From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lu Baolu Subject: Re: [PATCH v1 4/9] iommu/vt-d: Add bounce buffer API for domain map/unmap Date: Wed, 13 Mar 2019 10:04:41 +0800 Message-ID: References: <20190312060005.12189-1-baolu.lu@linux.intel.com> <20190312060005.12189-5-baolu.lu@linux.intel.com> <20190312163845.GA13141@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190312163845.GA13141@infradead.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Christoph Hellwig Cc: baolu.lu@linux.intel.com, David Woodhouse , Joerg Roedel , ashok.raj@intel.com, jacob.jun.pan@intel.com, alan.cox@intel.com, kevin.tian@intel.com, mika.westerberg@linux.intel.com, pengfei.xu@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jacob Pan List-Id: iommu@lists.linux-foundation.org Hi, On 3/13/19 12:38 AM, Christoph Hellwig wrote: > On Tue, Mar 12, 2019 at 02:00:00PM +0800, Lu Baolu wrote: >> This adds the APIs for bounce buffer specified domain >> map() and unmap(). The start and end partial pages will >> be mapped with bounce buffered pages instead. This will >> enhance the security of DMA buffer by isolating the DMA >> attacks from malicious devices. > > Please reuse the swiotlb code instead of reinventing it. > I don't think we are doing the same thing as swiotlb here. But it's always a good thing to reuse code if possible. I considered this when writing this code, but I found it's hard to do. Do you mind pointing me to the code which I could reuse? Best regards, Lu Baolu