From 174a78a8a5c0cf421236fe14efc5559717f050df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Thu, 7 Mar 2019 12:18:37 +0000 Subject: [PATCH] docs: clarify that spec-ctrl is only needed for Spectre v2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Berrangé Message-Id: <20190307121838.6345-2-berrange@redhat.com> Signed-off-by: Eduardo Habkost --- 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. @item @code{spec-ctrl} -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. Included by default in Intel CPU models with -IBRS suffix. @@ -249,8 +248,7 @@ included if using "Host passthrough" or "Host model". @item @code{ibpb} -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. Included by default in AMD CPU models with -IBPB suffix.