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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E121EC433DB for ; Tue, 12 Jan 2021 07:48:52 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 4BCD922DD3 for ; Tue, 12 Jan 2021 07:48:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BCD922DD3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yadro.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34442 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzEQ7-0000n8-7n for qemu-devel@archiver.kernel.org; Tue, 12 Jan 2021 02:48:51 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40082) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzENy-0000Fv-MX for qemu-devel@nongnu.org; Tue, 12 Jan 2021 02:46:38 -0500 Received: from mta-02.yadro.com ([89.207.88.252]:57246 helo=mta-01.yadro.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzENw-0001r3-Uj for qemu-devel@nongnu.org; Tue, 12 Jan 2021 02:46:38 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id ABA3D41281; Tue, 12 Jan 2021 07:46:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= in-reply-to:content-disposition:content-type:content-type :mime-version:references:message-id:subject:subject:from:from :date:date:received:received:received; s=mta-01; t=1610437591; x=1612251992; bh=WfVOY3sHPxIUMl3Iq1ki8NbSYH9tSqh2VpKGD7HE7hw=; b= nwKBCiLyrDqhU4OZ4OgK28kEQTMmr7T+7HiW0exZWblVYrZt/jpXgCp1ih0+85VV s36/1OpnotBC1kN615bo6h2VsWm2oojja8M8qrXeJ5F//aNjeBbGrHBtiCneGu8J aEmYE61xsPGeTBqFxhhBTp7T241+rtn0Zs5dDn8BCv8= X-Virus-Scanned: amavisd-new at yadro.com Received: from mta-01.yadro.com ([127.0.0.1]) by localhost (mta-01.yadro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ma3ghYMzaJfy; Tue, 12 Jan 2021 10:46:31 +0300 (MSK) Received: from T-EXCH-03.corp.yadro.com (t-exch-03.corp.yadro.com [172.17.100.103]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mta-01.yadro.com (Postfix) with ESMTPS id 4D2EC412FC; Tue, 12 Jan 2021 10:46:31 +0300 (MSK) Received: from localhost (172.17.204.212) by T-EXCH-03.corp.yadro.com (172.17.100.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.669.32; Tue, 12 Jan 2021 10:46:30 +0300 Date: Tue, 12 Jan 2021 10:46:16 +0300 From: Roman Bolshakov To: Hill Ma Subject: Re: [PATCH v2] hvf: guard xgetbv call. Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-Originating-IP: [172.17.204.212] X-ClientProxiedBy: T-EXCH-01.corp.yadro.com (172.17.10.101) To T-EXCH-03.corp.yadro.com (172.17.100.103) Received-SPF: pass client-ip=89.207.88.252; envelope-from=r.bolshakov@yadro.com; helo=mta-01.yadro.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, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: richard.henderson@linaro.org, qemu-devel@nongnu.org, dirty@apple.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jan 11, 2021 at 09:44:40PM -0800, Hill Ma wrote: > On Sun, Jan 10, 2021 at 8:38 PM Roman Bolshakov wrote: > > I'm not sure if eax should be modified with mask because the mask has no > > value per se. I.e. eax &= supp_xcr0 from below should be placed inside > > the if. It'd express clearly that eax is not modified unless xgetbv is > > supported. > > Like this? > > - uint64_t host_xcr0 = xgetbv(0); > - uint64_t supp_xcr0 = host_xcr0 & (XSTATE_FP_MASK | > XSTATE_SSE_MASK | > + uint64_t host_xcr0; > + if (xgetbv(ecx, 0, &host_xcr0)) { > + uint64_t supp_xcr0 = host_xcr0 & (XSTATE_FP_MASK | > XSTATE_SSE_MASK | > XSTATE_YMM_MASK | XSTATE_BNDREGS_MASK | > XSTATE_BNDCSR_MASK | XSTATE_OPMASK_MASK | > XSTATE_ZMM_Hi256_MASK | > XSTATE_Hi16_ZMM_MASK); > - eax &= supp_xcr0; > + eax &= supp_xcr0; > + } Yes. Thanks, Roman