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[23.128.96.18]) by mx.google.com with ESMTP id c10si13414444pfr.199.2021.04.12.07.32.41; Mon, 12 Apr 2021 07:32:54 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=Q7DrDWat; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240339AbhDLOcC (ORCPT + 99 others); Mon, 12 Apr 2021 10:32:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237806AbhDLOcB (ORCPT ); Mon, 12 Apr 2021 10:32:01 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FC96C061574; Mon, 12 Apr 2021 07:31:43 -0700 (PDT) Received: from zn.tnic (p200300ec2f052100b992cfc3eab27929.dip0.t-ipconnect.de [IPv6:2003:ec:2f05:2100:b992:cfc3:eab2:7929]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 859EB1EC03A0; Mon, 12 Apr 2021 16:31:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1618237901; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=Drxp9AwmCgzA/Iszpvwrzfn9ABJRPDxoumDeD2kDwN0=; b=Q7DrDWatKFZgNJBHP4Qx/QznmbVTPC09Oxn/rLikYikgm5ESUgyZ9nv+jmO5tKlGpYu9Ba 4BNTO9HquC5hp9c/AbTXnzd3Bz1o/F5bTf828MHOEK9nZD2LXxQIQ+UieBuwn0pk4GBZep j/3SmxTJ6kkkyWwd8fdnJ40mROyoVuk= Date: Mon, 12 Apr 2021 16:31:39 +0200 From: Borislav Petkov To: Florian Weimer Cc: Andy Lutomirski , "Bae, Chang Seok" , Dave Hansen , X86 ML , LKML , linux-abi@vger.kernel.org, "libc-alpha@sourceware.org" , Rich Felker , Kyle Huey , Keno Fischer Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features Message-ID: <20210412143139.GE24283@zn.tnic> References: <87lf9nk2ku.fsf@oldenburg.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87lf9nk2ku.fsf@oldenburg.str.redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 12, 2021 at 04:19:29PM +0200, Florian Weimer wrote: > Maybe we could have done this in 2016 when I reported this for the first > time. Now it is too late, as more and more software is using > CPUID-based detection for AVX-512. So as I said on another mail today, I don't think a library should rely solely on CPUID-based detection of features especially if those features need kernel support too. IOW, it should ask whether the kernel can handle those too, first. And the CPUID-faulting thing would solve stuff like that because then the kernel can *actually* get involved into answering something where it has a say in, too. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette