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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50127C433FE for ; Tue, 28 Sep 2021 05:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3818F6108F for ; Tue, 28 Sep 2021 05:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236379AbhI1FlD (ORCPT ); Tue, 28 Sep 2021 01:41:03 -0400 Received: from verein.lst.de ([213.95.11.211]:50132 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234243AbhI1Fk5 (ORCPT ); Tue, 28 Sep 2021 01:40:57 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id ED5FC67373; Tue, 28 Sep 2021 07:39:11 +0200 (CEST) Date: Tue, 28 Sep 2021 07:39:11 +0200 From: Christoph Hellwig To: Tianyu Lan Cc: Christoph Hellwig , "iommu@lists.linux-foundation.org" , "linux-arch@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "netdev@vger.kernel.org" , vkuznets , "parri.andrea@gmail.com" , "dave.hansen@intel.com" , Michael Kelley , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , "wei.liu@kernel.org" , Dexuan Cui , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "x86@kernel.org" , "hpa@zytor.com" , "dave.hansen@linux.intel.com" , "luto@kernel.org" , "peterz@infradead.org" , "konrad.wilk@oracle.com" , "boris.ostrovsky@oracle.com" , "jgross@suse.com" , "sstabellini@kernel.org" , "joro@8bytes.org" , "will@kernel.org" , "davem@davemloft.net" , "kuba@kernel.org" , "jejb@linux.ibm.com" , "martin.petersen@oracle.com" , "gregkh@linuxfoundation.org" , "arnd@arndb.de" , "m.szyprowski@samsung.com" , "robin.murphy@arm.com" , "brijesh.singh@amd.com" , Tianyu Lan , "thomas.lendacky@amd.com" , "pgonda@google.com" , "akpm@linux-foundation.org" , "kirill.shutemov@linux.intel.com" , "rppt@kernel.org" , "sfr@canb.auug.org.au" , "aneesh.kumar@linux.ibm.com" , "saravanand@fb.com" , "krish.sadhukhan@oracle.com" , "xen-devel@lists.xenproject.org" , "tj@kernel.org" , "rientjes@google.com" Subject: Re: [PATCH V5 12/12] net: netvsc: Add Isolation VM support for netvsc driver Message-ID: <20210928053911.GA29208@lst.de> References: <20210914133916.1440931-1-ltykernel@gmail.com> <20210914133916.1440931-13-ltykernel@gmail.com> <43e22b84-7273-4099-42ea-54b06f398650@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 27, 2021 at 10:26:43PM +0800, Tianyu Lan wrote: > Hi Christoph: > Gentile ping. The swiotlb and shared memory mapping changes in this > patchset needs your reivew. Could you have a look? I'm a little too busy for a review of such a huge patchset right now. That being said here are my comments from a very quick review: - the bare memremap usage in swiotlb looks strange and I'd definitively expect a well documented wrapper. - given that we can now hand out swiotlb memory for coherent mappings we need to carefully audit what happens when this memremaped memory gets mmaped or used through dma_get_sgtable - the netscv changes I'm not happy with at all. A large part of it is that the driver already has a bad structure, but this series is making it significantly worse. We'll need to find a way to use the proper dma mapping abstractions here. One option if you want to stick to the double vmapped buffer would be something like using dma_alloc_noncontigous plus a variant of dma_vmap_noncontiguous that takes the shared_gpa_boundary into account. 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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD605C4332F for ; Tue, 28 Sep 2021 05:39:23 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 7B84F610A5 for ; Tue, 28 Sep 2021 05:39:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7B84F610A5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 4869E80C91; Tue, 28 Sep 2021 05:39:23 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cg4HsC7_njpL; Tue, 28 Sep 2021 05:39:22 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 446A080C55; Tue, 28 Sep 2021 05:39:22 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2AF5EC000F; Tue, 28 Sep 2021 05:39:22 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id EEFBCC000D for ; Tue, 28 Sep 2021 05:39:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id EA7FA608CB for ; Tue, 28 Sep 2021 05:39:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id A6LlWl-ZODxb for ; Tue, 28 Sep 2021 05:39:20 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp3.osuosl.org (Postfix) with ESMTPS id C5E9460896 for ; Tue, 28 Sep 2021 05:39:19 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id ED5FC67373; Tue, 28 Sep 2021 07:39:11 +0200 (CEST) Date: Tue, 28 Sep 2021 07:39:11 +0200 From: Christoph Hellwig To: Tianyu Lan Subject: Re: [PATCH V5 12/12] net: netvsc: Add Isolation VM support for netvsc driver Message-ID: <20210928053911.GA29208@lst.de> References: <20210914133916.1440931-1-ltykernel@gmail.com> <20210914133916.1440931-13-ltykernel@gmail.com> <43e22b84-7273-4099-42ea-54b06f398650@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: "linux-hyperv@vger.kernel.org" , "brijesh.singh@amd.com" , "thomas.lendacky@amd.com" , "peterz@infradead.org" , "dave.hansen@linux.intel.com" , Michael Kelley , "dave.hansen@intel.com" , "hpa@zytor.com" , KY Srinivasan , "will@kernel.org" , Christoph Hellwig , "linux-arch@vger.kernel.org" , "sfr@canb.auug.org.au" , "wei.liu@kernel.org" , "sstabellini@kernel.org" , Stephen Hemminger , "xen-devel@lists.xenproject.org" , "linux-scsi@vger.kernel.org" , "aneesh.kumar@linux.ibm.com" , "x86@kernel.org" , Dexuan Cui , "mingo@redhat.com" , "pgonda@google.com" , "rientjes@google.com" , "kuba@kernel.org" , "jejb@linux.ibm.com" , "parri.andrea@gmail.com" , "jgross@suse.com" , Tianyu Lan , "arnd@arndb.de" , "konrad.wilk@oracle.com" , Haiyang Zhang , "bp@alien8.de" , "luto@kernel.org" , "krish.sadhukhan@oracle.com" , "tglx@linutronix.de" , "akpm@linux-foundation.org" , "boris.ostrovsky@oracle.com" , "martin.petersen@oracle.com" , "saravanand@fb.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "rppt@kernel.org" , "gregkh@linuxfoundation.org" , "tj@kernel.org" , vkuznets , "robin.murphy@arm.com" , "davem@davemloft.net" , "kirill.shutemov@linux.intel.com" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, Sep 27, 2021 at 10:26:43PM +0800, Tianyu Lan wrote: > Hi Christoph: > Gentile ping. The swiotlb and shared memory mapping changes in this > patchset needs your reivew. Could you have a look? I'm a little too busy for a review of such a huge patchset right now. That being said here are my comments from a very quick review: - the bare memremap usage in swiotlb looks strange and I'd definitively expect a well documented wrapper. - given that we can now hand out swiotlb memory for coherent mappings we need to carefully audit what happens when this memremaped memory gets mmaped or used through dma_get_sgtable - the netscv changes I'm not happy with at all. A large part of it is that the driver already has a bad structure, but this series is making it significantly worse. We'll need to find a way to use the proper dma mapping abstractions here. One option if you want to stick to the double vmapped buffer would be something like using dma_alloc_noncontigous plus a variant of dma_vmap_noncontiguous that takes the shared_gpa_boundary into account. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu