From patchwork Mon Mar 18 07:24:39 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: 2285791 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 11D92DF215 for ; Mon, 18 Mar 2013 07:29:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751811Ab3CRH32 (ORCPT ); Mon, 18 Mar 2013 03:29:28 -0400 Received: from mga01.intel.com ([192.55.52.88]:40927 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751608Ab3CRH3U (ORCPT ); Mon, 18 Mar 2013 03:29:20 -0400 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP; 18 Mar 2013 00:29:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,862,1355126400"; d="scan'208";a="304334899" Received: from yang-desktop.sh.intel.com ([10.239.47.153]) by fmsmga001.fm.intel.com with ESMTP; 18 Mar 2013 00:28:54 -0700 From: Yang Zhang To: kvm@vger.kernel.org Cc: gleb@redhat.com, mtosatti@redhat.com, xiantao.zhang@intel.com, Yang Zhang Subject: [PATCH v2 8/8] KVM: Use eoi to track RTC interrupt delivery status Date: Mon, 18 Mar 2013 15:24:39 +0800 Message-Id: <1363591479-4653-9-git-send-email-yang.z.zhang@intel.com> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: <1363591479-4653-1-git-send-email-yang.z.zhang@intel.com> References: <1363591479-4653-1-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 | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 67 insertions(+), 0 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 7e47da8..8d498e5 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -130,6 +130,48 @@ static void rtc_irq_get_dest_vcpu(struct kvm_ioapic *ioapic, int irq) kvm_get_dest_vcpu(ioapic->kvm, &irqe, ioapic->rtc_status.vcpu_map); } +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; + } + } +} + +static void rtc_irq_ack_eoi(struct kvm_vcpu *vcpu, + struct rtc_status *rtc_status, int irq) +{ + if (irq != 8) + return; + + if (test_bit(vcpu->vcpu_id, rtc_status->vcpu_map)) + --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 static void rtc_irq_reset(struct kvm_ioapic *ioapic) @@ -146,6 +188,22 @@ static void rtc_irq_get_dest_vcpu(struct kvm_ioapic *ioapic, int irq) { 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 int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx) @@ -282,6 +340,8 @@ 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); } @@ -306,6 +366,11 @@ 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)) @@ -313,6 +378,7 @@ 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); @@ -340,6 +406,7 @@ 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