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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 567DDCCD19F for ; Mon, 20 Oct 2025 16:45:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B036B10E2A6; Mon, 20 Oct 2025 16:45:05 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="uwACY+gA"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id ABF2010E2A6 for ; Mon, 20 Oct 2025 16:45:04 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 5DE5A62093; Mon, 20 Oct 2025 16:45:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90E34C116B1; Mon, 20 Oct 2025 16:45:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760978703; bh=TIx5NRTP5K3pYgUiu6kQ2tFh50oiXo0JG1oS7oaLLgM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uwACY+gAAHVeDRNLQa9LhoH9lcVFnZPzXatywkYG646bVhvuqsRPN14g1g/VNKLes WYNJREIXrJtYT7QbloBWC3KAb3tT4a4woiFgInEG+Q1ETN0Ps+qgi6JaeRCyXnfGma 5sgxwKokkXII1oj9idvsCFH+xzxFf+ctHebO0Crf8NoevzUCnORlmsx2c38BzGnEu/ s3EFcu5YRpFtIlMTjRKfKi1EEzzIFI6u24tuPRov6TF1nceX6GqjYmDq7yRyORhFLg hFkabH/anV7vAMpIABZ7pHq33jQbOvDbCcvoCX9x7Rpe/xWcFSBpnYpbbJKwrjEhRF yB30+vyIw7ITg== Date: Mon, 20 Oct 2025 19:44:57 +0300 From: Leon Romanovsky To: Jason Gunthorpe Cc: Alex Williamson , Andrew Morton , Bjorn Helgaas , Christian =?iso-8859-1?Q?K=F6nig?= , dri-devel@lists.freedesktop.org, iommu@lists.linux.dev, Jens Axboe , Joerg Roedel , kvm@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, Logan Gunthorpe , Marek Szyprowski , Robin Murphy , Sumit Semwal , Vivek Kasireddy , Will Deacon Subject: Re: [PATCH v5 9/9] vfio/pci: Add dma-buf export support for MMIO regions Message-ID: <20251020164457.GQ6199@unreal> References: <72ecaa13864ca346797e342d23a7929562788148.1760368250.git.leon@kernel.org> <20251017130249.GA309181@nvidia.com> <20251017161358.GC6199@unreal> <20251020161516.GU316284@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251020161516.GU316284@nvidia.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Oct 20, 2025 at 01:15:16PM -0300, Jason Gunthorpe wrote: > On Fri, Oct 17, 2025 at 07:13:58PM +0300, Leon Romanovsky wrote: > > > static int dma_ranges_to_p2p_phys(struct vfio_pci_dma_buf *priv, > > > struct vfio_device_feature_dma_buf *dma_buf, > > > struct vfio_region_dma_range *dma_ranges, > > > struct p2pdma_provider *provider) > > > { > > > struct pci_dev *pdev = priv->vdev->pdev; > > > phys_addr_t len = pci_resource_len(pdev, dma_buf->region_index); > > > phys_addr_t pci_start; > > > phys_addr_t pci_last; > > > u32 i; > > > > > > if (!len) > > > return -EINVAL; > > > pci_start = pci_resource_start(pdev, dma_buf->region_index); > > > pci_last = pci_start + len - 1; > > > for (i = 0; i < dma_buf->nr_ranges; i++) { > > > phys_addr_t last; > > > > > > if (!dma_ranges[i].length) > > > return -EINVAL; > > > > > > if (check_add_overflow(pci_start, dma_ranges[i].offset, > > > &priv->phys_vec[i].paddr) || > > > check_add_overflow(priv->phys_vec[i].paddr, > > > dma_ranges[i].length - 1, &last)) > > > return -EOVERFLOW; > > > if (last > pci_last) > > > return -EINVAL; > > > > > > priv->phys_vec[i].len = dma_ranges[i].length; > > > priv->size += priv->phys_vec[i].len; > > > } > > > priv->nr_ranges = dma_buf->nr_ranges; > > > priv->provider = provider; > > > return 0; > > > } > > > > I have these checks in validate_dmabuf_input(). > > Do you think that I need to add extra checks? > > I think they work better in this function, so I'd move them here. The main idea for validate_dmabuf_input() is to perform as much as possible checks before allocating kernel memory. Thanks > > Jason