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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 C167DC2D0C0 for ; Sun, 22 Dec 2019 10:44:04 +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 94354206D3 for ; Sun, 22 Dec 2019 10:44:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="RviHG0Qu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94354206D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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: Subject:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rW8Si1rFouSud7WygJP6HKt/X4nBjjfl/tJ67p3Ssd4=; b=RviHG0QuPntgWn wx1+jRbd9ggDfPfgAQd8Oieswom4zz9ts7fScDwkh2orYrbjlfl3A7/cLkUlMj7Fo+HTV9IrrVsws 1IZ8KLruoDdWU1ZDZWhY8uW2+m4TYixsE0lyFYln18fvVuEdCYgdBJa4/CSNU8yn9IGpM0gRd+A/H anRvRbezpvlC5ivXoMdbVhX3dFi5UtDQQbY5Hnd3WEtLeADhN23pqlaOmAqPiCldAv0SNZp0nQ1IO Uw8P0C+ewc+nfNrc1sgFkkxQwG2g9J+mRWvEfPRktSzL1DOwRAJhHjLJhNIImKzkEvm0eANxaYbW4 2XrIcvhk3GTIbcjHKnjg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iiyiR-0002um-SA; Sun, 22 Dec 2019 10:44:03 +0000 Received: from inca-roads.misterjones.org ([213.251.177.50]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iiyiO-0002tq-Gk for linux-arm-kernel@lists.infradead.org; Sun, 22 Dec 2019 10:44:01 +0000 Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=big-swifty.misterjones.org) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:AES256-GCM-SHA384:256) (Exim 4.80) (envelope-from ) id 1iiygN-0005Y6-Rv; Sun, 22 Dec 2019 11:43:56 +0100 Date: Sun, 22 Dec 2019 10:42:05 +0000 Message-ID: <86bls0iqv6.wl-maz@kernel.org> From: Marc Zyngier To: Andrew Murray Subject: Re: [PATCH v2 11/18] KVM: arm64: don't trap Statistical Profiling controls to EL2 In-Reply-To: <20191220143025.33853-12-andrew.murray@arm.com> References: <20191220143025.33853-1-andrew.murray@arm.com> <20191220143025.33853-12-andrew.murray@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/26 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: andrew.murray@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, sudeep.holla@arm.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191222_024400_699077_0155D3B8 X-CRM114-Status: GOOD ( 15.12 ) 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: kvm@vger.kernel.org, Marc Zyngier , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Sudeep Holla , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 20 Dec 2019 14:30:18 +0000, Andrew Murray wrote: > > As we now save/restore the profiler state there is no need to trap > accesses to the statistical profiling controls. Let's unset the > _TPMS bit. > > Signed-off-by: Andrew Murray > --- > arch/arm64/kvm/debug.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c > index 43487f035385..07ca783e7d9e 100644 > --- a/arch/arm64/kvm/debug.c > +++ b/arch/arm64/kvm/debug.c > @@ -88,7 +88,6 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) > * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR) > * - Debug ROM Address (MDCR_EL2_TDRA) > * - OS related registers (MDCR_EL2_TDOSA) > - * - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB) > * > * Additionally, KVM only traps guest accesses to the debug registers if > * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY > @@ -111,7 +110,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) > */ > vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; > vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | > - MDCR_EL2_TPMS | No. This is an *optional* feature (the guest could not be presented with the SPE feature, or the the support simply not be compiled in). If the guest is not allowed to see the feature, for whichever reason, the traps *must* be enabled and handled. M. -- Jazz is not dead, it just smells funny. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel