From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1A896116 for ; Tue, 13 Aug 2024 00:45:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723509936; cv=none; b=QMP6/mffQsprYsZ5FF2atPJSUFcdryv4DKpmKwglE8PIIQ06peVe9V7LS0Sm0P6TBytLC2udmz3B7FyudKxWVe3z1GNnyJZAjEQnvDaYUqqdrMet2YR2GAseJgAJpF9SJhsctMjVSf++aFZwep3aLnzTvoctniznpBBk4QISFIM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723509936; c=relaxed/simple; bh=1sBgTIKoJ6AjCZ9d/4YTN6ajHX8hpg8Jnb/EcKKS2RQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eQij6Ptj+wjKWpE62Nr3cDp5UY34X8tWZcJ6rE4JCHUqTW3G7p9ZLBC3cvbM3cdDeEvjWeAqYHOG6NNPOWpB9+4LX7Q+IHHvxrOE1nE7kTMV0xYqZyZmKFRNPX1SAzUFapkSteQeMFBGuJQb7EgXI5jthkSzeDo/bluC/MBZ6TU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=fgqw/8UX; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="fgqw/8UX" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-1fc65329979so45106475ad.0 for ; Mon, 12 Aug 2024 17:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1723509934; x=1724114734; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=1Beo73jI8KH5p03NxQPXLaupS8Ut84TtJmPr0+Y+H6g=; b=fgqw/8UX/rOFKnGO4Qw7UTr3fPRrjchwCWqqDMVWrfrnA5KtNi8sApteK5xebfWEAe 3alttG2i/SY5X//HIcW09qGywlfHaMlJkjSlqm+YNeTQTR0r4RCLK4qsE2iO1wEZLcGd LkGYpViyZ11vPUfG1DoRxRTGf2FVKI0vQ9xr5rHwbqlJYA7J+0wCB/QBdmM+NUjvfA2g Dj9nD+zaR3Gun6corO4RDKART+aaAphUjomNCUfLmIf2JU7VFO8dKDt6RtPEMQfgcvnD pIQVe1iuiG74phuO9Qpwnqv8uz57GXrzveaXy/2RKVD3XTHPRDClEvkV3ghkWrfP3u1j 1WBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723509934; x=1724114734; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=1Beo73jI8KH5p03NxQPXLaupS8Ut84TtJmPr0+Y+H6g=; b=Cy6BTwEsDVLzGbpE3NfVoZE02by17iUIkfd+BVvBYPdGLqYd5CJP9TNB/eE09H+dby t0nvo48U6jwpdmqwUwF3y2CvQY8GAhFGDsdPCY91aLjHfJ+Zoo7k2juY9OdMgc58kr4K 2YNFJgpSjya8kcD3kwzHb+QZfkzdTFXYtcd5bNma9BzKHGx32l0v5zhTDYANU5SJQbDm YLVMlxH36F7nVSs9mG0HfFI4wuXza8+SL6njBCfU+L9ldtYsEVjqS8CmEV4XbelL67b5 ln+ocXsGD0CNcnmCpKhhkmwig691OGcFfHDRjqydIDDUTpA6SPKl/Y9e/T8nUj2KsqvA jZ4g== X-Forwarded-Encrypted: i=1; AJvYcCUaa/dT2NQl4SibJpmofWOHTtgyJWjrFvfTg7u7qLe4B7dMcZ6ek41y4DLY2okJX6yfEBSvF07eA9c=@vger.kernel.org X-Gm-Message-State: AOJu0Yy2u9nJKS/9a2FK/TDKdzVmMsmSlFt+nypoP1y5pz+sfi9gQc9t Zn9cKhtTVIJylkifSl9lyMTdgbFbinz0b3YFYpFsnXBzjM0wDM+5LD6yQEOI0B4= X-Google-Smtp-Source: AGHT+IHdEc1RzSfknb4O0tEELFITV1/FMiLC99gVJNOSQQB/c+hZmMPVy98DA8PMYeZcE4ZXSNQJNQ== X-Received: by 2002:a17:902:e80b:b0:1fb:57e7:5bb4 with SMTP id d9443c01a7336-201ca1831c4mr26201755ad.37.1723509934094; Mon, 12 Aug 2024 17:45:34 -0700 (PDT) Received: from ghost ([2601:647:6700:64d0:239c:9f30:d4d6:f989]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201cd1c86ddsm2537295ad.263.2024.08.12.17.45.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Aug 2024 17:45:33 -0700 (PDT) Date: Mon, 12 Aug 2024 17:45:30 -0700 From: Charlie Jenkins To: Conor Dooley Cc: Rob Herring , Krzysztof Kozlowski , Paul Walmsley , Palmer Dabbelt , Albert Ou , Jisheng Zhang , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Samuel Holland , Jonathan Corbet , Shuah Khan , Guo Ren , Evan Green , Andy Chiu , Jessica Clarke , Andrew Jones , linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Conor Dooley , Heiko Stuebner Subject: Re: [PATCH v9 00/13] riscv: Add