Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934114AbeALQ2f (ORCPT + 1 other); Fri, 12 Jan 2018 11:28:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51706 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933994AbeALQ2e (ORCPT ); Fri, 12 Jan 2018 11:28:34 -0500 Date: Fri, 12 Jan 2018 10:28:24 -0600 From: Josh Poimboeuf To: Dave Hansen Cc: "Raj, Ashok" , Andy Lutomirski , LKML , Thomas Gleixner , Tim Chen , Linus Torvalds , Greg KH , Andrea Arcangeli , Andi Kleen , Arjan Van De Ven , David Woodhouse , Peter Zijlstra , Dan Williams , Paolo Bonzini , Jun Nakajima , Asit Mallick Subject: Re: [PATCH 1/5] x86/ibrs: Introduce native_rdmsrl, and native_wrmsrl Message-ID: <20180112162824.xenarh43dch62h5a@treble> References: <1515720739-43819-1-git-send-email-ashok.raj@intel.com> <1515720739-43819-2-git-send-email-ashok.raj@intel.com> <20180112015231.GA44418@otc-nc-03> <20180112030139.GA46095@otc-nc-03> <917cf067-c986-a459-ea87-7b7724c3c2d6@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <917cf067-c986-a459-ea87-7b7724c3c2d6@intel.com> User-Agent: Mutt/1.6.0.1 (2016-04-01) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 12 Jan 2018 16:28:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Jan 11, 2018 at 09:03:56PM -0800, Dave Hansen wrote: > On 01/11/2018 07:01 PM, Raj, Ashok wrote: > > On Thu, Jan 11, 2018 at 06:20:13PM -0800, Andy Lutomirski wrote: > >> On Thu, Jan 11, 2018 at 5:52 PM, Raj, Ashok wrote: > >>>> > >>>> What's wrong with native_read_msr()? > >>> > >>> Yes, i think i should have added to msr.h. The names didn't read as a > >>> pair, one was native_read_msr, wrmsrl could be taken over when paravirt is > >>> defined? > >> > >> Why do you need to override paravirt? > > > > The idea was since these MSR's are passed through we shouldn't need to > > handle them any differently. Also its best to do this as soon as possible > > and avoid longer paths to get this barrier to hardware. > > We were also worried about the indirect calls that are part of the > paravirt interfaces when retpolines are not in place. But aren't those patched with direct calls during boot? -- Josh