Merge tag 'vfio-v5.15-rc1' of git://github.com/awilliam/linux-vfio
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 2 Sep 2021 20:41:33 +0000 (13:41 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 2 Sep 2021 20:41:33 +0000 (13:41 -0700)
Pull VFIO updates from Alex Williamson:

 - Fix dma-valid return WAITED implementation (Anthony Yznaga)

 - SPDX license cleanups (Cai Huoqing)

 - Split vfio-pci-core from vfio-pci and enhance PCI driver matching to
   support future vendor provided vfio-pci variants (Yishai Hadas, Max
   Gurtovoy, Jason Gunthorpe)

 - Replace duplicated reflck with core support for managing first open,
   last close, and device sets (Jason Gunthorpe, Max Gurtovoy, Yishai
   Hadas)

 - Fix non-modular mdev support and don't nag about request callback
   support (Christoph Hellwig)

 - Add semaphore to protect instruction intercept handler and replace
   open-coded locks in vfio-ap driver (Tony Krowiak)

 - Convert vfio-ap to vfio_register_group_dev() API (Jason Gunthorpe)

* tag 'vfio-v5.15-rc1' of git://github.com/awilliam/linux-vfio: (37 commits)
  vfio/pci: Introduce vfio_pci_core.ko
  vfio: Use kconfig if XX/endif blocks instead of repeating 'depends on'
  vfio: Use select for eventfd
  PCI / VFIO: Add 'override_only' support for VFIO PCI sub system
  PCI: Add 'override_only' field to struct pci_device_id
  vfio/pci: Move module parameters to vfio_pci.c
  vfio/pci: Move igd initialization to vfio_pci.c
  vfio/pci: Split the pci_driver code out of vfio_pci_core.c
  vfio/pci: Include vfio header in vfio_pci_core.h
  vfio/pci: Rename ops functions to fit core namings
  vfio/pci: Rename vfio_pci_device to vfio_pci_core_device
  vfio/pci: Rename vfio_pci_private.h to vfio_pci_core.h
  vfio/pci: Rename vfio_pci.c to vfio_pci_core.c
  vfio/ap_ops: Convert to use vfio_register_group_dev()
  s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification
  s390/vfio-ap: r/w lock for PQAP interception handler function pointer
  vfio/type1: Fix vfio_find_dma_valid return
  vfio-pci/zdev: Remove repeated verbose license text
  vfio: platform: reset: Convert to SPDX identifier
  vfio: Remove struct vfio_device_ops open/release
  ...

1  2 
MAINTAINERS
drivers/pci/pci-driver.c
drivers/s390/crypto/vfio_ap_ops.c
drivers/vfio/pci/vfio_pci_core.c
include/linux/pci.h

diff --cc MAINTAINERS
Simple merge
Simple merge
@@@ -1162,29 -1158,26 +1147,25 @@@ static int vfio_ap_mdev_iommu_notifier(
   * The kvm->lock is taken to clear the guest's AP configuration which, under
   * certain circumstances, will result in a circular lock dependency if this is
   * done under the @matrix_mdev->lock.
 - *
   */
- static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
+ static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev,
+                                  struct kvm *kvm)
  {
-       /*
-        * If the KVM pointer is in the process of being set, wait until the
-        * process has completed.
-        */
-       wait_event_cmd(matrix_mdev->wait_for_kvm,
-                      !matrix_mdev->kvm_busy,
-                      mutex_unlock(&matrix_dev->lock),
-                      mutex_lock(&matrix_dev->lock));
+       if (kvm && kvm->arch.crypto.crycbd) {
+               down_write(&kvm->arch.crypto.pqap_hook_rwsem);
+               kvm->arch.crypto.pqap_hook = NULL;
+               up_write(&kvm->arch.crypto.pqap_hook_rwsem);
  
-       if (matrix_mdev->kvm) {
-               matrix_mdev->kvm_busy = true;
-               mutex_unlock(&matrix_dev->lock);
-               kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+               mutex_lock(&kvm->lock);
                mutex_lock(&matrix_dev->lock);
-               vfio_ap_mdev_reset_queues(matrix_mdev->mdev);
-               matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
-               kvm_put_kvm(matrix_mdev->kvm);
+               kvm_arch_crypto_clear_masks(kvm);
+               vfio_ap_mdev_reset_queues(matrix_mdev);
+               kvm_put_kvm(kvm);
                matrix_mdev->kvm = NULL;
-               matrix_mdev->kvm_busy = false;
-               wake_up_all(&matrix_mdev->wait_for_kvm);
+               mutex_unlock(&kvm->lock);
+               mutex_unlock(&matrix_dev->lock);
        }
  }
  
index 0000000,675616e..68198e0
mode 000000,100644..100644
--- /dev/null
@@@ -1,0 -1,2158 +1,2157 @@@
 -static unsigned int vfio_pci_set_vga_decode(void *opaque, bool single_vga)
+ // SPDX-License-Identifier: GPL-2.0-only
+ /*
+  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+  *     Author: Alex Williamson <alex.williamson@redhat.com>
+  *
+  * 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/vgaarb.h>
+ #include <linux/nospec.h>
+ #include <linux/sched/mm.h>
+ #include <linux/vfio_pci_core.h>
+ #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
+ #define DRIVER_DESC "core driver for VFIO based PCI devices"
+ static bool nointxmask;
+ static bool disable_vga;
+ static bool disable_idle_d3;
+ 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.
+  */
 -      struct vfio_pci_core_device *vdev = opaque;
 -      struct pci_dev *tmp = NULL, *pdev = vdev->pdev;
++static unsigned int vfio_pci_set_decode(struct pci_dev *pdev, bool single_vga)
+ {
 -      ret = vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
++      struct pci_dev *tmp = NULL;
+       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 void vfio_pci_probe_mmaps(struct vfio_pci_core_device *vdev)
+ {
+       struct resource *res;
+       int i;
+       struct vfio_pci_dummy_resource *dummy_res;
+       for (i = 0; i < PCI_STD_NUM_BARS; i++) {
+               int bar = i + PCI_STD_RESOURCES;
+               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;
+       }
+ }
+ struct vfio_pci_group_info;
+ static bool vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set);
+ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
+                                     struct vfio_pci_group_info *groups);
+ /*
+  * 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:
+               /* X550 */
+               case 0x1563:
+                       return true;
+               default:
+                       return false;
+               }
+       }
+       return false;
+ }
+ static void vfio_pci_probe_power_state(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       u16 pmcsr;
+       if (!pdev->pm_cap)
+               return;
+       pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
+       vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
+ }
+ /*
+  * pci_set_power_state() wrapper handling devices which perform a soft reset on
+  * D3->D0 transition.  Save state prior to D0/1/2->D3, stash it on the vdev,
+  * restore when returned to D0.  Saved separately from pci_saved_state for use
+  * by PM capability emulation and separately from pci_dev internal saved state
+  * to avoid it being overwritten and consumed around other resets.
+  */
+ int vfio_pci_set_power_state(struct vfio_pci_core_device *vdev, pci_power_t state)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       bool needs_restore = false, needs_save = false;
+       int ret;
+       if (vdev->needs_pm_restore) {
+               if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
+                       pci_save_state(pdev);
+                       needs_save = true;
+               }
+               if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
+                       needs_restore = true;
+       }
+       ret = pci_set_power_state(pdev, state);
+       if (!ret) {
+               /* D3 might be unsupported via quirk, skip unless in D3 */
+               if (needs_save && pdev->current_state >= PCI_D3hot) {
+                       vdev->pm_save = pci_store_saved_state(pdev);
+               } else if (needs_restore) {
+                       pci_load_and_free_saved_state(pdev, &vdev->pm_save);
+                       pci_restore_state(pdev);
+               }
+       }
+       return ret;
+ }
+ int vfio_pci_core_enable(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       int ret;
+       u16 cmd;
+       u8 msix_pos;
+       vfio_pci_set_power_state(vdev, 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)
+               pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
+       if (likely(!nointxmask)) {
+               if (vfio_pci_nointx(pdev)) {
+                       pci_info(pdev, "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;
+       return 0;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_enable);
+ void vfio_pci_core_disable(struct vfio_pci_core_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;
+       /* For needs_reset */
+       lockdep_assert_held(&vdev->vdev.dev_set->lock);
+       /* 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 (i = 0; i < PCI_STD_NUM_BARS; i++) {
+               bar = i + PCI_STD_RESOURCES;
+               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)) {
+               pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
+               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 get the locks ourselves to prevent a deadlock. The
+        * success of this is dependent on being able to lock the device,
+        * which is not always possible.
+        * We can not use the "try" reset interface here, which will
+        * overwrite the previously restored configuration information.
+        */
+       if (vdev->reset_works && pci_dev_trylock(pdev)) {
+               if (!__pci_reset_function_locked(pdev))
+                       vdev->needs_reset = false;
+               pci_dev_unlock(pdev);
+       }
+       pci_restore_state(pdev);
+ out:
+       pci_disable_device(pdev);
+       if (!vfio_pci_dev_set_try_reset(vdev->vdev.dev_set) && !disable_idle_d3)
+               vfio_pci_set_power_state(vdev, PCI_D3hot);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_disable);
+ static struct vfio_pci_core_device *get_pf_vdev(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *physfn = pci_physfn(vdev->pdev);
+       struct vfio_device *pf_dev;
+       if (!vdev->pdev->is_virtfn)
+               return NULL;
+       pf_dev = vfio_device_get_from_dev(&physfn->dev);
+       if (!pf_dev)
+               return NULL;
+       if (pci_dev_driver(physfn) != pci_dev_driver(vdev->pdev)) {
+               vfio_device_put(pf_dev);
+               return NULL;
+       }
+       return container_of(pf_dev, struct vfio_pci_core_device, vdev);
+ }
+ static void vfio_pci_vf_token_user_add(struct vfio_pci_core_device *vdev, int val)
+ {
+       struct vfio_pci_core_device *pf_vdev = get_pf_vdev(vdev);
+       if (!pf_vdev)
+               return;
+       mutex_lock(&pf_vdev->vf_token->lock);
+       pf_vdev->vf_token->users += val;
+       WARN_ON(pf_vdev->vf_token->users < 0);
+       mutex_unlock(&pf_vdev->vf_token->lock);
+       vfio_device_put(&pf_vdev->vdev);
+ }
+ void vfio_pci_core_close_device(struct vfio_device *core_vdev)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       vfio_pci_vf_token_user_add(vdev, -1);
+       vfio_spapr_pci_eeh_release(vdev->pdev);
+       vfio_pci_core_disable(vdev);
+       mutex_lock(&vdev->igate);
+       if (vdev->err_trigger) {
+               eventfd_ctx_put(vdev->err_trigger);
+               vdev->err_trigger = NULL;
+       }
+       if (vdev->req_trigger) {
+               eventfd_ctx_put(vdev->req_trigger);
+               vdev->req_trigger = NULL;
+       }
+       mutex_unlock(&vdev->igate);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_close_device);
+ void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev)
+ {
+       vfio_pci_probe_mmaps(vdev);
+       vfio_spapr_pci_eeh_open(vdev->pdev);
+       vfio_pci_vf_token_user_add(vdev, 1);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_finish_enable);
+ static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_type)
+ {
+       if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
+               u8 pin;
+               if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
+                   vdev->nointx || vdev->pdev->is_virtfn)
+                       return 0;
+               pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
+               return pin ? 1 : 0;
+       } 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_info {
+       int count;
+       struct vfio_group **groups;
+ };
+ 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_core_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_core_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;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_register_dev_region);
+ long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
+               unsigned long arg)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       unsigned long minsz;
+       if (cmd == VFIO_DEVICE_GET_INFO) {
