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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, 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 F2F1AC432C0 for ; Thu, 21 Nov 2019 23:18:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8A632063A for ; Thu, 21 Nov 2019 23:18:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=amacapital-net.20150623.gappssmtp.com header.i=@amacapital-net.20150623.gappssmtp.com header.b="qcNpQSUh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726685AbfKUXSt (ORCPT ); Thu, 21 Nov 2019 18:18:49 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:44938 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725956AbfKUXSt (ORCPT ); Thu, 21 Nov 2019 18:18:49 -0500 Received: by mail-pl1-f195.google.com with SMTP id az9so2271375plb.11 for ; Thu, 21 Nov 2019 15:18:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:cc:in-reply-to:to; bh=T/k6WfAKiK5ZAt7UUpRJgMNaBWYlBAGfNObz/8ZE1Ok=; b=qcNpQSUhVvcK/duPw0+fJJ0+qrQWmWj9LDXW1JdbDJ3IAdjrPEObFE4O5fWB4foMBy tWtcDdjeZ8ipVggAmvFqrTvk+8PnXTUKB9fW/GUz7SVzOEeIYZrg7ySPO7l8OWwAjf7x Rv5RTufvt5rE74Hs+rjxZV4xYO4vbBkpXeNj8S1sTHKhrudwgmRF9yfQDG9JwenwrNIL OyoBpCNjZMnnuC/COGy+CUkR7vND9gAudYqYfpBhweE5o7dFMGbe9MS/oEXDrprN3IPJ b6m0GGErJOBBKa1Ln3UvcQo32xHlUaLf04unp7Pz8CLTiaZ6LF5sZJfT3eOCWSqmmOIR EhAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:cc:in-reply-to:to; bh=T/k6WfAKiK5ZAt7UUpRJgMNaBWYlBAGfNObz/8ZE1Ok=; b=S7Ir0givgHTquEW0vluoP4+Xhd2LWA5yhw/+Iy8lmWrkvf2qmdhhsLHWLshPoJGVhx o6lPyb/eO1yJDsCWTU121AbUdxzTK4M0hoC3yGMXyTFc77a3+txrsy2kesZQ7vcRQFDu D0xg1NYmSHqDeLhnX4rHHv34S65S6539BUSGvPdUAn1iFB/9KfaWcGbyMe9TKHoCksuf beZEDQmzxj9VMwQMOxe5aTJBXRq2E5pjTRCPfJOMFlgdpcbW4khe455dSLE5cSAkLfHL APg+ElYLDD6un5bsAAmWVEtpeC2mYU35/hljdvp4b6+L/ubOWbGUI2oeTPkD3NbP0xhe ptBg== X-Gm-Message-State: APjAAAVferQQnxRVRd62C+wmNwmDAnn7pwINIO1pcPkbr85ATyDpxPPy zWg9XUTNksy/tZtH+CCkYh7Vcg== X-Google-Smtp-Source: APXvYqwQdE15+fpub3lzdCpJVDgkoYf7Nba5bI6C1TwUfcUiH7TmuX8lVAmihM82XQPJc+zmmO2h5A== X-Received: by 2002:a17:902:fe85:: with SMTP id x5mr11186143plm.292.1574378328671; Thu, 21 Nov 2019 15:18:48 -0800 (PST) Received: from ?IPv6:2600:1010:b062:827f:f4a7:a1e:b790:5671? ([2600:1010:b062:827f:f4a7:a1e:b790:5671]) by smtp.gmail.com with ESMTPSA id g30sm4084642pgm.23.2019.11.21.15.18.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Nov 2019 15:18:47 -0800 (PST) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Andy Lutomirski Mime-Version: 1.0 (1.0) Subject: Re: [PATCH v10 6/6] x86/split_lock: Enable split lock detection by kernel parameter Date: Thu, 21 Nov 2019 15:18:46 -0800 Message-Id: References: <3908561D78D1C84285E8C5FCA982C28F7F4DC167@ORSMSX115.amr.corp.intel.com> Cc: Peter Zijlstra , Ingo Molnar , "Yu, Fenghua" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , "Raj, Ashok" , "Shankar, Ravi V" , linux-kernel , x86 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F7F4DC167@ORSMSX115.amr.corp.intel.com> To: "Luck, Tony" X-Mailer: iPhone Mail (17A878) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Nov 21, 2019, at 2:29 PM, Luck, Tony wrote: >=20 > =EF=BB=BF >>=20 >> It would be really, really nice if we could pass this feature through to a= VM. Can we? >=20 > It's hard because the MSR is core scoped rather than thread scoped. So on= an HT > enabled system a pair of logical processors gets enabled/disabled together= . >=20 >=20 Well that sucks. Could we pass it through if the host has no HT? Debugging is *so* much easi= er in a VM. And HT is a bit dubious these days anyway.=