drivers/vfio/pci/vfio_pci_igd.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * VFIO PCI Intel Graphics support
  *
  * Copyright (C) 2016 Red Hat, Inc.  All rights reserved.
  *	Author: Alex Williamson <alex.williamson@redhat.com>
  *
  * Register a device specific region through which to provide read-only
  * access to the Intel IGD opregion.  The register defining the opregion
  * address is also virtualized to prevent user modification.
  */

 #include <linux/io.h>
 #include <linux/pci.h>
 #include <linux/uaccess.h>
 #include <linux/vfio.h>

 #include <linux/vfio_pci_core.h>

 #define OPREGION_SIGNATURE	"IntelGraphicsMem"
 #define OPREGION_SIZE		(8 * 1024)
 #define OPREGION_PCI_ADDR	0xfc

 #define OPREGION_RVDA		0x3ba
 #define OPREGION_RVDS		0x3c2
 #define OPREGION_VERSION	0x16

 struct igd_opregion_vbt {
 	void *opregion;
 	void *vbt_ex;
 };

 /**
  * igd_opregion_shift_copy() - Copy OpRegion to user buffer and shift position.
  * @dst: User buffer ptr to copy to.
  * @off: Offset to user buffer ptr. Increased by bytes on return.
  * @src: Source buffer to copy from.
  * @pos: Increased by bytes on return.
  * @remaining: Decreased by bytes on return.
  * @bytes: Bytes to copy and adjust off, pos and remaining.
  *
  * Copy OpRegion to offset from specific source ptr and shift the offset.
  *
  * Return: 0 on success, -EFAULT otherwise.
  *
  */
 static inline unsigned long igd_opregion_shift_copy(char __user *dst,
 						    loff_t *off,
 						    void *src,
 						    loff_t *pos,
 						    size_t *remaining,
 						    size_t bytes)
 {
 	if (copy_to_user(dst + (*off), src, bytes))
 		return -EFAULT;

 	*off += bytes;
 	*pos += bytes;
 	*remaining -= bytes;

 	return 0;
 }

 static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_device *vdev,
 			       char __user *buf, size_t count, loff_t *ppos,
 			       bool iswrite)
 {
 	unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
 	struct igd_opregion_vbt *opregionvbt = vdev->region[i].data;
 	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK, off = 0;
 	size_t remaining;

 	if (pos >= vdev->region[i].size || iswrite)
 		return -EINVAL;

 	count = min_t(size_t, count, vdev->region[i].size - pos);
 	remaining = count;

 	/* Copy until OpRegion version */
 	if (remaining && pos < OPREGION_VERSION) {
 		size_t bytes = min_t(size_t, remaining, OPREGION_VERSION - pos);

 		if (igd_opregion_shift_copy(buf, &off,
 					    opregionvbt->opregion + pos, &pos,
 					    &remaining, bytes))
 			return -EFAULT;
 	}

 	/* Copy patched (if necessary) OpRegion version */
 	if (remaining && pos < OPREGION_VERSION + sizeof(__le16)) {
 		size_t bytes = min_t(size_t, remaining,
 				     OPREGION_VERSION + sizeof(__le16) - pos);
 		__le16 version = *(__le16 *)(opregionvbt->opregion +
 					     OPREGION_VERSION);

 		/* Patch to 2.1 if OpRegion 2.0 has extended VBT */
 		if (le16_to_cpu(version) == 0x0200 && opregionvbt->vbt_ex)
 			version = cpu_to_le16(0x0201);

 		if (igd_opregion_shift_copy(buf, &off,
 					    &version + (pos - OPREGION_VERSION),
 					    &pos, &remaining, bytes))
 			return -EFAULT;
 	}

 	/* Copy until RVDA */
 	if (remaining && pos < OPREGION_RVDA) {
 		size_t bytes = min_t(size_t, remaining, OPREGION_RVDA - pos);

 		if (igd_opregion_shift_copy(buf, &off,
 					    opregionvbt->opregion + pos, &pos,
 					    &remaining, bytes))
 			return -EFAULT;
 	}

