From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A6315FBB1; Wed, 21 Aug 2024 14:45:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724251523; cv=none; b=qE7ufvivvjDEQMtZ/cqKBXHLcnvMqRTHwdelaRBtplpP0FAYPg18RxXfBh+Qo1TKQDRwO0TFIPzEj2W6vsEhDuyMKVnQl+Nu2xl42psIV2wrf0yQRgcqdp0s/7qJYJPcjJrFrNwS2QVCyxDS/IcmwmwayW1k0lHYeVq2pskuCiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724251523; c=relaxed/simple; bh=oSdN2mapCpigX8ncRReYsys7Ulxa5sWAPbuin0RYUvU=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=IO2W7BDlREzpjvGmmKQkAF5BO4NYiQdNsCLmw5ew6QkWvVSKL3Le832fMVZ3EbseGjpb61HxUQx9jDtlnLdZ59h6VopSTR845oG9mtfdDvzMFNZNTUKQ08Ga1PgzenJgOxBbnbVMbIpHDWqML0SBBLrwJYTWcWdk678ovZkMnLU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SVfN0mtm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SVfN0mtm" 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) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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.