From patchwork Thu Jul 30 06:21:41 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Rutherford X-Patchwork-Id: 6898731 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0AE88C05AD for ; Thu, 30 Jul 2015 06:22:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 01DEF2047D for ; Thu, 30 Jul 2015 06:22:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3F0B2045A for ; Thu, 30 Jul 2015 06:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751153AbbG3GWB (ORCPT ); Thu, 30 Jul 2015 02:22:01 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:35069 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750879AbbG3GWA (ORCPT ); Thu, 30 Jul 2015 02:22:00 -0400 Received: by pdrg1 with SMTP id g1so18955902pdr.2 for ; Wed, 29 Jul 2015 23:22:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:subject:date:message-id:in-reply-to:references; bh=N8LerMK5nkG5LMOT6W9L6sqp+G7twXXUp8dwYIytrYM=; b=U1BKw5A5l0JTI+MJLXsLMLNcg0APnMUA30RwPOj6iLJQHnD5qRcNgwaGk7MTz45qQT 1l66e337U2GmbypneQmy4Mk+4TS27GV3j8qVUP73RmTCSW/oTsVV8bqUSlEfkmvG1Gz8 Sqzu2J0evTlBDKJZgkc6Z440Wp0CmRGg9PTTzrV+O6vKP8BOAqAES7d2qT647sDOiQuV abVLfq6rGBMUu7bdHDGhl/rUFvA2/6n+ms6ztSy1RdQMGrW5u6tXrG6PS6vC9bnuqt4I R9xxCM0SPHUgx3gh0V1xq9YLerNTV9TvQlJEjQZvokF+ry7+DhIFRAXNTh7G8BDb3GV9 +P0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=N8LerMK5nkG5LMOT6W9L6sqp+G7twXXUp8dwYIytrYM=; b=MC2w9SNxKnzwnFG9tE4n9ovdN5zwYKp4K7uvgKsBN/3QlZ8GEpiKNDhAFbcev/LnZg QazuMbCVTyCkSfsRluSXlNloNW39atXCaop4S/+N7cEIEcDk12eD7hSKE2pvyjY2bFVA p+w2qCLGVaQdvJiQck2xQQcTnVELLTakLDllbZ7nT1meEolkkWRu/17I0qsbyNEz35n9 kWch2DJcnM+UrgH/MkLmCblqU/At4/P5ytO2qo4rb0HZPca74pvBNANEbghi8jJL2laJ tvMaWj9zVo0dQvHEFRAs6p3YKJ0+jIJ/hvnD2KDdbQNKU/t2vvDRD1mZAAhjBs5OIfl6 hkbA== X-Gm-Message-State: ALoCoQmbb+E1DOBT3YN+zKRACs86DhgcEj37jt46J8DbMAXX/oK3tHu+gk4VdcdTmBclfzetTBiH X-Received: by 10.70.63.37 with SMTP id d5mr103739347pds.162.1438237319896; Wed, 29 Jul 2015 23:21:59 -0700 (PDT) Received: from entropic.kir.corp.google.com ([172.31.8.128]) by smtp.gmail.com with ESMTPSA id qb10sm10099467pab.39.2015.07.29.23.21.58 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 29 Jul 2015 23:21:59 -0700 (PDT) From: Steve Rutherford To: kvm@vger.kernel.org Subject: [PATCH v7 2/4] KVM: x86: Add KVM exit for IOAPIC EOIs Date: Wed, 29 Jul 2015 23:21:41 -0700 Message-Id: <1438237303-19124-2-git-send-email-srutherford@google.com> X-Mailer: git-send-email 2.5.0.rc2.392.g76e840b In-Reply-To: <1438237303-19124-1-git-send-email-srutherford@google.com> References: <1438237303-19124-1-git-send-email-srutherford@google.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-8.2 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI level-triggered IOAPIC interrupts. Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs to be informed (which is identical to the EOI_EXIT_BITMAP field used by modern x86 processors, but can also be used to elide kvm IOAPIC EOI exits on older processors). [Note: A prototype using ResampleFDs found that decoupling the EOI from the VCPU's thread made it possible for the VCPU to not see a recent EOI after reentering the guest. This does not match real hardware.] Compile tested for Intel x86. Signed-off-by: Steve Rutherford --- Documentation/virtual/kvm/api.txt | 12 ++++++++++++ arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/lapic.c | 24 +++++++++++++++++------- arch/x86/kvm/x86.c | 11 +++++++++++ include/linux/kvm_host.h | 2 +- include/uapi/linux/kvm.h | 5 +++++ 6 files changed, 48 insertions(+), 8 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index b655024..78d0ae8 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3302,6 +3302,18 @@ Valid values for 'type' are: to ignore the request, or to gather VM memory core dump and/or reset/shutdown of the VM. + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; + +Indicates that the VCPU's in-kernel local APIC received an EOI for a +level-triggered IOAPIC interrupt. This exit only triggers when the +IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); +the userspace IOAPIC should process the EOI and retrigger the interrupt if +it is still asserted. Vector is the LAPIC interrupt vector for which the +EOI was received. + /* Fix the size of the union. */ char padding[256]; }; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b4fdf0c..b27f54d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -561,6 +561,8 @@ struct kvm_vcpu_arch { struct { bool pv_unhalted; } pv; + + int pending_ioapic_eoi; }; struct kvm_lpage_info { diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2f486d8..9e69296a 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -877,15 +877,25 @@ static bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector) static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) { - if (kvm_ioapic_handles_vector(apic, vector)) { - int trigger_mode; - if (apic_test_vector(vector, apic->regs + APIC_TMR)) - trigger_mode = IOAPIC_LEVEL_TRIG; - else - trigger_mode = IOAPIC_EDGE_TRIG; + int trigger_mode; + + /* Eoi the ioapic only if the ioapic doesn't own the vector. */ + if (!kvm_ioapic_handles_vector(apic, vector)) + return; - kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode); + /* Request a KVM exit to inform the userspace IOAPIC. */ + if (irqchip_split(apic->vcpu->kvm)) { + apic->vcpu->arch.pending_ioapic_eoi = vector; + kvm_make_request(KVM_REQ_IOAPIC_EOI_EXIT, apic->vcpu); + return; } + + if (apic_test_vector(vector, apic->regs + APIC_TMR)) + trigger_mode = IOAPIC_LEVEL_TRIG; + else + trigger_mode = IOAPIC_EDGE_TRIG; + + kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode); } static int apic_set_eoi(struct kvm_lapic *apic) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8e40ddf..4159f29 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6268,6 +6268,17 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_pmu_handle_event(vcpu); if (kvm_check_request(KVM_REQ_PMI, vcpu)) kvm_pmu_deliver_pmi(vcpu); + if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) { + BUG_ON(vcpu->arch.pending_ioapic_eoi > 255); + if (test_bit(vcpu->arch.pending_ioapic_eoi, + (void *) vcpu->arch.eoi_exit_bitmap)) { + vcpu->run->exit_reason = KVM_EXIT_IOAPIC_EOI; + vcpu->run->eoi.vector = + vcpu->arch.pending_ioapic_eoi; + r = 0; + goto out; + } + } if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu)) vcpu_scan_ioapic(vcpu); if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 1867b83..253717c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -140,6 +140,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_APIC_PAGE_RELOAD 25 #define KVM_REQ_SMI 26 #define KVM_REQ_HV_CRASH 27 +#define KVM_REQ_IOAPIC_EOI_EXIT 28 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1 @@ -1161,4 +1162,3 @@ static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val) } #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */ #endif - diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index e4304d0..c15f5d9 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -183,6 +183,7 @@ struct kvm_s390_skeys { #define KVM_EXIT_EPR 23 #define KVM_EXIT_SYSTEM_EVENT 24 #define KVM_EXIT_S390_STSI 25 +#define KVM_EXIT_IOAPIC_EOI 26 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -330,6 +331,10 @@ struct kvm_run { __u8 sel1; __u16 sel2; } s390_stsi; + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; /* Fix the size of the union. */ char padding[256]; };