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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 D3C67C4345F for ; Fri, 12 Apr 2024 16:18:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rvJap-0000Qd-5e; Fri, 12 Apr 2024 12:17:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rvJaj-0000Pw-KL for qemu-devel@nongnu.org; Fri, 12 Apr 2024 12:17:33 -0400 Received: from mail-pl1-x62b.google.com ([2607:f8b0:4864:20::62b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rvJah-0006aJ-H7 for qemu-devel@nongnu.org; Fri, 12 Apr 2024 12:17:28 -0400 Received: by mail-pl1-x62b.google.com with SMTP id d9443c01a7336-1e2bbc2048eso9397655ad.3 for ; Fri, 12 Apr 2024 09:17:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1712938644; x=1713543444; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=USoFStEqNXqZnRqMSDJ7Q4ksTEbQBxRG0TPfOFM2CtY=; b=Tc8WBqkLIcT1ZsKFCTg2/7cD1d1p9c/h9HHohi8tZqqqyM75jmtuI1in1wU2pvsxzk VGWJUseUyQV/BjtVSH2oJ7lqaIe3PbJG2CDj9nFjk2+gpKlOFpb4Jtpy3nC7OrdQKcMr 6bTUaIT8GeID0wZVM7zr8+6yX3gMpMGzPAycGElDK6/dx24pN14u5UBRNr9jAVWBq3/k wawI9xYIWbaovWhnJN27fJ+QkiXsKyIuMbniuJUJ4UU61M1+nnW9fj9hVjfDlYv6y5yr OXWq6UnRepTCmy+RjFtHCfrZY2XH8Y2ptL3sjXwKpUxiJLflq3zrDUajsQxqeUg5QNZR +8eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712938644; x=1713543444; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=USoFStEqNXqZnRqMSDJ7Q4ksTEbQBxRG0TPfOFM2CtY=; b=tZbaTfFdyQam3JSGYEs3FZw6z6VzK6ox6n8yeebEWH2m5R4QrpWWOrXflY1WdfvDqg +qdDH4AM+Is8qqL/hme4cRiBwv+VHMp9UqijGESgb3prAyOCj+m0S6W9aQNNIINJd6Px nNI1RkLlGmu8RuBAlPEVptuYbvlppzu1oWK0/Vwm2SKW+XK/i7PZMw7rU1mC3P1zCyww UeKzsf9tZg1vQxSfGKpixLv6o346uNZIBcn8saMF8CSUbRkCaJ4+sCC6TyUIIYdDxDUb +X5uiYlrc00WBso+z6X811ju8tngSj+vsoyYCfKB5jjvNeA2IZwP06Sp86dVkAXYo6Xm T27g== X-Gm-Message-State: AOJu0YwWkK7Ft9oD/+mFn3C4qBZSQIjrAoBllc2Ww8Fp1QSEhkewFSTK AXcoYVwSSEn585WVd/boZSB1Mfw+eVW3PPB+yHJ1amJ7omzHk9itPpUsE0pPjts= X-Google-Smtp-Source: AGHT+IEodbjFP7FO7ia+7vCP80/7g4ic0sKRsN1Wcb1qnj2wATUvmhVgvP70/O+a8lPQR5o/E0NHDA== X-Received: by 2002:a17:902:b287:b0:1de:f91:3cf3 with SMTP id u7-20020a170902b28700b001de0f913cf3mr2573948plr.55.1712938644386; Fri, 12 Apr 2024 09:17:24 -0700 (PDT) Received: from [192.168.0.4] (174-21-72-5.tukw.qwest.net. [174.21.72.5]) by smtp.gmail.com with ESMTPSA id h11-20020a170902f54b00b001e420abf8c1sm3169196plf.165.2024.04.12.09.17.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Apr 2024 09:17:24 -0700 (PDT) Message-ID: <21265e46-637d-46db-81e2-c2ae948e312f@linaro.org> Date: Fri, 12 Apr 2024 09:17:22 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 17/51] target/arm: Add cpu properties for SME To: Peter Maydell Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org References: <20220620175235.60881-1-richard.henderson@linaro.org> <20220620175235.60881-18-richard.henderson@linaro.org> Content-Language: en-US From: Richard Henderson In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::62b; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x62b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 4/12/24 04:36, Peter Maydell wrote: >> + 4) Disable the 512-bit vector length. This results in all the other >> + lengths supported by ``max`` defaulting to enabled >> + (128, 256, 1024 and 2048):: >> + >> + $ qemu-system-aarch64 -M virt -cpu max,sve512=off >> + > > I just noticed this while I was trying to understand the > SME and SVE property documentation -- the example 4 here > is in the SME property examples section, but it's changing > sve512, not sme512. Is that an error, or intentional? Error. > In the SME section we say that all other lengths default > to enabled, but in the SVE section we say that the > smaller lengths default to enabled but the longer > lengths are disabled. Is: > * the SVE part wrong? > * the SME part wrong? > * the behaviour deliberately different for SVE and SME > vector lengths? (If so, we should say so explicitly to > highlight that to users). The behaviour is deliberately different. See R_JRCSH and especially I_FQKMN: For example, this means that the set of supported SVLs might be discontiguous and might not start at the smallest permitted SVL. whereas for SVE, the implementation is required to support all powers of 2 up to the maximum (see e.g. the text for ZCR_EL3.LEN). r~