+               struct vfio_device_info info;
+               struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+               unsigned long capsz;
+               int ret;
+               minsz = offsetofend(struct vfio_device_info, num_irqs);
+               /* For backward compatibility, cannot require this */
+               capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
+               if (copy_from_user(&info, (void __user *)arg, minsz))
+                       return -EFAULT;
+               if (info.argsz < minsz)
+                       return -EINVAL;
+               if (info.argsz >= capsz) {
+                       minsz = capsz;
+                       info.cap_offset = 0;
+               }
+               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;
+               ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
+               if (ret && ret != -ENODEV) {
+                       pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
+                       return ret;
+               }
+               if (caps.size) {
+                       info.flags |= VFIO_DEVICE_FLAGS_CAPS;
+                       if (info.argsz < sizeof(info) + caps.size) {
+                               info.argsz = sizeof(info) + caps.size;
+                       } 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_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;
+                       u16 cmd;
+                       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?  Enable memory decode for
+                        * implicit access in pci_map_rom().
+                        */
+                       cmd = vfio_pci_memory_lock_and_enable(vdev);
+                       io = pci_map_rom(pdev, &size);
+                       if (io) {
+                               info.flags = VFIO_REGION_INFO_FLAG_READ;
+                               pci_unmap_rom(pdev, io);
+                       } else {
+                               info.size = 0;
+                       }
+                       vfio_pci_memory_unlock_and_restore(vdev, cmd);
+                       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 (vdev->region[i].ops->add_capability) {
+                               ret = vdev->region[i].ops->add_capability(vdev,
+                                               &vdev->region[i], &caps);
+                               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;
+                       fallthrough;
+               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) {
+               int ret;
+               if (!vdev->reset_works)
+                       return -EINVAL;
+               vfio_pci_zap_and_down_write_memory_lock(vdev);
+               ret = pci_try_reset_function(vdev->pdev);
+               up_write(&vdev->memory_lock);
+               return ret;
+       } 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_group **groups;
+               struct vfio_pci_group_info info;
+               bool slot = false;
+               int group_idx, 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 (group_idx = 0; group_idx < hdr.count; group_idx++) {
+                       struct vfio_group *group;
+                       struct fd f = fdget(group_fds[group_idx]);
+                       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[group_idx] = group;
+               }
+               kfree(group_fds);
+               /* release reference to groups on error */
+               if (ret)
+                       goto hot_reset_release;
+               info.count = hdr.count;
+               info.groups = groups;
+               ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info);
+ hot_reset_release:
+               for (group_idx--; group_idx >= 0; group_idx--)
+                       vfio_group_put_external_user(groups[group_idx]);
+               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);
+       } else if (cmd == VFIO_DEVICE_FEATURE) {
+               struct vfio_device_feature feature;
+               uuid_t uuid;
+               minsz = offsetofend(struct vfio_device_feature, flags);
+               if (copy_from_user(&feature, (void __user *)arg, minsz))
+                       return -EFAULT;
+               if (feature.argsz < minsz)
+                       return -EINVAL;
+               /* Check unknown flags */
+               if (feature.flags & ~(VFIO_DEVICE_FEATURE_MASK |
+                                     VFIO_DEVICE_FEATURE_SET |
+                                     VFIO_DEVICE_FEATURE_GET |
+                                     VFIO_DEVICE_FEATURE_PROBE))
+                       return -EINVAL;
+               /* GET & SET are mutually exclusive except with PROBE */
+               if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
+                   (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
+                   (feature.flags & VFIO_DEVICE_FEATURE_GET))
+                       return -EINVAL;
+               switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
+               case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN:
+                       if (!vdev->vf_token)
+                               return -ENOTTY;
+                       /*
+                        * We do not support GET of the VF Token UUID as this
+                        * could expose the token of the previous device user.
+                        */
+                       if (feature.flags & VFIO_DEVICE_FEATURE_GET)
+                               return -EINVAL;
+                       if (feature.flags & VFIO_DEVICE_FEATURE_PROBE)
+                               return 0;
+                       /* Don't SET unless told to do so */
+                       if (!(feature.flags & VFIO_DEVICE_FEATURE_SET))
+                               return -EINVAL;
+                       if (feature.argsz < minsz + sizeof(uuid))
+                               return -EINVAL;
+                       if (copy_from_user(&uuid, (void __user *)(arg + minsz),
+                                          sizeof(uuid)))
+                               return -EFAULT;
+                       mutex_lock(&vdev->vf_token->lock);
+                       uuid_copy(&vdev->vf_token->uuid, &uuid);
+                       mutex_unlock(&vdev->vf_token->lock);
+                       return 0;
+               default:
+                       return -ENOTTY;
+               }
+       }
+       return -ENOTTY;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl);
+ static ssize_t vfio_pci_rw(struct vfio_pci_core_device *vdev, char __user *buf,
+                          size_t count, loff_t *ppos, bool iswrite)
+ {
+       unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+       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;
+ }
+ ssize_t vfio_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
+               size_t count, loff_t *ppos)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       if (!count)
+               return 0;
+       return vfio_pci_rw(vdev, buf, count, ppos, false);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_read);
+ ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *buf,
+               size_t count, loff_t *ppos)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       if (!count)
+               return 0;
+       return vfio_pci_rw(vdev, (char __user *)buf, count, ppos, true);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_write);
+ /* Return 1 on zap and vma_lock acquired, 0 on contention (only with @try) */
+ static int vfio_pci_zap_and_vma_lock(struct vfio_pci_core_device *vdev, bool try)
+ {
+       struct vfio_pci_mmap_vma *mmap_vma, *tmp;
+       /*
+        * Lock ordering:
+        * vma_lock is nested under mmap_lock for vm_ops callback paths.
