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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEF39C433F5 for ; Mon, 8 Nov 2021 09:03:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E89360FC1 for ; Mon, 8 Nov 2021 09:03:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238284AbhKHJFr (ORCPT ); Mon, 8 Nov 2021 04:05:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:38405 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235592AbhKHJFq (ORCPT ); Mon, 8 Nov 2021 04:05:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636362181; 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; bh=DIt0yiHFSDrbNWT83YFxJ3NTN2gTGuSvPTfTKTC9zLQ=; b=jEIfJuicpMuCEa5wkbsh2Wv+iUm6dg9H5cAes+l7IDd7AAxQqzNMivNMzoyBexAjcZI4lK Y3ww/zQaIed31IyXeZr0yE8DPD3a9i3DqJHBtZNqkNWygT1nWMdGHoY8I7XxjsR4tsY6mf ZSsAmZGOY0MqL0bfhPPmmXrZA5FNKTY= 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-197-uL-OogzLMC6KIedenxW0BA-1; Mon, 08 Nov 2021 04:02:56 -0500 X-MC-Unique: uL-OogzLMC6KIedenxW0BA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3BBCE1572B; Mon, 8 Nov 2021 09:02:54 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.194.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id AB71519C79; Mon, 8 Nov 2021 09:02:46 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: "H. Peter Anvin" , Jim Mattson , Paolo Bonzini , Joerg Roedel , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Maxim Levitsky , Borislav Petkov Subject: [PATCH v4] KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active Date: Mon, 8 Nov 2021 11:02:45 +0200 Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using standard kvm's inject_pending_event, and not via APICv/AVIC. Since this is a debug feature, just inhibit APICv/AVIC while KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU. Fixes: 61e5f69ef0837 ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ") Reported-by: Vitaly Kuznetsov Signed-off-by: Maxim Levitsky Reviewed-and-tested-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/avic.c | 3 ++- arch/x86/kvm/vmx/vmx.c | 3 ++- arch/x86/kvm/x86.c | 20 ++++++++++++++++++++ 4 files changed, 25 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 88fce6ab4bbd7..8f6e15b95a4d8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1034,6 +1034,7 @@ struct kvm_x86_msr_filter { #define APICV_INHIBIT_REASON_IRQWIN 3 #define APICV_INHIBIT_REASON_PIT_REINJ 4 #define APICV_INHIBIT_REASON_X2APIC 5 +#define APICV_INHIBIT_REASON_BLOCKIRQ 6 struct kvm_arch { unsigned long n_used_mmu_pages; diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 8052d92069e01..affc0ea98d302 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -904,7 +904,8 @@ bool svm_check_apicv_inhibit_reasons(ulong bit) BIT(APICV_INHIBIT_REASON_NESTED) | BIT(APICV_INHIBIT_REASON_IRQWIN) | BIT(APICV_INHIBIT_REASON_PIT_REINJ) | - BIT(APICV_INHIBIT_REASON_X2APIC); + BIT(APICV_INHIBIT_REASON_X2APIC) | + BIT(APICV_INHIBIT_REASON_BLOCKIRQ); return supported & BIT(bit); } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 71f54d85f104c..e4fc9ff7cd944 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7565,7 +7565,8 @@ static void hardware_unsetup(void) static bool vmx_check_apicv_inhibit_reasons(ulong bit) { ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) | - BIT(APICV_INHIBIT_REASON_HYPERV); + BIT(APICV_INHIBIT_REASON_HYPERV) | + BIT(APICV_INHIBIT_REASON_BLOCKIRQ); return supported & BIT(bit); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ac83d873d65b0..6064ac47c8a37 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10703,6 +10703,24 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, return ret; } +static void kvm_arch_vcpu_guestdbg_update_apicv_inhibit(struct kvm *kvm) +{ + bool inhibit = false; + struct kvm_vcpu *vcpu; + int i; + + down_write(&kvm->arch.apicv_update_lock); + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (vcpu->guest_debug & KVM_GUESTDBG_BLOCKIRQ) { + inhibit = true; + break; + } + } + __kvm_request_apicv_update(kvm, !inhibit, APICV_INHIBIT_REASON_BLOCKIRQ); + up_write(&kvm->arch.apicv_update_lock); +} + int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) { @@ -10755,6 +10773,8 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, static_call(kvm_x86_update_exception_bitmap)(vcpu); + kvm_arch_vcpu_guestdbg_update_apicv_inhibit(vcpu->kvm); + r = 0; out: -- 2.26.3