From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753350AbeBJAbn (ORCPT ); Fri, 9 Feb 2018 19:31:43 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:47786 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbeBJAbl (ORCPT ); Fri, 9 Feb 2018 19:31:41 -0500 MIME-Version: 1.0 Message-ID: <806c274d-5d9a-432a-bf04-f154be89cb7f@default> Date: Fri, 9 Feb 2018 16:31:22 -0800 (PST) From: Liran Alon To: Cc: , , , , , , , Subject: Re: [PATCH v2] x86/kvm/vmx: Don't halt vcpu when L1 is injecting events to L2 X-Mailer: Zimbra on Oracle Beehive Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8800 signatures=668666 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802100003 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w1A0VrSS028207 ----- chao.gao@intel.com 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 v2: > - Remove VID stuff. Only handle event injection in this patch. > --- > 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..42f39d9 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 for optimization. I would remove the "for optimization." from the comment. > + */ > + if ((vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) && > + !(vmcs12->vm_entry_intr_info_field & > VECTORING_INFO_VALID_MASK)) VECTORING_INFO_VALID_MASK is used in KVM code against vmcs12->idt_vectoring_info_field. I think you should use INTR_INFO_VALID_MASK to be consistent with rest of code. > return kvm_vcpu_halt(vcpu); > > vmx->nested.nested_run_pending = 1; > -- > 1.9.1 In addition, commit title should be written in format of: "KVM: VMX: Don't halt vcpu when L1 is injecting events to L2" (Makes it easier to grep in git log). Other than that, seems good to me. :) Reviewed-by: Liran Alon Thanks, -Liran