From patchwork Fri Jan 4 22:01:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 209566 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 D48512C0087 for ; Sat, 5 Jan 2013 09:47:09 +1100 (EST) Received: from localhost ([::1]:60616 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TrFJo-0003ie-Bp for incoming@patchwork.ozlabs.org; Fri, 04 Jan 2013 17:00:48 -0500 Received: from eggs.gnu.org ([208.118.235.92]:60127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TrFIo-0001y2-Mu for qemu-devel@nongnu.org; Fri, 04 Jan 2013 16:59:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TrFIm-0005B6-8k for qemu-devel@nongnu.org; Fri, 04 Jan 2013 16:59:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55193) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TrFIm-0005AU-01 for qemu-devel@nongnu.org; Fri, 04 Jan 2013 16:59:44 -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 r04Lxfcd032308 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 4 Jan 2013 16:59:41 -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 r04LxZVU026956; Fri, 4 Jan 2013 16:59:36 -0500 Received: by blackpad.lan.raisama.net (Postfix, from userid 500) id 65E0A203D43; Fri, 4 Jan 2013 20:01:14 -0200 (BRST) From: Eduardo Habkost To: qemu-devel@nongnu.org Date: Fri, 4 Jan 2013 20:01:09 -0200 Message-Id: <1357336872-7200-9-git-send-email-ehabkost@redhat.com> In-Reply-To: <1357336872-7200-1-git-send-email-ehabkost@redhat.com> References: <1357336872-7200-1-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 qom-cpu 08/11] 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 Reviewed-by: Gleb Natapov --- 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. Changes v2: - Coding style fix --- 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 ce64b98..a9dd959 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -974,7 +974,7 @@ 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());