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 2ACFFC433EF for ; Thu, 11 Nov 2021 13:24:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09B7861213 for ; Thu, 11 Nov 2021 13:24:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233414AbhKKN1c (ORCPT ); Thu, 11 Nov 2021 08:27:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49230 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233389AbhKKN1b (ORCPT ); Thu, 11 Nov 2021 08:27:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636637082; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n3WqyrBq2uTJR8bpD8MKc2sLqvPUK4BN0YHRdeMyR0k=; b=hJX6mF9TFKumWbxSQJ12XSCPEUmwY0qJcjoaWtaFPnpF14kfVTxIp3MO35kHlBmFWtzTmo +h3dazAcJo61vDrGothQWe8We8Z6r7YVcR0+1kABR9JfnE49ygBwr9IOAzrVIZqOrVg8h5 yHt/4Pp6jEQW+wiIptM/yhDouVqAxjk= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-264-8yj53UKwOSyHuPpjqmlSoA-1; Thu, 11 Nov 2021 08:24:39 -0500 X-MC-Unique: 8yj53UKwOSyHuPpjqmlSoA-1 Received: by mail-ed1-f70.google.com with SMTP id x13-20020a05640226cd00b003e2bf805a02so5347218edd.23 for ; Thu, 11 Nov 2021 05:24:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=n3WqyrBq2uTJR8bpD8MKc2sLqvPUK4BN0YHRdeMyR0k=; b=1bK6v/oLGoNX8mtRXfJnPqqVRZXuJQsjHCdFuCpwS3wHLxrhIHXFxj/PH2K4/dXnUs Hw8Qk9bS8tLRoLhaO3efrOUqITvY6E87cNwMcHp0fIJpHX4wbaLxYcarYBwxG7ou3JIg k6vSjmy6xM8pXLFcx54CHzmv0LY/QogIgPFe95yK6BUBYzUuw3ykjUl7/N+b+mtH+wjX XLMWDiiC9NRnQzbFoO6pRo72QdrIew19uD98z4yVZrU/+VxBSU1EDtydIUbp9ia1sLJY jkeFziiUT98ohAz+DVJIRkuUOk5haatqIdskmlCSf21w1cUrTfci1KCS2LJgB+q06z1d xk9w== X-Gm-Message-State: AOAM530T6Lj7J8kEAoRQbTNZTMArwYtqtpCUeTwP0Ws6T0afcT8H+bUm AMjUQCj/HEc5qxae/54J73jD3jRZKNu8IJ0MKOWBbyAMMnzlc27OmWywwTA72CGVB0lTRWSbU+A IElM32T1hQPR2YmrkkMGSStEO X-Received: by 2002:a17:907:1c1f:: with SMTP id nc31mr9435975ejc.210.1636637077975; Thu, 11 Nov 2021 05:24:37 -0800 (PST) X-Google-Smtp-Source: ABdhPJz4Rc9RSHfyPuquSvW65YFg3YPh5YwwspZVNv/qX0D7M932u2rP7K0HG2NJ0phRnS7ZSu7eHg== X-Received: by 2002:a17:907:1c1f:: with SMTP id nc31mr9435941ejc.210.1636637077764; Thu, 11 Nov 2021 05:24:37 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:63a7:c72e:ea0e:6045? ([2001:b07:6468:f312:63a7:c72e:ea0e:6045]) by smtp.gmail.com with ESMTPSA id em21sm1342487ejc.103.2021.11.11.05.24.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Nov 2021 05:24:37 -0800 (PST) Message-ID: <511ea6df-ae7e-dbbb-8b11-95d6f440ddb3@redhat.com> Date: Thu, 11 Nov 2021 14:24:34 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v4] KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active Content-Language: en-US To: Maxim Levitsky , kvm@vger.kernel.org Cc: "H. Peter Anvin" , Jim Mattson , Joerg Roedel , Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Borislav Petkov References: <20211108090245.166408-1-mlevitsk@redhat.com> From: Paolo Bonzini In-Reply-To: <20211108090245.166408-1-mlevitsk@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/8/21 10:02, Maxim Levitsky wrote: > 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: > Queued, thanks. Paolo