From 174a78a8a5c0cf421236fe14efc5559717f050df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Thu, 7 Mar 2019 12:18:37 +0000
Subject: [PATCH] docs: clarify that spec-ctrl is only needed for Spectre v2
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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 <berrange@redhat.com>
Message-Id: <20190307121838.6345-2-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
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.