From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751984AbeBHKaE (ORCPT ); Thu, 8 Feb 2018 05:30:04 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57272 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751014AbeBHKaD (ORCPT ); Thu, 8 Feb 2018 05:30:03 -0500 Subject: Re: [PATCH] x86/kvm/vmx: Don't halt vcpu when L1 is injecting events to L2 To: Chao Gao , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Liran Alon References: <1518066816-7197-1-git-send-email-chao.gao@intel.com> From: Paolo Bonzini Message-ID: <7de4e758-08cc-2c45-b0aa-dfe28dfef398@redhat.com> Date: Thu, 8 Feb 2018 11:29:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <1518066816-7197-1-git-send-email-chao.gao@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/02/2018 06:13, Chao Gao wrote: > Although L2 is in halt state, it will be in the active state after > VM entry if the VM entry is vectoring. Halting the vcpu here means > the event won't be injected to L2 and this decision isn't reported > to L1. Thus L0 drops an event that should be injected to L2. > > Because virtual interrupt delivery may wake L2 vcpu, if VID is enabled, > do the same thing -- don't halt L2. This second part seems wrong to me, or at least overly general. Perhaps you mean if RVI>0? Thanks, Paolo > Signed-off-by: Chao Gao > --- > arch/x86/kvm/vmx.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index bb5b488..e1fe4e4 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -10985,8 +10985,14 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) > if (ret) > return ret; > > - if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) > - return kvm_vcpu_halt(vcpu); > + if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) { > + u32 intr_info = vmcs_read32(VM_ENTRY_INTR_INFO_FIELD); > + u32 exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); > + > + if (!(intr_info & VECTORING_INFO_VALID_MASK) && > + !(exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY)) > + return kvm_vcpu_halt(vcpu); > + } > vmx->nested.nested_run_pending = 1; > >