docs: clarify that spec-ctrl is only needed for Spectre v2

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>
This commit is contained in:
Daniel P. Berrangé 2019-03-07 12:18:37 +00:00 committed by Eduardo Habkost
parent bb4928c7ca
commit 174a78a8a5
1 changed files with 2 additions and 4 deletions

View File

@ -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.