From mboxrd@z Thu Jan 1 00:00:00 1970 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 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH 1/2] docs: clarify that spec-ctrl is only needed for Spectre v2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Eduardo Habkost , Richard Henderson , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= 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