From patchwork Fri Mar 22 05:24:05 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: 2318111 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 D61D140B29 for ; Fri, 22 Mar 2013 05:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932688Ab3CVF2n (ORCPT ); Fri, 22 Mar 2013 01:28:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:6384 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932672Ab3CVF2l (ORCPT ); Fri, 22 Mar 2013 01:28:41 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 21 Mar 2013 22:28:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,890,1355126400"; d="scan'208";a="305949987" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by orsmga002.jf.intel.com with ESMTP; 21 Mar 2013 22:28:22 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v6 6/6] KVM: Use eoi to track RTC interrupt delivery status Date: Fri, 22 Mar 2013 13:24:05 +0800 Message-Id: <1363929845-29005-7-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1363929845-29005-1-git-send-email-yang.z.zhang@intel.com> References: <1363929845-29005-1-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 | 40 +++++++++++++++++++++++++++++++++++++++- 1 files changed, 39 insertions(+), 1 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index c991e58..df16daf 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -114,6 +114,29 @@ static void rtc_irq_restore(struct kvm_ioapic *ioapic) ioapic->rtc_status.pending_eoi = pending_eoi; } +static void rtc_irq_ack_eoi(struct kvm_vcpu *vcpu, + struct rtc_status *rtc_status, int irq) +{ + if (irq != RTC_GSI) + return; + + if (test_and_clear_bit(vcpu->vcpu_id, rtc_status->dest_map)) + --rtc_status->pending_eoi; + + WARN_ON(rtc_status->pending_eoi < 0); +} + +static bool rtc_irq_check(struct kvm_ioapic *ioapic, int irq) +{ + if (irq != RTC_GSI) + 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) { union kvm_ioapic_redirect_entry *pent; @@ -229,6 +252,7 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq) { 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", @@ -244,7 +268,14 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq) irqe.level = 1; irqe.shorthand = 0; - return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); + if (irq == RTC_GSI) { + 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, @@ -268,6 +299,11 @@ 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)) { + ret = 0; /* coalesced */ + goto out; + } ioapic->irr |= mask; if ((edge && old_irr != ioapic->irr) || (!edge && !entry.fields.remote_irr)) @@ -275,6 +311,7 @@ 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); @@ -302,6 +339,7 @@ static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, if (ent->fields.vector != vector) continue; + rtc_irq_ack_eoi(vcpu, &ioapic->rtc_status, i); /* * We are dropping lock while calling ack notifiers because ack * notifier callbacks for assigned devices call into IOAPIC