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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 12396C64EB8 for ; Wed, 3 Oct 2018 14:41:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CBD3D2089F for ; Wed, 3 Oct 2018 14:41:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CBD3D2089F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727381AbeJCV3x (ORCPT ); Wed, 3 Oct 2018 17:29:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58474 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726748AbeJCV3x (ORCPT ); Wed, 3 Oct 2018 17:29:53 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id B1F053082A42; Wed, 3 Oct 2018 14:41:11 +0000 (UTC) Received: from [10.36.117.154] (ovpn-117-154.ams2.redhat.com [10.36.117.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ED0D54121; Wed, 3 Oct 2018 14:41:09 +0000 (UTC) Subject: Re: [PATCH] kvm: nVMX: fix entry with pending interrupt if APICv is enabled To: Nikita Leshenko , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Sean Christopherson , Liran Alon , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <1538567267-2343-1-git-send-email-pbonzini@redhat.com> <31248579054378dd2b820682c8ea99c9fb9b62cb.camel@oracle.com> From: Paolo Bonzini Openpgp: preference=signencrypt Autocrypt: addr=pbonzini@redhat.com; prefer-encrypt=mutual; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0f UGFvbG8gQm9uemluaSA8Ym9uemluaUBnbnUub3JnPsLBTQQTAQIAIwUCVEJ7AwIbAwcLCQgH AwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEH4VEAzNNmmxNcwOniaZVLsuy1lW/ntYCA0Caz0i sHpmecK8aWlvL9wpQCk4GlOX9L1emyYXZPmzIYB0IRqmSzAlZxi+A2qm9XOxs5gJ2xqMEXX5 FMtUH3kpkWWJeLqe7z0EoQdUI4EG988uv/tdZyqjUn2XJE+K01x7r3MkUSFz/HZKZiCvYuze VlS0NTYdUt5jBXualvAwNKfxEkrxeHjxgdFHjYWhjflahY7TNRmuqPM/Lx7wAuyoDjlYNE40 Z+Kun4/KjMbjgpcF4Nf3PJQR8qXI6p3so2qsSn91tY7DFSJO6v2HwFJkC2jU95wxfNmTEUZc znXahYbVOwCDJRuPrE5GKFd/XJU9u5hNtr/uYipHij01WXal2cce1S5mn1/HuM1yo1u8xdHy IupCd57EWI948e8BlhpujUCU2tzOb2iYS0kpmJ9/oLVZrOcSZCcCl2P0AaCAsj59z2kwQS9D du0WxUs8waso0Qq6tDEHo8yLCOJDzSz4oojTtWe4zsulVnWV+wu70AioemAT8S6JOtlu60C5 dHgQUD1Tp+ReXpDKXmjbASJx4otvW0qah3o6JaqO79tbDqIvncu3tewwp6c85uZd48JnIOh3 utBAu684nJakbbvZUGikJfxd887ATQRUQnHuAQgAx4dxXO6/Zun0eVYOnr5GRl76+2UrAAem Vv9Yfn2PbDIbxXqLff7oyVJIkw4WdhQIIvvtu5zH24iYjmdfbg8iWpP7NqxUQRUZJEWbx2CR wkMHtOmzQiQ2tSLjKh/cHeyFH68xjeLcinR7jXMrHQK+UCEw6jqi1oeZzGvfmxarUmS0uRuf fAb589AJW50kkQK9VD/9QC2FJISSUDnRC0PawGSZDXhmvITJMdD4TjYrePYhSY4uuIV02v02 8TVAaYbIhxvDY0hUQE4r8ZbGRLn52bEzaIPgl1p/adKfeOUeMReg/CkyzQpmyB1TSk8lDMxQ zCYHXAzwnGi8WU9iuE1P0wARAQABwsEzBBgBAgAJBQJUQnHuAhsMAAoJEH4VEAzNNmmxp1EO oJy0uZggJm7gZKeJ7iUpeX4eqUtqelUw6gU2daz2hE/jsxsTbC/w5piHmk1H1VWDKEM4bQBT uiJ0bfo55SWsUNN+c9hhIX+Y8LEe22izK3w7mRpvGcg+/ZRG4DEMHLP6JVsv5GMpoYwYOmHn plOzCXHvmdlW0i6SrMsBDl9rw4AtIa6bRwWLim1lQ6EM3PWifPrWSUPrPcw4OLSwFk0CPqC4 HYv/7ZnASVkR5EERFF3+6iaaVi5OgBd81F1TCvCX2BEyIDRZLJNvX3TOd5FEN+lIrl26xecz 876SvcOb5SL5SKg9/rCBufdPSjojkGFWGziHiFaYhbuI2E+NfWLJtd+ZvWAAV+O0d8vFFSvr iy9enJ8kxJwhC0ECbSKFY+W1eTIhMD3aeAKY90drozWEyHhENf4l/V+Ja5vOnW+gCDQkGt2Y 1lJAPPSIqZKvHzGShdh8DduC0U3xYkfbGAUvbxeepjgzp0uEnBXfPTy09JGpgWbg0w91GyfT /ujKaGd4vxG2Ei+MMNDmS1SMx7wu0evvQ5kT9NPzyq8R2GIhVSiAd2jioGuTjX6AZCFv3ToO 53DliFMkVTecLptsXaesuUHgL9dKIfvpm+rNXRn9wAwGjk0X/A== Message-ID: <2a649203-b4c1-7ad2-6e1f-ed73dd9dbd28@redhat.com> Date: Wed, 3 Oct 2018 