From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] KVM: x86: Check KVM_REQ_IMMEDIATE_EXIT after enable_irq_window Date: Sun, 28 Apr 2013 11:29:51 +0300 Message-ID: <20130428082951.GD30504@redhat.com> References: <517CCE8E.6010805@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Marcelo Tosatti , kvm , "Nakajima, Jun" , "Ren, Yongjie" To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:53885 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751057Ab3D1I3z (ORCPT ); Sun, 28 Apr 2013 04:29:55 -0400 Content-Disposition: inline In-Reply-To: <517CCE8E.6010805@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On Sun, Apr 28, 2013 at 09:23:58AM +0200, Jan Kiszka wrote: > From: Jan Kiszka > > The VMX implementation of enable_irq_window will raise > KVM_REQ_IMMEDIATE_EXIT if an interrupt window shall be opened during > nested vmrun. We have to transfer this request into the local variable > to avoid looping over a continuously re-asserted request on vmentry. > > This issue only affects nested VMX scenarios. > > Signed-off-by: Jan Kiszka So KVM_REQ_IMMEDIATE_EXIT does not behave like request bit should. What about dropping it and letting enable_irq_window() return true if immediate exit is needed. > --- > arch/x86/kvm/x86.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 2a434bf..57ff14a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -5759,6 +5759,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) > kvm_x86_ops->enable_irq_window(vcpu); > > + req_immediate_exit = > + kvm_check_request(KVM_REQ_IMMEDIATE_EXIT, vcpu); > + The code will become: req_immediate_exit = kvm_x86_ops->enable_irq_window(vcpu); > if (kvm_lapic_enabled(vcpu)) { > /* > * Update architecture specific hints for APIC > -- > 1.7.3.4 -- Gleb.