From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754856Ab1BUJrh (ORCPT ); Mon, 21 Feb 2011 04:47:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1035 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753147Ab1BUJrg (ORCPT ); Mon, 21 Feb 2011 04:47:36 -0500 Date: Mon, 21 Feb 2011 11:47:31 +0200 From: Gleb Natapov To: Lai Jiangshan Cc: "kvm@vger.kernel.org" , LKML , Avi Kivity , Marcelo Tosatti Subject: Re: [PATCH] kvm: allow RO page when atomic && !write_fault Message-ID: <20110221094731.GI14984@redhat.com> References: <4D61E058.9080201@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D61E058.9080201@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 21, 2011 at 11:47:36AM +0800, Lai Jiangshan wrote: > > Atomic-able hva_to_pfn() patches and allow-read-only-page patches > are merged almost the same time. But hva_to_pfn() does not handle > these two issues well together. > > When @atomic && !@write_fault && host-is-read-only-page-mapped > the code will return fault_page, actually, it will be better > if we return the pfn of the read-only-page. > This patch will conflict with not yet applied https://lkml.org/lkml/2011/2/1/94 What it the status of that patch? > Signed-off-by: Lai Jiangshan > --- > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 1fa0d29..f49cfc0 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1060,31 +1060,27 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, > BUG_ON(!write_fault && !writable); > > if (writable) > - *writable = true; > + *writable = write_fault; > > if (atomic || async) > - npages = __get_user_pages_fast(addr, 1, 1, page); > + npages = __get_user_pages_fast(addr, 1, write_fault, page); > > if (unlikely(npages != 1) && !atomic) { > might_sleep(); > - > - if (writable) > - *writable = write_fault; > - > npages = get_user_pages_fast(addr, 1, write_fault, page); > + } > > - /* map read fault as writable if possible */ > - if (unlikely(!write_fault) && npages == 1) { > - struct page *wpage[1]; > + /* map read fault as writable if possible */ > + if (unlikely(!write_fault) && npages == 1) { > + struct page *wpage[1]; > > - npages = __get_user_pages_fast(addr, 1, 1, wpage); > - if (npages == 1) { > - *writable = true; > - put_page(page[0]); > - page[0] = wpage[0]; > - } > - npages = 1; > + npages = __get_user_pages_fast(addr, 1, 1, wpage); > + if (npages == 1) { > + *writable = true; > + put_page(page[0]); > + page[0] = wpage[0]; > } > + npages = 1; > } > > if (unlikely(npages != 1)) { > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Gleb.