From patchwork Wed Apr 10 13:22:20 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhang, Yang Z" X-Patchwork-Id: 2421201 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id E32FCDF2E5 for ; Wed, 10 Apr 2013 13:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935411Ab3DJN1D (ORCPT ); Wed, 10 Apr 2013 09:27:03 -0400 Received: from mga03.intel.com ([143.182.124.21]:30707 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935355Ab3DJN1B (ORCPT ); Wed, 10 Apr 2013 09:27:01 -0400 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 10 Apr 2013 06:27:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,447,1363158000"; d="scan'208";a="225523850" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by AZSMGA002.ch.intel.com with ESMTP; 10 Apr 2013 06:26:58 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: pbonzini@redhat.com, gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v9 7/7] KVM: Use eoi to track RTC interrupt delivery status Date: Wed, 10 Apr 2013 21:22:20 +0800 Message-Id: <1365600140-8472-8-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1365600140-8472-1-git-send-email-yang.z.zhang@intel.com> References: <1365600140-8472-1-git-send-email-yang.z.zhang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Yang Zhang Current interrupt coalescing logci which only used by RTC has conflict with Posted Interrupt. This patch introduces a new mechinism to use eoi to track interrupt: When delivering an interrupt to vcpu, the pending_eoi set to number of vcpu that received the interrupt. And decrease it when each vcpu writing eoi. No subsequent RTC interrupt can deliver to vcpu until all vcpus write eoi. Signed-off-by: Yang Zhang --- virt/kvm/ioapic.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 files changed, 38 insertions(+), 1 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index a49fcd5..aeac154 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -147,6 +147,26 @@ static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic) __rtc_irq_eoi_tracking_restore_one(vcpu); } +static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu) +{ + if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) + --ioapic->rtc_status.pending_eoi; + + WARN_ON(ioapic->rtc_status.pending_eoi < 0); +} + +static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic, int irq, + bool line_status) +{ + if (irq != RTC_GSI || !line_status) + return false; + + if (ioapic->rtc_status.pending_eoi > 0) + return true; /* coalesced */ + + return false; +} + static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx, bool line_status) { @@ -260,6 +280,7 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) { union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq]; struct kvm_lapic_irq irqe; + int ret; ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x " "vector=%x trig_mode=%x\n", @@ -275,7 +296,15 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) irqe.level = 1; irqe.shorthand = 0; - return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); + if (irq == RTC_GSI && line_status) { + BUG_ON(ioapic->rtc_status.pending_eoi != 0); + ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, + ioapic->rtc_status.dest_map); + ioapic->rtc_status.pending_eoi = ret; + } else + ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); + + return ret; } int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, @@ -299,6 +328,11 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, ret = 1; } else { int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG); + + if (rtc_irq_check_coalesced(ioapic, irq, line_status)) { + ret = 0; /* coalesced */ + goto out; + } ioapic->irr |= mask; if ((edge && old_irr != ioapic->irr) || (!edge && !entry.fields.remote_irr)) @@ -306,6 +340,7 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, else ret = 0; /* report coalesced interrupt */ } +out: trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0); spin_unlock(&ioapic->lock); @@ -333,6 +368,8 @@ static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, if (ent->fields.vector != vector) continue; + if (i == RTC_GSI) + rtc_irq_eoi(ioapic, vcpu); /* * We are dropping lock while calling ack notifiers because ack * notifier callbacks for assigned devices call into IOAPIC