From patchwork Wed Mar 20 11:36:19 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: 2306871 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 DEBC040B29 for ; Wed, 20 Mar 2013 11:40:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757912Ab3CTLkq (ORCPT ); Wed, 20 Mar 2013 07:40:46 -0400 Received: from mga14.intel.com ([143.182.124.37]:14698 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756611Ab3CTLkk (ORCPT ); Wed, 20 Mar 2013 07:40:40 -0400 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga102.ch.intel.com with ESMTP; 20 Mar 2013 04:40:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,877,1355126400"; d="scan'208";a="216885420" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by AZSMGA002.ch.intel.com with ESMTP; 20 Mar 2013 04:40:38 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v4 7/7] KVM: Use eoi to track RTC interrupt delivery status Date: Wed, 20 Mar 2013 19:36:19 +0800 Message-Id: <1363779379-20212-8-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1363779379-20212-1-git-send-email-yang.z.zhang@intel.com> References: <1363779379-20212-1-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 need_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 | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 69 insertions(+), 0 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 2b35123..2165f5a 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -180,6 +180,50 @@ static void rtc_irq_restore(struct kvm_ioapic *ioapic) } ioapic->rtc_status.need_eoi = need_eoi; } + +static void rtc_irq_set_eoi(struct kvm_ioapic *ioapic, int irq) +{ + union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq]; + + if (irq != 8) + return; + + if (likely(!bitmap_empty(ioapic->rtc_status.vcpu_map, KVM_MAX_VCPUS))) { + if (entry->fields.delivery_mode == APIC_DM_LOWEST) + ioapic->rtc_status.need_eoi = 1; + else { + int weight; + weight = bitmap_weight(ioapic->rtc_status.vcpu_map, + sizeof(ioapic->rtc_status.vcpu_map)); + ioapic->rtc_status.need_eoi = weight; + } + bitmap_copy(ioapic->rtc_status.expected_eoi_bitmap, + ioapic->rtc_status.vcpu_map, KVM_MAX_VCPUS); + } +} + +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->expected_eoi_bitmap)) + --rtc_status->need_eoi; + + WARN_ON(rtc_status->need_eoi < 0); +} + +static bool rtc_irq_check(struct kvm_ioapic *ioapic, int irq) +{ + if (irq != 8) + return false; + + if (ioapic->rtc_status.need_eoi > 0) + return true; /* coalesced */ + + return false; +} #else void kvm_vcpu_scan_ioapic(struct kvm *kvm) { @@ -195,6 +239,22 @@ static void rtc_irq_restore(struct kvm_ioapic *ioapic) { return; } + +static void rtc_irq_set_eoi(struct kvm_ioapic *ioapic, int irq) +{ + 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 void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) @@ -262,6 +322,8 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq) irqe.level = 1; irqe.shorthand = 0; + rtc_irq_set_eoi(ioapic, irq); + return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe); } @@ -286,6 +348,11 @@ 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)) @@ -293,6 +360,7 @@ 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); @@ -320,6 +388,7 @@ 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