From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [PATCH] KVM: x86: Convert INIT and SIPI signals into
 synchronously handled events
Date: Tue, 12 Mar 2013 15:25:17 +0200
Message-ID: <20130312132517.GC11223@redhat.com>
References: <513F1529.3040309@siemens.com>
 <513F1A63.9070107@redhat.com>
 <513F2688.2080902@siemens.com>
 <513F273F.5020108@siemens.com>
 <513F2A11.7030904@redhat.com>
 <513F2AAD.4050008@siemens.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	kvm <kvm@vger.kernel.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:20170 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751749Ab3CLNZV (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 12 Mar 2013 09:25:21 -0400
Content-Disposition: inline
In-Reply-To: <513F2AAD.4050008@siemens.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Tue, Mar 12, 2013 at 02:16:29PM +0100, Jan Kiszka wrote:
> On 2013-03-12 14:13, Paolo Bonzini wrote:
> > Il 12/03/2013 14:01, Jan Kiszka ha scritto:
> >>>>>> For example, should kvm_arch_interrupt_allowed return zero if the VCPU
> >>>>>> is in the INIT_RECEIVED state?
> >>>>
> >>>> Yeah, that probably makes sense beyond async_pf.
> >> Wait: If you perform a proper reset on INIT already, we would clear IF
> >> thus prevent also async_pf injections. On the other hand,
> >> kvm_arch_can_inject_async_page_present returns true if apf.msr_val &
> >> KVM_ASYNC_PF_ENABLED is not set - shouldn't that be cleared on reset as
> >> well? Hmm...
> > 
> > So if you split the reset (which is done on INIT) from setting up CS on
> > SIPI, you kill two birds with a stone, or at least one and a half: you
> > clear IF as you wrote above, and INIT on BSP almost works (the only
> > missing bit should be setting the mp_state to KVM_MP_STATE_RUNNABLE).
> 
> ...unless the async_pf MSR is cleared on reset as well.
> 
It is:
vcpu->arch.apf.msr_val = 0;
--
			Gleb.