From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935481AbeBMOil (ORCPT ); Tue, 13 Feb 2018 09:38:41 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48114 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935246AbeBMOik (ORCPT ); Tue, 13 Feb 2018 09:38:40 -0500 Subject: Re: [PATCH v3] 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: <1518314790-31774-1-git-send-email-chao.gao@intel.com> From: Paolo Bonzini Message-ID: <6164ecd6-cf6e-dfc9-812a-b99706468f8b@redhat.com> Date: Tue, 13 Feb 2018 15:38:35 +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: <1518314790-31774-1-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 11/02/2018 03:06, 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 according to SDM 26.6.2 Activity > State. 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. > > Cc: Liran Alon > Signed-off-by: Chao Gao > --- > changes in v3: > - s/VECTORING_INFO_VALID_MASK/INTR_INFO_VALID_MASK > - Changes of subject, comments. > > Changes in v2: > - Remove VID stuff. Only handle event injection in this patch. > > Signed-off-by: Chao Gao > --- > arch/x86/kvm/vmx.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index bb5b488..cf7c2fc 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -10985,7 +10985,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) > if (ret) > return ret; > > - if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) > + /* > + * If we're entering a halted L2 vcpu and the L2 vcpu won't be woken > + * by event injection, halt vcpu. > + */ > + if ((vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) && > + !(vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK)) > return kvm_vcpu_halt(vcpu); > > vmx->nested.nested_run_pending = 1; > Queued, thanks (haven't yet tried the new test). Paolo