From nobody Sun Nov 9 22:25:16 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1551962304628683.516007846965; Thu, 7 Mar 2019 04:38:24 -0800 (PST) Received: from localhost ([127.0.0.1]:50493 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1sI3-00062S-2U for importer@patchew.org; Thu, 07 Mar 2019 07:38:23 -0500 Received: from eggs.gnu.org ([209.51.188.92]:42604) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1rz1-0006I4-LV for qemu-devel@nongnu.org; Thu, 07 Mar 2019 07:18:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1rz0-0001NU-T1 for qemu-devel@nongnu.org; Thu, 07 Mar 2019 07:18:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46782) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1rz0-0001NB-ND for qemu-devel@nongnu.org; Thu, 07 Mar 2019 07:18:42 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 05C9C3089E61; Thu, 7 Mar 2019 12:18:42 +0000 (UTC) Received: from dhcp-17-75.lcy.redhat.com (unknown [10.42.17.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id 10EC560C1B; Thu, 7 Mar 2019 12:18:40 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Date: Thu, 7 Mar 2019 12:18:37 +0000 Message-Id: <20190307121838.6345-2-berrange@redhat.com> In-Reply-To: <20190307121838.6345-1-berrange@redhat.com> References: <20190307121838.6345-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 07 Mar 2019 12:18:42 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 1/2] docs: clarify that spec-ctrl is only needed for Spectre v2 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Eduardo Habkost , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" The docs currently say that the spec-ctrl feature is needed for both Spectre variants, but it is only used to address Spectre v2. Also remove the note about retpolines. The guest OS is usually treated as a blackbox from host mgmt pov, so it won't have knowledge about use of retpolines and thus should unconditionally expose spec-ctrl, allowing the guest to decide whether to use it or not. Signed-off-by: Daniel P. Berrang=C3=A9 --- docs/qemu-cpu-models.texi | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/docs/qemu-cpu-models.texi b/docs/qemu-cpu-models.texi index 1b72584161..0ce528806d 100644 --- a/docs/qemu-cpu-models.texi +++ b/docs/qemu-cpu-models.texi @@ -158,8 +158,7 @@ support this feature. =20 @item @code{spec-ctrl} =20 -Required to enable the Spectre (CVE-2017-5753 and CVE-2017-5715) fix, -in cases where retpolines are not sufficient. +Required to enable the Spectre v2 (CVE-2017-5715) fix. =20 Included by default in Intel CPU models with -IBRS suffix. =20 @@ -249,8 +248,7 @@ included if using "Host passthrough" or "Host model". =20 @item @code{ibpb} =20 -Required to enable the Spectre (CVE-2017-5753 and CVE-2017-5715) fix, -in cases where retpolines are not sufficient. +Required to enable the Spectre v2 (CVE-2017-5715) fix. =20 Included by default in AMD CPU models with -IBPB suffix. =20 --=20 2.20.1