+        * The memory_lock semaphore is used by both code paths calling
+        * into this function to zap vmas and the vm_ops.fault callback
+        * to protect the memory enable state of the device.
+        *
+        * When zapping vmas we need to maintain the mmap_lock => vma_lock
+        * ordering, which requires using vma_lock to walk vma_list to
+        * acquire an mm, then dropping vma_lock to get the mmap_lock and
+        * reacquiring vma_lock.  This logic is derived from similar
+        * requirements in uverbs_user_mmap_disassociate().
+        *
+        * mmap_lock must always be the top-level lock when it is taken.
+        * Therefore we can only hold the memory_lock write lock when
+        * vma_list is empty, as we'd need to take mmap_lock to clear
+        * entries.  vma_list can only be guaranteed empty when holding
+        * vma_lock, thus memory_lock is nested under vma_lock.
+        *
+        * This enables the vm_ops.fault callback to acquire vma_lock,
+        * followed by memory_lock read lock, while already holding
+        * mmap_lock without risk of deadlock.
+        */
+       while (1) {
+               struct mm_struct *mm = NULL;
+               if (try) {
+                       if (!mutex_trylock(&vdev->vma_lock))
+                               return 0;
+               } else {
+                       mutex_lock(&vdev->vma_lock);
+               }
+               while (!list_empty(&vdev->vma_list)) {
+                       mmap_vma = list_first_entry(&vdev->vma_list,
+                                                   struct vfio_pci_mmap_vma,
+                                                   vma_next);
+                       mm = mmap_vma->vma->vm_mm;
+                       if (mmget_not_zero(mm))
+                               break;
+                       list_del(&mmap_vma->vma_next);
+                       kfree(mmap_vma);
+                       mm = NULL;
+               }
+               if (!mm)
+                       return 1;
+               mutex_unlock(&vdev->vma_lock);
+               if (try) {
+                       if (!mmap_read_trylock(mm)) {
+                               mmput(mm);
+                               return 0;
+                       }
+               } else {
+                       mmap_read_lock(mm);
+               }
+               if (try) {
+                       if (!mutex_trylock(&vdev->vma_lock)) {
+                               mmap_read_unlock(mm);
+                               mmput(mm);
+                               return 0;
+                       }
+               } else {
+                       mutex_lock(&vdev->vma_lock);
+               }
+               list_for_each_entry_safe(mmap_vma, tmp,
+                                        &vdev->vma_list, vma_next) {
+                       struct vm_area_struct *vma = mmap_vma->vma;
+                       if (vma->vm_mm != mm)
+                               continue;
+                       list_del(&mmap_vma->vma_next);
+                       kfree(mmap_vma);
+                       zap_vma_ptes(vma, vma->vm_start,
+                                    vma->vm_end - vma->vm_start);
+               }
+               mutex_unlock(&vdev->vma_lock);
+               mmap_read_unlock(mm);
+               mmput(mm);
+       }
+ }
+ void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev)
+ {
+       vfio_pci_zap_and_vma_lock(vdev, false);
+       down_write(&vdev->memory_lock);
+       mutex_unlock(&vdev->vma_lock);
+ }
+ u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev)
+ {
+       u16 cmd;
+       down_write(&vdev->memory_lock);
+       pci_read_config_word(vdev->pdev, PCI_COMMAND, &cmd);
+       if (!(cmd & PCI_COMMAND_MEMORY))
+               pci_write_config_word(vdev->pdev, PCI_COMMAND,
+                                     cmd | PCI_COMMAND_MEMORY);
+       return cmd;
+ }
+ void vfio_pci_memory_unlock_and_restore(struct vfio_pci_core_device *vdev, u16 cmd)
+ {
+       pci_write_config_word(vdev->pdev, PCI_COMMAND, cmd);
+       up_write(&vdev->memory_lock);
+ }
+ /* Caller holds vma_lock */
+ static int __vfio_pci_add_vma(struct vfio_pci_core_device *vdev,
+                             struct vm_area_struct *vma)
+ {
+       struct vfio_pci_mmap_vma *mmap_vma;
+       mmap_vma = kmalloc(sizeof(*mmap_vma), GFP_KERNEL);
+       if (!mmap_vma)
+               return -ENOMEM;
+       mmap_vma->vma = vma;
+       list_add(&mmap_vma->vma_next, &vdev->vma_list);
+       return 0;
+ }
+ /*
+  * Zap mmaps on open so that we can fault them in on access and therefore
+  * our vma_list only tracks mappings accessed since last zap.
