From patchwork Fri May 10 03:09:44 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Wood X-Patchwork-Id: 2548251 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id E48103FE37 for ; Fri, 10 May 2013 03:10:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755815Ab3EJDJ6 (ORCPT ); Thu, 9 May 2013 23:09:58 -0400 Received: from co9ehsobe004.messaging.microsoft.com ([207.46.163.27]:25961 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755305Ab3EJDJy (ORCPT ); Thu, 9 May 2013 23:09:54 -0400 Received: from mail104-co9-R.bigfish.com (10.236.132.246) by CO9EHSOBE041.bigfish.com (10.236.130.104) with Microsoft SMTP Server id 14.1.225.23; Fri, 10 May 2013 03:09:53 +0000 Received: from mail104-co9 (localhost [127.0.0.1]) by mail104-co9-R.bigfish.com (Postfix) with ESMTP id E317F46091F; Fri, 10 May 2013 03:09:53 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzzz1f42h1ee6h1de0h1fdah1202h1e76h1d1ah1d2ah1fc6hzz8275bhz2dh2a8h668h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1d0ch1d2eh1d3fh1155h) Received: from mail104-co9 (localhost.localdomain [127.0.0.1]) by mail104-co9 (MessageSwitch) id 1368155392299375_9323; Fri, 10 May 2013 03:09:52 +0000 (UTC) Received: from CO9EHSMHS022.bigfish.com (unknown [10.236.132.241]) by mail104-co9.bigfish.com (Postfix) with ESMTP id 463A820007B; Fri, 10 May 2013 03:09:52 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CO9EHSMHS022.bigfish.com (10.236.130.32) with Microsoft SMTP Server (TLS) id 14.1.225.23; Fri, 10 May 2013 03:09:52 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-003.039d.mgd.msft.net (10.84.1.16) with Microsoft SMTP Server (TLS) id 14.2.328.11; Fri, 10 May 2013 03:09:51 +0000 Received: from snotra.am.freescale.net ([10.214.85.10]) by tx30smr01.am.freescale.net (8.14.3/8.14.0) with ESMTP id r4A39i20025681; Thu, 9 May 2013 20:09:50 -0700 From: Scott Wood To: Alexander Graf , Benjamin Herrenschmidt CC: , , , Scott Wood Subject: [PATCH v2 4/4] kvm/ppc: IRQ disabling cleanup Date: Thu, 9 May 2013 22:09:44 -0500 Message-ID: <1368155384-11035-5-git-send-email-scottwood@freescale.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1368155384-11035-1-git-send-email-scottwood@freescale.com> References: <1368155384-11035-1-git-send-email-scottwood@freescale.com> MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Simplify the handling of lazy EE by going directly from fully-enabled to hard-disabled. This replaces the lazy_irq_pending() check (including its misplaced kvm_guest_exit() call). As suggested by Tiejun Chen, move the interrupt disabling into kvmppc_prepare_to_enter() rather than have each caller do it. Also move the IRQ enabling on heavyweight exit into kvmppc_prepare_to_enter(). Don't move kvmppc_fix_ee_before_entry() into kvmppc_prepare_to_enter(), so that the caller can avoid marking interrupts enabled earlier than necessary (e.g. book3s_pr waits until after FP save/restore is done). Signed-off-by: Scott Wood --- arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ arch/powerpc/kvm/book3s_pr.c | 12 +++--------- arch/powerpc/kvm/booke.c | 9 ++------- arch/powerpc/kvm/powerpc.c | 21 ++++++++------------- 4 files changed, 19 insertions(+), 29 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 6885846..e4474f8 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -404,6 +404,12 @@ static inline void kvmppc_fix_ee_before_entry(void) trace_hardirqs_on(); #ifdef CONFIG_PPC64 + /* + * To avoid races, the caller must have gone directly from having + * interrupts fully-enabled to hard-disabled. + */ + WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS); + /* Only need to enable IRQs by hard enabling them after this */ local_paca->irq_happened = 0; local_paca->soft_enabled = 1; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 0b97ce4..e61e39e 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -884,14 +884,11 @@ program_interrupt: * and if we really did time things so badly, then we just exit * again due to a host external interrupt. */ - local_irq_disable(); s = kvmppc_prepare_to_enter(vcpu); - if (s <= 0) { - local_irq_enable(); + if (s <= 0) r = s; - } else { + else kvmppc_fix_ee_before_entry(); - } } trace_kvm_book3s_reenter(r, vcpu); @@ -1121,12 +1118,9 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) * really did time things so badly, then we just exit again due to * a host external interrupt. */ - local_irq_disable(); ret = kvmppc_prepare_to_enter(vcpu); - if (ret <= 0) { - local_irq_enable(); + if (ret <= 0) goto out; - } /* Save FPU state in stack */ if (current->thread.regs->msr & MSR_FP) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index eb89b83..f7c0111 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -666,10 +666,8 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) return -EINVAL; } - local_irq_disable(); s = kvmppc_prepare_to_enter(vcpu); if (s <= 0) { - local_irq_enable(); ret = s; goto out; } @@ -1148,14 +1146,11 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu, * aren't already exiting to userspace for some other reason. */ if (!(r & RESUME_HOST)) { - local_irq_disable(); s = kvmppc_prepare_to_enter(vcpu); - if (s <= 0) { - local_irq_enable(); + if (s <= 0) r = (s << 2) | RESUME_HOST | (r & RESUME_FLAG_NV); - } else { + else kvmppc_fix_ee_before_entry(); - } } return r; diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 4e05f8c..f8659aa 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -64,12 +64,14 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) { int r = 1; - WARN_ON_ONCE(!irqs_disabled()); + WARN_ON(irqs_disabled()); + hard_irq_disable(); + while (true) { if (need_resched()) { local_irq_enable(); cond_resched(); - local_irq_disable(); + hard_irq_disable(); continue; } @@ -95,7 +97,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) local_irq_enable(); trace_kvm_check_requests(vcpu); r = kvmppc_core_check_requests(vcpu); - local_irq_disable(); + hard_irq_disable(); if (r > 0) continue; break; @@ -108,21 +110,14 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) } #ifdef CONFIG_PPC64 - /* lazy EE magic */ - hard_irq_disable(); - if (lazy_irq_pending()) { - /* Got an interrupt in between, try again */ - local_irq_enable(); - local_irq_disable(); - kvm_guest_exit(); - continue; - } + WARN_ON(lazy_irq_pending()); #endif kvm_guest_enter(); - break; + return r; } + local_irq_enable(); return r; } #endif /* CONFIG_KVM_BOOK3S_64_HV */