From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Woodhouse Date: Wed, 05 Aug 2009 08:19:59 +0000 Subject: Re: [PATCH 4/4] Bug Fix drivers/pci/intel-iommu.c: convert pfn_lo Message-Id: <1249460399.9324.350.camel@macbook.infradead.org> List-Id: References: <200908042017.n74KHsNw018095@bz-web1.app.phx.redhat.com> <20090804221119.GA21544@linux-os.sc.intel.com> In-Reply-To: <20090804221119.GA21544@linux-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Fenghua Yu Cc: Tony Luck , iommu@lists.linux-foundation.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, 2009-08-04 at 15:11 -0700, Fenghua Yu wrote: > The iova->pfn_lo should be converted to VTD page address before it's passed to > iommu_flush_dev_iotlb(). > > This issue may cause DMA failure on PAGE_SIZE>VTD_PAGE_SIZE platforms e.g. ia64 > platforms. > > Signed-off-by: Fenghua Yu I think this one is wrong. We allocate IOVA space in MM pages, not DMA pages -- so the pfn_lo is an MM page already, and shifting by PAGE_SHIFT is the right thing to do. (I could be tempted to allocate it in DMA pages instead, but that's a different story). -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation