From patchwork Thu Jun 11 17:58:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 6590911 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AC0E99F399 for ; Thu, 11 Jun 2015 17:58:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C641420411 for ; Thu, 11 Jun 2015 17:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3C1C203B0 for ; Thu, 11 Jun 2015 17:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755172AbbFKR6q (ORCPT ); Thu, 11 Jun 2015 13:58:46 -0400 Received: from foss.arm.com ([217.140.101.70]:57123 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755166AbbFKR6p (ORCPT ); Thu, 11 Jun 2015 13:58:45 -0400 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 4A0822A; Thu, 11 Jun 2015 10:58:53 -0700 (PDT) Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.209.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CDF283F23A; Thu, 11 Jun 2015 10:58:40 -0700 (PDT) From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: Christoffer Dall Subject: [PATCH] arm/arm64: KVM: vgic: Do not save GICH_HCR / ICH_HCR_EL2 Date: Thu, 11 Jun 2015 18:58:24 +0100 Message-Id: <1434045504-11549-1-git-send-email-marc.zyngier@arm.com> X-Mailer: git-send-email 2.1.4 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The GIC Hypervisor Configuration Register is used to enable the delivery of virtual interupts to a guest, as well as to define in which conditions maintenance interrupts are delivered to the host. This register doesn't contain any information that we need to read back (the EOIcount is utterly useless for us). So let's save ourselves some cycles, and not save it before writing zero to it. Signed-off-by: Marc Zyngier --- arch/arm/kvm/interrupts_head.S | 3 --- arch/arm64/kvm/vgic-v2-switch.S | 3 --- arch/arm64/kvm/vgic-v3-switch.S | 2 -- 3 files changed, 8 deletions(-) diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 35e4a3a..82a4ac9 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -412,7 +412,6 @@ vcpu .req r0 @ vcpu pointer always in r0 add r11, vcpu, #VCPU_VGIC_CPU /* Save all interesting registers */ - ldr r3, [r2, #GICH_HCR] ldr r4, [r2, #GICH_VMCR] ldr r5, [r2, #GICH_MISR] ldr r6, [r2, #GICH_EISR0] @@ -420,7 +419,6 @@ vcpu .req r0 @ vcpu pointer always in r0 ldr r8, [r2, #GICH_ELRSR0] ldr r9, [r2, #GICH_ELRSR1] ldr r10, [r2, #GICH_APR] -ARM_BE8(rev r3, r3 ) ARM_BE8(rev r4, r4 ) ARM_BE8(rev r5, r5 ) ARM_BE8(rev r6, r6 ) @@ -429,7 +427,6 @@ ARM_BE8(rev r8, r8 ) ARM_BE8(rev r9, r9 ) ARM_BE8(rev r10, r10 ) - str r3, [r11, #VGIC_V2_CPU_HCR] str r4, [r11, #VGIC_V2_CPU_VMCR] str r5, [r11, #VGIC_V2_CPU_MISR] #ifdef CONFIG_CPU_ENDIAN_BE8 diff --git a/arch/arm64/kvm/vgic-v2-switch.S b/arch/arm64/kvm/vgic-v2-switch.S index f002fe1..3f00071 100644 --- a/arch/arm64/kvm/vgic-v2-switch.S +++ b/arch/arm64/kvm/vgic-v2-switch.S @@ -47,7 +47,6 @@ __save_vgic_v2_state: add x3, x0, #VCPU_VGIC_CPU /* Save all interesting registers */ - ldr w4, [x2, #GICH_HCR] ldr w5, [x2, #GICH_VMCR] ldr w6, [x2, #GICH_MISR] ldr w7, [x2, #GICH_EISR0] @@ -55,7 +54,6 @@ __save_vgic_v2_state: ldr w9, [x2, #GICH_ELRSR0] ldr w10, [x2, #GICH_ELRSR1] ldr w11, [x2, #GICH_APR] -CPU_BE( rev w4, w4 ) CPU_BE( rev w5, w5 ) CPU_BE( rev w6, w6 ) CPU_BE( rev w7, w7 ) @@ -64,7 +62,6 @@ CPU_BE( rev w9, w9 ) CPU_BE( rev w10, w10 ) CPU_BE( rev w11, w11 ) - str w4, [x3, #VGIC_V2_CPU_HCR] str w5, [x3, #VGIC_V2_CPU_VMCR] str w6, [x3, #VGIC_V2_CPU_MISR] CPU_LE( str w7, [x3, #VGIC_V2_CPU_EISR] ) diff --git a/arch/arm64/kvm/vgic-v3-switch.S b/arch/arm64/kvm/vgic-v3-switch.S index 617a012..3c20730 100644 --- a/arch/arm64/kvm/vgic-v3-switch.S +++ b/arch/arm64/kvm/vgic-v3-switch.S @@ -48,13 +48,11 @@ dsb st // Save all interesting registers - mrs_s x4, ICH_HCR_EL2 mrs_s x5, ICH_VMCR_EL2 mrs_s x6, ICH_MISR_EL2 mrs_s x7, ICH_EISR_EL2 mrs_s x8, ICH_ELSR_EL2 - str w4, [x3, #VGIC_V3_CPU_HCR] str w5, [x3, #VGIC_V3_CPU_VMCR] str w6, [x3, #VGIC_V3_CPU_MISR] str w7, [x3, #VGIC_V3_CPU_EISR]