diff options
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 88 |
1 files changed, 82 insertions, 6 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 188b1ff03f5f..d624a527777f 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -110,6 +110,74 @@ static inline bool vfio_pci_is_vga(struct pci_dev *pdev) return (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA; } +static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev) +{ + struct resource *res; + int bar; + struct vfio_pci_dummy_resource *dummy_res; + + INIT_LIST_HEAD(&vdev->dummy_resources_list); + + for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) { + res = vdev->pdev->resource + bar; + + if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP)) + goto no_mmap; + + if (!(res->flags & IORESOURCE_MEM)) + goto no_mmap; + + /* + * The PCI core shouldn't set up a resource with a + * type but zero size. But there may be bugs that + * cause us to do that. + */ + if (!resource_size(res)) + goto no_mmap; + + if (resource_size(res) >= PAGE_SIZE) { + vdev->bar_mmap_supported[bar] = true; + continue; + } + + if (!(res->start & ~PAGE_MASK)) { + /* + * Add a dummy resource to reserve the remainder + * of the exclusive page in case that hot-add + * device's bar is assigned into it. + */ + dummy_res = kzalloc(sizeof(*dummy_res), GFP_KERNEL); + if (dummy_res == NULL) + goto no_mmap; + + dummy_res->resource.name = "vfio sub-page reserved"; + dummy_res->resource.start = res->end + 1; + dummy_res->resource.end = res->start + PAGE_SIZE - 1; + dummy_res->resource.flags = res->flags; + if (request_resource(res->parent, + &dummy_res->resource)) { + kfree(dummy_res); + goto no_mmap; + } + dummy_res->index = bar; + list_add(&dummy_res->res_next, + &vdev->dummy_resources_list); + vdev->bar_mmap_supported[bar] = true; + continue; + } + /* + * Here we don't handle the case when the BAR is not page + * aligned because we can't expect the BAR will be + * assigned into the same location in a page in guest + * when we passthrough the BAR. And it's hard to access + * this BAR in userspace because we have no way to get + * the BAR's location in a page. + */ +no_mmap: + vdev->bar_mmap_supported[bar] = false; + } +} + static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev); static void vfio_pci_disable(struct vfio_pci_device *vdev); @@ -218,12 +286,15 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) } } + vfio_pci_probe_mmaps(vdev); + return 0; } static void vfio_pci_disable(struct vfio_pci_device *vdev) { struct pci_dev *pdev = vdev->pdev; + struct vfio_pci_dummy_resource *dummy_res, *tmp; int i, bar; /* Stop the device from further DMA */ @@ -252,6 +323,13 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) vdev->barmap[bar] = NULL; } + list_for_each_entry_safe(dummy_res, tmp, + &vdev->dummy_resources_list, res_next) { + list_del(&dummy_res->res_next); + release_resource(&dummy_res->resource); + kfree(dummy_res); + } + vdev->needs_reset = true; /* @@ -623,9 +701,7 @@ static long vfio_pci_ioctl(void *device_data, info.flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; - if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && - pci_resource_flags(pdev, info.index) & - IORESOURCE_MEM && info.size >= PAGE_SIZE) { + if (vdev->bar_mmap_supported[info.index]) { info.flags |= VFIO_REGION_INFO_FLAG_MMAP; if (info.index == vdev->msix_bar) { ret = msix_sparse_mmap_cap(vdev, &caps); @@ -1049,16 +1125,16 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) return -EINVAL; if (index >= VFIO_PCI_ROM_REGION_INDEX) return -EINVAL; - if (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM)) + if (!vdev->bar_mmap_supported[index]) return -EINVAL; - phys_len = pci_resource_len(pdev, index); + phys_len = PAGE_ALIGN(pci_resource_len(pdev, index)); req_len = vma->vm_end - vma->vm_start; pgoff = vma->vm_pgoff & ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1); req_start = pgoff << PAGE_SHIFT; - if (phys_len < PAGE_SIZE || req_start + req_len > phys_len) + if (req_start + req_len > phys_len) return -EINVAL; if (index == vdev->msix_bar) { |