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[209.132.180.67]) by mx.google.com with ESMTP id z61-v6si2780778plb.669.2018.01.31.14.07.20; Wed, 31 Jan 2018 14:07:35 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=ekz0fSNW; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753419AbeAaWG5 (ORCPT + 99 others); Wed, 31 Jan 2018 17:06:57 -0500 Received: from mail-it0-f43.google.com ([209.85.214.43]:34735 "EHLO mail-it0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751980AbeAaWGz (ORCPT ); Wed, 31 Jan 2018 17:06:55 -0500 Received: by mail-it0-f43.google.com with SMTP id m11so27423iti.1 for ; Wed, 31 Jan 2018 14:06:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=Wdq/MYhMHPWMbQmUAgHb8eURrKYTRwOBvxBoK7wl1+0=; b=ekz0fSNW+vZEWj95cBfNmaB2PRXF4FanbWDp9MbdbLbKly4g6uvXeA1y98sKT3BhPD 67zJ0IuYeDsPrxv6ONj0D0pLOpjnn36qLNnlHSSegNIuxar5pTSUGadt4m6TxSVfc5Cb iqLLjBUQHkbBf8PQnMoHp5AJjjra+Tanpm6O5ZxB1A0xZ3aTZ70lXlbyuMjzUbuF7VNQ YEdnHSOJqeLyIOgV3OQGFHUMK+M/SZm5b8HkJTNtOFkB7FeyvuYtyYQzmLeiMJ9CsuNB +TXHAac9TbnQKrlvG+xWGDr0L9ZaJgA367p75jM/oeA82WkbVM3WqHQAovEXF2VWfFRH GXBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Wdq/MYhMHPWMbQmUAgHb8eURrKYTRwOBvxBoK7wl1+0=; b=rDsa9mx+Mwoi/BLn0o68UPlYIFyDpV2zNtFL2siEzMiT08TluvO+B8zZwRzgC1COJP 2tlA7VzJcWaGxTMjF5d6i/Ol9r0LmWQ2QuLiNfFVPKibgPHdYdX3zQmLzo7pY2mSrnx9 UQJPdgeWG20TyyoOUBn712sYfDTka+5zPlJI4KSZJQmEo5OiwUKHxGwwnw/VXXx2cabE qELC7qExdXYQAnfFvQF6JTVwz4XXZRVQImRmxduDh+z//yYQFryjP0acoPgWT2Rdghcu cAadiU+7R22fbQrPxmXwEaK2t/zXiGvZDosAavck7/s3nIHMdDX1zEkUU17Q/HFMKJMK ydXQ== X-Gm-Message-State: AKwxytf5IH7Id0ZgHRFaCNjoYKyAbrTWpFqr2Myv7mAdwhi2mPmuvX3k NwvFnOoE2BhnzHYPDShvFA7Iqijvj83Jy2N4ihAJyQ== X-Received: by 10.36.10.20 with SMTP id 20mr36665692itw.127.1517436414751; Wed, 31 Jan 2018 14:06:54 -0800 (PST) MIME-Version: 1.0 Received: by 10.107.128.7 with HTTP; Wed, 31 Jan 2018 14:06:54 -0800 (PST) In-Reply-To: <1517435981.18619.215.camel@infradead.org> References: <1517427467-28567-1-git-send-email-karahmed@amazon.de> <1517427467-28567-5-git-send-email-karahmed@amazon.de> <06cb88da-f355-41ed-380f-7daa8ddf6159@amazon.com> <67dca2bb-1298-c7fa-f681-018e4edc6725@redhat.com> <16d89e09-fbfc-4a08-00a6-40cfb4776018@redhat.com> <1517435981.18619.215.camel@infradead.org> From: Jim Mattson Date: Wed, 31 Jan 2018 14:06:54 -0800 Message-ID: Subject: Re: [PATCH v5 4/5] KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL To: David Woodhouse Cc: Paolo Bonzini , KarimAllah Ahmed , KarimAllah Ahmed , kvm list , LKML , "the arch/x86 maintainers" , Asit Mallick , Arjan Van De Ven , Dave Hansen , Andi Kleen , Andrea Arcangeli , Linus Torvalds , Tim Chen , Thomas Gleixner , Dan Williams , Jun Nakajima , Greg KH , Andy Lutomirski , Ashok Raj Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 31, 2018 at 1:59 PM, David Woodhouse wrote: > I'm actually working on IBRS_ALL at the moment. > > I was tempted to *not* let the guests turn it off. Expose SPEC_CTRL but > just make it a no-op. Maybe we could convince Intel to add a LOCK bit to IA32_SPEC_CTRL like the one in IA32_FEATURE_CONTROL.