 	/* Copy modified (if necessary) RVDA */
 	if (remaining && pos < OPREGION_RVDA + sizeof(__le64)) {
 		size_t bytes = min_t(size_t, remaining,
 				     OPREGION_RVDA + sizeof(__le64) - pos);
 		__le64 rvda = cpu_to_le64(opregionvbt->vbt_ex ?
 					  OPREGION_SIZE : 0);

 		if (igd_opregion_shift_copy(buf, &off,
 					    &rvda + (pos - OPREGION_RVDA),
 					    &pos, &remaining, bytes))
 			return -EFAULT;
 	}

 	/* Copy the rest of OpRegion */
 	if (remaining && pos < OPREGION_SIZE) {
 		size_t bytes = min_t(size_t, remaining, OPREGION_SIZE - pos);

 		if (igd_opregion_shift_copy(buf, &off,
 					    opregionvbt->opregion + pos, &pos,
 					    &remaining, bytes))
 			return -EFAULT;
 	}

 	/* Copy extended VBT if exists */
 	if (remaining &&
 	    copy_to_user(buf + off, opregionvbt->vbt_ex + (pos - OPREGION_SIZE),
 			 remaining))
 		return -EFAULT;

 	*ppos += count;

 	return count;
 }

 static void vfio_pci_igd_release(struct vfio_pci_core_device *vdev,
 				 struct vfio_pci_region *region)
 {
 	struct igd_opregion_vbt *opregionvbt = region->data;

 	if (opregionvbt->vbt_ex)
 		memunmap(opregionvbt->vbt_ex);

 	memunmap(opregionvbt->opregion);
 	kfree(opregionvbt);
 }

 static const struct vfio_pci_regops vfio_pci_igd_regops = {
 	.rw		= vfio_pci_igd_rw,
 	.release	= vfio_pci_igd_release,
 };

 static int vfio_pci_igd_opregion_init(struct vfio_pci_core_device *vdev)
 {
 	__le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);
 	u32 addr, size;
 	struct igd_opregion_vbt *opregionvbt;
 	int ret;
 	u16 version;

 	ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
 	if (ret)
 		return ret;

 	if (!addr || !(~addr))
 		return -ENODEV;

 	opregionvbt = kzalloc(sizeof(*opregionvbt), GFP_KERNEL);
 	if (!opregionvbt)
 		return -ENOMEM;

 	opregionvbt->opregion = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);
 	if (!opregionvbt->opregion) {
 		kfree(opregionvbt);
 		return -ENOMEM;
 	}

 	if (memcmp(opregionvbt->opregion, OPREGION_SIGNATURE, 16)) {
 		memunmap(opregionvbt->opregion);
 		kfree(opregionvbt);
 		return -EINVAL;
 	}

 	size = le32_to_cpu(*(__le32 *)(opregionvbt->opregion + 16));
 	if (!size) {
 		memunmap(opregionvbt->opregion);
 		kfree(opregionvbt);
 		return -EINVAL;
 	}

 	size *= 1024; /* In KB */

 	/*
 	 * OpRegion and VBT:
 	 * When VBT data doesn't exceed 6KB, it's stored in Mailbox #4.
 	 * When VBT data exceeds 6KB size, Mailbox #4 is no longer large enough
 	 * to hold the VBT data, the Extended VBT region is introduced since
 	 * OpRegion 2.0 to hold the VBT data. Since OpRegion 2.0, RVDA/RVDS are
 	 * introduced to define the extended VBT data location and size.
 	 * OpRegion 2.0: RVDA defines the absolute physical address of the
 	 *   extended VBT data, RVDS defines the VBT data size.
 	 * OpRegion 2.1 and above: RVDA defines the relative address of the
 	 *   extended VBT data to OpRegion base, RVDS defines the VBT data size.
 	 *
 	 * Due to the RVDA definition diff in OpRegion VBT (also the only diff
 	 * between 2.0 and 2.1), exposing OpRegion and VBT as a contiguous range
 	 * for OpRegion 2.0 and above makes it possible to support the
 	 * non-contiguous VBT through a single vfio region. From r/w ops view,
 	 * only contiguous VBT after OpRegion with version 2.1+ is exposed,
 	 * regardless the host OpRegion is 2.0 or non-contiguous 2.1+. The r/w
 	 * ops will on-the-fly shift the actural offset into VBT so that data at
 	 * correct position can be returned to the requester.
 	 */
 	version = le16_to_cpu(*(__le16 *)(opregionvbt->opregion +
 					  OPREGION_VERSION));
 	if (version >= 0x0200) {
 		u64 rvda = le64_to_cpu(*(__le64 *)(opregionvbt->opregion +
 						   OPREGION_RVDA));
 		u32 rvds = le32_to_cpu(*(__le32 *)(opregionvbt->opregion +
 						   OPREGION_RVDS));