16:41:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <31248579054378dd2b820682c8ea99c9fb9b62cb.camel@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 03 Oct 2018 14:41:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/10/2018 16:36, Nikita Leshenko wrote: > On Wed, 2018-10-03 at 13:47 +0200, Paolo Bonzini wrote: >> Commit b5861e5cf2fcf83031ea3e26b0a69d887adf7d21 introduced a check on >> the interrupt-window and NMI-window CPU execution controls in order to >> inject an external interrupt vmexit before the first guest instruction >> executes. However, when APIC virtualization is enabled the host does not >> need a vmexit in order to inject an interrupt at the next interrupt window; >> instead, it just places the interrupt vector in RVI and the processor will >> inject it as soon as possible. Therefore, on machines with APICv it is >> not enough to check the CPU execution controls: the same scenario can also >> happen if RVI>0. >> >> Fixes: b5861e5cf2fcf83031ea3e26b0a69d887adf7d21 >> Cc: Nikita Leshchenko >> Cc: Sean Christopherson >> Cc: Liran Alon >> Cc: Radim Krčmář >> Signed-off-by: Paolo Bonzini >> --- >> arch/x86/kvm/vmx.c | 16 +++++++++++----- >> 1 file changed, 11 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 6ef2d5b139b9..c0c7689f0049 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -10280,6 +10280,11 @@ static void vmx_hwapic_isr_update(struct kvm_vcpu *vcpu, int max_isr) >> } >> } >> >> +static u8 vmx_get_rvi(void) >> +{ >> + return vmcs_read16(GUEST_INTR_STATUS) & 0xff; >> +} >> + >> static void vmx_set_rvi(int vector) >> { >> u16 status; >> @@ -12593,10 +12598,13 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual) >> struct vmcs12 *vmcs12 = get_vmcs12(vcpu); >> bool from_vmentry = !!exit_qual; >> u32 dummy_exit_qual; >> - u32 vmcs01_cpu_exec_ctrl; >> + bool evaluate_pending_interrupts; >> int r = 0; >> >> - vmcs01_cpu_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); >> + evaluate_pending_interrupts = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) & >> + (CPU_BASED_VIRTUAL_INTR_PENDING | CPU_BASED_VIRTUAL_NMI_PENDING); >> + if (enable_apicv && kvm_vcpu_apicv_active(vcpu)) >> + evaluate_pending_interrupts |= vmx_get_rvi() > 0; > > You should check for RVI > VPPR, similarly to how it is done in > vmx_guest_apic_has_interrupt(). True, however that would only result in a spurious KVM_REQ_EVENT. Unlike vmx_guest_apic_has_interrupt, we would have to check the TPR shadow and SVI instead of the nested APIC page, so you'd have one more VMREAD---and little benefit in the common case. What do you think about adding a comment? > Also, now that you introduced vmx_get_rvi(), it could be nice to use it > in vmx_guest_apic_has_interrupt() as well. True that. Paolo > Apart from that, looks good. > > Reviewed-by: Nikita Leshenko > > Thanks, > Nikita > >> >> enter_guest_mode(vcpu); >> >> @@ -12650,10 +12658,8 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual) >> * instead. Thus, we force L0 to perform pending event >> * evaluation by requesting a KVM_REQ_EVENT. >> */ >> - if (vmcs01_cpu_exec_ctrl & >> - (CPU_BASED_VIRTUAL_INTR_PENDING | CPU_BASED_VIRTUAL_NMI_PENDING)) { >> + if (evaluate_pending_interrupts) >> kvm_make_request(KVM_REQ_EVENT, vcpu); >> - } >> >> /* >> * Note no nested_vmx_succeed or nested_vmx_fail here. At this point >