From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96A3BC433E0 for ; Thu, 6 Aug 2020 12:01:07 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 72C6E22D03 for ; Thu, 6 Aug 2020 12:01:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72C6E22D03 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k3ce9-0005c9-NG; Thu, 06 Aug 2020 09:57:13 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k3ce7-0005c4-SN for xen-devel@lists.xenproject.org; Thu, 06 Aug 2020 09:57:11 +0000 X-Inumbo-ID: 82258e23-b800-4150-b2ed-01af3552afdf Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 82258e23-b800-4150-b2ed-01af3552afdf; Thu, 06 Aug 2020 09:57:11 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7632EAC12; Thu, 6 Aug 2020 09:57:27 +0000 (UTC) Subject: Re: [PATCH v4 07/14] iommu: make map, unmap and flush all take both an order and a count To: Paul Durrant References: <20200804134209.8717-1-paul@xen.org> <20200804134209.8717-8-paul@xen.org> From: Jan Beulich Message-ID: <2765087f-4168-191d-c547-cbc2e74d3fee@suse.com> Date: Thu, 6 Aug 2020 11:57:12 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200804134209.8717-8-paul@xen.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Kevin Tian , Stefano Stabellini , Julien Grall , Wei Liu , Andrew Cooper , Paul Durrant , Ian Jackson , George Dunlap , Jun Nakajima , xen-devel@lists.xenproject.org, Volodymyr Babchuk , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 04.08.2020 15:42, Paul Durrant wrote: > From: Paul Durrant > > At the moment iommu_map() and iommu_unmap() take a page order but not a > count, whereas iommu_iotlb_flush() takes a count but not a page order. > This patch simply makes them consistent with each other. Why can't we do with just a count, where order gets worked out by functions knowing how to / wanting to deal with higher order pages? > --- a/xen/arch/x86/mm/p2m-ept.c > +++ b/xen/arch/x86/mm/p2m-ept.c > @@ -843,7 +843,7 @@ out: > need_modify_vtd_table ) > { > if ( iommu_use_hap_pt(d) ) > - rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), > + rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), 1, Forgot to drop the "1 << "? (There are then I think two more instances further down.) > --- a/xen/common/memory.c > +++ b/xen/common/memory.c > @@ -851,12 +851,12 @@ int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp, > > this_cpu(iommu_dont_flush_iotlb) = 0; > > - ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done, > + ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), 0, done, Arguments wrong way round? (This risk of inverting their order is one of the primary reasons why I think we want just a count.) I'm also uncertain about the use of 0 vs PAGE_ORDER_4K here. > IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified); > if ( unlikely(ret) && rc >= 0 ) > rc = ret; > > - ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done, > + ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), 0, done, Same here then. Jan