From patchwork Thu Mar 21 10:49:24 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: 2312061 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 CF43DE00DD for ; Thu, 21 Mar 2013 10:53:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755097Ab3CUKxo (ORCPT ); Thu, 21 Mar 2013 06:53:44 -0400 Received: from mga03.intel.com ([143.182.124.21]:36208 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755058Ab3CUKxm (ORCPT ); Thu, 21 Mar 2013 06:53:42 -0400 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 21 Mar 2013 03:53:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,884,1355126400"; d="scan'208";a="217299381" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by AZSMGA002.ch.intel.com with ESMTP; 21 Mar 2013 03:53:40 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v5 6/6] KVM: Use eoi to track RTC interrupt delivery status Date: Thu, 21 Mar 2013 18:49:24 +0800 Message-Id: <1363862964-25148-7-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1363862964-25148-1-git-send-email-yang.z.zhang@intel.com> References: <1363862964-25148-1-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 | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 52 insertions(+), 1 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index a5ee8bf..3aec0a2 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -109,6 +109,29 @@ 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 != 8) + 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 != 8) + return false; + + if (ioapic->rtc_status.pending_eoi > 0) + return true; /* coalesced */ + + return false; +} #else static void rtc_irq_reset(struct kvm_ioapic *ioapic) { @@ -119,6 +142,17 @@ static void rtc_irq_restore(struct kvm_ioapic *ioapic) { return; } + +static void rtc_irq_ack_eoi(struct kvm_vcpu *vcpu, + struct rtc_status *rtc_status, int irq) +{ + return; +} + +static bool rtc_irq_check(struct kvm_ioapic *ioapic, int irq) +{ + return false; +} #endif static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx) @@ -236,6 +270,7 @@ 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", @@ -251,7 +286,16 @@ 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); +#ifdef CONFIG_X86 + if (irq == 8) { + ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, + ioapic->rtc_status.dest_map); + ioapic->rtc_status.pending_eoi = ret; + } else +#endif + 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, @@ -275,6 +319,11 @@ 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)) @@ -282,6 +331,7 @@ 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); @@ -309,6 +359,7 @@ 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