// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012 Red Hat, Inc. All rights reserved. * Author: Alex Williamson * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if IS_ENABLED(CONFIG_EEH) #include #endif #include "vfio_pci_priv.h" #define DRIVER_AUTHOR "Alex Williamson " #define DRIVER_DESC "core driver for VFIO based PCI devices" static bool nointxmask; static bool disable_vga; static bool disable_idle_d3; /* List of PF's that vfio_pci_core_sriov_configure() has been called on */ static DEFINE_MUTEX(vfio_pci_sriov_pfs_mutex); static LIST_HEAD(vfio_pci_sriov_pfs); struct vfio_pci_dummy_resource { struct resource resource; int index; struct list_head res_next; }; struct vfio_pci_vf_token { struct mutex lock; uuid_t uuid; int users; }; struct vfio_pci_mmap_vma { struct vm_area_struct *vma; struct list_head vma_next; }; 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_decode(struct pci_dev *pdev, bool single_vga) { 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_ACCOUNT); 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 void 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, struct iommufd_ctx *iommufd_ctx); /* * 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; /* Prevent changing power state for PFs with VFs enabled */ if (pci_num_vf(pdev) && state > PCI_D0) return -EBUSY; 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) { /* * The current PCI state will be saved locally in * 'pm_save' during the D3hot transition. When the * device state is changed to D0 again with the current * function, then pci_store_saved_state() will restore * the state and will free the memory pointed by * 'pm_save'. There are few cases where the PCI power * state can be changed to D0 without the involvement * of the driver. For these cases, free the earlier * allocated memory first before overwriting 'pm_save' * to prevent the memory leak. */ kfree(vdev->pm_save); 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; } static int vfio_pci_runtime_pm_entry(struct vfio_pci_core_device *vdev, struct eventfd_ctx *efdctx) { /* * The vdev power related flags are protected with 'memory_lock' * semaphore. */ vfio_pci_zap_and_down_write_memory_lock(vdev); if (vdev->pm_runtime_engaged) { up_write(&vdev->memory_lock); return -EINVAL; } vdev->pm_runtime_engaged = true; vdev->pm_wake_eventfd_ctx = efdctx; pm_runtime_put_noidle(&vdev->pdev->dev); up_write(&vdev->memory_lock); return 0; } static int vfio_pci_core_pm_entry(struct vfio_device *device, u32 flags, void __user *arg, size_t argsz) { struct vfio_pci_core_device *vdev = container_of(device, struct vfio_pci_core_device, vdev); int ret; ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0); if (ret != 1) return ret; /* * Inside vfio_pci_runtime_pm_entry(), only the runtime PM usage count * will be decremented. The pm_runtime_put() will be invoked again * while returning from the ioctl and then the device can go into * runtime suspended state. */ return vfio_pci_runtime_pm_entry(vdev, NULL); } static int vfio_pci_core_pm_entry_with_wakeup( struct vfio_device *device, u32 flags, struct vfio_device_low_power_entry_with_wakeup __user *arg, size_t argsz) { struct vfio_pci_core_device *vdev = container_of(device, struct vfio_pci_core_device, vdev); struct vfio_device_low_power_entry_with_wakeup entry; struct eventfd_ctx *efdctx; int ret; ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, sizeof(entry)); if (ret != 1) return ret; if (copy_from_user(&entry, arg, sizeof(entry))) return -EFAULT; if (entry.wakeup_eventfd < 0) return -EINVAL; efdctx = eventfd_ctx_fdget(entry.wakeup_eventfd); if (IS_ERR(efdctx)) return PTR_ERR(efdctx); ret = vfio_pci_runtime_pm_entry(vdev, efdctx); if (ret) eventfd_ctx_put(efdctx); return ret; } static void __vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev) { if (vdev->pm_runtime_engaged) { vdev->pm_runtime_engaged = false; pm_runtime_get_noresume(&vdev->pdev->dev); if (vdev->pm_wake_eventfd_ctx) { eventfd_ctx_put(vdev->pm_wake_eventfd_ctx); vdev->pm_wake_eventfd_ctx = NULL; } } } static void vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev) { /* * The vdev power related flags are protected with 'memory_lock' * semaphore. */ down_write(&vdev->memory_lock); __vfio_pci_runtime_pm_exit(vdev); up_write(&vdev->memory_lock); } static int vfio_pci_core_pm_exit(struct vfio_device *device, u32 flags, void __user *arg, size_t argsz) { struct vfio_pci_core_device *vdev = container_of(device, struct vfio_pci_core_device, vdev); int ret; ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0); if (ret != 1) return ret; /* * The device is always in the active state here due to pm wrappers * around ioctls. If the device had entered a low power state and * pm_wake_eventfd_ctx is valid, vfio_pci_core_runtime_resume() has * already signaled the eventfd and exited low power mode itself. * pm_runtime_engaged protects the redundant call here. */ vfio_pci_runtime_pm_exit(vdev); return 0; } #ifdef CONFIG_PM static int