From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33C2C4968FD; Wed, 10 Jun 2026 15:44:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=150.107.74.76 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781106282; cv=none; b=eKLNRV0M7xdo8jlSXiqYfR3jyYfvQl8yPGNh7lsLnABqxwuxDTNhcV3os5zkVIA2DSZAVF5n9iykUmqRVlVKLsGLB8XVwMrH0hgDyBpOXaE4568/BLLfAUiph4pknjRIwxMufab1d4c7Q1YauvcE7TWC5CgUoHqoPSliTO/DMU8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781106282; c=relaxed/simple; bh=TR65VXt3Kh4Z13yu5SLht6OFWPrPzsUOL4V3GB+SmNY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dCQkOWFbaOft13lI5YT+SGCb4AJB500rhwzBzGqW6xUJPb7dTSBE/hcZ1ltyrIznUUvo4ASBozJYkRXTfbNrkAMKzhOq4rUreQWIkz9iiN6HJcpekGDn5hI7J1hH0i+f7waLR2Xc2szZAy0V65v7m6WPp93MTtf82LVc2zE4nQc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org; spf=pass smtp.mailfrom=ozlabs.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b=jikI5sAk; arc=none smtp.client-ip=150.107.74.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ozlabs.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="jikI5sAk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs.org; s=201707; t=1781106277; bh=/AMLEXw+Pi51wv7aHqZNO3AP0p86FvVpQuguO7FivKU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jikI5sAkcCh7A9sGjh9b99G6kqdxS7+IUcTv41XXowrXuj/swAldeOCAchPuy+gaM MaWlNRTCPcEltdL9WGYCVrJ2T5RI/Nh5OwlKRWluPgzO/GvdQHZyfTGugaQWTVvK+r SAE1+G6CXuqRiKDUtPGjZg5KBrQ20pexHsZih+vuWfP5vCCproIjjEfJR9aTXYcHCH R0DfAcqScg6/NAmtLa7JHl3Q6BLgctSvcCVZiwIkfaHa1LhlX3gV/DFuYxpQ4RPo6G 2cSHWiCEjpOxkB0Tlg+St+jvSf9jjPxVph+eOjsAgZcONgrAf9a3yJw6F+OiLV1bfu a70EcjEDVlNFA== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mail.ozlabs.org (Postfix) with ESMTPSA id 4gb97m4gSxz4x3q; Thu, 11 Jun 2026 01:44:36 +1000 (AEST) From: Matt Evans To: Alex Williamson , Leon Romanovsky , Jason Gunthorpe , Alex Mastro , =?UTF-8?q?Christian=20K=C3=B6nig?= , Bjorn Helgaas , Logan Gunthorpe Cc: Mahmoud Adam , David Matlack , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Sumit Semwal , Kevin Tian , Ankit Agrawal , Pranjal Shrivastava , Alistair Popple , Vivek Kasireddy , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH v3 5/9] vfio/pci: Provide a user-facing name for BAR mappings Date: Wed, 10 Jun 2026 16:43:19 +0100 Message-ID: <20260610154327.37758-6-matt@ozlabs.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260610154327.37758-1-matt@ozlabs.org> References: <20260610154327.37758-1-matt@ozlabs.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since converting BAR mmap()s to using DMABUFs, we lose the original device path in /proc//maps, lsof, etc. Generate a debug-oriented synthetic 'filename' based on the cdev, plus BDF, plus resource index. This applies only to BAR mappings via the VFIO device fd, as explicitly-exported DMABUFs are named by userspace via the DMA_BUF_SET_NAME ioctl. Signed-off-by: Matt Evans --- drivers/vfio/pci/vfio_pci_dmabuf.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index 2fd3629789bf..8f7f1b909b94 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -4,6 +4,7 @@ #include #include #include +#include #include "vfio_pci_priv.h" @@ -470,6 +471,7 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, { struct vfio_pci_dma_buf *priv; unsigned long vma_pgoff = vma->vm_pgoff & (VFIO_PCI_OFFSET_MASK >> PAGE_SHIFT); + char *bufname; int ret; priv = kzalloc_obj(*priv); @@ -482,6 +484,20 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, goto err_free_priv; } + bufname = kzalloc(DMA_BUF_NAME_LEN, GFP_KERNEL); + if (!bufname) { + ret = -ENOMEM; + goto err_free_phys; + } + + /* + * Maximum size of the friendly debug name is + * vfio1234567890:ffff:ff:3f.7/5 = 30, which fits within + * DMA_BUF_NAME_LEN. + */ + snprintf(bufname, DMA_BUF_NAME_LEN, "%s:%s/%x", + dev_name(&vdev->vdev.device), pci_name(vdev->pdev), res_index); + /* * The DMABUF begins from the mmap()'s BAR offset, i.e. the * start of the VMA corresponds to byte 0 of the DMABUF and @@ -500,7 +516,7 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, priv->provider = pcim_p2pdma_provider(vdev->pdev, res_index); if (!priv->provider) { ret = -EINVAL; - goto err_free_phys; + goto err_free_name; } priv->phys_vec[0].paddr = phys_start + ((u64)vma_pgoff << PAGE_SHIFT); @@ -508,7 +524,7 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, ret = vfio_pci_dmabuf_export(vdev, priv, O_CLOEXEC | O_RDWR); if (ret) - goto err_free_phys; + goto err_free_name; /* * Ownership of the DMABUF file transfers to the VMA so that @@ -523,8 +539,15 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, vma->vm_file = priv->dmabuf->file; vma->vm_private_data = priv; + spin_lock(&priv->dmabuf->name_lock); + kfree(priv->dmabuf->name); + priv->dmabuf->name = bufname; + spin_unlock(&priv->dmabuf->name_lock); + return 0; +err_free_name: + kfree(bufname); err_free_phys: kfree(priv->phys_vec); err_free_priv: -- 2.50.1 (Apple Git-155)