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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 791AAC38142 for ; Mon, 23 Jan 2023 14:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232143AbjAWOLI (ORCPT ); Mon, 23 Jan 2023 09:11:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230245AbjAWOLG (ORCPT ); Mon, 23 Jan 2023 09:11:06 -0500 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CACE3173C; Mon, 23 Jan 2023 06:11:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1674483066; x=1706019066; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=S0d9Nb/yC6VAaBIa1D02pKGjTNBVJ6RLf6lkHDss3E8=; b=DdqzycnLUjlpHHGJ/ZsEII428O7Wo3cDvf0B80fWQGIJU6Y7hYQKZgIE 0EqC8uecE0b2ML2teWHJB6trKk2cKrYO3GxmM54x6e8kBqbpUQeISmEjS 4sios8oEwn6gI2VDTVbQaXTt6pt/bMceAfuEOOpWy4KD9nIt4PcBT5LmH H/+buTFFmQ/XA24Y1gQIQwkWmjiOdj96XQEeHti0DPIURC7Dp/IMESwoC ZOqI1Yk/MbPjJxDxJPDD6XD452tzk6n1tg9rsBDgqtX+dawguA52Om1v/ k0V5FJVY/J28Z1N7XkHTsjE/yI0f+V1o6pvxuFSghU26dcyGGmTsF+quP A==; X-IronPort-AV: E=Sophos;i="5.97,239,1669100400"; d="asc'?scan'208";a="197739625" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa3.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 23 Jan 2023 07:11:05 -0700 Received: from chn-vm-ex04.mchp-main.com (10.10.85.152) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Mon, 23 Jan 2023 07:11:04 -0700 Received: from wendy (10.10.115.15) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16 via Frontend Transport; Mon, 23 Jan 2023 07:11:03 -0700 Date: Mon, 23 Jan 2023 14:10:39 +0000 From: Conor Dooley To: Alexandre Ghiti CC: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , , , , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= Subject: Re: [PATCH resend v3] riscv: Allow to downgrade paging mode from the command line Message-ID: References: <20230123105135.814154-1-alexghiti@rivosinc.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="yXobd+UY1nEQhU1d" Content-Disposition: inline In-Reply-To: <20230123105135.814154-1-alexghiti@rivosinc.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --yXobd+UY1nEQhU1d Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 23, 2023 at 11:51:35AM +0100, Alexandre Ghiti wrote: > Add 2 early command line parameters that allow to downgrade satp mode > (using the same naming as x86): > - "no5lvl": use a 4-level page table (down from sv57 to sv48) > - "no4lvl": use a 3-level page table (down from sv57/sv48 to sv39) >=20 > Note that going through the device tree to get the kernel command line > works with ACPI too since the efi stub creates a device tree anyway with > the command line. >=20 > Also, as those params are treated very early in the boot process and we > use standard device tree functions that may be kasan instrumented, we > only enable them for !KASAN configurations. >=20 > Reviewed-by: Bj=F6rn T=F6pel > Signed-off-by: Alexandre Ghiti > --- >=20 > v3: > - Massage commit log to make no4lvl clearer, as asked by Conor > - Add a note to kernel-parameters.txt regarding the impossibility to use > those parameters when KASAN is enabled, as suggested by Conor For the improved descriptions & commit message: Reviewed-by: Conor Dooley Apologies for complaining about the missing changelog earlier! Conor. --yXobd+UY1nEQhU1d Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCY86VXwAKCRB4tDGHoIJi 0jY5AP4u/lkQ5s1usVmQJyS6cnYs6jE7Ft+3KsAeLXCPetcYhQD+MS7SEq+uA2kL FsNU/AncvpfJtWmuEP1UDkLCS8DFwAM= =gOqR -----END PGP SIGNATURE----- --yXobd+UY1nEQhU1d--