From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752282Ab1BVIXt (ORCPT ); Tue, 22 Feb 2011 03:23:49 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:58973 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751123Ab1BVIXs (ORCPT ); Tue, 22 Feb 2011 03:23:48 -0500 Message-ID: <4D6372AE.2040104@cn.fujitsu.com> Date: Tue, 22 Feb 2011 16:24:14 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: Gleb Natapov CC: "kvm@vger.kernel.org" , LKML , Avi Kivity , Marcelo Tosatti Subject: Re: [PATCH] kvm: allow RO page when atomic && !write_fault References: <4D61E058.9080201@cn.fujitsu.com> <20110221094731.GI14984@redhat.com> In-Reply-To: <20110221094731.GI14984@redhat.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-02-22 16:22:39, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-02-22 16:22:40, Serialize complete at 2011-02-22 16:22:40 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/21/2011 05:47 PM, Gleb Natapov wrote: > 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? I will update/resend this patch after the patch you referred applied. Thanks, Lai > >> 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. > -- > 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 >