From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753640AbdIIXDV (ORCPT ); Sat, 9 Sep 2017 19:03:21 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43076 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753616AbdIIXDS (ORCPT ); Sat, 9 Sep 2017 19:03:18 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Christoffer Dall" , "Marc Zyngier" Date: Sat, 09 Sep 2017 22:47:15 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 158/233] arm64: KVM: Preserve RES1 bits in SCTLR_EL2 In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.48-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit d68c1f7fd1b7148dab5fe658321d511998969f2d upstream. __do_hyp_init has the rather bad habit of ignoring RES1 bits and writing them back as zero. On a v8.0-8.2 CPU, this doesn't do anything bad, but may end-up being pretty nasty on future revisions of the architecture. Let's preserve those bits so that we don't have to fix this later on. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall [bwh: Backported to 3.16: - s/ELx/EL2/ - Adjust filename, context] Signed-off-by: Ben Hutchings --- --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -89,6 +89,11 @@ #define SCTLR_EL2_C (1 << 2) #define SCTLR_EL2_A (1 << 1) #define SCTLR_EL2_M 1 + +#define SCTLR_EL2_RES1 ((1 << 4) | (1 << 5) | (1 << 11) | (1 << 16) | \ + (1 << 16) | (1 << 18) | (1 << 22) | (1 << 23) | \ + (1 << 28) | (1 << 29)) + #define SCTLR_EL2_FLAGS (SCTLR_EL2_M | SCTLR_EL2_A | SCTLR_EL2_C | \ SCTLR_EL2_SA | SCTLR_EL2_I) --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -84,10 +84,12 @@ __do_hyp_init: tlbi alle2 dsb sy - mrs x4, sctlr_el2 - and x4, x4, #SCTLR_EL2_EE // preserve endianness of EL2 - ldr x5, =SCTLR_EL2_FLAGS - orr x4, x4, x5 + /* + * Preserve all the RES1 bits while setting the default flags, + * as well as the EE bit on BE. + */ + ldr x4, =(SCTLR_EL2_RES1 | SCTLR_EL2_FLAGS) +CPU_BE( orr x4, x4, #SCTLR_EL2_EE) msr sctlr_el2, x4 isb