+  */
+ static void vfio_pci_mmap_open(struct vm_area_struct *vma)
+ {
+       zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
+ }
+ static void vfio_pci_mmap_close(struct vm_area_struct *vma)
+ {
+       struct vfio_pci_core_device *vdev = vma->vm_private_data;
+       struct vfio_pci_mmap_vma *mmap_vma;
+       mutex_lock(&vdev->vma_lock);
+       list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
+               if (mmap_vma->vma == vma) {
+                       list_del(&mmap_vma->vma_next);
+                       kfree(mmap_vma);
+                       break;
+               }
+       }
+       mutex_unlock(&vdev->vma_lock);
+ }
+ static vm_fault_t vfio_pci_mmap_fault(struct vm_fault *vmf)
+ {
+       struct vm_area_struct *vma = vmf->vma;
+       struct vfio_pci_core_device *vdev = vma->vm_private_data;
+       struct vfio_pci_mmap_vma *mmap_vma;
+       vm_fault_t ret = VM_FAULT_NOPAGE;
+       mutex_lock(&vdev->vma_lock);
+       down_read(&vdev->memory_lock);
+       if (!__vfio_pci_memory_enabled(vdev)) {
+               ret = VM_FAULT_SIGBUS;
+               goto up_out;
+       }
+       /*
+        * We populate the whole vma on fault, so we need to test whether
+        * the vma has already been mapped, such as for concurrent faults
+        * to the same vma.  io_remap_pfn_range() will trigger a BUG_ON if
+        * we ask it to fill the same range again.
+        */
+       list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
+               if (mmap_vma->vma == vma)
+                       goto up_out;
+       }
+       if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+                              vma->vm_end - vma->vm_start,
+                              vma->vm_page_prot)) {
+               ret = VM_FAULT_SIGBUS;
+               zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
+               goto up_out;
+       }
+       if (__vfio_pci_add_vma(vdev, vma)) {
+               ret = VM_FAULT_OOM;
+               zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
+       }
+ up_out:
+       up_read(&vdev->memory_lock);
+       mutex_unlock(&vdev->vma_lock);
+       return ret;
+ }
+ static const struct vm_operations_struct vfio_pci_mmap_ops = {
+       .open = vfio_pci_mmap_open,
+       .close = vfio_pci_mmap_close,
+       .fault = vfio_pci_mmap_fault,
+ };
+ int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       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 (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
+               return -EINVAL;
+       if (vma->vm_end < vma->vm_start)
+               return -EINVAL;
+       if ((vma->vm_flags & VM_SHARED) == 0)
+               return -EINVAL;
+       if (index >= VFIO_PCI_NUM_REGIONS) {
+               int regnum = index - VFIO_PCI_NUM_REGIONS;
+               struct vfio_pci_region *region = vdev->region + regnum;
+               if (region->ops && region->ops->mmap &&
+                   (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
+                       return region->ops->mmap(vdev, region, vma);
+               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;
+       /*
+        * See remap_pfn_range(), called from vfio_pci_fault() but we can't
+        * change vm_flags within the fault handler.  Set them now.
+        */
+       vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+       vma->vm_ops = &vfio_pci_mmap_ops;
+       return 0;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_mmap);
+ void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       struct pci_dev *pdev = vdev->pdev;
+       mutex_lock(&vdev->igate);
+       if (vdev->req_trigger) {
+               if (!(count % 10))
+                       pci_notice_ratelimited(pdev,
+                               "Relaying device request to user (#%u)\n",
+                               count);
+               eventfd_signal(vdev->req_trigger, 1);
+       } else if (count == 0) {
+               pci_warn(pdev,
+                       "No device request channel registered, blocked until released by user\n");
+       }
+       mutex_unlock(&vdev->igate);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_request);
+ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
+                                     bool vf_token, uuid_t *uuid)
+ {
+       /*
+        * There's always some degree of trust or collaboration between SR-IOV
+        * PF and VFs, even if just that the PF hosts the SR-IOV capability and
+        * can disrupt VFs with a reset, but often the PF has more explicit
+        * access to deny service to the VF or access data passed through the
+        * VF.  We therefore require an opt-in via a shared VF token (UUID) to
+        * represent this trust.  This both prevents that a VF driver might
+        * assume the PF driver is a trusted, in-kernel driver, and also that
+        * a PF driver might be replaced with a rogue driver, unknown to in-use
+        * VF drivers.
+        *
+        * Therefore when presented with a VF, if the PF is a vfio device and
+        * it is bound to the vfio-pci driver, the user needs to provide a VF
+        * token to access the device, in the form of appending a vf_token to
+        * the device name, for example:
+        *
+        * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
+        *
+        * When presented with a PF which has VFs in use, the user must also
+        * provide the current VF token to prove collaboration with existing
+        * VF users.  If VFs are not in use, the VF token provided for the PF
+        * device will act to set the VF token.
+        *
+        * If the VF token is provided but unused, an error is generated.
