| Alex Williamson | 5846ff5 | 2016-02-22 16:02:43 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * VFIO PCI Intel Graphics support |
| 3 | * |
| 4 | * Copyright (C) 2016 Red Hat, Inc. All rights reserved. |
| 5 | * Author: Alex Williamson <alex.williamson@redhat.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * Register a device specific region through which to provide read-only |
| 12 | * access to the Intel IGD opregion. The register defining the opregion |
| 13 | * address is also virtualized to prevent user modification. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/io.h> |
| 17 | #include <linux/pci.h> |
| 18 | #include <linux/uaccess.h> |
| 19 | #include <linux/vfio.h> |
| 20 | |
| 21 | #include "vfio_pci_private.h" |
| 22 | |
| 23 | #define OPREGION_SIGNATURE "IntelGraphicsMem" |
| 24 | #define OPREGION_SIZE (8 * 1024) |
| 25 | #define OPREGION_PCI_ADDR 0xfc |
| 26 | |
| 27 | static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf, |
| 28 | size_t count, loff_t *ppos, bool iswrite) |
| 29 | { |
| 30 | unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS; |
| 31 | void *base = vdev->region[i].data; |
| 32 | loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; |
| 33 | |
| 34 | if (pos >= vdev->region[i].size || iswrite) |
| 35 | return -EINVAL; |
| 36 | |
| 37 | count = min(count, (size_t)(vdev->region[i].size - pos)); |
| 38 | |
| 39 | if (copy_to_user(buf, base + pos, count)) |
| 40 | return -EFAULT; |
| 41 | |
| 42 | *ppos += count; |
| 43 | |
| 44 | return count; |
| 45 | } |
| 46 | |
| 47 | static void vfio_pci_igd_release(struct vfio_pci_device *vdev, |
| 48 | struct vfio_pci_region *region) |
| 49 | { |
| 50 | memunmap(region->data); |
| 51 | } |
| 52 | |
| 53 | static const struct vfio_pci_regops vfio_pci_igd_regops = { |
| 54 | .rw = vfio_pci_igd_rw, |
| 55 | .release = vfio_pci_igd_release, |
| 56 | }; |
| 57 | |
| 58 | int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev) |
| 59 | { |
| 60 | __le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR); |
| 61 | u32 addr, size; |
| 62 | void *base; |
| 63 | int ret; |
| 64 | |
| 65 | ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr); |
| 66 | if (ret) |
| 67 | return ret; |
| 68 | |
| 69 | if (!addr || !(~addr)) |
| 70 | return -ENODEV; |
| 71 | |
| 72 | base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB); |
| 73 | if (!base) |
| 74 | return -ENOMEM; |
| 75 | |
| 76 | if (memcmp(base, OPREGION_SIGNATURE, 16)) { |
| 77 | memunmap(base); |
| 78 | return -EINVAL; |
| 79 | } |
| 80 | |
| 81 | size = le32_to_cpu(*(__le32 *)(base + 16)); |
| 82 | if (!size) { |
| 83 | memunmap(base); |
| 84 | return -EINVAL; |
| 85 | } |
| 86 | |
| 87 | size *= 1024; /* In KB */ |
| 88 | |
| 89 | if (size != OPREGION_SIZE) { |
| 90 | memunmap(base); |
| 91 | base = memremap(addr, size, MEMREMAP_WB); |
| 92 | if (!base) |
| 93 | return -ENOMEM; |
| 94 | } |
| 95 | |
| 96 | ret = vfio_pci_register_dev_region(vdev, |
| 97 | PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE, |
| 98 | VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, |
| 99 | &vfio_pci_igd_regops, size, VFIO_REGION_INFO_FLAG_READ, base); |
| 100 | if (ret) { |
| 101 | memunmap(base); |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | /* Fill vconfig with the hw value and virtualize register */ |
| 106 | *dwordp = cpu_to_le32(addr); |
| 107 | memset(vdev->pci_config_map + OPREGION_PCI_ADDR, |
| 108 | PCI_CAP_ID_INVALID_VIRT, 4); |
| 109 | |
| 110 | return ret; |
| 111 | } |