 		/* The extended VBT is valid only when RVDA/RVDS are non-zero */
 		if (rvda && rvds) {
 			size += rvds;

 			/*
 			 * Extended VBT location by RVDA:
 			 * Absolute physical addr for 2.0.
 			 * Relative addr to OpRegion header for 2.1+.
 			 */
 			if (version == 0x0200)
 				addr = rvda;
 			else
 				addr += rvda;

 			opregionvbt->vbt_ex = memremap(addr, rvds, MEMREMAP_WB);
 			if (!opregionvbt->vbt_ex) {
 				memunmap(opregionvbt->opregion);
 				kfree(opregionvbt);
 				return -ENOMEM;
 			}
 		}
 	}

 	ret = vfio_pci_register_dev_region(vdev,
 		PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
 		VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, &vfio_pci_igd_regops,
 		size, VFIO_REGION_INFO_FLAG_READ, opregionvbt);
 	if (ret) {
 		if (opregionvbt->vbt_ex)
 			memunmap(opregionvbt->vbt_ex);

 		memunmap(opregionvbt->opregion);
 		kfree(opregionvbt);
 		return ret;
 	}

 	/* Fill vconfig with the hw value and virtualize register */
 	*dwordp = cpu_to_le32(addr);
 	memset(vdev->pci_config_map + OPREGION_PCI_ADDR,
 	       PCI_CAP_ID_INVALID_VIRT, 4);

 	return ret;
 }

 static ssize_t vfio_pci_igd_cfg_rw(struct vfio_pci_core_device *vdev,
 				   char __user *buf, size_t count, loff_t *ppos,
 				   bool iswrite)
 {
 	unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
 	struct pci_dev *pdev = vdev->region[i].data;
 	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
 	size_t size;
 	int ret;

 	if (pos >= vdev->region[i].size || iswrite)
 		return -EINVAL;

 	size = count = min(count, (size_t)(vdev->region[i].size - pos));

 	if ((pos & 1) && size) {
 		u8 val;

 		ret = pci_user_read_config_byte(pdev, pos, &val);
 		if (ret)
 			return ret;

 		if (copy_to_user(buf + count - size, &val, 1))
 			return -EFAULT;

 		pos++;
 		size--;
 	}

 	if ((pos & 3) && size > 2) {
 		u16 val;

 		ret = pci_user_read_config_word(pdev, pos, &val);
 		if (ret)
 			return ret;

 		val = cpu_to_le16(val);
 		if (copy_to_user(buf + count - size, &val, 2))
 			return -EFAULT;

 		pos += 2;
 		size -= 2;
 	}

 	while (size > 3) {
 		u32 val;

 		ret = pci_user_read_config_dword(pdev, pos, &val);
 		if (ret)
 			return ret;

 		val = cpu_to_le32(val);
 		if (copy_to_user(buf + count - size, &val, 4))
 			return -EFAULT;

 		pos += 4;
 		size -= 4;
 	}

 	while (size >= 2) {
 		u16 val;

 		ret = pci_user_read_config_word(pdev, pos, &val);
 		if (ret)
 			return ret;

 		val = cpu_to_le16(val);
 		if (copy_to_user(buf + count - size, &val, 2))
 			return -EFAULT;

 		pos += 2;
 		size -= 2;
 	}

 	while (size) {
 		u8 val;

 		ret = pci_user_read_config_byte(pdev, pos, &val);
 		if (ret)
 			return ret;

 		if (copy_to_user(buf + count - size, &val, 1))
 			return -EFAULT;

