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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 9E151C7618B for ; Thu, 25 Jul 2019 11:49:08 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 7A80A229F9 for ; Thu, 25 Jul 2019 11:49:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A80A229F9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 51B32D9D; Thu, 25 Jul 2019 11:49:08 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id A377DB7A for ; Thu, 25 Jul 2019 11:49:07 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 2D138775 for ; Thu, 25 Jul 2019 11:49:07 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id A9AA868BFE; Thu, 25 Jul 2019 13:49:03 +0200 (CEST) Date: Thu, 25 Jul 2019 13:49:03 +0200 From: Christoph Hellwig To: Lu Baolu Subject: Re: [PATCH v5 06/10] swiotlb: Zero out bounce buffer for untrusted device Message-ID: <20190725114903.GB31065@lst.de> References: <20190725031717.32317-1-baolu.lu@linux.intel.com> <20190725031717.32317-7-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190725031717.32317-7-baolu.lu@linux.intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alan.cox@intel.com, Christoph Hellwig , Stefano Stabellini , ashok.raj@intel.com, Jonathan Corbet , pengfei.xu@intel.com, Ingo Molnar , David Woodhouse , kevin.tian@intel.com, Konrad Rzeszutek Wilk , Steven Rostedt , Bjorn Helgaas , Boris Ostrovsky , mika.westerberg@linux.intel.com, Juergen Gross , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jacob.jun.pan@intel.com, Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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 Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org > index 43c88626a1f3..edc84a00b9f9 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -35,6 +35,7 @@ > #include > #include > #include > +#include > #ifdef CONFIG_DEBUG_FS > #include > #endif > @@ -562,6 +563,11 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, > */ > for (i = 0; i < nslots; i++) > io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); > + > + /* Zero out the bounce buffer if the consumer is untrusted. */ > + if (dev_is_untrusted(hwdev)) > + memset(phys_to_virt(tlb_addr), 0, alloc_size); Hmm. Maybe we need to move the untrusted flag to struct device? Directly poking into the pci_dev from swiotlb is a bit of a layering violation. > + > if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && > (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) > swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); Also for the case where we bounce here we only need to zero the padding (if there is any), so I think we could optimize this a bit. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu