From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] KVM: nVMX: Rework event injection and recovery Date: Wed, 20 Feb 2013 17:57:50 +0200 Message-ID: <20130220155750.GQ3600@redhat.com> References: <5124C93B.50902@siemens.com> <5124E381.90008@siemens.com> <20130220153057.GP3600@redhat.com> <5124F10B.4050800@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Marcelo Tosatti , kvm , "Nadav Har'El" , "Nakajima, Jun" To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:54313 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934180Ab3BTP56 (ORCPT ); Wed, 20 Feb 2013 10:57:58 -0500 Content-Disposition: inline In-Reply-To: <5124F10B.4050800@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Feb 20, 2013 at 04:51:39PM +0100, Jan Kiszka wrote: > On 2013-02-20 16:30, Gleb Natapov wrote: > > On Wed, Feb 20, 2013 at 03:53:53PM +0100, Jan Kiszka wrote: > >> On 2013-02-20 14:01, Jan Kiszka wrote: > >>> This aligns VMX more with SVM regarding event injection and recovery for > >>> nested guests. The changes allow to inject interrupts directly from L0 > >>> to L2. > >>> > >>> One difference to SVM is that we always transfer the pending event > >>> injection into the architectural state of the VCPU and then drop it from > >>> there if it turns out that we left L2 to enter L1. > >>> > >>> VMX and SVM are now identical in how they recover event injections from > >>> unperformed vmlaunch/vmresume: We detect that VM_ENTRY_INTR_INFO_FIELD > >>> still contains a valid event and, if yes, transfer the content into L1's > >>> idt_vectoring_info_field. > >>> > >>> To avoid that we incorrectly leak an event into the architectural VCPU > >>> state that L1 wants to inject, we skip cancellation on nested run. > >>> > >>> Signed-off-by: Jan Kiszka > >>> --- > >>> > >>> Survived moderate testing here and (currently) makes sense to me, but > >>> please review very carefully. I wouldn't be surprised if I'm still > >>> missing some subtle corner case. > >> > >> Forgot to point this out again: It still takes "KVM: nVMX: Fix injection > >> of PENDING_INTERRUPT and NMI_WINDOW exits to L1" to make L0->L2 > >> injection work. So this patch logically depends on it. > >> > > But this patch has hunks from that patch. > > Not mechanically. > What do you mean? > If you prefer me merging them together, let me know. > For review not necessary, for applying preferably. -- Gleb.