Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752141AbdFOFG7 (ORCPT ); Thu, 15 Jun 2017 01:06:59 -0400 Received: from ozlabs.ru ([107.173.13.209]:34378 "EHLO ozlabs.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbdFOFG5 (ORCPT ); Thu, 15 Jun 2017 01:06:57 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , kvm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yongji Xie , Alex Williamson , Benjamin Herrenschmidt , Gavin Shan , Paul Mackerras , David Gibson , Yongji Xie , Michael Roth , Paul Mackerras Subject: [PATCH kernel 3/3] vfio-pci: Allow to expose MSI-X table to userspace if interrupt remapping is enabled Date: Thu, 15 Jun 2017 15:06:42 +1000 Message-Id: <20170615050642.8197-4-aik@ozlabs.ru> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170615050642.8197-1-aik@ozlabs.ru> References: <20170615050642.8197-1-aik@ozlabs.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2981 Lines: 82 From: Yongji Xie This patch tries to expose MSI-X tables to userspace if hardware enables interrupt remapping which can ensure that a given PCI device can only shoot the MSIs assigned for it. So we could never worry that userspace driver can hurt other devices by writing to the exposed MSI-X table directly. Signed-off-by: Yongji Xie Signed-off-by: Michael Roth Signed-off-by: Paul Mackerras --- drivers/vfio/pci/vfio_pci.c | 18 +++++++++++++++--- drivers/vfio/pci/vfio_pci_rdwr.c | 3 ++- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 324c52e3a1a4..700e9d04dab5 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -564,8 +564,12 @@ static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev, end = pci_resource_len(vdev->pdev, vdev->msix_bar); - /* If MSI-X table is aligned to the start or end, only one area */ - if (((vdev->msix_offset & PAGE_MASK) == 0) || + /* + * If MSI-X table is allowed to mmap because of the capability + * of IRQ remapping or aligned to the start or end, only one area + */ + if ((vdev->pdev->bus->bus_flags & PCI_BUS_FLAGS_MSI_REMAP) || + ((vdev->msix_offset & PAGE_MASK) == 0) || (PAGE_ALIGN(vdev->msix_offset + vdev->msix_size) >= end)) nr_areas = 1; @@ -577,6 +581,12 @@ static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev, sparse->nr_areas = nr_areas; + if (vdev->pdev->bus->bus_flags & PCI_BUS_FLAGS_MSI_REMAP) { + sparse->areas[i].offset = 0; + sparse->areas[i].size = end; + goto out; + } + if (vdev->msix_offset & PAGE_MASK) { sparse->areas[i].offset = 0; sparse->areas[i].size = vdev->msix_offset & PAGE_MASK; @@ -590,6 +600,7 @@ static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev, i++; } +out: ret = vfio_info_add_capability(caps, VFIO_REGION_INFO_CAP_SPARSE_MMAP, sparse); kfree(sparse); @@ -1115,7 +1126,8 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) if (req_start + req_len > phys_len) return -EINVAL; - if (index == vdev->msix_bar) { + if (index == vdev->msix_bar && + !(pdev->bus->bus_flags & PCI_BUS_FLAGS_MSI_REMAP)) { /* * Disallow mmaps overlapping the MSI-X table; users don't * get to touch this directly. We could find somewhere diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index 357243d76f10..5378f2c3ac8e 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -164,7 +164,8 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf, } else io = vdev->barmap[bar]; - if (bar == vdev->msix_bar) { + if (bar == vdev->msix_bar && + !(pdev->bus->bus_flags & PCI_BUS_FLAGS_MSI_REMAP)) { x_start = vdev->msix_offset; x_end = vdev->msix_offset + vdev->msix_size; } -- 2.11.0