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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 9B3D3C52D6F for ; Wed, 21 Aug 2024 14:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tWDtXehqrA+eG30oaVB4kKdsw4OLY4QKiaTPxI4vn1M=; b=nq2dPQi8q++Fbws9dpfwjYLGAF BcaUcdfqp56ZTBhxesYHkvdcv/qYMf1aEZnTUY3e988dFWdvHz69QuugSLDDcX/UYj2KXcpmzou5g LVaIiaqRHtvTQUkKqjaF1Wiz09dKqZCT0wkU1Q3oP9n3577YRAu88RlrGostC/86/FE5qACzKs4lY SAG/uLEOrQmdK+zokF1gMt0G2IfXP/kXgLo4pxMH1LzVVFgMqJdMY6NpAbobKyzHmb5QLRD6GE8N0 6d4M687d6LnH73OXmYVuERpIkf02lV4KvXN93Gx1lcXmXwVwT6rDhGbP+G+3vWnA2659+E/Angt9z TfbkDbaw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgmbI-00000009MrY-0TqZ; Wed, 21 Aug 2024 14:46:16 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgmaS-00000009Mjh-1OFW for linux-arm-kernel@lists.infradead.org; Wed, 21 Aug 2024 14:45:25 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id E4534A41C85; Wed, 21 Aug 2024 14:45:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29BD3C32786; Wed, 21 Aug 2024 14:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1724251523; bh=oSdN2mapCpigX8ncRReYsys7Ulxa5sWAPbuin0RYUvU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SVfN0mtmkqzc6ENOWWEy0Wy8xGKZvj+7PobPUjuDdatCKOhBqe0VaCKn5MClguufT q/WmNKx2+OWHR5GU+cQud/xjvjH8SAION2ceLSVSLIPbufW50KicPLfWbCzZG9HEGB JjCHnEm/lla4ow2ICaoXSidtqDTLboegDMTedfTgREM8VF5UvzQPE1aUVuv9MKSM4o 4KY0FPHssFcJY7NfnFSkXXg8N+WYfK5ZbkobyQ6KJuPBXF/qR23j8JhT63E1vtHr+6 xVtRrT1/DfcRk+BjbPK1BPdfdvdveCIgqi9knCo/elT0fHXGEDeBd67HgnjWk+SXm+ +qPuVn6zNg7eg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1sgmaO-005cqv-Sd; Wed, 21 Aug 2024 15:45:20 +0100 Date: Wed, 21 Aug 2024 15:45:20 +0100 Message-ID: <86cym2x7cv.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Oliver Upton , James Morse , Suzuki K Poulose , Catalin Marinas , Will Deacon , Joey Gouly , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] KVM: arm64: Control visibility of S1PIE related sysregs to userspace In-Reply-To: References: <20240821-kvm-arm64-hide-pie-regs-v1-0-08cb3c79cb57@kernel.org> <86ed6ixa32.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: broonie@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, joey.gouly@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240821_074524_461822_AA145A65 X-CRM114-Status: GOOD ( 17.44 ) 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 On Wed, 21 Aug 2024 15:01:54 +0100, Mark Brown wrote: > > [1 ] > On Wed, Aug 21, 2024 at 02:46:25PM +0100, Marc Zyngier wrote: > > Mark Brown wrote: > > > > Mark Brown (2): > > > KVM: arm64: Hide TCR2_EL1 from userspace when disabled for guests > > > KVM: arm64: Hide S1PIE registers from userspace when disabled for guests > > > If you are going to do this, please add it on top of [1], and handle > > the corresponding EL2 registers. > > OK. To confirm, this is a desirable change? Yes. Ultimately, we need to revisit the way we deal with visibility, as adding a myriad of helpers checking a combination of features doesn't scale. That information should exist as a static table, just like the trap bits. But until then, that's probably the way. M. -- Without deviation from the norm, progress is not possible.