@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.
can be used for guest CPUs.
+@item @code{stibp}
+
+Required to enable stronger Spectre v2 (CVE-2017-5715) fixes in some
+operating systems.
+
+Must be explicitly turned on for all Intel CPU models.
+
+Requires the host CPU microcode to support this feature before it
+can be used for guest CPUs.
+
+
@item @code{ssbd}
Required to enable the CVE-2018-3639 fix
@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.
can be used for guest CPUs.
+@item @code{stibp}
+
+Required to enable stronger Spectre v2 (CVE-2017-5715) fixes in some
+operating systems.
+
+Must be explicitly turned on for all AMD CPU models.
+
+Requires the host CPU microcode to support this feature before it
+can be used for guest CPUs.
+
+
@item @code{virt-ssbd}
Required to enable the CVE-2018-3639 fix