From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41623) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cEJip-0000j1-Mc for qemu-devel@nongnu.org; Tue, 06 Dec 2016 12:40:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cEJil-0003rm-6Z for qemu-devel@nongnu.org; Tue, 06 Dec 2016 12:40:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46638) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cEJil-0003qc-0L for qemu-devel@nongnu.org; Tue, 06 Dec 2016 12:40:03 -0500 Date: Tue, 6 Dec 2016 10:40:01 -0700 From: Alex Williamson Message-ID: <20161206104001.49390d41@t450s.home> In-Reply-To: <1481044425-23920-1-git-send-email-kwankhede@nvidia.com> References: <1481044425-23920-1-git-send-email-kwankhede@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/2] vfio iommu: Fix size argument to vfio_find_dma() in pin_pages/unpin_pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kirti Wankhede Cc: pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, 6 Dec 2016 22:43:45 +0530 Kirti Wankhede wrote: > vfio_dma keeps track of address range from (dma->iova + 0) to > (dma->iova + dma->size - 1), while vfio_find_dma() search logic looks for > range from (dma->iova + 1) to (dma->iova + dma->size). Also not true as described in reply to 1/2. > In vfio_find_dma(), when the start address is equal to dma->iova and size > is 0, check for the end of search range makes it to take wrong side of > RB-tree. That fails the search even though the address is present in > mapped dma ranges. > In functions pin_pages and unpin_pages, the iova which is being searched > is base address of page to be pinned or unpinned. So here size should be > set to PAGE_SIZE, as argument to vfio_find_dma. > > Signed-off-by: Kirti Wankhede > Signed-off-by: Neo Jia > --- > drivers/vfio/vfio_iommu_type1.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 8e9e94ccb2ff..023fba7b8d5a 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -581,7 +581,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, > struct vfio_pfn *vpfn; > > iova = user_pfn[i] << PAGE_SHIFT; > - dma = vfio_find_dma(iommu, iova, 0); > + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); > if (!dma) { > ret = -EINVAL; > goto pin_unwind; > @@ -622,7 +622,7 @@ pin_unwind: > dma_addr_t iova; > > iova = user_pfn[j] << PAGE_SHIFT; > - dma = vfio_find_dma(iommu, iova, 0); > + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); > vfio_unpin_page_external(dma, iova, do_accounting); > phys_pfn[j] = 0; > } > @@ -659,7 +659,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data, > dma_addr_t iova; > > iova = user_pfn[i] << PAGE_SHIFT; > - dma = vfio_find_dma(iommu, iova, 0); > + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); > if (!dma) > goto unpin_exit; > vfio_unpin_page_external(dma, iova, do_accounting);