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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 D440CC4320A for ; Wed, 25 Aug 2021 16:18:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2D3261163 for ; Wed, 25 Aug 2021 16:18:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242016AbhHYQTF (ORCPT ); Wed, 25 Aug 2021 12:19:05 -0400 Received: from foss.arm.com ([217.140.110.172]:54768 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240932AbhHYQSf (ORCPT ); Wed, 25 Aug 2021 12:18:35 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A36DD1042; Wed, 25 Aug 2021 09:17:49 -0700 (PDT) Received: from monolith.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2F1AA3F66F; Wed, 25 Aug 2021 09:17:48 -0700 (PDT) From: Alexandru Elisei To: maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, linux-kernel@vger.kernel.org Cc: Sudeep Holla Subject: [RFC PATCH v4 23/39] KVM: arm64: VHE: Clear MDCR_EL2.E2PB in vcpu_put() Date: Wed, 25 Aug 2021 17:17:59 +0100 Message-Id: <20210825161815.266051-24-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210825161815.266051-1-alexandru.elisei@arm.com> References: <20210825161815.266051-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sudeep Holla On VHE systems, the kernel executes at EL2 and configures the profiling buffer to use the EL2&0 translation regime and to trap accesses from the guest by clearing MDCR_EL2.E2PB. In vcpu_put(), KVM does a bitwise or with the E2PB mask, preserving its value. This has been correct so far, since MDCR_EL2.E2B has the same value (0b00) for all VMs, as set by kvm_arm_setup_mdcr_el2(). However, this will change when KVM enables support for SPE in guests. For such guests KVM will configure the profiling buffer to use the EL1&0 translation regime, a setting that is obviously undesirable to be preserved for the host running at EL2. Let's avoid this situation by explicitly clearing E2PB in vcpu_put(). [ Alexandru E: Reworded commit ] Signed-off-by: Sudeep Holla Signed-off-by: Alexandru Elisei --- arch/arm64/kvm/hyp/vhe/switch.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index b3229924d243..86d4c8c33f3e 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -95,9 +95,7 @@ void deactivate_traps_vhe_put(void) { u64 mdcr_el2 = read_sysreg(mdcr_el2); - mdcr_el2 &= MDCR_EL2_HPMN_MASK | - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | - MDCR_EL2_TPMS; + mdcr_el2 &= MDCR_EL2_HPMN_MASK | MDCR_EL2_TPMS; write_sysreg(mdcr_el2, mdcr_el2); -- 2.33.0