From patchwork Fri Nov 15 08:35:01 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pingfan liu X-Patchwork-Id: 291506 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 3352D2C0374 for ; Fri, 15 Nov 2013 19:34:27 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756846Ab3KOIe0 (ORCPT ); Fri, 15 Nov 2013 03:34:26 -0500 Received: from mail-ob0-f182.google.com ([209.85.214.182]:44169 "EHLO mail-ob0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754944Ab3KOIe0 (ORCPT ); Fri, 15 Nov 2013 03:34:26 -0500 Received: by mail-ob0-f182.google.com with SMTP id wp18so3542109obc.13 for ; Fri, 15 Nov 2013 00:34:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=l4Q800e/oSnIziU2HOaKk2WIhSFME5VgVDZHNcZrzfU=; b=S1obt+l86jdjmig+EreaFilelrWNUmBUISGrCe9tn5qPJ0/4WCxLIseTVNuiqdO3v7 jTXDgiNM3JM1I8xpz6XueAy37HxxkVk+3Y/HyMC4rxgyf9RXgBNFXl1z6Jo/7VOzEGSK m6hHVQKWsRCc+1y7HtmnzSAf+YD7nbSvmL0fF08HjhHgkBQyWh3rJwBRzrUu4ghZKAQY 2hAhVQxF4oOa68saLtrqne6Ydcznt/UOdeh70E1rN4W2O1hEieEp+DtRiF7jIq1c7xx1 WrOw3ghAW+EJ/UBSo/NNJ+we99xn5vq8hrl6JIJWDNrEi4F+lWlTDdqqzM+QbdoksCGT aODg== X-Received: by 10.182.92.231 with SMTP id cp7mr187286obb.82.1384504465878; Fri, 15 Nov 2013 00:34:25 -0800 (PST) Received: from localhost ([202.108.130.138]) by mx.google.com with ESMTPSA id z5sm2743121obg.13.2013.11.15.00.34.23 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 15 Nov 2013 00:34:25 -0800 (PST) From: Liu Ping Fan To: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org Cc: Benjamin Herrenschmidt , Paul Mackerras , Alexander Graf Subject: [PATCH v2] powerpc: kvm: optimize "sc 1" as fast return Date: Fri, 15 Nov 2013 16:35:01 +0800 Message-Id: <1384504501-19348-2-git-send-email-pingfank@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1384504501-19348-1-git-send-email-pingfank@linux.vnet.ibm.com> References: <1384504501-19348-1-git-send-email-pingfank@linux.vnet.ibm.com> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org In some scene, e.g openstack CI, PR guest can trigger "sc 1" frequently, this patch optimizes the path by directly delivering BOOK3S_INTERRUPT_SYSCALL to HV guest, so powernv can return to HV guest without heavy exit, i.e, no need to swap TLB, HTAB,.. etc Signed-off-by: Liu Ping Fan --- arch/powerpc/kvm/book3s_hv.c | 6 ------ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++++++++++- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 62a2b5a..73dc852 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -628,12 +628,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, /* hcall - punt to userspace */ int i; - if (vcpu->arch.shregs.msr & MSR_PR) { - /* sc 1 from userspace - reflect to guest syscall */ - kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_SYSCALL); - r = RESUME_GUEST; - break; - } run->papr_hcall.nr = kvmppc_get_gpr(vcpu, 3); for (i = 0; i < 9; ++i) run->papr_hcall.args[i] = kvmppc_get_gpr(vcpu, 4 + i); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index c71103b..a463f08 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1388,7 +1388,8 @@ kvmppc_hisi: hcall_try_real_mode: ld r3,VCPU_GPR(R3)(r9) andi. r0,r11,MSR_PR - bne guest_exit_cont + /* sc 1 from userspace - reflect to guest syscall */ + bne sc_1_fast_return clrrdi r3,r3,2 cmpldi r3,hcall_real_table_end - hcall_real_table bge guest_exit_cont @@ -1409,6 +1410,14 @@ hcall_try_real_mode: ld r11,VCPU_MSR(r4) b fast_guest_return +sc_1_fast_return: + mtspr SPRN_SRR0,r10 + mtspr SPRN_SRR1,r11 + li r10, BOOK3S_INTERRUPT_SYSCALL + li r11, (MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */ + rotldi r11, r11, 63 + b fast_guest_return + /* We've attempted a real mode hcall, but it's punted it back * to userspace. We need to restore some clobbered volatiles * before resuming the pass-it-to-qemu path */