Received: by 10.223.185.116 with SMTP id b49csp2736238wrg; Mon, 5 Mar 2018 07:57:25 -0800 (PST) X-Google-Smtp-Source: AG47ELsg3/7LvTh8TrzmZYWvGzLL+kwS493JRHAqH2/pXDKzqFqXQUb52Gyvw6cE+1ovdl6NKKCQ X-Received: by 2002:a17:902:1486:: with SMTP id k6-v6mr13919155pla.376.1520265445583; Mon, 05 Mar 2018 07:57:25 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1520265445; cv=none; d=google.com; s=arc-20160816; b=U5g5QsNPiWsperyV0vDcCAM7PKnlBqq34UBywOixHX1Lz6thuDDAedyBezJH3QMZHm RzUrRQcYpbK3obckem9nXa7r57VlNjrD9wOsjEbNptYfH5xFg1Imp+DVpMGJfSmDrQEb 9U0Lb0F8cHqWCbbrCqr5cFW7nzVHjye/qxUNZ0fLxnx7dMtxaRw2CXN9IzHf7ljPHCvL P9spaktAUFGK6WZ2gkTthTqU25atCJhOM70A7GRdb9JdhTEbfjsC3ix2GYq2zzU7sf25 wBdMjxSi5HW/4Inf6yGqUUDD4EeZHjpanBWhjo3qeakHVZ+S3LLAgkt3j5pecsmcYX0D A2BA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=Ffi+4iMzmEdsMl3LHtaT0demmVhgpc4dlkpxKuFYXWg=; b=JzjzsKyeoVys8yf2zD/tOhcbnTC/0n8GZazWMJj3EGjU2zfArIzBV0ZJzcVq6gU005 +TW7HlkIX/WwxxxI6NKAqBrgVSYMKeOECuXLL6we0jJ0xBrWgnMbystGr4ZooWznaSZ2 xaa0P6ESMD9yFz1+VneHWdjuFy2+zU5+3GbfpUuFcgEW+6to+BJzbxmOmO4NU6WAPmsk YLuX3+HyCq9w/0PX+LN6VisEDUWe+2LfUl79ySJDBrkmhP6isFUU0EcDfr1I6j7O+1Vq JI/j0TIEo2dWFXC150vkkxW0JX5uNST+rsVNuFO9KBB+cSHSuvv3sub1X8cJrFwoHzVL ptCA== ARC-Authentication-Results: i=1; mx.google.com; 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 Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 27si10395515pft.376.2018.03.05.07.57.11; Mon, 05 Mar 2018 07:57:25 -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; 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 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752577AbeCEP4D (ORCPT + 99 others); Mon, 5 Mar 2018 10:56:03 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:52554 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751679AbeCEP4C (ORCPT ); Mon, 5 Mar 2018 10:56:02 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D1B2914; Mon, 5 Mar 2018 07:56:01 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BD8CB3F5BA; Mon, 5 Mar 2018 07:55:59 -0800 (PST) Date: Mon, 5 Mar 2018 15:55:57 +0000 From: Mark Rutland To: Timur Tabi Cc: Shanker Donthineni , Thomas Speier , Vikram Sethi , Sean Campbell , Marc Zyngier , Catalin Marinas , Will Deacon , linux-kernel , Christoffer Dall , kvmarm , linux-arm-kernel Subject: Re: [PATCH] arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening Message-ID: <20180305155557.2iidi6346zcwz6r2@lakrids.cambridge.arm.com> References: <1520027418-10646-1-git-send-email-shankerd@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 05, 2018 at 09:52:19AM -0600, Timur Tabi wrote: > On Fri, Mar 2, 2018 at 3:50 PM, Shanker Donthineni > wrote: > > diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h > > index bb26382..6ecc249 100644 > > --- a/arch/arm64/include/asm/cpucaps.h > > +++ b/arch/arm64/include/asm/cpucaps.h > > @@ -43,7 +43,7 @@ > > #define ARM64_SVE 22 > > #define ARM64_UNMAP_KERNEL_AT_EL0 23 > > #define ARM64_HARDEN_BRANCH_PREDICTOR 24 > > -#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25 > > +/* #define ARM64_UNALLOCATED_ENTRY 25 */ > > Why not just delete the entry? Deleting the entry, and renumbering subsequent entries is the right thing to do. > Is ARM64_NCAPS never supposed to get smaller? It's internal to the kernel, and it makes sense to keep it as small as possible. There are datastructures allocated for each entry, like the static key array. Thanks, Mark.