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 D161EC433EF for ; Fri, 10 Dec 2021 16:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243528AbhLJQeb (ORCPT ); Fri, 10 Dec 2021 11:34:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243506AbhLJQea (ORCPT ); Fri, 10 Dec 2021 11:34:30 -0500 Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [IPv6:2a00:1450:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A965FC0617A1; Fri, 10 Dec 2021 08:30:54 -0800 (PST) Received: by mail-ed1-x52b.google.com with SMTP id r25so31204889edq.7; Fri, 10 Dec 2021 08:30:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=QyyEZSg62CUGQrR/JY1N25k8MMdyiG5r1T7BESy/8iU=; b=l6YUCAjLA0ZPxv9qpax9/tkyAgQuL0jB36tdFk+BWQ5VYbRmUgk75sQyxWOpCWl6QG bq7C5x4V0MekpTrUDv3Bf1ndMAa1gwmaHJIg+m8mWMvL/lsbTU/85H7qjwGPhw3OXx1M uLX/Shp7YbHWWzgXJVpUZ3WXD2R2fjisOjfuXhn/eewlOYMGAHV9BPgJ9Ay3qL/xrpoE cqwjiBxW+gyty/mg8l++aE5c0R4C8ERpTedWmj8A47kANjsdOHkzI1llWmuZxSF9mamX aSoITmYsrcWfXXYKreTi17r+4te/zvbS+HumkJGyiTdYAUrmNCgig4LcTEX+Cj1o9tKy uhRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=QyyEZSg62CUGQrR/JY1N25k8MMdyiG5r1T7BESy/8iU=; b=7LySGFsWUpBmR7jaM630SqJMIDbbPxA9tVeg6xo20PASach++3vKJT7X+p0BOkkAcZ ETMcB0Ap3yrFvi8w9WMwV7RcI854tc8/qvSdKSrxMi4BHsTmuulJTHHNmxWFx4C0CSD8 uoPFA3923osJYCb2Fc3Wt8OJwLZlZXbopwMMyHwCuFBr/YfHk3JWCGJ2rHW41y8RPkxJ NJq9CFrnWXwLijSt2RKyez1nstQSd/826oS91hKFnbX4AUieMHUtaljUTlKXADoPtHFt LNQ/a96LeCUU7KtWmdCFJ7bQ5rtMgx9enaRJIci2FVVavySPg6HO/D2mXPVl9mzJsZ+Y PHnQ== X-Gm-Message-State: AOAM530ImJpy3JrccTdu1Ru9L4wFxQw+6sUXJEnVevLy+MMhyYarTNU4 05aC85FUxrmO5c7PQE75SmQ= X-Google-Smtp-Source: ABdhPJxq9AxXtWpYm551ltAU4ryJ1RnS7IMBXGfsGYuQLfT6QiuQXGtxD7iJYJdlWWn+sAzdrOiibw== X-Received: by 2002:a17:906:7e44:: with SMTP id z4mr24276540ejr.539.1639153852631; Fri, 10 Dec 2021 08:30:52 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:48f9:bea:a04c:3dfe? ([2001:b07:6468:f312:48f9:bea:a04c:3dfe]) by smtp.googlemail.com with ESMTPSA id oz11sm1747169ejc.81.2021.12.10.08.30.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 10 Dec 2021 08:30:52 -0800 (PST) Sender: Paolo Bonzini Message-ID: Date: Fri, 10 Dec 2021 17:30:51 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH 18/19] kvm: x86: AMX XCR0 support for guest Content-Language: en-US To: Yang Zhong , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com Cc: seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, jing2.liu@intel.com References: <20211208000359.2853257-1-yang.zhong@intel.com> <20211208000359.2853257-19-yang.zhong@intel.com> From: Paolo Bonzini In-Reply-To: <20211208000359.2853257-19-yang.zhong@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/8/21 01:03, Yang Zhong wrote: > + > +#ifdef CONFIG_X86_64 > + if ((xcr0 & XFEATURE_MASK_XTILE) && > + ((xcr0 & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE)) > + return 1; > +#else > + /* > + * Intel AMX instructions can be executed only in 64-bit mode but > + * XSAVE can operate on XTILECFG and XTILEDATA in any mode. > + * Since the FPU core follows SDM recommendation to set > + * XCR[18:17] only in 64-bit environment, here also prevent any > + * guest OS from setting the two bits when host is 32-bit. > + * > + * XFEATURE_MASK_XTILE cannot be used since it is 0 in this case. > + */ > + xcr0 &= ~(XFEATURE_MASK_XTILE_DATA | XFEATURE_MASK_XTILE_CFG); > +#endif This should not be necessary, because on a 32-bit system the bits won't be part of supported_xcr0. Paolo