From patchwork Mon Apr 8 14:17:49 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: 2408641 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 8D6923FE81 for ; Mon, 8 Apr 2013 14:22:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936262Ab3DHOW1 (ORCPT ); Mon, 8 Apr 2013 10:22:27 -0400 Received: from mga03.intel.com ([143.182.124.21]:9233 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936256Ab3DHOW0 (ORCPT ); Mon, 8 Apr 2013 10:22:26 -0400 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 08 Apr 2013 07:22:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,432,1363158000"; d="scan'208";a="224549916" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by AZSMGA002.ch.intel.com with ESMTP; 08 Apr 2013 07:22:23 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v8 7/7] KVM: Use eoi to track RTC interrupt delivery status Date: Mon, 8 Apr 2013 22:17:49 +0800 Message-Id: <1365430669-31126-8-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1365430669-31126-1-git-send-email-yang.z.zhang@intel.com> References: <1365430669-31126-1-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 | 41 ++++++++++++++++++++++++++++++++++++++++- 1 files changed, 40 insertions(+), 1 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 8d1f662..197ef97 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -149,6 +149,29 @@ static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic) __rtc_irq_eoi_tracking_restore_one(vcpu, vector); } +static void rtc_irq_ack_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu, + int irq) +{ + if (irq != RTC_GSI) + return; + + 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(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) { @@ -262,6 +285,7 @@ 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", @@ -277,7 +301,15 @@ 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, @@ -301,6 +333,11 @@ 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(ioapic, irq, line_status)) { + ret = 0; /* coalesced */ + goto out; + } ioapic->irr |= mask; if ((edge && old_irr != ioapic->irr) || (!edge && !entry.fields.remote_irr)) @@ -308,6 +345,7 @@ 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); @@ -335,6 +373,7 @@ static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, if (ent->fields.vector != vector) continue; + rtc_irq_ack_eoi(ioapic, vcpu, i); /* * We are dropping lock while calling ack notifiers because ack * notifier callbacks for assigned devices call into IOAPIC