From patchwork Wed Jan 29 16:12:59 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 3552261 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AA8B49F382 for ; Wed, 29 Jan 2014 16:14:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 78FE3201B9 for ; Wed, 29 Jan 2014 16:14:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3308920125 for ; Wed, 29 Jan 2014 16:14:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753013AbaA2QOh (ORCPT ); Wed, 29 Jan 2014 11:14:37 -0500 Received: from cantor2.suse.de ([195.135.220.15]:54484 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752837AbaA2QNZ (ORCPT ); Wed, 29 Jan 2014 11:13:25 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id C03F87501F; Wed, 29 Jan 2014 16:13:19 +0000 (UTC) From: Alexander Graf To: kvm@vger.kernel.org Cc: kvm-ppc@vger.kernel.org, gleb@redhat.com, Paolo Bonzini , Scott Wood Subject: [PULL 20/36] kvm/ppc: IRQ disabling cleanup Date: Wed, 29 Jan 2014 17:12:59 +0100 Message-Id: <1391011995-4891-21-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1391011995-4891-1-git-send-email-agraf@suse.de> References: <1391011995-4891-1-git-send-email-agraf@suse.de> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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 From: Scott Wood 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(). Signed-off-by: Scott Wood Signed-off-by: Alexander Graf --- arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ arch/powerpc/kvm/book3s_pr.c | 14 ++++++-------- arch/powerpc/kvm/booke.c | 12 +++++------- arch/powerpc/kvm/powerpc.c | 26 +++++++++----------------- 4 files changed, 26 insertions(+), 32 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index 629277d..fcd53f0 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -456,6 +456,12 @@ 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 aedba68..e82fafd 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -999,14 +999,14 @@ 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 { + /* interrupts now hard-disabled */ kvmppc_fix_ee_before_entry(); } + kvmppc_handle_lost_ext(vcpu); } @@ -1219,12 +1219,10 @@ static int kvmppc_vcpu_run_pr(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; - } + /* interrupts now hard-disabled */ /* Save FPU state in thread_struct */ if (current->thread.regs->msr & MSR_FP) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 6a8c32e..07b89c7 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -643,7 +643,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu) local_irq_enable(); kvm_vcpu_block(vcpu); clear_bit(KVM_REQ_UNHALT, &vcpu->requests); - local_irq_disable(); + hard_irq_disable(); kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS); r = 1; @@ -688,13 +688,12 @@ 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; } + /* interrupts now hard-disabled */ #ifdef CONFIG_PPC_FPU /* Save userspace FPU state in stack */ @@ -1187,12 +1186,11 @@ 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 { + /* interrupts now hard-disabled */ kvmppc_fix_ee_before_entry(); } } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 026dfaa..3cf541a 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -68,14 +68,16 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) */ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) { - int r = 1; + int r; + + WARN_ON(irqs_disabled()); + hard_irq_disable(); - WARN_ON_ONCE(!irqs_disabled()); while (true) { if (need_resched()) { local_irq_enable(); cond_resched(); - local_irq_disable(); + hard_irq_disable(); continue; } @@ -101,7 +103,7 @@ 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; @@ -113,22 +115,12 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) continue; } -#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; - } -#endif - kvm_guest_enter(); - break; + return 1; } + /* return to host */ + local_irq_enable(); return r; } EXPORT_SYMBOL_GPL(kvmppc_prepare_to_enter);