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 } 112