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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72E5FC04A6A for ; Thu, 3 Aug 2023 01:25:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231444AbjHCBZn (ORCPT ); Wed, 2 Aug 2023 21:25:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231269AbjHCBZm (ORCPT ); Wed, 2 Aug 2023 21:25:42 -0400 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED4E9273C; Wed, 2 Aug 2023 18:25:41 -0700 (PDT) Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-1bbf3da0ea9so3438255ad.2; Wed, 02 Aug 2023 18:25:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691025941; x=1691630741; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=zWBAuG3c06Da9ELH4rE5nxlRVcg2TZcFu5fJ+OOQAks=; b=Ve6qFtWN2nnwmHGSTU0+Ba2p/1c/CwQsa39gfEFvIqHEqPzu7/vEEwtv7BGvl4ukfL H++7fGMaHlcek/3uesecl3Xmvp0HKfRWiYb9MfyKOZGEH9LlJB2/b3dsfmu3mzRfmifI +g3l+BSq2aaSxQviaLrunCmDLsSky93WV9ZmuxEW2r4h5fkTq5IzUpphg1BfUORkClu4 8P+XyuilbPer2FXWESB7L50ZcMkGaMN0X3zQ6pgirjzosmZ0ZmhCxM9d/0y1p1PJi5cJ 3/p1q+ujiaKXIxF+JmNjHf+wER6k/prdUwOZI0Lv1NHBhuduC/k/GTT0kWLIQU2GGENI WEyg== X-Gm-Message-State: ABy/qLZAfhO0QFhKmw/m/keUP7iJDxhJdPL8c0uuuhtEeRbNtF40n1NJ 0m42ugrso7WjRs79i54lYXg= X-Google-Smtp-Source: APBJJlGg3g/NxUbke1+MzTLDtzvJmK3VM5Kg5CjoArXQVKLrRZlgMjpcmKC82Ectrxe/wO+cgZIZVg== X-Received: by 2002:a17:903:1cb:b0:1b8:2ba0:c9c0 with SMTP id e11-20020a17090301cb00b001b82ba0c9c0mr18130270plh.59.1691025941149; Wed, 02 Aug 2023 18:25:41 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id x16-20020a170902ec9000b001bc39aa63ebsm176829plg.121.2023.08.02.18.25.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Aug 2023 18:25:40 -0700 (PDT) Date: Thu, 3 Aug 2023 01:25:34 +0000 From: Wei Liu To: Nuno Das Neves Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, mikelley@microsoft.com, kys@microsoft.com, wei.liu@kernel.org, haiyangz@microsoft.com, decui@microsoft.com, ssengar@linux.microsoft.com, mukeshrathor@microsoft.com, stanislav.kinsburskiy@gmail.com, jinankjain@linux.microsoft.com, apais@linux.microsoft.com, Tianyu.Lan@microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, will@kernel.org, catalin.marinas@arm.com Subject: Re: [PATCH 01/15] hyperv-tlfs: Change shared HV_REGISTER_* defines to HV_MSR_* Message-ID: References: <1690487690-2428-1-git-send-email-nunodasneves@linux.microsoft.com> <1690487690-2428-2-git-send-email-nunodasneves@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1690487690-2428-2-git-send-email-nunodasneves@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, Jul 27, 2023 at 12:54:36PM -0700, Nuno Das Neves wrote: > In x86 hyperv-tlfs, HV_REGISTER_ prefix is used to indicate MSRs > accessed via rdmsrl/wrmsrl. But in ARM64, HV_REGISTER_ instead indicates > VP registers accessed via get/set vp registers hypercall. > > This is due to HV_REGISTER_* names being used by hv_set/get_register, > with the arch-specific version delegating to the appropriate mechanism. > > The problem is, using prefix HV_REGISTER_ for MSRs will conflict with > VP registers when they are introduced for x86 in future. > > This patch solves the issue by: > > 1. Defining all the x86 MSRs with a consistent prefix: HV_X64_MSR_. > This is so HV_REGISTER_ can be reserved for VP registers. > > 2. Change the non-arch-specific alias used by hv_set/get_register to > HV_MSR_. This is also happens to be the same name HyperV uses for this > purpose. > > Signed-off-by: Nuno Das Neves Assuming the prior (private?) discussion with Michael led to this patch: Acked-by: Wei Liu