percpu: Separate decrypted varaibles anytime encryption can be enabled

BugLink: https://bugs.launchpad.net/bugs/1866678
commit 264b0d2bee148073c117e7bbbde5be7125a53be1 upstream.

CONFIG_VIRTUALIZATION may not be enabled for memory encrypted guests.  If
disabled, decrypted per-CPU variables may end up sharing the same page
with variables that should be left encrypted.

Always separate per-CPU variables that should be decrypted into their own
page anytime memory encryption can be enabled in the guest rather than
rely on any other config option that may not be enabled.

Fixes: ac26963a1175 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 2d2096ba1cfeca2672b8c368cb49975985d67363..90b8ce813fa6cb495193544ec9017b98de6ffe52 100644 (file)
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -176,8 +176,7 @@
  * Declaration/definition used for per-CPU variables that should be accessed
  * as decrypted when memory encryption is enabled in the guest.
  */
-#if defined(CONFIG_VIRTUALIZATION) && defined(CONFIG_AMD_MEM_ENCRYPT)
-
+#ifdef CONFIG_AMD_MEM_ENCRYPT
 #define DECLARE_PER_CPU_DECRYPTED(type, name)                          \
        DECLARE_PER_CPU_SECTION(type, name, "..decrypted")