From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754152AbbIBWih (ORCPT ); Wed, 2 Sep 2015 18:38:37 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:33630 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752579AbbIBWif (ORCPT ); Wed, 2 Sep 2015 18:38:35 -0400 Date: Wed, 2 Sep 2015 15:38:21 -0700 From: Steve Rutherford To: Paolo Bonzini Cc: "Zhang, Yang Z" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "alex.williamson@redhat.com" , "srutherford@intel.com" , "Gudimetla, Giridhar Kumar" , "Nakajima, Jun" Subject: Re: [PATCH 1/2] KVM: x86: set TMR when the interrupt is accepted Message-ID: <20150902223821.GA1464@google.com> References: <55BB2B62.1030605@redhat.com> <55BF21E1.5030100@redhat.com> <55BF48A4.5030409@redhat.com> <55C062EC.20006@redhat.com> <55CC47E4.5090200@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55CC47E4.5090200@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 13, 2015 at 09:31:48AM +0200, Paolo Bonzini wrote: Pinging this thread. Should I put together a patch to make split irqchip work properly with the old TMR behavior? > > > On 13/08/2015 08:35, Zhang, Yang Z wrote: > >> You may be right. It is safe if no future hardware plans to use > >> it. Let me check with our hardware team to see whether it will be > >> used or not in future. > > > > After checking with Jun, there is no guarantee that the guest running > > on another CPU will operate properly if hypervisor modify the vTMR > > from another CPU. So the hypervisor should not to do it. > > I guess I can cause a vmexit on level-triggered interrupts, it's not a > big deal, but no weasel words, please. > > What's going to break, and where is it documented? > > Paolo > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html