From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC373C11F66 for ; Tue, 13 Jul 2021 14:21:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9589260230 for ; Tue, 13 Jul 2021 14:21:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236920AbhGMOYA (ORCPT ); Tue, 13 Jul 2021 10:24:00 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53470 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236917AbhGMOXz (ORCPT ); Tue, 13 Jul 2021 10:23:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626186065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NizuknTonLPtfV10+PDZQabcKPTYBFw/w+7o4Dzz+h4=; b=E3igu3a9H/wTnVD6gCLU3EFpCe2y5GE4zVZo24PO1CboizOB6HrelS3QPs4JOe2e02OmZc lR8mJjqSw5iUpxDCap+/BPSnai7XQ/RhcUn4wgx7WWtDisCgRiSt3NEy/F+31C/o5lHDmm TjDSEhzmsWPOPBo1K97/GXesVbGMSts= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-391-g7sPQ8PxNc2RUF4p3PzceA-1; Tue, 13 Jul 2021 10:21:04 -0400 X-MC-Unique: g7sPQ8PxNc2RUF4p3PzceA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5788291FCC0; Tue, 13 Jul 2021 14:21:02 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.192.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3F16B6267C; Tue, 13 Jul 2021 14:20:58 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Jim Mattson , Joerg Roedel , Borislav Petkov , Vitaly Kuznetsov , Wanpeng Li , Paolo Bonzini , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Sean Christopherson , Maxim Levitsky Subject: [PATCH v2 7/8] KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC Date: Tue, 13 Jul 2021 17:20:22 +0300 Message-Id: <20210713142023.106183-8-mlevitsk@redhat.com> In-Reply-To: <20210713142023.106183-1-mlevitsk@redhat.com> References: <20210713142023.106183-1-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently it is possible to have the following scenario: 1. AVIC is disabled by svm_refresh_apicv_exec_ctrl 2. svm_vcpu_blocking calls avic_vcpu_put which does nothing 3. svm_vcpu_unblocking enables the AVIC (due to KVM_REQ_APICV_UPDATE) and then calls avic_vcpu_load 4. warning is triggered in avic_vcpu_load since AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK was never cleared While it is possible to just remove the warning, it seems to be more robust to fully disable/enable AVIC in svm_refresh_apicv_exec_ctrl by calling the avic_vcpu_load/avic_vcpu_put Signed-off-by: Maxim Levitsky --- arch/x86/kvm/svm/avic.c | 43 ++++++++++++++++++++++------------------- arch/x86/kvm/svm/svm.c | 8 ++++++-- arch/x86/kvm/x86.c | 10 ++++++++-- 3 files changed, 37 insertions(+), 24 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 64d1e1b6a305..0e4370fe0868 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -80,6 +80,28 @@ enum avic_ipi_failure_cause { AVIC_IPI_FAILURE_INVALID_BACKING_PAGE, }; + +static void __avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +{ + if (is_run) + avic_vcpu_load(vcpu, vcpu->cpu); + else + avic_vcpu_put(vcpu); +} + +/* + * This function is called during VCPU halt/unhalt. + */ +static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + svm->avic_is_running = is_run; + + if (kvm_vcpu_apicv_active(vcpu)) + __avic_set_running(vcpu, is_run); +} + /* Note: * This function is called from IOMMU driver to notify * SVM to schedule in a particular vCPU of a particular VM. @@ -667,6 +689,7 @@ void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) } vmcb_mark_dirty(vmcb, VMCB_AVIC); + __avic_set_running(vcpu, activated); svm_set_pi_irte_mode(vcpu, activated); } @@ -960,9 +983,6 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) int h_physical_id = kvm_cpu_get_apicid(cpu); struct vcpu_svm *svm = to_svm(vcpu); - if (!kvm_vcpu_apicv_active(vcpu)) - return; - /* * Since the host physical APIC id is 8 bits, * we can support host APIC ID upto 255. @@ -990,9 +1010,6 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu) u64 entry; struct vcpu_svm *svm = to_svm(vcpu); - if (!kvm_vcpu_apicv_active(vcpu)) - return; - entry = READ_ONCE(*(svm->avic_physical_id_cache)); if (entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK) avic_update_iommu_vcpu_affinity(vcpu, -1, 0); @@ -1001,20 +1018,6 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu) WRITE_ONCE(*(svm->avic_physical_id_cache), entry); } -/* - * This function is called during VCPU halt/unhalt. - */ -static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) -{ - struct vcpu_svm *svm = to_svm(vcpu); - - svm->avic_is_running = is_run; - if (is_run) - avic_vcpu_load(vcpu, vcpu->cpu); - else - avic_vcpu_put(vcpu); -} - void svm_vcpu_blocking(struct kvm_vcpu *vcpu) { avic_set_running(vcpu, false); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index d14be8aba2d7..2c291dfa0e04 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1505,12 +1505,16 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) sd->current_vmcb = svm->vmcb; indirect_branch_prediction_barrier(); } - avic_vcpu_load(vcpu, cpu); + + if (kvm_vcpu_apicv_active(vcpu)) + avic_vcpu_load(vcpu, cpu); } static void svm_vcpu_put(struct kvm_vcpu *vcpu) { - avic_vcpu_put(vcpu); + if (kvm_vcpu_apicv_active(vcpu)) + avic_vcpu_put(vcpu); + svm_prepare_host_switch(vcpu); ++vcpu->stat.host_state_reload; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a91e35b92447..213d332664e2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9177,12 +9177,18 @@ void kvm_make_scan_ioapic_request(struct kvm *kvm) void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) { + bool activate; + if (!lapic_in_kernel(vcpu)) return; mutex_lock(&vcpu->kvm->apicv_update_lock); - vcpu->arch.apicv_active = kvm_apicv_activated(vcpu->kvm); + activate = kvm_apicv_activated(vcpu->kvm); + if (vcpu->arch.apicv_active == activate) + goto out; + + vcpu->arch.apicv_active = activate; kvm_apic_update_apicv(vcpu); static_call(kvm_x86_refresh_apicv_exec_ctrl)(vcpu); @@ -9194,7 +9200,7 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) */ if (!vcpu->arch.apicv_active) kvm_make_request(KVM_REQ_EVENT, vcpu); - +out: mutex_unlock(&vcpu->kvm->apicv_update_lock); } EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv); -- 2.26.3