 		pos++;
 		size--;
 	}

 	*ppos += count;

 	return count;
 }

 static void vfio_pci_igd_cfg_release(struct vfio_pci_core_device *vdev,
 				     struct vfio_pci_region *region)
 {
 	struct pci_dev *pdev = region->data;

 	pci_dev_put(pdev);
 }

 static const struct vfio_pci_regops vfio_pci_igd_cfg_regops = {
 	.rw		= vfio_pci_igd_cfg_rw,
 	.release	= vfio_pci_igd_cfg_release,
 };

 static int vfio_pci_igd_cfg_init(struct vfio_pci_core_device *vdev)
 {
 	struct pci_dev *host_bridge, *lpc_bridge;
 	int ret;

 	host_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
 	if (!host_bridge)
 		return -ENODEV;

 	if (host_bridge->vendor != PCI_VENDOR_ID_INTEL ||
 	    host_bridge->class != (PCI_CLASS_BRIDGE_HOST << 8)) {
 		pci_dev_put(host_bridge);
 		return -EINVAL;
 	}

 	ret = vfio_pci_register_dev_region(vdev,
 		PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
 		VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG,
 		&vfio_pci_igd_cfg_regops, host_bridge->cfg_size,
 		VFIO_REGION_INFO_FLAG_READ, host_bridge);
 	if (ret) {
 		pci_dev_put(host_bridge);
 		return ret;
 	}

 	lpc_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x1f, 0));
 	if (!lpc_bridge)
 		return -ENODEV;

 	if (lpc_bridge->vendor != PCI_VENDOR_ID_INTEL ||
 	    lpc_bridge->class != (PCI_CLASS_BRIDGE_ISA << 8)) {
 		pci_dev_put(lpc_bridge);
 		return -EINVAL;
 	}

 	ret = vfio_pci_register_dev_region(vdev,
 		PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
 		VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG,
 		&vfio_pci_igd_cfg_regops, lpc_bridge->cfg_size,
 		VFIO_REGION_INFO_FLAG_READ, lpc_bridge);
 	if (ret) {
 		pci_dev_put(lpc_bridge);
 		return ret;
 	}

 	return 0;
 }

 int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
 {
 	int ret;

 	ret = vfio_pci_igd_opregion_init(vdev);
 	if (ret)
 		return ret;

 	ret = vfio_pci_igd_cfg_init(vdev);
 	if (ret)
 		return ret;

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* VFIO PCI Intel Graphics support
	*
	* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
	* Author: Alex Williamson <alex.williamson@redhat.com>
	*
	* Register a device specific region through which to provide read-only
	* access to the Intel IGD opregion. The register defining the opregion
	* address is also virtualized to prevent user modification.
	*/

	#include <linux/io.h>
	#include <linux/pci.h>
	#include <linux/uaccess.h>
	#include <linux/vfio.h>

	#include <linux/vfio_pci_core.h>

	#define OPREGION_SIGNATURE "IntelGraphicsMem"
	#define OPREGION_SIZE (8 * 1024)
	#define OPREGION_PCI_ADDR 0xfc

	#define OPREGION_RVDA 0x3ba
	#define OPREGION_RVDS 0x3c2
	#define OPREGION_VERSION 0x16

	struct igd_opregion_vbt {
	void *opregion;
	void *vbt_ex;
	};

	/**
	* igd_opregion_shift_copy() - Copy OpRegion to user buffer and shift position.
	* @dst: User buffer ptr to copy to.
	* @off: Offset to user buffer ptr. Increased by bytes on return.
	* @src: Source buffer to copy from.
	* @pos: Increased by bytes on return.
	* @remaining: Decreased by bytes on return.
	* @bytes: Bytes to copy and adjust off, pos and remaining.
	*
	* Copy OpRegion to offset from specific source ptr and shift the offset.
	*
	* Return: 0 on success, -EFAULT otherwise.
	*
	*/
	static inline unsigned long igd_opregion_shift_copy(char __user *dst,
	loff_t *off,
	void *src,
	loff_t *pos,
	size_t *remaining,
	size_t bytes)
	{
	if (copy_to_user(dst + (*off), src, bytes))
	return -EFAULT;

	*off += bytes;
	*pos += bytes;
	*remaining -= bytes;

	return 0;
	}

	static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_device *vdev,
	char __user buf, size_t count, loff_t ppos,
	bool iswrite)
	{
	unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
	struct igd_opregion_vbt *opregionvbt = vdev->region[i].data;
	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK, off = 0;
	size_t remaining;

	if (pos >= vdev->region[i].size \|\| iswrite)
	return -EINVAL;

	count = min_t(size_t, count, vdev->region[i].size - pos);
	remaining = count;

	/* Copy until OpRegion version */
	if (remaining && pos < OPREGION_VERSION) {
	size_t bytes = min_t(size_t, remaining, OPREGION_VERSION - pos);

	if (igd_opregion_shift_copy(buf, &off,
	opregionvbt->opregion + pos, &pos,
	&remaining, bytes))
	return -EFAULT;
	}

	/* Copy patched (if necessary) OpRegion version */
	if (remaining && pos < OPREGION_VERSION + sizeof(__le16)) {
	size_t bytes = min_t(size_t, remaining,
	OPREGION_VERSION + sizeof(__le16) - pos);
	__le16 version = (__le16 )(opregionvbt->opregion +
	OPREGION_VERSION);

	/* Patch to 2.1 if OpRegion 2.0 has extended VBT */
	if (le16_to_cpu(version) == 0x0200 && opregionvbt->vbt_ex)
	version = cpu_to_le16(0x0201);

	if (igd_opregion_shift_copy(buf, &off,
	&version + (pos - OPREGION_VERSION),
	&pos, &remaining, bytes))
	return -EFAULT;
	}

	/* Copy until RVDA */
	if (remaining && pos < OPREGION_RVDA) {
	size_t bytes = min_t(size_t, remaining, OPREGION_RVDA - pos);

	if (igd_opregion_shift_copy(buf, &off,
	opregionvbt->opregion + pos, &pos,
	&remaining, bytes))
	return -EFAULT;
	}

	/* Copy modified (if necessary) RVDA */
	if (remaining && pos < OPREGION_RVDA + sizeof(__le64)) {
	size_t bytes = min_t(size_t, remaining,
	OPREGION_RVDA + sizeof(__le64) - pos);
	__le64 rvda = cpu_to_le64(opregionvbt->vbt_ex ?
	OPREGION_SIZE : 0);

	if (igd_opregion_shift_copy(buf, &off,
	&rvda + (pos - OPREGION_RVDA),
	&pos, &remaining, bytes))
	return -EFAULT;
	}

	/* Copy the rest of OpRegion */
	if (remaining && pos < OPREGION_SIZE) {
	size_t bytes = min_t(size_t, remaining, OPREGION_SIZE - pos);

	if (igd_opregion_shift_copy(buf, &off,
	opregionvbt->opregion + pos, &pos,
	&remaining, bytes))
	return -EFAULT;
	}

	/* Copy extended VBT if exists */
	if (remaining &&
	copy_to_user(buf + off, opregionvbt->vbt_ex + (pos - OPREGION_SIZE),
	remaining))
	return -EFAULT;

	*ppos += count;

	return count;
	}

	static void vfio_pci_igd_release(struct vfio_pci_core_device *vdev,
	struct vfio_pci_region *region)
	{
	struct igd_opregion_vbt *opregionvbt = region->data;

	if (opregionvbt->vbt_ex)
	memunmap(opregionvbt->vbt_ex);

	memunmap(opregionvbt->opregion);
	kfree(opregionvbt);
	}

	static const struct vfio_pci_regops vfio_pci_igd_regops = {
	.rw = vfio_pci_igd_rw,
	.release = vfio_pci_igd_release,
	};

	static int vfio_pci_igd_opregion_init(struct vfio_pci_core_device *vdev)
	{
	__le32 dwordp = (__le32 )(vdev->vconfig + OPREGION_PCI_ADDR);
	u32 addr, size;
	struct igd_opregion_vbt *opregionvbt;
	int ret;
	u16 version;

	ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
	if (ret)
	return ret;

	if (!addr \|\| !(~addr))
	return -ENODEV;

	opregionvbt = kzalloc(sizeof(*opregionvbt), GFP_KERNEL);
	if (!opregionvbt)
	return -ENOMEM;

	opregionvbt->opregion = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);
	if (!opregionvbt->opregion) {
	kfree(opregionvbt);
	return -ENOMEM;
	}

	if (memcmp(opregionvbt->opregion, OPREGION_SIGNATURE, 16)) {
	memunmap(opregionvbt->opregion);
	kfree(opregionvbt);
	return -EINVAL;
	}

	size = le32_to_cpu((__le32 )(opregionvbt->opregion + 16));
	if (!size) {
	memunmap(opregionvbt->opregion);
	kfree(opregionvbt);
	return -EINVAL;
	}

	size = 1024; / In KB */

	/*
	* OpRegion and VBT:
	* When VBT data doesn't exceed 6KB, it's stored in Mailbox #4.
	* When VBT data exceeds 6KB size, Mailbox #4 is no longer large enough
	* to hold the VBT data, the Extended VBT region is introduced since
	* OpRegion 2.0 to hold the VBT data. Since OpRegion 2.0, RVDA/RVDS are
	* introduced to define the extended VBT data location and size.
	* OpRegion 2.0: RVDA defines the absolute physical address of the
	* extended VBT data, RVDS defines the VBT data size.
	* OpRegion 2.1 and above: RVDA defines the relative address of the
	* extended VBT data to OpRegion base, RVDS defines the VBT data size.
	*
	* Due to the RVDA definition diff in OpRegion VBT (also the only diff
	* between 2.0 and 2.1), exposing OpRegion and VBT as a contiguous range
	* for OpRegion 2.0 and above makes it possible to support the
	* non-contiguous VBT through a single vfio region. From r/w ops view,
	* only contiguous VBT after OpRegion with version 2.1+ is exposed,
	* regardless the host OpRegion is 2.0 or non-contiguous 2.1+. The r/w
	* ops will on-the-fly shift the actural offset into VBT so that data at
	* correct position can be returned to the requester.
	*/
	version = le16_to_cpu((__le16 )(opregionvbt->opregion +
	OPREGION_VERSION));
	if (version >= 0x0200) {
	u64 rvda = le64_to_cpu((__le64 )(opregionvbt->opregion +
	OPREGION_RVDA));
	u32 rvds = le32_to_cpu((__le32 )(opregionvbt->opregion +
	OPREGION_RVDS));

	/* The extended VBT is valid only when RVDA/RVDS are non-zero */
	if (rvda && rvds) {
	size += rvds;

	/*
	* Extended VBT location by RVDA:
	* Absolute physical addr for 2.0.
	* Relative addr to OpRegion header for 2.1+.
	*/
	if (version == 0x0200)
	addr = rvda;
	else
	addr += rvda;

	opregionvbt->vbt_ex = memremap(addr, rvds, MEMREMAP_WB);
	if (!opregionvbt->vbt_ex) {
	memunmap(opregionvbt->opregion);
	kfree(opregionvbt);
	return -ENOMEM;
	}
	}
	}

	ret = vfio_pci_register_dev_region(vdev,
	PCI_VENDOR_ID_INTEL \| VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
	VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, &vfio_pci_igd_regops,
	size, VFIO_REGION_INFO_FLAG_READ, opregionvbt);
	if (ret) {
	if (opregionvbt->vbt_ex)
	memunmap(opregionvbt->vbt_ex);

	memunmap(opregionvbt->opregion);
	kfree(opregionvbt);
	return ret;
	}

	/* Fill vconfig with the hw value and virtualize register */
	*dwordp = cpu_to_le32(addr);
	memset(vdev->pci_config_map + OPREGION_PCI_ADDR,
	PCI_CAP_ID_INVALID_VIRT, 4);

	return ret;
	}

	static ssize_t vfio_pci_igd_cfg_rw(struct vfio_pci_core_device *vdev,
	char __user buf, size_t count, loff_t ppos,
	bool iswrite)
	{
	unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
	struct pci_dev *pdev = vdev->region[i].data;
	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
	size_t size;
	int ret;

	if (pos >= vdev->region[i].size \|\| iswrite)
	return -EINVAL;

	size = count = min(count, (size_t)(vdev->region[i].size - pos));

	if ((pos & 1) && size) {
	u8 val;

	ret = pci_user_read_config_byte(pdev, pos, &val);
	if (ret)
	return ret;

	if (copy_to_user(buf + count - size, &val, 1))
	return -EFAULT;

	pos++;
	size--;
	}

	if ((pos & 3) && size > 2) {
	u16 val;

	ret = pci_user_read_config_word(pdev, pos, &val);
	if (ret)
	return ret;

	val = cpu_to_le16(val);
	if (copy_to_user(buf + count - size, &val, 2))
	return -EFAULT;

	pos += 2;
	size -= 2;
	}

	while (size > 3) {
	u32 val;

	ret = pci_user_read_config_dword(pdev, pos, &val);
	if (ret)
	return ret;

	val = cpu_to_le32(val);
	if (copy_to_user(buf + count - size, &val, 4))
	return -EFAULT;

	pos += 4;
	size -= 4;
	}

	while (size >= 2) {
	u16 val;

	ret = pci_user_read_config_word(pdev, pos, &val);
	if (ret)
	return ret;

	val = cpu_to_le16(val);
	if (copy_to_user(buf + count - size, &val, 2))
	return -EFAULT;

	pos += 2;
	size -= 2;
	}

	while (size) {
	u8 val;

	ret = pci_user_read_config_byte(pdev, pos, &val);
	if (ret)
	return ret;

	if (copy_to_user(buf + count - size, &val, 1))
	return -EFAULT;

	pos++;
	size--;
	}

	*ppos += count;

	return count;
	}

	static void vfio_pci_igd_cfg_release(struct vfio_pci_core_device *vdev,
	struct vfio_pci_region *region)
	{
	struct pci_dev *pdev = region->data;

	pci_dev_put(pdev);
	}

	static const struct vfio_pci_regops vfio_pci_igd_cfg_regops = {
	.rw = vfio_pci_igd_cfg_rw,
	.release = vfio_pci_igd_cfg_release,
	};

	static int vfio_pci_igd_cfg_init(struct vfio_pci_core_device *vdev)
	{
	struct pci_dev host_bridge, lpc_bridge;
	int ret;

	host_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
	if (!host_bridge)
	return -ENODEV;

	if (host_bridge->vendor != PCI_VENDOR_ID_INTEL \|\|
	host_bridge->class != (PCI_CLASS_BRIDGE_HOST << 8)) {
	pci_dev_put(host_bridge);
	return -EINVAL;
	}

	ret = vfio_pci_register_dev_region(vdev,
	PCI_VENDOR_ID_INTEL \| VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
	VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG,
	&vfio_pci_igd_cfg_regops, host_bridge->cfg_size,
	VFIO_REGION_INFO_FLAG_READ, host_bridge);
	if (ret) {
	pci_dev_put(host_bridge);
	return ret;
	}

	lpc_bridge = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0x1f, 0));
	if (!lpc_bridge)
	return -ENODEV;

	if (lpc_bridge->vendor != PCI_VENDOR_ID_INTEL \|\|
	lpc_bridge->class != (PCI_CLASS_BRIDGE_ISA << 8)) {
	pci_dev_put(lpc_bridge);
	return -EINVAL;
	}

	ret = vfio_pci_register_dev_region(vdev,
	PCI_VENDOR_ID_INTEL \| VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
	VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG,
	&vfio_pci_igd_cfg_regops, lpc_bridge->cfg_size,
	VFIO_REGION_INFO_FLAG_READ, lpc_bridge);
	if (ret) {
	pci_dev_put(lpc_bridge);
	return ret;
	}

	return 0;
	}

	int vfio_pci_igd_init(struct vfio_pci_core_device *vdev)
	{
	int ret;

	ret = vfio_pci_igd_opregion_init(vdev);
	if (ret)
	return ret;

	ret = vfio_pci_igd_cfg_init(vdev);
	if (ret)
	return ret;

	return 0;
	}