support for xtheadvector Message-ID: References: <20240806-xtheadvector-v9-0-62a56d2da5d0@rivosinc.com> <20240809-slapping-graph-461287bac506@spud> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240809-slapping-graph-461287bac506@spud> On Fri, Aug 09, 2024 at 11:31:15PM +0100, Conor Dooley wrote: > On Tue, Aug 06, 2024 at 05:31:36PM -0700, Charlie Jenkins wrote: > > xtheadvector is a custom extension that is based upon riscv vector > > version 0.7.1 [1]. All of the vector routines have been modified to > > support this alternative vector version based upon whether xtheadvector > > was determined to be supported at boot. > > > > vlenb is not supported on the existing xtheadvector hardware, so a > > devicetree property thead,vlenb is added to provide the vlenb to Linux. > > > > There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is > > used to request which thead vendor extensions are supported on the > > current platform. This allows future vendors to allocate hwprobe keys > > for their vendor. > > > > Support for xtheadvector is also added to the vector kselftests. > > So uh, since noone seems to have brought it up, in the light of the issues > with thead's vector implementation, (https://ghostwriteattack.com/) do we > want to enable it at all? I can make it clear in the kconfig that xtheadvector is succeptible to this attack and that it should be enabled with caution. I think we should let people that understand the risk to enable it. - Charlie 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 1BB40C3DA7F for ; Tue, 13 Aug 2024 00:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=jmt5vs56pMzdWEHYJawd5HK37SVY0KpeACe1Wsj1zQQ=; b=293K40cjMJzRUa nAXmwIb+Sit6Wl+H9EmPZayV/5OmBHXpB5tDgYCwM4ganvFWNwkT0kzUtkfCOU8PvK2J244AyKS5v ZY7UBZFwirZUgCctw2fiB/QKTuO90GY3bgybx5/pI7VfYUV8pa28rVLlor/QygTZFwpWRwEQyo7Jx fph8bVMBAweerytESD+ce3CImw8FKuTzZ1BYUIp4nb/MwDf9d3X6h9r5nb56Be4wS466ZTbweUacA QS7wBmKpjzsjXCoC4pFto6jNj4Ox3KJ0HXwmn4TEs1FhLsXGrAbjmfG3ZTXZDd4CE7q4EQUdko6Ds kesspiYeFw6uWCKihS8w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdffP-00000001w0z-1eC0; Tue, 13 Aug 2024 00:45:39 +0000 Received: from mail-pl1-x633.google.com ([2607:f8b0:4864:20::633]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdffL-00000001w09-3pV0 for linux-riscv@lists.infradead.org; Tue, 13 Aug 2024 00:45:38 +0000 Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-1fc4fcbb131so37404975ad.3 for ; Mon, 12 Aug 2024 17:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1723509934; x=1724114734; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=1Beo73jI8KH5p03NxQPXLaupS8Ut84TtJmPr0+Y+H6g=; b=E7uANOSzQIHBiA4xM/U7GzHxoUkHHrYf74Qd/IH/fUuxL8j0l9tRB2Pj0gq5CKny2O EjenQnVXmRbTpG+eaQ9QH9lFUosuy2RFDmLpp5purUp+MxgkFIBH9MS8HwT4plK8T96u /AeGCXNYRZO8Rb6/GzveBPejNtB0C8apWqnIh6ZNeLB1Hp9caHg+Xvmss7VjwptJYXw2 Ev8eFhTS0bUnIRY5EoeJ+U9H5f7DkTsFAf/vLQDhzV+c0OArgCp94rLEInapca4hE6zE AzMffMLIrn6JDqQqfqXeBgEIS3QF21uYmgoVPdS0Z9uWWs/L5xdBcIxNZErGuPVgbvIt ndhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723509934; x=1724114734; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=1Beo73jI8KH5p03NxQPXLaupS8Ut84TtJmPr0+Y+H6g=; b=BXOwgFZ7ed8fZB1elf01qfvJHMC3Gli14W3r6/FMWvPcqMhpgZ3I/EaaRwFDN71xuM