From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: Nested paging in nested SVM setup Date: Wed, 20 Aug 2014 08:55:01 +0200 Message-ID: <53F44645.2000708@redhat.com> References: <53A179C4.9060203@gmail.com> <53A18A6D.2050407@siemens.com> <53F44440.6070408@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: Valentine Sinitsyn , Jan Kiszka , kvm@vger.kernel.org Return-path: Received: from mail-wi0-f173.google.com ([209.85.212.173]:61567 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbaHTGzF (ORCPT ); Wed, 20 Aug 2014 02:55:05 -0400 Received: by mail-wi0-f173.google.com with SMTP id f8so6546920wiw.12 for ; Tue, 19 Aug 2014 23:55:04 -0700 (PDT) In-Reply-To: <53F44440.6070408@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 20/08/2014 08:46, Valentine Sinitsyn ha scritto: > > You can see the problem here: the code tries to access APIC MMIO > register, which is trapped by KVM's MMU code (at nested page table > walk). During MMIO access emulation, KVM decides to inject 0x23c > exception (which looks wrong, as there is no exception with this number > defined). After that things become flawed (pay attention to empty reason > in the last line; the VMCB is certainly not in the state KVM > expects/supports). > > I'm no KVM expert, and will be grateful for debugging suggestions (or > maybe even assistance). Is the 0x23c always the same? Can you try this patch? diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 204422de3fed..194e9300a31b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -346,6 +346,7 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu, kvm_make_request(KVM_REQ_EVENT, vcpu); + WARN_ON(nr > 0x1f); if (!vcpu->arch.exception.pending) { queue: vcpu->arch.exception.pending = true; Paolo