From patchwork Wed Apr 25 12:38:22 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 154902 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E741BB6EEB for ; Wed, 25 Apr 2012 22:38:25 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752434Ab2DYMiY (ORCPT ); Wed, 25 Apr 2012 08:38:24 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53399 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751313Ab2DYMiX (ORCPT ); Wed, 25 Apr 2012 08:38:23 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id F1CD28FFEB; Wed, 25 Apr 2012 14:38:22 +0200 (CEST) From: Alexander Graf To: kvm list Cc: kvm-ppc , Benjamin Herrenschmidt Subject: [PATCH 2/2] KVM: PPC: Book3S: PR: No isync in slbie path Date: Wed, 25 Apr 2012 14:38:22 +0200 Message-Id: <1335357502-30113-2-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <1335357502-30113-1-git-send-email-agraf@suse.de> References: <1335357502-30113-1-git-send-email-agraf@suse.de> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org While messing around with the SLBs we're running in real mode. The entry to guest space goes through rfid, which is context synchronizing, so there's no need to manually synchronize anything through isync. With this patch and a simple priviledged SPR access loop guest, I get a speed bump from 2035607 to 2181301 exits per second. Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_64_slb.S | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S index f2e6e48..56b983e 100644 --- a/arch/powerpc/kvm/book3s_64_slb.S +++ b/arch/powerpc/kvm/book3s_64_slb.S @@ -90,8 +90,6 @@ slb_exit_skip_ ## num: or r10, r10, r12 slbie r10 - isync - /* Fill SLB with our shadow */ lbz r12, SVCPU_SLB_MAX(r3)