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 406154B8DF7; Wed, 15 Jul 2026 17:48:22 +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=1784137704; cv=none; b=Fl9bVzhidm4UtRCp7jECuWf+nGb6oIwcyfccm3uIUCEnTr6sfQb1Ck3lVOSk9PZD0HW7/PCS0dTOQOq8NonlH9n7ToKIZnPeSzAwDiQhJrjtGwGi78Gj0FePGQkcR7KC7kD51NX6gtuXCC3DOBXeejRpWvMm0DBzI4xib1yVVnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784137704; c=relaxed/simple; bh=6LZgKMmkYjFRBzmjr2YBs+EvhOt9EISp4sBE6VBi5go=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MiWoEUTITDuoeRle0h73COh4Sww/uLF0aUAGNpiuciL2lQW6B4mehDF+A/HoKXpvgmVByEkYOGSJILG6WK+lugXGzcLZLf4lv2uWCvPmRgIlzlgAtVEJcS+2F9DnWyyCEquu3qLHIWRJJO+EjsmWBe9lyWAGgKFWz5hz0p/ZibQ= 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=NBm5LAeG; 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="NBm5LAeG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs.org; s=201707; t=1784137700; bh=S4yvVhd4segS5bNIQO9q6OScsB0g9zWVml9R9MFW9Pg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NBm5LAeGHqKWbz0gNKtD6ohMNo9zh2qT+iwC86PbhY+D3gata01U4sPFYywI5NP+h TGeFjSzr9UZfokkV5nIYDY/6Q5hGqXhEYxJsi+iEq7J9xO2B2AgroTJ4dVZbocJiZy jEbnd2gLLjbvAaId6JSeQZ/tW7NItMKto+tlt3AvcAPct5CryNUI6ALFN4YD/S9GiQ 9ywtcxjMwMCS1uDkBxsF4tHqATj1dT/IQVCJtCx6lwByKPeApfMDN0A0Oj86v8j+c4 C1kNxTuwfo2X4UGVkKm0/0fD/UKQiZLmA1xtHXdZJ3SXzK/ZHXPWmLi5K+/frUwvuT 7jzLjnMYYjHhA== 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 4h0kDM496sz4wCH; Thu, 16 Jul 2026 03:48:19 +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 , Kevin Tian , Pranjal Shrivastava , Longfang Liu Cc: Mahmoud Adam , David Matlack , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Sumit Semwal , Ankit Agrawal , 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 v5 6/9] vfio/pci: Provide a user-facing name for BAR mappings Date: Wed, 15 Jul 2026 18:47:29 +0100 Message-ID: <20260715174737.15287-7-matt@ozlabs.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260715174737.15287-1-matt@ozlabs.org> References: <20260715174737.15287-1-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 Reviewed-by: Pranjal Shrivastava --- drivers/vfio/pci/vfio_pci_dmabuf.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index 46b3cf5dc94b..51606ff3cdc6 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" @@ -486,6 +487,7 @@ 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); @@ -498,6 +500,15 @@ int vfio_pci_core_mmap_prep_dmabuf(struct vfio_pci_core_device *vdev, goto err_free_priv; } + bufname = kasprintf(GFP_KERNEL, "%s:%s/%x", + dev_name(&vdev->vdev.device), pci_name(vdev->pdev), + res_index); + + if (!bufname) { + ret = -ENOMEM; + goto err_free_phys; + } + /* * The DMABUF begins from the mmap()'s BAR offset, i.e. the * start of the VMA corresponds to byte 0 of the DMABUF and @@ -516,7 +527,7 @@ 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); @@ -524,7 +535,7 @@ 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 @@ -539,8 +550,15 @@ 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)