From patchwork Fri Jan 4 15:37:41 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 209481 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1348E2C0086 for ; Sat, 5 Jan 2013 02:36:41 +1100 (EST) Received: from localhost ([::1]:44133 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tr9K2-00049F-R0 for incoming@patchwork.ozlabs.org; Fri, 04 Jan 2013 10:36:38 -0500 Received: from eggs.gnu.org ([208.118.235.92]:57377) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tr9Jh-0003w7-6L for qemu-devel@nongnu.org; Fri, 04 Jan 2013 10:36:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tr9Jf-0004dB-GP for qemu-devel@nongnu.org; Fri, 04 Jan 2013 10:36:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50400) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tr9Jf-0004cl-71 for qemu-devel@nongnu.org; Fri, 04 Jan 2013 10:36:15 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r04FaDtY016026 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 4 Jan 2013 10:36:13 -0500 Received: from blackpad.lan.raisama.net (vpn1-7-13.gru2.redhat.com [10.97.7.13]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r04Fa7eL025460; Fri, 4 Jan 2013 10:36:07 -0500 Received: by blackpad.lan.raisama.net (Postfix, from userid 500) id 056C5203D38; Fri, 4 Jan 2013 13:37:45 -0200 (BRST) From: Eduardo Habkost To: qemu-devel@nongnu.org Date: Fri, 4 Jan 2013 13:37:41 -0200 Message-Id: <1357313864-31026-7-git-send-email-ehabkost@redhat.com> In-Reply-To: <1357313864-31026-1-git-send-email-ehabkost@redhat.com> References: <1357313864-31026-1-git-send-email-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kvm@vger.kernel.org, libvir-list@redhat.com, Joerg Roedel , Igor Mammedov , Jiri Denemark , =?UTF-8?q?Andreas=20F=C3=A4rber?= Subject: [Qemu-devel] [PATCH 6/9] target-i386: check/enforce: Check SVM flag support as well X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org When nested SVM is supported, the kernel returns the SVM flag on GET_SUPPORTED_CPUID[1], so we can check the SVM flag safely on kvm_check_features_against_host(). I don't know why the original code ignored the SVM flag. Maybe it was because kvm_cpu_fill_host() used the CPUID instruction directly instead of GET_SUPPORTED_CPUID [1] Older kernels (before v2.6.37) returned the SVM flag even if nested SVM was _not_ supported. So the only cases where this patch should change behavior is when SVM is being requested by the user or the CPU model, but not supported by the host. And on these cases we really want QEMU to abort if the "enforce" option is set. Signed-off-by: Eduardo Habkost --- Cc: Joerg Roedel Cc: kvm@vger.kernel.org Cc: libvir-list@redhat.com Cc: Jiri Denemark I'm CCing libvirt people in case having SVM enabled by default may cause trouble when libvirt starts using the "enforce" flag. I don't know if libvirt expects most of the QEMU CPU models to have nested SVM enabled. --- target-i386/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 13075c7..21aceed 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -969,7 +969,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) {&guest_def->ext2_features, &host_def.ext2_features, ~0, ext2_feature_name, 0x80000001, R_EDX}, {&guest_def->ext3_features, &host_def.ext3_features, - ~CPUID_EXT3_SVM, ext3_feature_name, 0x80000001, R_ECX}}; + ~0, ext3_feature_name, 0x80000001, R_ECX}}; assert(kvm_enabled());