From patchwork Tue Oct 27 17:27:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 11861171 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 1D0AFC55178 for ; Tue, 27 Oct 2020 17:29:19 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 703AF21D24 for ; Tue, 27 Oct 2020 17:29:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sz7/TGnw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 703AF21D24 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ScN/t6Eq9R2FxiLAP9snMkvaTawOV1XhL5ThN/uCgqI=; b=sz7/TGnwguCBjL/m0lgGFz8D4 /AAuK7tHfbmEQQ1iagRoqvn0wf9AscA2JXuqO/nnMPjH4JCB42T7fVcuPCDc/4LQL0Y+NkSZuGUPK CfD92KIlZzk7GlI6WGbw8kKvbIVvi7yo8rg1JBRvWJz0a/kL6AlPGLd5EMh5P5+Bpbo+f5lT7q3Cc q/TLsZKLQbnflMVqiJT0EER3KFuCOOhmlE7XaPq9FkCp6eb2qLK693kYzUaQ2/4sh7TpkYkhu0NA2 838+efwqmJkPxAMpyDYktfm6pQkHxrzggabtQidEPew+fCmARCso3NY2msKuscjmZ++3jAJjSKQPc ZEEFSnaOg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXSlk-0005ZL-GM; Tue, 27 Oct 2020 17:28:24 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXSjv-0004ra-3M for linux-arm-kernel@lists.infradead.org; Tue, 27 Oct 2020 17:26:32 +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 916E1150C; Tue, 27 Oct 2020 10:26:30 -0700 (PDT) Received: from monolith.localdoman (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 630953F719; Tue, 27 Oct 2020 10:26:29 -0700 (PDT) From: Alexandru Elisei To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [RFC PATCH v3 12/16] KVM: arm64: VHE: Clear MDCR_EL2.E2PB in vcpu_put() Date: Tue, 27 Oct 2020 17:27:01 +0000 Message-Id: <20201027172705.15181-13-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027172705.15181-1-alexandru.elisei@arm.com> References: <20201027172705.15181-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201027_132631_287586_07F68CB1 X-CRM114-Status: GOOD ( 12.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: suzuki.poulose@arm.com, maz@kernel.org, james.morse@arm.com, Sudeep Holla , will@kernel.org, julien.thierry.kdev@gmail.com 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. 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: Rebased on top of 5.10-rc1, 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 fe69de16dadc..3f4db1fa388b 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -97,9 +97,7 @@ 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);