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 92C6F16D314; Thu, 18 Apr 2024 20:00:08 +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=1713470408; cv=none; b=nqg9TR9hkFsjJ1+BZnpOjQBZEzBH6iZduhEFQiUSGi5D3vUw6rnvhAAh2UdD988pVp+/fTfS1K8/F2yRNE7U1lLMUUhULg8mxgqtlwj6JMjrhyu7aXPs3C0RbACJkgi8DrIFxFwtxNwhlJBBIg4oZD2wuOvdae3Z/7TVU9tq2pQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713470408; c=relaxed/simple; bh=HWefGnwQI2HwNz4Knpy1Fh114LZYu0wgCLBTdlxtmUM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=G+tkgY+fvZtBuM+ENr0k0NIhjhFuMoia0wjM7de6oC5nPQLeab0L4kERid5AuOYxFghLc6FvsR7UuXlhG2JRnGtkBgVOAsgJuwGf3qWUdX0gx9wEJEgXFiV1H1m+81kO1UvcjGXRqMkGyy31QYL6ayZ+jySJyU7DNDAEbum0xuo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eY4rQTR0; 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="eY4rQTR0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6AAFC113CC; Thu, 18 Apr 2024 20:00:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713470408; bh=HWefGnwQI2HwNz4Knpy1Fh114LZYu0wgCLBTdlxtmUM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eY4rQTR0vB3nF31du2IEDKNwwn+Arhad3fDAJYF8yZ1FJh3Dhu/OomZi51qGz0+xm yra/nkWPz4cFawkghV0gdBKi6ECmIsqrPWj3/SQU3/50UuGZrAWlq2RS2efp5kTKhn sEsyCi98quhg615KvU+4ANrTH8KbscCy6oiuVNXuib7kuD0Id9WX3lNppWvtA90Im5 0AKhCGhrvZTB2b9mhHgqt6RU8CbmlUzz8j1iWRciRpAczvqRefIU8Dz3FAeIcL/OOI zD8tMN5uEBWYh68fDMPlqOQL0e7l0KYx5v22crgl35DzYqXvHmF+v+qdFjxzsYhJvr 6SFqrgLNKRXPw== Date: Thu, 18 Apr 2024 21:00:01 +0100 From: Conor Dooley To: Eric Biggers Cc: Conor Dooley , Andy Chiu , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Stuebner , Guo Ren , Rob Herring , Krzysztof Kozlowski , Jonathan Corbet , Evan Green , =?iso-8859-1?Q?Cl=E9ment_L=E9ger?= , Shuah Khan , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , Vincent Chen , Greentime Hu , devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Joel Granados , Jerry Shih Subject: Re: [PATCH v4 7/9] riscv: vector: adjust minimum Vector requirement to ZVE32X Message-ID: <20240418-dolphin-epileptic-749c9628e5a9@spud> References: <20240412-zve-detection-v4-0-e0c45bb6b253@sifive.com> <20240412-zve-detection-v4-7-e0c45bb6b253@sifive.com> <20240418-brook-chili-4d3e61d1a55c@wendy> <20240418155256.GA2410@sol.localdomain> <20240418-ultimatum-yam-11de4b063b83@spud> <20240418173203.GA1081@sol.localdomain> <20240418173946.GB1081@sol.localdomain> <20240418-sterling-sanding-d59c3b0a2aaa@spud> <20240418184129.GA1071@sol.localdomain> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MEYWdzN/KoxvaYBs" Content-Disposition: inline In-Reply-To: <20240418184129.GA1071@sol.localdomain> --MEYWdzN/KoxvaYBs Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 18, 2024 at 11:41:29AM -0700, Eric Biggers wrote: > If the RISC-V kernel ever disables V, then it should also disable everyth= ing > that depends on V. >=20 > This would be similar to how on x86, if the kernel decides to disable AVX= to > mitigate the Gather Data Sampling vulnerability, it also disables AVX2, A= VX512, > VAES, VPCLMULQDQ, etc. See cpuid_deps[] in arch/x86/kernel/cpu/cpuid-dep= s.c. >=20 > Sometimes CPU features depend on other ones. That's just the way things = work. =F0=9F=A4=A8 > Whenever possible that should be handled centrally, not pushed down to ev= ery > user both in-kernel and userspace. FWIW, anything detected but rejected while probing the DT or ACPI tables will cause riscv_isa_extension_available() (or other APIs) to return false. --MEYWdzN/KoxvaYBs Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZiF7wQAKCRB4tDGHoIJi 0lrQAP0ZnhY2j8dAgcGtM2slb23/HOfAFrbbsZhuBfSx0uoWSAEAubVPWlDs59pJ eFvw6AB3RzfrfggfMB1wA9nLHCZYzQs= =Ogch -----END PGP SIGNATURE----- --MEYWdzN/KoxvaYBs--