From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D37DC10F14 for ; Thu, 10 Oct 2019 08:48:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05B8D208C3 for ; Thu, 10 Oct 2019 08:48:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697337; bh=S+0Okuy49xg+IxUOb8mc1qP1Q2gPrQqsCjKimb1zDNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GBlBqi/ZKbMklN6k9XolnTQYiwII/i2rWz/8Hn8TlscQa3MpBTDW7yrJQuUfbEfej k15NRfXj8yZYBOiEFmaDgEEGlL7GpVY3wBTMeag2l1ZCrVqi4PCH38LhU3VB92CAMX wZutE4acZqr2J6RKxKGnhnGkCZ3eNq4BzLybKBRc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389715AbfJJIs4 (ORCPT ); Thu, 10 Oct 2019 04:48:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:55308 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389713AbfJJIsz (ORCPT ); Thu, 10 Oct 2019 04:48:55 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 69DC22064A; Thu, 10 Oct 2019 08:48:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697334; bh=S+0Okuy49xg+IxUOb8mc1qP1Q2gPrQqsCjKimb1zDNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yq6Ck7RClMeZdbGEkk7oSbNVvgPsxu+weTGT1uba8Sd3X8N8N6H0OU2KfqOgczcPC KkxUiu5stn5Z1Wndsw7cgHKUliGHIyjqHA3mF7riZ3EI81SNLySUMWYlVGYic2kSrb FSekAmFkaoJ6n7rNEAQrhIpAaHxKAfgUjjHIQRhU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Jeremy Linton , Andre Przywara , Catalin Marinas , Stefan Wahren , Will Deacon , Ard Biesheuvel Subject: [PATCH 4.19 104/114] arm64: Use firmware to detect CPUs that are not affected by Spectre-v2 Date: Thu, 10 Oct 2019 10:36:51 +0200 Message-Id: <20191010083613.719382595@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marc Zyngier commit 517953c2c47f9c00a002f588ac856a5bc70cede3 upstream. The SMCCC ARCH_WORKAROUND_1 service can indicate that although the firmware knows about the Spectre-v2 mitigation, this particular CPU is not vulnerable, and it is thus not necessary to call the firmware on this CPU. Let's use this information to our benefit. Signed-off-by: Marc Zyngier Signed-off-by: Jeremy Linton Reviewed-by: Andre Przywara Reviewed-by: Catalin Marinas Tested-by: Stefan Wahren Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/cpu_errata.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -198,22 +198,36 @@ static int detect_harden_bp_fw(void) case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_hvc_arch_workaround_1; + /* This is a guest, no need to patch KVM vectors */ + smccc_start = NULL; + smccc_end = NULL; + break; + default: return -1; - cb = call_hvc_arch_workaround_1; - /* This is a guest, no need to patch KVM vectors */ - smccc_start = NULL; - smccc_end = NULL; + } break; case PSCI_CONDUIT_SMC: arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_smc_arch_workaround_1; + smccc_start = __smccc_workaround_1_smc_start; + smccc_end = __smccc_workaround_1_smc_end; + break; + default: return -1; - cb = call_smc_arch_workaround_1; - smccc_start = __smccc_workaround_1_smc_start; - smccc_end = __smccc_workaround_1_smc_end; + } break; default: