text: /*
   * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   *     Author: Alex Williamson <alex.williamson@redhat.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * Derived from original vfio:
   * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
   * Author: Tom Lyon, pugs@cisco.com
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/device.h>
  #include <linux/eventfd.h>
  #include <linux/file.h>
  #include <linux/interrupt.h>
  #include <linux/iommu.h>
  #include <linux/module.h>
  #include <linux/mutex.h>
  #include <linux/notifier.h>
  #include <linux/pci.h>
  #include <linux/pm_runtime.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/uaccess.h>
  #include <linux/vfio.h>
  #include <linux/vgaarb.h>
  #include <linux/nospec.h>
  
  #include "vfio_pci_private.h"
  
  #define DRIVER_VERSION  "0.2"
  #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
  
  static char ids[1024] __initdata;
  module_param_string(ids, ids, sizeof(ids), 0);
  MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");
  
  static bool nointxmask;
  module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(nointxmask,
  		  "Disable support for PCI 2.3 style INTx masking.  If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");
  
  #ifdef CONFIG_VFIO_PCI_VGA
  static bool disable_vga;
  module_param(disable_vga, bool, S_IRUGO);
  MODULE_PARM_DESC(disable_vga, "Disable VGA resource access through vfio-pci");
  #endif
  
  static bool disable_idle_d3;
  module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR);
  MODULE_PARM_DESC(disable_idle_d3,
  		 "Disable using the PCI D3 low power state for idle, unused devices");
  
  static DEFINE_MUTEX(driver_lock);
  
  static inline bool vfio_vga_disabled(void)
  {
  #ifdef CONFIG_VFIO_PCI_VGA
  	return disable_vga;
  #else
  	return true;
  #endif
  }
  
  /*
   * Our VGA arbiter participation is limited since we don't know anything
   * about the device itself.  However, if the device is the only VGA device
   * downstream of a bridge and VFIO VGA support is disabled, then we can
   * safely return legacy VGA IO and memory as not decoded since the user
   * has no way to get to it and routing can be disabled externally at the
   * bridge.
   */
  static unsigned int vfio_pci_set_vga_decode(void *opaque, bool single_vga)
  {
  	struct vfio_pci_device *vdev = opaque;
  	struct pci_dev *tmp = NULL, *pdev = vdev->pdev;
  	unsigned char max_busnr;
  	unsigned int decodes;
  
  	if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus))
  		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
  		       VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  
  	max_busnr = pci_bus_max_busnr(pdev->bus);
  	decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
  
  	while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) {
  		if (tmp == pdev ||
  		    pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) ||
  		    pci_is_root_bus(tmp->bus))
  			continue;
  
  		if (tmp->bus->number >= pdev->bus->number &&
  		    tmp->bus->number <= max_busnr) {
  			pci_dev_put(tmp);
  			decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  			break;
  		}
  	}
  
  	return decodes;
  }
  
  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);
  
  /*
   * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
   * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
   * If a device implements the former but not the latter we would typically
   * expect broken_intx_masking be set and require an exclusive interrupt.
   * However since we do have control of the device's ability to assert INTx,
   * we can instead pretend that the device does not implement INTx, virtualizing
   * the pin register to report zero and maintaining DisINTx set on the host.
   */
  static bool vfio_pci_nointx(struct pci_dev *pdev)
  {
  	switch (pdev->vendor) {
  	case PCI_VENDOR_ID_INTEL:
  		switch (pdev->device) {
  		/* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
  		case 0x1572:
  		case 0x1574:
  		case 0x1580 ... 0x1581:
  		case 0x1583 ... 0x158b:
  		case 0x37d0 ... 0x37d2:
  			return true;
  		default:
  			return false;
  		}
  	}
  
  	return false;
  }
  
  static int vfio_pci_enable(struct vfio_pci_device *vdev)
  {
  	struct pci_dev *pdev = vdev->pdev;
  	int ret;
  	u16 cmd;
  	u8 msix_pos;
  
  	pci_set_power_state(pdev, PCI_D0);
  
  	/* Don't allow our initial saved state to include busmaster */
  	pci_clear_master(pdev);
  
  	ret = pci_enable_device(pdev);
  	if (ret)
  		return ret;
  
  	/* If reset fails because of the device lock, fail this path entirely */
  	ret = pci_try_reset_function(pdev);
  	if (ret == -EAGAIN) {
  		pci_disable_device(pdev);
  		return ret;
  	}
  
  	vdev->reset_works = !ret;
  	pci_save_state(pdev);
  	vdev->pci_saved_state = pci_store_saved_state(pdev);
  	if (!vdev->pci_saved_state)
  		pr_debug("%s: Couldn't store %s saved state\n",
  			 __func__, dev_name(&pdev->dev));
  
  	if (likely(!nointxmask)) {
  		if (vfio_pci_nointx(pdev)) {
  			dev_info(&pdev->dev, "Masking broken INTx support\n");
  			vdev->nointx = true;
  			pci_intx(pdev, 0);
  		} else
  			vdev->pci_2_3 = pci_intx_mask_supported(pdev);
  	}
  
  	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
  	if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
  		cmd &= ~PCI_COMMAND_INTX_DISABLE;
  		pci_write_config_word(pdev, PCI_COMMAND, cmd);
  	}
  
  	ret = vfio_config_init(vdev);
  	if (ret) {
  		kfree(vdev->pci_saved_state);
  		vdev->pci_saved_state = NULL;
  		pci_disable_device(pdev);
  		return ret;
  	}
  
  	msix_pos = pdev->msix_cap;
  	if (msix_pos) {
  		u16 flags;
  		u32 table;
  
  		pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
  		pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
  
  		vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
  		vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
  		vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
  	} else
  		vdev->msix_bar = 0xFF;
  
  	if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
  		vdev->has_vga = true;
  
  
  	if (vfio_pci_is_vga(pdev) &&
  	    pdev->vendor == PCI_VENDOR_ID_INTEL &&
  	    IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
  		ret = vfio_pci_igd_init(vdev);
  		if (ret) {
  			dev_warn(&vdev->pdev->dev,
  				 "Failed to setup Intel IGD regions\n");
  			vfio_pci_disable(vdev);
  			return ret;
  		}
  	}
  
  	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;
  	struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
  	int i, bar;
  
  	/* Stop the device from further DMA */
  	pci_clear_master(pdev);
  
  	vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
  				VFIO_IRQ_SET_ACTION_TRIGGER,
  				vdev->irq_type, 0, 0, NULL);
  
  	/* Device closed, don't need mutex here */
  	list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
  				 &vdev->ioeventfds_list, next) {
  		vfio_virqfd_disable(&ioeventfd->virqfd);
  		list_del(&ioeventfd->next);
  		kfree(ioeventfd);
  	}
  	vdev->ioeventfds_nr = 0;
  
  	vdev->virq_disabled = false;
  
  	for (i = 0; i < vdev->num_regions; i++)
  		vdev->region[i].ops->release(vdev, &vdev->region[i]);
  
  	vdev->num_regions = 0;
  	kfree(vdev->region);
  	vdev->region = NULL; /* don't krealloc a freed pointer */
  
  	vfio_config_free(vdev);
  
  	for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
  		if (!vdev->barmap[bar])
  			continue;
  		pci_iounmap(pdev, vdev->barmap[bar]);
  		pci_release_selected_regions(pdev, 1 << bar);
  		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;
  
  	/*
  	 * If we have saved state, restore it.  If we can reset the device,
  	 * even better.  Resetting with current state seems better than
  	 * nothing, but saving and restoring current state without reset
  	 * is just busy work.
  	 */
  	if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
  		pr_info("%s: Couldn't reload %s saved state\n",
  			__func__, dev_name(&pdev->dev));
  
  		if (!vdev->reset_works)
  			goto out;
  
  		pci_save_state(pdev);
  	}
  
  	/*
  	 * Disable INTx and MSI, presumably to avoid spurious interrupts
  	 * during reset.  Stolen from pci_reset_function()
  	 */
  	pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
  
  	/*
  	 * Try to reset the device.  The success of this is dependent on
  	 * being able to lock the device, which is not always possible.
  	 */
  	if (vdev->reset_works && !pci_try_reset_function(pdev))
  		vdev->needs_reset = false;
  
  	pci_restore_state(pdev);
  out:
  	pci_disable_device(pdev);
  
  	vfio_pci_try_bus_reset(vdev);
  
  	if (!disable_idle_d3)
  		pci_set_power_state(pdev, PCI_D3hot);
  }
  
  static void vfio_pci_release(void *device_data)
  {
  	struct vfio_pci_device *vdev = device_data;
  
  	mutex_lock(&driver_lock);
  
  	if (!(--vdev->refcnt)) {
  		vfio_spapr_pci_eeh_release(vdev->pdev);
  		vfio_pci_disable(vdev);
  	}
  
  	mutex_unlock(&driver_lock);
  
  	module_put(THIS_MODULE);
  }
  
  static int vfio_pci_open(void *device_data)
  {
  	struct vfio_pci_device *vdev = device_data;
  	int ret = 0;
  
  	if (!try_module_get(THIS_MODULE))
  		return -ENODEV;
  
  	mutex_lock(&driver_lock);
  
  	if (!vdev->refcnt) {
  		ret = vfio_pci_enable(vdev);
  		if (ret)
  			goto error;
  
  		vfio_spapr_pci_eeh_open(vdev->pdev);
  	}
  	vdev->refcnt++;
  error:
  	mutex_unlock(&driver_lock);
  	if (ret)
  		module_put(THIS_MODULE);
  	return ret;
  }
  
  static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
  {
  	if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
  		u8 pin;
  		pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
  		if (IS_ENABLED(CONFIG_VFIO_PCI_INTX) && !vdev->nointx && pin)
  			return 1;
  
  	} else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
  		u8 pos;
  		u16 flags;
  
  		pos = vdev->pdev->msi_cap;
  		if (pos) {
  			pci_read_config_word(vdev->pdev,
  					     pos + PCI_MSI_FLAGS, &flags);
  			return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
  		}
  	} else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
  		u8 pos;
  		u16 flags;
  
  		pos = vdev->pdev->msix_cap;
  		if (pos) {
  			pci_read_config_word(vdev->pdev,
  					     pos + PCI_MSIX_FLAGS, &flags);
  
  			return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
  		}
  	} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
  		if (pci_is_pcie(vdev->pdev))
  			return 1;
  	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
  		return 1;
  	}
  
  	return 0;
  }
  
  static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
  {
  	(*(int *)data)++;
  	return 0;
  }
  
  struct vfio_pci_fill_info {
  	int max;
  	int cur;
  	struct vfio_pci_dependent_device *devices;
  };
  
  static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
  {
  	struct vfio_pci_fill_info *fill = data;
  	struct iommu_group *iommu_group;
  
  	if (fill->cur == fill->max)
  		return -EAGAIN; /* Something changed, try again */
  
  	iommu_group = iommu_group_get(&pdev->dev);
  	if (!iommu_group)
  		return -EPERM; /* Cannot reset non-isolated devices */
  
  	fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
  	fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
  	fill->devices[fill->cur].bus = pdev->bus->number;
  	fill->devices[fill->cur].devfn = pdev->devfn;
  	fill->cur++;
  	iommu_group_put(iommu_group);
  	return 0;
  }
  
  struct vfio_pci_group_entry {
  	struct vfio_group *group;
  	int id;
  };
  
  struct vfio_pci_group_info {
  	int count;
  	struct vfio_pci_group_entry *groups;
  };
  
  static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
  {
  	struct vfio_pci_group_info *info = data;
  	struct iommu_group *group;
  	int id, i;
  
  	group = iommu_group_get(&pdev->dev);
  	if (!group)
  		return -EPERM;
  
  	id = iommu_group_id(group);
  
  	for (i = 0; i < info->count; i++)
  		if (info->groups[i].id == id)
  			break;
  
  	iommu_group_put(group);
  
  	return (i == info->count) ? -EINVAL : 0;
  }
  
  static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
  {
  	for (; pdev; pdev = pdev->bus->self)
  		if (pdev->bus == slot->bus)
  			return (pdev->slot == slot);
  	return false;
  }
  
  struct vfio_pci_walk_info {
  	int (*fn)(struct pci_dev *, void *data);
  	void *data;
  	struct pci_dev *pdev;
  	bool slot;
  	int ret;
  };
  
  static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
  {
  	struct vfio_pci_walk_info *walk = data;
  
  	if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
  		walk->ret = walk->fn(pdev, walk->data);
  
  	return walk->ret;
  }
  
  static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
  					 int (*fn)(struct pci_dev *,
  						   void *data), void *data,
  					 bool slot)
  {
  	struct vfio_pci_walk_info walk = {
  		.fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
  	};
  
  	pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
  
  	return walk.ret;
  }
  
  static int msix_mmappable_cap(struct vfio_pci_device *vdev,
  			      struct vfio_info_cap *caps)
  {
  	struct vfio_info_cap_header header = {
  		.id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
  		.version = 1
  	};
  
  	return vfio_info_add_capability(caps, &header, sizeof(header));
  }
  
  int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
  				 unsigned int type, unsigned int subtype,
  				 const struct vfio_pci_regops *ops,
  				 size_t size, u32 flags, void *data)
  {
  	struct vfio_pci_region *region;
  
  	region = krealloc(vdev->region,
  			  (vdev->num_regions + 1) * sizeof(*region),
  			  GFP_KERNEL);
  	if (!region)
  		return -ENOMEM;
  
  	vdev->region = region;
  	vdev->region[vdev->num_regions].type = type;
  	vdev->region[vdev->num_regions].subtype = subtype;
  	vdev->region[vdev->num_regions].ops = ops;
  	vdev->region[vdev->num_regions].size = size;
  	vdev->region[vdev->num_regions].flags = flags;
  	vdev->region[vdev->num_regions].data = data;
  
  	vdev->num_regions++;
  
  	return 0;
  }
  
  static long vfio_pci_ioctl(void *device_data,
  			   unsigned int cmd, unsigned long arg)
  {
  	struct vfio_pci_device *vdev = device_data;
  	unsigned long minsz;
  
  	if (cmd == VFIO_DEVICE_GET_INFO) {
  		struct vfio_device_info info;
  
  		minsz = offsetofend(struct vfio_device_info, num_irqs);
  
  		if (copy_from_user(&info, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (info.argsz < minsz)
  			return -EINVAL;
  
  		info.flags = VFIO_DEVICE_FLAGS_PCI;
  
  		if (vdev->reset_works)
  			info.flags |= VFIO_DEVICE_FLAGS_RESET;
  
  		info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
  		info.num_irqs = VFIO_PCI_NUM_IRQS;
  
  		return copy_to_user((void __user *)arg, &info, minsz) ?
  			-EFAULT : 0;
  
  	} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
  		struct pci_dev *pdev = vdev->pdev;
  		struct vfio_region_info info;
  		struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
  		int i, ret;
  
  		minsz = offsetofend(struct vfio_region_info, offset);
  
  		if (copy_from_user(&info, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (info.argsz < minsz)
  			return -EINVAL;
  
  		switch (info.index) {
  		case VFIO_PCI_CONFIG_REGION_INDEX:
  			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
  			info.size = pdev->cfg_size;
  			info.flags = VFIO_REGION_INFO_FLAG_READ |
  				     VFIO_REGION_INFO_FLAG_WRITE;
  			break;
  		case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
  			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
  			info.size = pci_resource_len(pdev, info.index);
  			if (!info.size) {
  				info.flags = 0;
  				break;
  			}
  
  			info.flags = VFIO_REGION_INFO_FLAG_READ |
  				     VFIO_REGION_INFO_FLAG_WRITE;
  			if (vdev->bar_mmap_supported[info.index]) {
  				info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
  				if (info.index == vdev->msix_bar) {
  					ret = msix_mmappable_cap(vdev, &caps);
  					if (ret)
  						return ret;
  				}
  			}
  
  			break;
  		case VFIO_PCI_ROM_REGION_INDEX:
  		{
  			void __iomem *io;
  			size_t size;
  
  			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
  			info.flags = 0;
  
  			/* Report the BAR size, not the ROM size */
  			info.size = pci_resource_len(pdev, info.index);
  			if (!info.size) {
  				/* Shadow ROMs appear as PCI option ROMs */
  				if (pdev->resource[PCI_ROM_RESOURCE].flags &
  							IORESOURCE_ROM_SHADOW)
  					info.size = 0x20000;
  				else
  					break;
  			}
  
  			/* Is it really there? */
  			io = pci_map_rom(pdev, &size);
  			if (!io || !size) {
  				info.size = 0;
  				break;
  			}
  			pci_unmap_rom(pdev, io);
  
  			info.flags = VFIO_REGION_INFO_FLAG_READ;
  			break;
  		}
  		case VFIO_PCI_VGA_REGION_INDEX:
  			if (!vdev->has_vga)
  				return -EINVAL;
  
  			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
  			info.size = 0xc0000;
  			info.flags = VFIO_REGION_INFO_FLAG_READ |
  				     VFIO_REGION_INFO_FLAG_WRITE;
  
  			break;
  		default:
  		{
  			struct vfio_region_info_cap_type cap_type = {
  					.header.id = VFIO_REGION_INFO_CAP_TYPE,
  					.header.version = 1 };
  
  			if (info.index >=
  			    VFIO_PCI_NUM_REGIONS + vdev->num_regions)
  				return -EINVAL;
  			info.index = array_index_nospec(info.index,
  							VFIO_PCI_NUM_REGIONS +
  							vdev->num_regions);
  
  			i = info.index - VFIO_PCI_NUM_REGIONS;
  
  			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
  			info.size = vdev->region[i].size;
  			info.flags = vdev->region[i].flags;
  
  			cap_type.type = vdev->region[i].type;
  			cap_type.subtype = vdev->region[i].subtype;
  
  			ret = vfio_info_add_capability(&caps, &cap_type.header,
  						       sizeof(cap_type));
  			if (ret)
  				return ret;
  
  		}
  		}
  
  		if (caps.size) {
  			info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
  			if (info.argsz < sizeof(info) + caps.size) {
  				info.argsz = sizeof(info) + caps.size;
  				info.cap_offset = 0;
  			} else {
  				vfio_info_cap_shift(&caps, sizeof(info));
  				if (copy_to_user((void __user *)arg +
  						  sizeof(info), caps.buf,
  						  caps.size)) {
  					kfree(caps.buf);
  					return -EFAULT;
  				}
  				info.cap_offset = sizeof(info);
  			}
  
  			kfree(caps.buf);
  		}
  
  		return copy_to_user((void __user *)arg, &info, minsz) ?
  			-EFAULT : 0;
  
  	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
  		struct vfio_irq_info info;
  
  		minsz = offsetofend(struct vfio_irq_info, count);
  
  		if (copy_from_user(&info, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
  			return -EINVAL;
  
  		switch (info.index) {
  		case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
  		case VFIO_PCI_REQ_IRQ_INDEX:
  			break;
  		case VFIO_PCI_ERR_IRQ_INDEX:
  			if (pci_is_pcie(vdev->pdev))
  				break;
  		/* fall through */
  		default:
  			return -EINVAL;
  		}
  
  		info.flags = VFIO_IRQ_INFO_EVENTFD;
  
  		info.count = vfio_pci_get_irq_count(vdev, info.index);
  
  		if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
  			info.flags |= (VFIO_IRQ_INFO_MASKABLE |
  				       VFIO_IRQ_INFO_AUTOMASKED);
  		else
  			info.flags |= VFIO_IRQ_INFO_NORESIZE;
  
  		return copy_to_user((void __user *)arg, &info, minsz) ?
  			-EFAULT : 0;
  
  	} else if (cmd == VFIO_DEVICE_SET_IRQS) {
  		struct vfio_irq_set hdr;
  		u8 *data = NULL;
  		int max, ret = 0;
  		size_t data_size = 0;
  
  		minsz = offsetofend(struct vfio_irq_set, count);
  
  		if (copy_from_user(&hdr, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		max = vfio_pci_get_irq_count(vdev, hdr.index);
  
  		ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
  						 VFIO_PCI_NUM_IRQS, &data_size);
  		if (ret)
  			return ret;
  
  		if (data_size) {
  			data = memdup_user((void __user *)(arg + minsz),
  					    data_size);
  			if (IS_ERR(data))
  				return PTR_ERR(data);
  		}
  
  		mutex_lock(&vdev->igate);
  
  		ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
  					      hdr.start, hdr.count, data);
  
  		mutex_unlock(&vdev->igate);
  		kfree(data);
  
  		return ret;
  
  	} else if (cmd == VFIO_DEVICE_RESET) {
  		return vdev->reset_works ?
  			pci_try_reset_function(vdev->pdev) : -EINVAL;
  
  	} else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
  		struct vfio_pci_hot_reset_info hdr;
  		struct vfio_pci_fill_info fill = { 0 };
  		struct vfio_pci_dependent_device *devices = NULL;
  		bool slot = false;
  		int ret = 0;
  
  		minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
  
  		if (copy_from_user(&hdr, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (hdr.argsz < minsz)
  			return -EINVAL;
  
  		hdr.flags = 0;
  
  		/* Can we do a slot or bus reset or neither? */
  		if (!pci_probe_reset_slot(vdev->pdev->slot))
  			slot = true;
  		else if (pci_probe_reset_bus(vdev->pdev->bus))
  			return -ENODEV;
  
  		/* How many devices are affected? */
  		ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
  						    vfio_pci_count_devs,
  						    &fill.max, slot);
  		if (ret)
  			return ret;
  
  		WARN_ON(!fill.max); /* Should always be at least one */
  
  		/*
  		 * If there's enough space, fill it now, otherwise return
  		 * -ENOSPC and the number of devices affected.
  		 */
  		if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
  			ret = -ENOSPC;
  			hdr.count = fill.max;
  			goto reset_info_exit;
  		}
  
  		devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
  		if (!devices)
  			return -ENOMEM;
  
  		fill.devices = devices;
  
  		ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
  						    vfio_pci_fill_devs,
  						    &fill, slot);
  
  		/*
  		 * If a device was removed between counting and filling,
  		 * we may come up short of fill.max.  If a device was
  		 * added, we'll have a return of -EAGAIN above.
  		 */
  		if (!ret)
  			hdr.count = fill.cur;
  
  reset_info_exit:
  		if (copy_to_user((void __user *)arg, &hdr, minsz))
  			ret = -EFAULT;
  
  		if (!ret) {
  			if (copy_to_user((void __user *)(arg + minsz), devices,
  					 hdr.count * sizeof(*devices)))
  				ret = -EFAULT;
  		}
  
  		kfree(devices);
  		return ret;
  
  	} else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
  		struct vfio_pci_hot_reset hdr;
  		int32_t *group_fds;
  		struct vfio_pci_group_entry *groups;
  		struct vfio_pci_group_info info;
  		bool slot = false;
  		int i, count = 0, ret = 0;
  
  		minsz = offsetofend(struct vfio_pci_hot_reset, count);
  
  		if (copy_from_user(&hdr, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (hdr.argsz < minsz || hdr.flags)
  			return -EINVAL;
  
  		/* Can we do a slot or bus reset or neither? */
  		if (!pci_probe_reset_slot(vdev->pdev->slot))
  			slot = true;
  		else if (pci_probe_reset_bus(vdev->pdev->bus))
  			return -ENODEV;
  
  		/*
  		 * We can't let userspace give us an arbitrarily large
  		 * buffer to copy, so verify how many we think there
  		 * could be.  Note groups can have multiple devices so
  		 * one group per device is the max.
  		 */
  		ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
  						    vfio_pci_count_devs,
  						    &count, slot);
  		if (ret)
  			return ret;
  
  		/* Somewhere between 1 and count is OK */
  		if (!hdr.count || hdr.count > count)
  			return -EINVAL;
  
  		group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
  		groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
  		if (!group_fds || !groups) {
  			kfree(group_fds);
  			kfree(groups);
  			return -ENOMEM;
  		}
  
  		if (copy_from_user(group_fds, (void __user *)(arg + minsz),
  				   hdr.count * sizeof(*group_fds))) {
  			kfree(group_fds);
  			kfree(groups);
  			return -EFAULT;
  		}
  
  		/*
  		 * For each group_fd, get the group through the vfio external
  		 * user interface and store the group and iommu ID.  This
  		 * ensures the group is held across the reset.
  		 */
  		for (i = 0; i < hdr.count; i++) {
  			struct vfio_group *group;
  			struct fd f = fdget(group_fds[i]);
  			if (!f.file) {
  				ret = -EBADF;
  				break;
  			}
  
  			group = vfio_group_get_external_user(f.file);
  			fdput(f);
  			if (IS_ERR(group)) {
  				ret = PTR_ERR(group);
  				break;
  			}
  
  			groups[i].group = group;
  			groups[i].id = vfio_external_user_iommu_id(group);
  		}
  
  		kfree(group_fds);
  
  		/* release reference to groups on error */
  		if (ret)
  			goto hot_reset_release;
  
  		info.count = hdr.count;
  		info.groups = groups;
  
  		/*
  		 * Test whether all the affected devices are contained
  		 * by the set of groups provided by the user.
  		 */
  		ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
  						    vfio_pci_validate_devs,
  						    &info, slot);
  		if (!ret)
  			/* User has access, do the reset */
  			ret = pci_reset_bus(vdev->pdev);
  
  hot_reset_release:
  		for (i--; i >= 0; i--)
  			vfio_group_put_external_user(groups[i].group);
  
  		kfree(groups);
  		return ret;
  	} else if (cmd == VFIO_DEVICE_IOEVENTFD) {
  		struct vfio_device_ioeventfd ioeventfd;
  		int count;
  
  		minsz = offsetofend(struct vfio_device_ioeventfd, fd);
  
  		if (copy_from_user(&ioeventfd, (void __user *)arg, minsz))
  			return -EFAULT;
  
  		if (ioeventfd.argsz < minsz)
  			return -EINVAL;
  
  		if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
  			return -EINVAL;
  
  		count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
  
  		if (hweight8(count) != 1 || ioeventfd.fd < -1)
  			return -EINVAL;
  
  		return vfio_pci_ioeventfd(vdev, ioeventfd.offset,
  					  ioeventfd.data, count, ioeventfd.fd);
  	}
  
  	return -ENOTTY;
  }
  
  static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
  			   size_t count, loff_t *ppos, bool iswrite)
  {
  	unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
  	struct vfio_pci_device *vdev = device_data;
  
  	if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
  		return -EINVAL;
  
  	switch (index) {
  	case VFIO_PCI_CONFIG_REGION_INDEX:
  		return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
  
  	case VFIO_PCI_ROM_REGION_INDEX:
  		if (iswrite)
  			return -EINVAL;
  		return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
  
  	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
  		return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
  
  	case VFIO_PCI_VGA_REGION_INDEX:
  		return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
  	default:
  		index -= VFIO_PCI_NUM_REGIONS;
  		return vdev->region[index].ops->rw(vdev, buf,
  						   count, ppos, iswrite);
  	}
  
  	return -EINVAL;
  }
  
  static ssize_t vfio_pci_read(void *device_data, char __user *buf,
  			     size_t count, loff_t *ppos)
  {
  	if (!count)
  		return 0;
  
  	return vfio_pci_rw(device_data, buf, count, ppos, false);
  }
  
  static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
  			      size_t count, loff_t *ppos)
  {
  	if (!count)
  		return 0;
  
  	return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
  }
  
  static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
  {
  	struct vfio_pci_device *vdev = device_data;
  	struct pci_dev *pdev = vdev->pdev;
  	unsigned int index;
  	u64 phys_len, req_len, pgoff, req_start;
  	int ret;
  
  	index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
  
  	if (vma->vm_end < vma->vm_start)
  		return -EINVAL;
  	if ((vma->vm_flags & VM_SHARED) == 0)
  		return -EINVAL;
  	if (index >= VFIO_PCI_ROM_REGION_INDEX)
  		return -EINVAL;
  	if (!vdev->bar_mmap_supported[index])
  		return -EINVAL;
  
  	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 (req_start + req_len > phys_len)
  		return -EINVAL;
  
  	/*
  	 * Even though we don't make use of the barmap for the mmap,
  	 * we need to request the region and the barmap tracks that.
  	 */
  	if (!vdev->barmap[index]) {
  		ret = pci_request_selected_regions(pdev,
  						   1 << index, "vfio-pci");
  		if (ret)
  			return ret;
  
  		vdev->barmap[index] = pci_iomap(pdev, index, 0);
  		if (!vdev->barmap[index]) {
  			pci_release_selected_regions(pdev, 1 << index);
  			return -ENOMEM;
  		}
  	}
  
  	vma->vm_private_data = vdev;
  	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  	vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
  
  	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
  			       req_len, vma->vm_page_prot);
  }
  
  static void vfio_pci_request(void *device_data, unsigned int count)
  {
  	struct vfio_pci_device *vdev = device_data;
  
  	mutex_lock(&vdev->igate);
  
  	if (vdev->req_trigger) {
  		if (!(count % 10))
  			dev_notice_ratelimited(&vdev->pdev->dev,
  				"Relaying device request to user (#%u)\n",
  				count);
  		eventfd_signal(vdev->req_trigger, 1);
  	} else if (count == 0) {
  		dev_warn(&vdev->pdev->dev,
  			"No device request channel registered, blocked until released by user\n");
  	}
  
  	mutex_unlock(&vdev->igate);
  }
  
  static const struct vfio_device_ops vfio_pci_ops = {
  	.name		= "vfio-pci",
  	.open		= vfio_pci_open,
  	.release	= vfio_pci_release,
  	.ioctl		= vfio_pci_ioctl,
  	.read		= vfio_pci_read,
  	.write		= vfio_pci_write,
  	.mmap		= vfio_pci_mmap,
  	.request	= vfio_pci_request,
  };
  
  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
  {
  	struct vfio_pci_device *vdev;
  	struct iommu_group *group;
  	int ret;
  
  	if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
  		return -EINVAL;
  
  	/*
  	 * Prevent binding to PFs with VFs enabled, this too easily allows
  	 * userspace instance with VFs and PFs from the same device, which
  	 * cannot work.  Disabling SR-IOV here would initiate removing the
  	 * VFs, which would unbind the driver, which is prone to blocking
  	 * if that VF is also in use by vfio-pci.  Just reject these PFs
  	 * and let the user sort it out.
  	 */
  	if (pci_num_vf(pdev)) {
  		pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
  		return -EBUSY;
  	}
  
  	group = vfio_iommu_group_get(&pdev->dev);
  	if (!group)
  		return -EINVAL;
  
  	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
  	if (!vdev) {
  		vfio_iommu_group_put(group, &pdev->dev);
  		return -ENOMEM;
  	}
  
  	vdev->pdev = pdev;
  	vdev->irq_type = VFIO_PCI_NUM_IRQS;
  	mutex_init(&vdev->igate);
  	spin_lock_init(&vdev->irqlock);
  	mutex_init(&vdev->ioeventfds_lock);
  	INIT_LIST_HEAD(&vdev->ioeventfds_list);
  
  	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
  	if (ret) {
  		vfio_iommu_group_put(group, &pdev->dev);
  		kfree(vdev);
  		return ret;
  	}
  
  	if (vfio_pci_is_vga(pdev)) {
  		vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
  		vga_set_legacy_decoding(pdev,
  					vfio_pci_set_vga_decode(vdev, false));
  	}
  
  	if (!disable_idle_d3) {
  		/*
  		 * pci-core sets the device power state to an unknown value at
  		 * bootup and after being removed from a driver.  The only
  		 * transition it allows from this unknown state is to D0, which
  		 * typically happens when a driver calls pci_enable_device().
  		 * We're not ready to enable the device yet, but we do want to
  		 * be able to get to D3.  Therefore first do a D0 transition
  		 * before going to D3.
  		 */
  		pci_set_power_state(pdev, PCI_D0);
  		pci_set_power_state(pdev, PCI_D3hot);
  	}
  
  	return ret;
  }
  
  static void vfio_pci_remove(struct pci_dev *pdev)
  {
  	struct vfio_pci_device *vdev;
  
  	vdev = vfio_del_group_dev(&pdev->dev);
  	if (!vdev)
  		return;
  
  	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
  	kfree(vdev->region);
  	mutex_destroy(&vdev->ioeventfds_lock);
  	kfree(vdev);
  
  	if (vfio_pci_is_vga(pdev)) {
  		vga_client_register(pdev, NULL, NULL, NULL);
  		vga_set_legacy_decoding(pdev,
  				VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
  				VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM);
  	}
  
  	if (!disable_idle_d3)
  		pci_set_power_state(pdev, PCI_D0);
  }
  
  static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
  						  pci_channel_state_t state)
  {
  	struct vfio_pci_device *vdev;
  	struct vfio_device *device;
  
  	device = vfio_device_get_from_dev(&pdev->dev);
  	if (device == NULL)
  		return PCI_ERS_RESULT_DISCONNECT;
  
  	vdev = vfio_device_data(device);
  	if (vdev == NULL) {
  		vfio_device_put(device);
  		return PCI_ERS_RESULT_DISCONNECT;
  	}
  
  	mutex_lock(&vdev->igate);
  
  	if (vdev->err_trigger)
  		eventfd_signal(vdev->err_trigger, 1);
  
  	mutex_unlock(&vdev->igate);
  
  	vfio_device_put(device);
  
  	return PCI_ERS_RESULT_CAN_RECOVER;
  }
  
  static const struct pci_error_handlers vfio_err_handlers = {
  	.error_detected = vfio_pci_aer_err_detected,
  };
  
  static struct pci_driver vfio_pci_driver = {
  	.name		= "vfio-pci",
  	.id_table	= NULL, /* only dynamic ids */
  	.probe		= vfio_pci_probe,
  	.remove		= vfio_pci_remove,
  	.err_handler	= &vfio_err_handlers,
  };
  
  struct vfio_devices {
  	struct vfio_device **devices;
  	int cur_index;
  	int max_index;
  };
  
  static int vfio_pci_get_devs(struct pci_dev *pdev, void *data)
  {
  	struct vfio_devices *devs = data;
  	struct vfio_device *device;
  
  	if (devs->cur_index == devs->max_index)
  		return -ENOSPC;
  
  	device = vfio_device_get_from_dev(&pdev->dev);
  	if (!device)
  		return -EINVAL;
  
  	if (pci_dev_driver(pdev) != &vfio_pci_driver) {
  		vfio_device_put(device);
  		return -EBUSY;
  	}
  
  	devs->devices[devs->cur_index++] = device;
  	return 0;
  }
  
  /*
   * Attempt to do a bus/slot reset if there are devices affected by a reset for
   * this device that are needs_reset and all of the affected devices are unused
   * (!refcnt).  Callers are required to hold driver_lock when calling this to
   * prevent device opens and concurrent bus reset attempts.  We prevent device
   * unbinds by acquiring and holding a reference to the vfio_device.
   *
   * NB: vfio-core considers a group to be viable even if some devices are
   * bound to drivers like pci-stub or pcieport.  Here we require all devices
   * to be bound to vfio_pci since that's the only way we can be sure they
   * stay put.
   */
  static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
  {
  	struct vfio_devices devs = { .cur_index = 0 };
  	int i = 0, ret = -EINVAL;
  	bool needs_reset = false, slot = false;
  	struct vfio_pci_device *tmp;
  
  	if (!pci_probe_reset_slot(vdev->pdev->slot))
  		slot = true;
  	else if (pci_probe_reset_bus(vdev->pdev->bus))
  		return;
  
  	if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
  					  &i, slot) || !i)
  		return;
  
  	devs.max_index = i;
  	devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL);
  	if (!devs.devices)
  		return;
  
  	if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
  					  vfio_pci_get_devs, &devs, slot))
  		goto put_devs;
  
  	for (i = 0; i < devs.cur_index; i++) {
  		tmp = vfio_device_data(devs.devices[i]);
  		if (tmp->needs_reset)
  			needs_reset = true;
  		if (tmp->refcnt)
  			goto put_devs;
  	}
  
  	if (needs_reset)
  		ret = pci_reset_bus(vdev->pdev);
  
  put_devs:
  	for (i = 0; i < devs.cur_index; i++) {
  		tmp = vfio_device_data(devs.devices[i]);
  		if (!ret)
  			tmp->needs_reset = false;
  
  		if (!tmp->refcnt && !disable_idle_d3)
  			pci_set_power_state(tmp->pdev, PCI_D3hot);
  
  		vfio_device_put(devs.devices[i]);
  	}
  
  	kfree(devs.devices);
  }
  
  static void __exit vfio_pci_cleanup(void)
  {
  	pci_unregister_driver(&vfio_pci_driver);
  	vfio_pci_uninit_perm_bits();
  }
  
  static void __init vfio_pci_fill_ids(void)
  {
  	char *p, *id;
  	int rc;
  
  	/* no ids passed actually */
  	if (ids[0] == '\0')
  		return;
  
  	/* add ids specified in the module parameter */
  	p = ids;
  	while ((id = strsep(&p, ","))) {
  		unsigned int vendor, device, subvendor = PCI_ANY_ID,
  			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
  		int fields;
  
  		if (!strlen(id))
  			continue;
  
  		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
  				&vendor, &device, &subvendor, &subdevice,
  				&class, &class_mask);
  
  		if (fields < 2) {
  			pr_warn("invalid id string \"%s\"\n", id);
  			continue;
  		}
  
  		rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
  				   subvendor, subdevice, class, class_mask, 0);
  		if (rc)
  			pr_warn("failed to add dynamic id [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x (%d)\n",
  				vendor, device, subvendor, subdevice,
  				class, class_mask, rc);
  		else
  			pr_info("add [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x\n",
  				vendor, device, subvendor, subdevice,
  				class, class_mask);
  	}
  }
  
  static int __init vfio_pci_init(void)
  {
  	int ret;
  
  	/* Allocate shared config space permision data used by all devices */
  	ret = vfio_pci_init_perm_bits();
  	if (ret)
  		return ret;
  
  	/* Register and scan for devices */
  	ret = pci_register_driver(&vfio_pci_driver);
  	if (ret)
  		goto out_driver;
  
  	vfio_pci_fill_ids();
  
  	return 0;
  
  out_driver:
  	vfio_pci_uninit_perm_bits();
  	return ret;
  }
  
  module_init(vfio_pci_init);
  module_exit(vfio_pci_cleanup);
  
  MODULE_VERSION(DRIVER_VERSION);
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  