+        */
+       if (!vdev->pdev->is_virtfn && !vdev->vf_token && !vf_token)
+               return 0; /* No VF token provided or required */
+       if (vdev->pdev->is_virtfn) {
+               struct vfio_pci_core_device *pf_vdev = get_pf_vdev(vdev);
+               bool match;
+               if (!pf_vdev) {
+                       if (!vf_token)
+                               return 0; /* PF is not vfio-pci, no VF token */
+                       pci_info_ratelimited(vdev->pdev,
+                               "VF token incorrectly provided, PF not bound to vfio-pci\n");
+                       return -EINVAL;
+               }
+               if (!vf_token) {
+                       vfio_device_put(&pf_vdev->vdev);
+                       pci_info_ratelimited(vdev->pdev,
+                               "VF token required to access device\n");
+                       return -EACCES;
+               }
+               mutex_lock(&pf_vdev->vf_token->lock);
+               match = uuid_equal(uuid, &pf_vdev->vf_token->uuid);
+               mutex_unlock(&pf_vdev->vf_token->lock);
+               vfio_device_put(&pf_vdev->vdev);
+               if (!match) {
+                       pci_info_ratelimited(vdev->pdev,
+                               "Incorrect VF token provided for device\n");
+                       return -EACCES;
+               }
+       } else if (vdev->vf_token) {
+               mutex_lock(&vdev->vf_token->lock);
+               if (vdev->vf_token->users) {
+                       if (!vf_token) {
+                               mutex_unlock(&vdev->vf_token->lock);
+                               pci_info_ratelimited(vdev->pdev,
+                                       "VF token required to access device\n");
+                               return -EACCES;
+                       }
+                       if (!uuid_equal(uuid, &vdev->vf_token->uuid)) {
+                               mutex_unlock(&vdev->vf_token->lock);
+                               pci_info_ratelimited(vdev->pdev,
+                                       "Incorrect VF token provided for device\n");
+                               return -EACCES;
+                       }
+               } else if (vf_token) {
+                       uuid_copy(&vdev->vf_token->uuid, uuid);
+               }
+               mutex_unlock(&vdev->vf_token->lock);
+       } else if (vf_token) {
+               pci_info_ratelimited(vdev->pdev,
+                       "VF token incorrectly provided, not a PF or VF\n");
+               return -EINVAL;
+       }
+       return 0;
+ }
+ #define VF_TOKEN_ARG "vf_token="
+ int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf)
+ {
+       struct vfio_pci_core_device *vdev =
+               container_of(core_vdev, struct vfio_pci_core_device, vdev);
+       bool vf_token = false;
+       uuid_t uuid;
+       int ret;
+       if (strncmp(pci_name(vdev->pdev), buf, strlen(pci_name(vdev->pdev))))
+               return 0; /* No match */
+       if (strlen(buf) > strlen(pci_name(vdev->pdev))) {
+               buf += strlen(pci_name(vdev->pdev));
+               if (*buf != ' ')
+                       return 0; /* No match: non-whitespace after name */
+               while (*buf) {
+                       if (*buf == ' ') {
+                               buf++;
+                               continue;
+                       }
+                       if (!vf_token && !strncmp(buf, VF_TOKEN_ARG,
+                                                 strlen(VF_TOKEN_ARG))) {
+                               buf += strlen(VF_TOKEN_ARG);
+                               if (strlen(buf) < UUID_STRING_LEN)
+                                       return -EINVAL;
+                               ret = uuid_parse(buf, &uuid);
+                               if (ret)
+                                       return ret;
+                               vf_token = true;
+                               buf += UUID_STRING_LEN;
+                       } else {
+                               /* Unknown/duplicate option */
+                               return -EINVAL;
+                       }
+               }
+       }
+       ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid);
+       if (ret)
+               return ret;
+       return 1; /* Match */
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_match);
+ static int vfio_pci_bus_notifier(struct notifier_block *nb,
+                                unsigned long action, void *data)
+ {
+       struct vfio_pci_core_device *vdev = container_of(nb,
+                                                   struct vfio_pci_core_device, nb);
+       struct device *dev = data;
+       struct pci_dev *pdev = to_pci_dev(dev);
+       struct pci_dev *physfn = pci_physfn(pdev);
+       if (action == BUS_NOTIFY_ADD_DEVICE &&
+           pdev->is_virtfn && physfn == vdev->pdev) {
+               pci_info(vdev->pdev, "Captured SR-IOV VF %s driver_override\n",
+                        pci_name(pdev));
+               pdev->driver_override = kasprintf(GFP_KERNEL, "%s",
+                                                 vdev->vdev.ops->name);
+       } else if (action == BUS_NOTIFY_BOUND_DRIVER &&
+                  pdev->is_virtfn && physfn == vdev->pdev) {
+               struct pci_driver *drv = pci_dev_driver(pdev);
+               if (drv && drv != pci_dev_driver(vdev->pdev))
+                       pci_warn(vdev->pdev,
+                                "VF %s bound to driver %s while PF bound to driver %s\n",
+                                pci_name(pdev), drv->name,
+                                pci_dev_driver(vdev->pdev)->name);
+       }
+       return 0;
+ }
+ static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       int ret;
+       if (!pdev->is_physfn)
+               return 0;
+       vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
+       if (!vdev->vf_token)
+               return -ENOMEM;
+       mutex_init(&vdev->vf_token->lock);
+       uuid_gen(&vdev->vf_token->uuid);
+       vdev->nb.notifier_call = vfio_pci_bus_notifier;
+       ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
+       if (ret) {
+               kfree(vdev->vf_token);
+               return ret;
+       }
+       return 0;
+ }
+ static void vfio_pci_vf_uninit(struct vfio_pci_core_device *vdev)
+ {
+       if (!vdev->vf_token)
+               return;
+       bus_unregister_notifier(&pci_bus_type, &vdev->nb);
+       WARN_ON(vdev->vf_token->users);
+       mutex_destroy(&vdev->vf_token->lock);
+       kfree(vdev->vf_token);
+ }
+ static int vfio_pci_vga_init(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       int ret;
+       if (!vfio_pci_is_vga(pdev))
+               return 0;
 -      vga_set_legacy_decoding(pdev, vfio_pci_set_vga_decode(vdev, false));
++      ret = vga_client_register(pdev, vfio_pci_set_decode);
+       if (ret)
+               return ret;
 -      vga_client_register(pdev, NULL, NULL, NULL);
++      vga_set_legacy_decoding(pdev, vfio_pci_set_decode(pdev, false));
+       return 0;
+ }
+ static void vfio_pci_vga_uninit(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       if (!vfio_pci_is_vga(pdev))
+               return;
++      vga_client_unregister(pdev);
+       vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
+                                             VGA_RSRC_LEGACY_IO |
+                                             VGA_RSRC_LEGACY_MEM);
+ }
+ void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
+                              struct pci_dev *pdev,
+                              const struct vfio_device_ops *vfio_pci_ops)
+ {
+       vfio_init_group_dev(&vdev->vdev, &pdev->dev, vfio_pci_ops);
+       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->dummy_resources_list);
+       INIT_LIST_HEAD(&vdev->ioeventfds_list);
+       mutex_init(&vdev->vma_lock);
+       INIT_LIST_HEAD(&vdev->vma_list);
+       init_rwsem(&vdev->memory_lock);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_init_device);
+ void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev)
+ {
+       mutex_destroy(&vdev->igate);
+       mutex_destroy(&vdev->ioeventfds_lock);
+       mutex_destroy(&vdev->vma_lock);
+       vfio_uninit_group_dev(&vdev->vdev);
+       kfree(vdev->region);
+       kfree(vdev->pm_save);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_uninit_device);
+ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       struct iommu_group *group;
+       int ret;
+       if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
+               return -EINVAL;
+       /*
+        * Prevent binding to PFs with VFs enabled, the VFs might be in use
+        * by the host or other users.  We cannot capture the VFs if they
+        * already exist, nor can we track VF users.  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;
+       if (pci_is_root_bus(pdev->bus)) {
+               ret = vfio_assign_device_set(&vdev->vdev, vdev);
+       } else if (!pci_probe_reset_slot(pdev->slot)) {
+               ret = vfio_assign_device_set(&vdev->vdev, pdev->slot);
+       } else {
+               /*
+                * If there is no slot reset support for this device, the whole
+                * bus needs to be grouped together to support bus-wide resets.
+                */
+               ret = vfio_assign_device_set(&vdev->vdev, pdev->bus);
+       }
+       if (ret)
+               goto out_group_put;
+       ret = vfio_pci_vf_init(vdev);
+       if (ret)
+               goto out_group_put;
+       ret = vfio_pci_vga_init(vdev);
+       if (ret)
+               goto out_vf;
+       vfio_pci_probe_power_state(vdev);
+       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.
+                */
+               vfio_pci_set_power_state(vdev, PCI_D0);
+               vfio_pci_set_power_state(vdev, PCI_D3hot);
+       }
+       ret = vfio_register_group_dev(&vdev->vdev);
+       if (ret)
+               goto out_power;
+       return 0;
+ out_power:
+       if (!disable_idle_d3)
+               vfio_pci_set_power_state(vdev, PCI_D0);
+ out_vf:
+       vfio_pci_vf_uninit(vdev);
+ out_group_put:
+       vfio_iommu_group_put(group, &pdev->dev);
+       return ret;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
+ void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev)
+ {
+       struct pci_dev *pdev = vdev->pdev;
+       pci_disable_sriov(pdev);
+       vfio_unregister_group_dev(&vdev->vdev);
+       vfio_pci_vf_uninit(vdev);
+       vfio_pci_vga_uninit(vdev);
+       vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
+       if (!disable_idle_d3)
+               vfio_pci_set_power_state(vdev, PCI_D0);
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device);
+ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
+                                                 pci_channel_state_t state)
+ {
+       struct vfio_pci_core_device *vdev;
+       struct vfio_device *device;
+       device = vfio_device_get_from_dev(&pdev->dev);
+       if (device == NULL)
+               return PCI_ERS_RESULT_DISCONNECT;
+       vdev = container_of(device, struct vfio_pci_core_device, vdev);
+       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;
+ }
+ int vfio_pci_core_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
+ {
+       struct vfio_device *device;
+       int ret = 0;
+       device = vfio_device_get_from_dev(&pdev->dev);
+       if (!device)
+               return -ENODEV;
+       if (nr_virtfn == 0)
+               pci_disable_sriov(pdev);
+       else
+               ret = pci_enable_sriov(pdev, nr_virtfn);
+       vfio_device_put(device);
+       return ret < 0 ? ret : nr_virtfn;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_sriov_configure);
+ const struct pci_error_handlers vfio_pci_core_err_handlers = {
+       .error_detected = vfio_pci_aer_err_detected,
+ };
+ EXPORT_SYMBOL_GPL(vfio_pci_core_err_handlers);
+ static bool vfio_dev_in_groups(struct vfio_pci_core_device *vdev,
+                              struct vfio_pci_group_info *groups)
+ {
+       unsigned int i;
+       for (i = 0; i < groups->count; i++)
+               if (groups->groups[i] == vdev->vdev.group)
+                       return true;
+       return false;
+ }
+ static int vfio_pci_is_device_in_set(struct pci_dev *pdev, void *data)
+ {
+       struct vfio_device_set *dev_set = data;
+       struct vfio_device *cur;
+       list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
+               if (cur->dev == &pdev->dev)
+                       return 0;
+       return -EBUSY;
+ }
+ /*
+  * vfio-core considers a group to be viable and will create a vfio_device even
+  * if some devices are bound to drivers like pci-stub or pcieport. Here we
+  * require all PCI devices to be inside our dev_set since that ensures they stay
+  * put and that every driver controlling the device can co-ordinate with the
+  * device reset.
+  *
+  * Returns the pci_dev to pass to pci_reset_bus() if every PCI device to be
+  * reset is inside the dev_set, and pci_reset_bus() can succeed. NULL otherwise.
+  */
+ static struct pci_dev *
+ vfio_pci_dev_set_resettable(struct vfio_device_set *dev_set)
+ {
+       struct pci_dev *pdev;
+       lockdep_assert_held(&dev_set->lock);
+       /*
+        * By definition all PCI devices in the dev_set share the same PCI
+        * reset, so any pci_dev will have the same outcomes for
+        * pci_probe_reset_*() and pci_reset_bus().
+        */
+       pdev = list_first_entry(&dev_set->device_list,
+                               struct vfio_pci_core_device,
+                               vdev.dev_set_list)->pdev;
+       /* pci_reset_bus() is supported */
+       if (pci_probe_reset_slot(pdev->slot) && pci_probe_reset_bus(pdev->bus))
+               return NULL;
+       if (vfio_pci_for_each_slot_or_bus(pdev, vfio_pci_is_device_in_set,
+                                         dev_set,
+                                         !pci_probe_reset_slot(pdev->slot)))
+               return NULL;
+       return pdev;
+ }
+ /*
+  * We need to get memory_lock for each device, but devices can share mmap_lock,
+  * therefore we need to zap and hold the vma_lock for each device, and only then
+  * get each memory_lock.
+  */
+ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
+                                     struct vfio_pci_group_info *groups)
+ {
+       struct vfio_pci_core_device *cur_mem;
+       struct vfio_pci_core_device *cur_vma;
+       struct vfio_pci_core_device *cur;
+       struct pci_dev *pdev;
+       bool is_mem = true;
+       int ret;
+       mutex_lock(&dev_set->lock);
+       cur_mem = list_first_entry(&dev_set->device_list,
+                                  struct vfio_pci_core_device,
+                                  vdev.dev_set_list);
+       pdev = vfio_pci_dev_set_resettable(dev_set);
+       if (!pdev) {
+               ret = -EINVAL;
+               goto err_unlock;
+       }
+       list_for_each_entry(cur_vma, &dev_set->device_list, vdev.dev_set_list) {
+               /*
+                * Test whether all the affected devices are contained by the
+                * set of groups provided by the user.
+                */
+               if (!vfio_dev_in_groups(cur_vma, groups)) {
+                       ret = -EINVAL;
+                       goto err_undo;
+               }
+               /*
+                * Locking multiple devices is prone to deadlock, runaway and
+                * unwind if we hit contention.
+                */
+               if (!vfio_pci_zap_and_vma_lock(cur_vma, true)) {
+                       ret = -EBUSY;
+                       goto err_undo;
+               }
+       }
+       cur_vma = NULL;
+       list_for_each_entry(cur_mem, &dev_set->device_list, vdev.dev_set_list) {
+               if (!down_write_trylock(&cur_mem->memory_lock)) {
+                       ret = -EBUSY;
+                       goto err_undo;
+               }
+               mutex_unlock(&cur_mem->vma_lock);
+       }
+       cur_mem = NULL;
+       ret = pci_reset_bus(pdev);
+ err_undo:
+       list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
+               if (cur == cur_mem)
+                       is_mem = false;
+               if (cur == cur_vma)
+                       break;
+               if (is_mem)
+                       up_write(&cur->memory_lock);
+               else
+                       mutex_unlock(&cur->vma_lock);
+       }
+ err_unlock:
+       mutex_unlock(&dev_set->lock);
+       return ret;
+ }
+ static bool vfio_pci_dev_set_needs_reset(struct vfio_device_set *dev_set)
+ {
+       struct vfio_pci_core_device *cur;
+       bool needs_reset = false;
+       list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
+               /* No VFIO device in the set can have an open device FD */
+               if (cur->vdev.open_count)
+                       return false;
+               needs_reset |= cur->needs_reset;
+       }
+       return needs_reset;
+ }
+ /*
+  * If a bus or slot reset is available for the provided dev_set and:
+  *  - All of the devices affected by that bus or slot reset are unused
+  *  - At least one of the affected devices is marked dirty via
+  *    needs_reset (such as by lack of FLR support)
+  * Then attempt to perform that bus or slot reset.
+  * Returns true if the dev_set was reset.
+  */
+ static bool vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set)
+ {
+       struct vfio_pci_core_device *cur;
+       struct pci_dev *pdev;
+       int ret;
+       if (!vfio_pci_dev_set_needs_reset(dev_set))
+               return false;
+       pdev = vfio_pci_dev_set_resettable(dev_set);
+       if (!pdev)
+               return false;
+       ret = pci_reset_bus(pdev);
+       if (ret)
+               return false;
+       list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
+               cur->needs_reset = false;
+               if (!disable_idle_d3)
+                       vfio_pci_set_power_state(cur, PCI_D3hot);
+       }
+       return true;
+ }
+ void vfio_pci_core_set_params(bool is_nointxmask, bool is_disable_vga,
+                             bool is_disable_idle_d3)
+ {
+       nointxmask = is_nointxmask;
+       disable_vga = is_disable_vga;
+       disable_idle_d3 = is_disable_idle_d3;
+ }
+ EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);
+ static void vfio_pci_core_cleanup(void)
+ {
+       vfio_pci_uninit_perm_bits();
+ }
+ static int __init vfio_pci_core_init(void)
+ {
+       /* Allocate shared config space permission data used by all devices */
+       return vfio_pci_init_perm_bits();
+ }
+ module_init(vfio_pci_core_init);
+ module_exit(vfio_pci_core_cleanup);
+ MODULE_LICENSE("GPL v2");
+ MODULE_AUTHOR(DRIVER_AUTHOR);
+ MODULE_DESCRIPTION(DRIVER_DESC);
Simple merge