From patchwork Wed Aug 25 16:17:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 12458315 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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 93204C4338F for ; Wed, 25 Aug 2021 16:35:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4C04E610A3 for ; Wed, 25 Aug 2021 16:35:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4C04E610A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AQMIELg3spCsCXEGDhpO33lbBP5WPKPJR4Fh7LbyS6E=; b=DRofAFcKFu3qPD MS8JG8HTCXhsPab1eEFQGs4a3465Z8WOg1tNJJ1WHfMZG0T1MQZH5ruSlJRuDrfDAjf02BWcWKm6J DSeS9l5j1g2PX/jmnKu2dX8aBaoYCvfWHXdH0t6G2avmjRLbjybNEulJ3Io4e7oIkj2C4E8yyvgEF tRSquRo/BK8lPUCfJW3XNg5/uSWLGmuf0q/G2w6623PaS8DxdxG7tg8SVbo+pg5S2S8zDcbsXMLjo Wlv0eHwV52HzQcnK2AFBDY9ml7U3sw5o06w7wMDn3i/UpA19K6kpUHHNS45Yq1JyJkYYqWf2tYNxu voQKnhNk+rZAZOGglV+Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mIvqO-007oSf-Uk; Wed, 25 Aug 2021 16:33:41 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mIvb5-007gdi-4I for linux-arm-kernel@lists.infradead.org; Wed, 25 Aug 2021 16:17:52 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210825_091751_277993_66CD42E1 X-CRM114-Status: GOOD ( 10.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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);