DVzje5oK/7mu+UnqrtYynnSSwNSGDNzSXVmzZLHjCos1TZ+ATKOhmDGUIstHV3Ygqvz1 5x3YDW434lWVTNC+a7Br+SRUzwLqotBHek66PpOcNlL3tm7774IgNwOWOX2K1hKWKbkI cJlGFFafuFArJURaX/xTs829ZdBjFIOQUIf3U/Iy7zxI3labMyFjhuOj3zNo9120wBRf tZ/AxicarR//aIkDBOUq6knNqrEvUhtjyAH4wP3f+KP1/bQ7dJHv0p/75JrWk9iraRQa hAAg== X-Forwarded-Encrypted: i=1; AJvYcCVn/WtCswcbGhvv4LlRrlblSbIXfspzsYy5Qjg8sS3IfFLrHRZBe5nZsajtB5NZhL6/OVZgUwu0J8qN0A==@lists.infradead.org X-Gm-Message-State: AOJu0YyJtK8ur2B4RjA0O0xnO4QqavmMb39WgwBA4fM32OI55LNug3N1 FxFeVVtrzXa4zCZlsXSvdKUGevJIoamd42z4knFvuZRIq9Jq1vUusZrywpmU4J8= X-Google-Smtp-Source: AGHT+IHdEc1RzSfknb4O0tEELFITV1/FMiLC99gVJNOSQQB/c+hZmMPVy98DA8PMYeZcE4ZXSNQJNQ== X-Received: by 2002:a17:902:e80b:b0:1fb:57e7:5bb4 with SMTP id d9443c01a7336-201ca1831c4mr26201755ad.37.1723509934094; Mon, 12 Aug 2024 17:45:34 -0700 (PDT) Received: from ghost ([2601:647:6700:64d0:239c:9f30:d4d6:f989]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201cd1c86ddsm2537295ad.263.2024.08.12.17.45.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Aug 2024 17:45:33 -0700 (PDT) Date: Mon, 12 Aug 2024 17:45:30 -0700 From: Charlie Jenkins To: Conor Dooley Cc: Rob Herring , Krzysztof Kozlowski , Paul Walmsley , Palmer Dabbelt , Albert Ou , Jisheng Zhang , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Samuel Holland , Jonathan Corbet , Shuah Khan , Guo Ren , Evan Green , Andy Chiu , Jessica Clarke , Andrew Jones , linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Conor Dooley , Heiko Stuebner Subject: Re: [PATCH v9 00/13] riscv: Add support for xtheadvector Message-ID: References: <20240806-xtheadvector-v9-0-62a56d2da5d0@rivosinc.com> <20240809-slapping-graph-461287bac506@spud> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240809-slapping-graph-461287bac506@spud> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240812_174536_233362_D4901A33 X-CRM114-Status: GOOD ( 19.93 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, Aug 09, 2024 at 11:31:15PM +0100, Conor Dooley wrote: > On Tue, Aug 06, 2024 at 05:31:36PM -0700, Charlie Jenkins wrote: > > xtheadvector is a custom extension that is based upon riscv vector > > version 0.7.1 [1]. All of the vector routines have been modified to > > support this alternative vector version based upon whether xtheadvector > > was determined to be supported at boot. > > > > vlenb is not supported on the existing xtheadvector hardware, so a > > devicetree property thead,vlenb is added to provide the vlenb to Linux. > > > > There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is > > used to request which thead vendor extensions are supported on the > > current platform. This allows future vendors to allocate hwprobe keys > > for their vendor. > > > > Support for xtheadvector is also added to the vector kselftests. > > So uh, since noone seems to have brought it up, in the light of the issues > with thead's vector implementation, (https://ghostwriteattack.com/) do we > want to enable it at all? I can make it clear in the kconfig that xtheadvector is succeptible to this attack and that it should be enabled with caution. I think we should let people that understand the risk to enable it. - Charlie _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv