPT ); Fri, 4 Sep 2009 16:19:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934061AbZIDUTc (ORCPT ); Fri, 4 Sep 2009 16:19:32 -0400 Received: from kroah.org ([198.145.64.141]:36207 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934024AbZIDUOa (ORCPT ); Fri, 4 Sep 2009 16:14:30 -0400 X-Mailbox-Line: From gregkh@mini.kroah.org Fri Sep 4 13:08:53 2009 Message-Id: <20090904200853.830967661@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Fri, 04 Sep 2009 13:07:36 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Avi Kivity Subject: [patch 24/48] KVM: SVM: Remove port 80 passthrough References: <20090904200712.724048145@mini.kroah.org> Content-Disposition: inline; filename=kvm-svm-remove-port-80-passthrough.patch In-Reply-To: <20090904201112.GA8274@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1311 Lines: 30 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Avi Kivity (cherry picked from commit 99f85a28a78e96d28907fe036e1671a218fee597) KVM optimizes guest port 80 accesses by passthing them through to the host. Some AMD machines die on port 80 writes, allowing the guest to hard-lock the host. Remove the port passthrough to avoid the problem. Reported-by: Piotr Jaroszyński Tested-by: Piotr Jaroszyński Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 1 - 1 file changed, 1 deletion(-) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -429,7 +429,6 @@ static __init int svm_hardware_setup(voi iopm_va = page_address(iopm_pages); memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER)); - clear_bit(0x80, iopm_va); /* allow direct access to PC debug port */ iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT; if (boot_cpu_has(X86_FEATURE_NX)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/