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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 4A848C282C7 for ; Thu, 31 Jan 2019 08:19:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 264AB20881 for ; Thu, 31 Jan 2019 08:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731367AbfAaITE (ORCPT ); Thu, 31 Jan 2019 03:19:04 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38956 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725855AbfAaITD (ORCPT ); Thu, 31 Jan 2019 03:19:03 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C8AEF80D; Thu, 31 Jan 2019 00:19:02 -0800 (PST) Received: from localhost (e113682-lin.copenhagen.arm.com [10.32.144.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 393D33F589; Thu, 31 Jan 2019 00:19:02 -0800 (PST) Date: Thu, 31 Jan 2019 09:19:00 +0100 From: Christoffer Dall To: Julien Thierry Cc: James Morse , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, mark.rutland@arm.com, Arnd Bergmann , linux-arch@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts Message-ID: <20190131081900.GM13482@e113682-lin.lund.arm.com> References: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> <1548084825-8803-2-git-send-email-julien.thierry@arm.com> <8e8c4f5b-5b83-7bbc-1b84-36d68e210968@arm.com> <847c54ef-ea41-eea5-8aff-72e0cea465f8@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <847c54ef-ea41-eea5-8aff-72e0cea465f8@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 28, 2019 at 03:42:42PM +0000, Julien Thierry wrote: > Hi James, > > On 28/01/2019 11:48, James Morse wrote: > > Hi Julien, > > > > On 21/01/2019 15:33, Julien Thierry wrote: > >> When using VHE, the host needs to clear HCR_EL2.TGE bit in order > >> to interract with guest TLBs, switching from EL2&0 translation regime > > > > (interact) > > > > > >> to EL1&0. > >> > >> However, some non-maskable asynchronous event could happen while TGE is > >> cleared like SDEI. Because of this address translation operations > >> relying on EL2&0 translation regime could fail (tlb invalidation, > >> userspace access, ...). > >> > >> Fix this by properly setting HCR_EL2.TGE when entering NMI context and > >> clear it if necessary when returning to the interrupted context. > > > > Yes please. This would not have been fun to debug! > > > > Reviewed-by: James Morse > > > > > > Thanks. > > > > > I was looking for why we need core code to do this, instead of updating the > > arch's call sites. Your 'irqdesc: Add domain handlers for NMIs' patch (pointed > > to from the cover letter) is the reason: core-code calls nmi_enter()/nmi_exit() > > itself. > > > > Yes, that's the main reason. > I wondered the same thing, but I don't understand the explanation :( Why can't we do a local_daif_mask() around the (very small) calls that clear TGE instead? Thanks, Christoffer 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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 5AB4CC169C4 for ; Thu, 31 Jan 2019 08:22:24 +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 1092120881 for ; Thu, 31 Jan 2019 08:22:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Lj6UuBeK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1092120881 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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:In-Reply-To:MIME-Version:References: 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=j3ZAakTFd+tum0E70cwhYVe5n/jPxuDlhnOFO+MmsWg=; b=Lj6UuBeK9/Hr/0 3QmDteUmM0RwscMBklQJ+HixEb5OMmDBCl2qXahowqJuUsU4uB4wYo1ry1O505qmwO5j9BwBQDPS4 yRuvqnuHiRt7W5qUOdEcNuPVPO2eDyN2FKGhC5W+STl4xoaFWm0jGjzaZAN8SIa6z/5qVBeI9xQQn xpJrMr4n7tT0nregU4KNC0r7lfyVwpCqMXm0ePq8ErPBjFLqlrVTA83m7eeEB2Gm74iqAgZGVJOY/ oko4n3Z0p+PKGpHNzkycWePdHcpwyQTcOl1m8zSBpV67UevaLEhwZk2op/lAtc4gadPqFSjAjNQs2 tz3h6nU0x4+WC7zSANBA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gp7bu-0002Fc-FR; Thu, 31 Jan 2019 08:22:10 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gp7Yu-0006Q8-OU for linux-arm-kernel@lists.infradead.org; Thu, 31 Jan 2019 08:19:41 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C8AEF80D; Thu, 31 Jan 2019 00:19:02 -0800 (PST) Received: from localhost (e113682-lin.copenhagen.arm.com [10.32.144.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 393D33F589; Thu, 31 Jan 2019 00:19:02 -0800 (PST) Date: Thu, 31 Jan 2019 09:19:00 +0100 From: Christoffer Dall To: Julien Thierry Subject: Re: [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts Message-ID: <20190131081900.GM13482@e113682-lin.lund.arm.com> References: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> <1548084825-8803-2-git-send-email-julien.thierry@arm.com> <8e8c4f5b-5b83-7bbc-1b84-36d68e210968@arm.com> <847c54ef-ea41-eea5-8aff-72e0cea465f8@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <847c54ef-ea41-eea5-8aff-72e0cea465f8@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190131_001905_364541_4B271440 X-CRM114-Status: GOOD ( 17.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-arch@vger.kernel.org, daniel.thompson@linaro.org, Arnd Bergmann , marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, James Morse , joel@joelfernandes.org, 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 Mon, Jan 28, 2019 at 03:42:42PM +0000, Julien Thierry wrote: > Hi James, > > On 28/01/2019 11:48, James Morse wrote: > > Hi Julien, > > > > On 21/01/2019 15:33, Julien Thierry wrote: > >> When using VHE, the host needs to clear HCR_EL2.TGE bit in order > >> to interract with guest TLBs, switching from EL2&0 translation regime > > > > (interact) > > > > > >> to EL1&0. > >> > >> However, some non-maskable asynchronous event could happen while TGE is > >> cleared like SDEI. Because of this address translation operations > >> relying on EL2&0 translation regime could fail (tlb invalidation, > >> userspace access, ...). > >> > >> Fix this by properly setting HCR_EL2.TGE when entering NMI context and > >> clear it if necessary when returning to the interrupted context. > > > > Yes please. This would not have been fun to debug! > > > > Reviewed-by: James Morse > > > > > > Thanks. > > > > > I was looking for why we need core code to do this, instead of updating the > > arch's call sites. Your 'irqdesc: Add domain handlers for NMIs' patch (pointed > > to from the cover letter) is the reason: core-code calls nmi_enter()/nmi_exit() > > itself. > > > > Yes, that's the main reason. > I wondered the same thing, but I don't understand the explanation :( Why can't we do a local_daif_mask() around the (very small) calls that clear TGE instead? Thanks, Christoffer _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel