From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760420Ab0JISoP (ORCPT ); Sat, 9 Oct 2010 14:44:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36439 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756787Ab0JISoO (ORCPT ); Sat, 9 Oct 2010 14:44:14 -0400 Message-ID: <4CB0B7C5.5030609@redhat.com> Date: Sat, 09 Oct 2010 20:43:17 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: Gleb Natapov CC: kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com, riel@redhat.com, cl@linux-foundation.org, mtosatti@redhat.com Subject: Re: [PATCH v6 06/12] Add PV MSR to enable asynchronous page faults delivery. References: <1286207794-16120-1-git-send-email-gleb@redhat.com> <1286207794-16120-7-git-send-email-gleb@redhat.com> <4CADC3F2.2050506@redhat.com> <20101007175943.GH2397@redhat.com> In-Reply-To: <20101007175943.GH2397@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2010 07:59 PM, Gleb Natapov wrote: > On Thu, Oct 07, 2010 at 02:58:26PM +0200, Avi Kivity wrote: > > On 10/04/2010 05:56 PM, Gleb Natapov wrote: > > >+ > > >+ Physical address points to 32 bit memory location that will be written > > >+ to by the hypervisor at the time of asynchronous page fault injection to > > >+ indicate type of asynchronous page fault. Value of 1 means that the page > > >+ referred to by the page fault is not present. Value 2 means that the > > >+ page is now available. > > > > "The must not enable interrupts before the reason is read, or it may > > be overwritten by another apf". > > > > Document the fact that disabling interrupts disables APFs. > > > > How does the guest distinguish betweem APFs and ordinary page faults? > > > > What's the role of cr2? > > > > When disabling APF, all pending APFs are flushed and may or may not > > get a completion. > > > > Is a "page available" notification guaranteed to arrive on the same > > vcpu that took the "page not present" fault? > > > You mean documentation is lacking? :) > I mean you should be able to write guest support code without reading the host code, just the documentation. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.