From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: nVMX: Shadowing of CPU_BASED_VM_EXEC_CONTROL broken Date: Wed, 08 Oct 2014 12:29:18 +0200 Message-ID: <543511FE.3060108@siemens.com> References: <5434F5F9.3030803@siemens.com> <20141008092539.GA16561@kernel> <5435092A.3090704@siemens.com> <54350FD4.10403@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: kvm , Bandan Das To: Paolo Bonzini , Wanpeng Li Return-path: Received: from david.siemens.de ([192.35.17.14]:57406 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755052AbaJHK33 (ORCPT ); Wed, 8 Oct 2014 06:29:29 -0400 In-Reply-To: <54350FD4.10403@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2014-10-08 12:20, Paolo Bonzini wrote: > Il 08/10/2014 11:51, Jan Kiszka ha scritto: >>>> Could you point out where the other places L0 sets >>>> CPU_BASED_VIRTUAL_INTR_PENDING before entering L2? >> enable_irq_window(). I instrumented it, and it showed up right before >> vmcs12 state became corrupted. > > But it would write to the vmcs02, not to the shadow VMCS; the shadow > VMCS is active during copy_shadow_to_vmcs12/copy_vmcs12_to_shadow, and > at no other time. It is not clear to me how the VIRTUAL_INTR_PENDING > bit ended up from the vmcs02 (where it is perfectly fine) to the vmcs12. Well, but somehow that bit ends up in vmcs12, that's a fact. Also that the proble disappears when shadowing is disabled. Need to think about the path again. Maybe there is just a bug, not a conceptual issue. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux