From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753435AbbCJWh4 (ORCPT ); Tue, 10 Mar 2015 18:37:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39097 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752629AbbCJWhw (ORCPT ); Tue, 10 Mar 2015 18:37:52 -0400 Date: Tue, 10 Mar 2015 19:37:13 -0300 From: Marcelo Tosatti To: Radim =?utf-8?B?S3LEjW3DocWZ?= Cc: Joel Schopp , Gleb Natapov , Paolo Bonzini , kvm@vger.kernel.org, David Kaplan , Joerg Roedel , linux-kernel@vger.kernel.org, Borislav Petkov Subject: Re: [PATCH] x86: svm: make wbinvd faster Message-ID: <20150310223713.GA17773@amt.cnet> References: <20150228001917.15247.41063.stgit@joelvmguard2.amd.com> <20150309232846.GB12125@amt.cnet> <20150310110131.GA12854@potion.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20150310110131.GA12854@potion.brq.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 10, 2015 at 12:01:31PM +0100, Radim Krčmář wrote: > 2015-03-09 20:28-0300, Marcelo Tosatti: > > On Fri, Feb 27, 2015 at 06:19:18PM -0600, Joel Schopp wrote: > > > From: David Kaplan > > > No need to re-decode WBINVD since we know what it is from the intercept. > > > > > > Signed-off-by: David Kaplan > > > [extracted from larger unlrelated patch, forward ported, tested] > > > Signed-off-by: Joel Schopp > > > > Can't you disable the intercept if need_emulate_wbinvd(vcpu) == false? > > I don't think we want to: it should be faster to intercept and ignore > than to invalidate all caches. The exit doesn't affect other physical > cores and costs just about 10(?) L3 cache misses. Yes, right.