From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: nVMX: Rework event injection and recovery Date: Wed, 20 Feb 2013 16:51:39 +0100 Message-ID: <5124F10B.4050800@siemens.com> References: <5124C93B.50902@siemens.com> <5124E381.90008@siemens.com> <20130220153057.GP3600@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm , "Nadav Har'El" , "Nakajima, Jun" To: Gleb Natapov Return-path: Received: from goliath.siemens.de ([192.35.17.28]:28838 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935396Ab3BTPvu (ORCPT ); Wed, 20 Feb 2013 10:51:50 -0500 In-Reply-To: <20130220153057.GP3600@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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. If you prefer me merging them together, let me know. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux