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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 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 2FC1BC2D0C0 for ; Sat, 21 Dec 2019 13:12:36 +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 F0EF421927 for ; Sat, 21 Dec 2019 13:12:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="i3grHLzW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0EF421927 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: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ObqtRN1no1ETtYafQXRS//ViY1A4JYKxX0UhYG7kX98=; b=i3grHLzWRMYc47 +KXIe2dnOKCxYimEIZ/eeOVV9AR5+6ZD0TWa9KYalvClBC1nZkWZ2oqVhZPOxsyxM0v1JCq5d6iNT EJW0zNqOUEe79zhtWjdK3OfZ1cduw0xYHiYzopcND7BtYFk+myja7v472yCJUVUt4SQLIoJ2q3QJo 6sBwnt5N6OXkWH5RNsD192Z9X4a3eSfOZ00e/IAD+MlvgK9+EtgEFvIllXoduoBTii+3sRWyLjUBy a6Z6ZAsBRz5WjBURDooHbIWpZZvdD2B30fX/a3fL7GJHBuZD9kSFs6Ej+vGmGYzndLVxeom9h6UPF 8TUkYtHkIAOtQZzHwNjQ==; 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 1iieYW-0004tX-9Z; Sat, 21 Dec 2019 13:12:28 +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 1iieYS-0004sn-Td for linux-arm-kernel@lists.infradead.org; Sat, 21 Dec 2019 13:12:26 +0000 Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:AES256-GCM-SHA384:256) (Exim 4.80) (envelope-from ) id 1iieYK-0002tv-Gk; Sat, 21 Dec 2019 14:12:16 +0100 Date: Sat, 21 Dec 2019 13:12:14 +0000 From: Marc Zyngier To: Andrew Murray Subject: Re: [PATCH v2 02/18] arm64: KVM: reset E2PB correctly in MDCR_EL2 when exiting the guest(VHE) Message-ID: <20191221131214.769a140e@why> In-Reply-To: <20191220143025.33853-3-andrew.murray@arm.com> References: <20191220143025.33853-1-andrew.murray@arm.com> <20191220143025.33853-3-andrew.murray@arm.com> Organization: Approximate X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: andrew.murray@arm.com, will@kernel.org, catalin.marinas@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-20191221_051225_098789_1D9EDBC5 X-CRM114-Status: GOOD ( 16.30 ) 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, Catalin Marinas , linux-kernel@vger.kernel.org, Sudeep Holla , will@kernel.org, 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 14:30:09 +0000 Andrew Murray wrote: > From: Sudeep Holla > > On VHE systems, the reset value for MDCR_EL2.E2PB=b00 which defaults > to profiling buffer using the EL2 stage 1 translations. Does the reset value actually matter here? I don't see it being specific to VHE systems, and all we're trying to achieve is to restore the SPE configuration to a state where it can be used by the host. > However if the > guest are allowed to use profiling buffers changing E2PB settings, we How can the guest be allowed to change E2PB settings? Or do you mean here that allowing the guest to use SPE will mandate changes of the E2PB settings, and that we'd better restore the hypervisor state once we exit? > need to ensure we resume back MDCR_EL2.E2PB=b00. Currently we just > do bitwise '&' with MDCR_EL2_E2PB_MASK which will retain the value. > > So fix it by clearing all the bits in E2PB. > > Signed-off-by: Sudeep Holla > Signed-off-by: Andrew Murray > --- > arch/arm64/kvm/hyp/switch.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 72fbbd86eb5e..250f13910882 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -228,9 +228,7 @@ 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); > I'm OK with this change, but I believe the commit message could use some tidying up. Thanks, 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