vfio_pci_core_runtime_suspend(struct device *dev) { struct vfio_pci_core_device *vdev = dev_get_drvdata(dev); down_write(&vdev->memory_lock); /* * The user can move the device into D3hot state before invoking * power management IOCTL. Move the device into D0 state here and then * the pci-driver core runtime PM suspend function will move the device * into the low power state. Also, for the devices which have * NoSoftRst-, it will help in restoring the original state * (saved locally in 'vdev->pm_save'). */ vfio_pci_set_power_state(vdev, PCI_D0); up_write(&vdev->memory_lock); /* * If INTx is enabled, then mask INTx before going into the runtime * suspended state and unmask the same in the runtime resume. * If INTx has already been masked by the user, then * vfio_pci_intx_mask() will return false and in that case, INTx * should not be unmasked in the runtime resume. */ vdev->pm_intx_masked = ((vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX) && vfio_pci_intx_mask(vdev)); return 0; } static int vfio_pci_core_runtime_resume(struct device *dev) { struct vfio_pci_core_device *vdev = dev_get_drvdata(dev); /* * Resume with a pm_wake_eventfd_ctx signals the eventfd and exit * low power mode. */ down_write(&vdev->memory_lock); if (vdev->pm_wake_eventfd_ctx) { eventfd_signal(vdev->pm_wake_eventfd_ctx, 1); __vfio_pci_runtime_pm_exit(vdev); } up_write(&vdev->memory_lock); if (vdev->pm_intx_masked) vfio_pci_intx_unmask(vdev); return 0; } #endif /* CONFIG_PM */ /* * The pci-driver core runtime PM routines always save the device state * before going into suspended state. If the device is going into low power * state with only with runtime PM ops, then no explicit handling is needed * for the devices which have NoSoftRst-. */ static const struct dev_pm_ops vfio_pci_core_pm_ops = { SET_RUNTIME_PM_OPS(vfio_pci_core_runtime_suspend, vfio_pci_core_runtime_resume, NULL) }; int vfio_pci_core_enable(struct vfio_pci_core_device *vdev) { struct pci_dev *pdev = vdev->pdev; int ret; u16 cmd; u8 msix_pos; if (!disable_idle_d3) { ret = pm_runtime_resume_and_get(&pdev->dev); if (ret < 0) return ret; } /* Don't allow our initial saved state to include busmaster */ pci_clear_master(pdev); ret = pci_enable_device(pdev); if (ret) goto out_power; /* If reset fails because of the device lock, fail this path entirely */ ret = pci_try_reset_function(pdev); if (ret == -EAGAIN) goto out_disable_device; 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_pci_zdev_open_device(vdev); if (ret) goto out_free_state; ret = vfio_config_init(vdev); if (ret) goto out_free_zdev; 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; vdev->has_dyn_msix = pci_msix_can_alloc_dyn(pdev); } else { vdev->msix_bar = 0xFF; vdev->has_dyn_msix = false; } if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev)) vdev->has_vga = true; return 0; out_free_zdev: vfio_pci_zdev_close_device(vdev); out_free_state: kfree(vdev->pci_saved_state); vdev->pci_saved_state = NULL; out_disable_device: pci_disable_device(pdev); out_power: if (!disable_idle_d3) pm_runtime_put(&pdev->dev); return ret; } 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); /* * This function can be invoked while the power state is non-D0. * This non-D0 power state can be with or without runtime PM. * vfio_pci_runtime_pm_exit() will internally increment the usage * count corresponding to pm_runtime_put() called during low power * feature entry and then pm_runtime_resume() will wake up the device, * if the device has already gone into the suspended state. Otherwise, * the vfio_pci_set_power_state() will change the device power state * to D0. */ vfio_pci_runtime_pm_exit(vdev); pm_runtime_resume(&pdev->dev); /* * This function calls __pci_reset_function_locked() which internally * can use pci_pm_reset() for the function reset. pci_pm_reset() will * fail if the power state is non-D0. Also, for the devices which * have NoSoftRst-, the reset function can cause the PCI config space * reset without restoring the original state (saved locally in * 'vdev->pm_save'). */ vfio_pci_set_power_state(vdev, PCI_D0); /* 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; vfio_pci_zdev_close_device(vdev); /* * 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); vfio_pci_dev_set_try_reset(vdev->vdev.dev_set); /* Put the pm-runtime usage counter acquired during enable */ if (!disable_idle_d3) pm_runtime_put(&pdev->dev); } EXPORT_SYMBOL_GPL(vfio_pci_core_disable); 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); if (vdev->sriov_pf_core_dev) { mutex_lock(&vdev->sriov_pf_core_dev->vf_token->lock); WARN_ON(!vdev->sriov_pf_core_dev->vf_token->users); vdev->sriov_pf_core_dev->vf_token->users--; mutex_unlock(&vdev->sriov_pf_core_dev->vf_token->lock); } #if IS_ENABLED(CONFIG_EEH) eeh_dev_release(vdev->pdev); #endif 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); #if IS_ENABLED(CONFIG_EEH) eeh_dev_open(vdev->pdev); #endif if (vdev->sriov_pf_core_dev) { mutex_lock(&vdev->sriov_pf_core_dev->vf_token->lock); vdev->sriov_pf_core_dev->vf_token->users++; mutex_unlock(&vdev->sriov_pf_core_dev->vf_token->lock); } } 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 { struct vfio_device *vdev; struct vfio_pci_dependent_device *devices; int nr_devices; u32 count; u32 flags; }; static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) { struct vfio_pci_dependent_device *info; struct vfio_pci_fill_info *fill = data; /* The topology changed since we counted devices */ if (fill->count >= fill->nr_devices) return -EAGAIN; info = &fill->devices[fill->count++]; info->segment = pci_domain_nr(pdev->bus); info->bus = pdev->bus->number; info->devfn = pdev->devfn; if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) { struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev); struct vfio_device_set *dev_set = fill->vdev->dev_set; struct vfio_device *vdev; /* * hot-reset requires all affected devices be represented in * the dev_set. */ vdev = vfio_find_device_in_devset(dev_set, &pdev->dev); if (!vdev) { info->devid = VFIO_PCI_DEVID_NOT_OWNED; } else { int id = vfio_iommufd_get_dev_id(vdev, iommufd); if (id > 0) info->devid = id; else if (id == -ENOENT) info->devid = VFIO_PCI_DEVID_OWNED; else info->devid = VFIO_PCI_DEVID_NOT_OWNED; } /* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */ if (info->devid == VFIO_PCI_DEVID_NOT_OWNED) fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; } else { struct iommu_group *iommu_group; iommu_group = iommu_group_get(&pdev->dev); if (!iommu_group) return -EPERM; /* Cannot reset non-isolated devices */ info->group_id = iommu_group_id(iommu_group); iommu_group_put(iommu_group); } return 0; } struct vfio_pci_group_info { int count; struct file **files; }; 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 *pdev, 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_core_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_ACCOUNT); 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_core_register_dev_region); static int vfio_pci_info_atomic_cap(struct vfio_pci_core_device *vdev, struct vfio_info_cap *caps) { struct vfio_device_info_cap_pci_atomic_comp cap = { .header.id = VFIO_DEVICE_INFO_CAP_PCI_ATOMIC_COMP, .header.version = 1 }; struct pci_dev *pdev = pci_physfn(vdev->pdev); u32 devcap2; pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &devcap2); if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP32) && !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP32)) cap.flags |= VFIO_PCI_ATOMIC_COMP32; if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP64) && !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP64)) cap.flags |= VFIO_PCI_ATOMIC_COMP64; if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP128) && !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP128)) cap.flags |= VFIO_PCI_ATOMIC_COMP128; if (!cap.flags) return -ENODEV; return vfio_info_add_capability(caps, &cap.header, sizeof(cap)); } static int vfio_pci_ioctl_get_info(struct vfio_pci_core_device *vdev, struct vfio_device_info __user *arg) { unsigned long minsz = offsetofend(struct vfio_device_info, num_irqs); struct vfio_device_info info = {}; struct vfio_info_cap caps = { .buf = NULL, .size = 0 }; int ret; if (copy_from_user(&info, arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; minsz = min_t(size_t, info.argsz, sizeof(info)); 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; } ret = vfio_pci_info_atomic_cap(vdev, &caps); if (ret && ret != -ENODEV) { pci_warn(vdev->pdev, "Failed to setup AtomicOps info capability\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(arg + 1, caps.buf, caps.size)) { kfree(caps.buf); return -EFAULT; } info.cap_offset = sizeof(*arg); } kfree(caps.buf); } return copy_to_user(arg, &info, minsz) ? -EFAULT : 0; } static int vfio_pci_ioctl_get_region_info(struct vfio_pci_core_device *vdev, struct vfio_region_info __user *arg) { unsigned long minsz = offsetofend(struct vfio_region_info, offset); struct pci_dev *pdev = vdev->pdev; struct vfio_region_info info; struct vfio_info_cap caps = { .buf = NULL, .size = 0 }; int i, ret; if (copy_from_user(&info, 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(arg + 1, caps.buf, caps.size)) { kfree(caps.buf); return -EFAULT; } info.cap_offset = sizeof(*arg); } kfree(caps.buf); } return copy_to_user(arg, &info, minsz) ? -EFAULT : 0; } static int vfio_pci_ioctl_get_irq_info(struct vfio_pci_core_device *vdev, struct vfio_irq_info __user *arg) { unsigned long minsz = offsetofend(struct vfio_irq_info, count); struct vfio_irq_info info; if (copy_from_user(&info, 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 if (info.index != VFIO_PCI_MSIX_IRQ_INDEX || !vdev->has_dyn_msix) info.flags |= VFIO_IRQ_INFO_NORESIZE; return copy_to_user(arg, &info, minsz) ? -EFAULT : 0; } static int vfio_pci_ioctl_set_irqs(struct vfio_pci_core_device *vdev, struct vfio_irq_set __user *arg) { unsigned long minsz = offsetofend(struct vfio_irq_set, count); struct vfio_irq_set hdr; u8 *data = NULL; int max, ret = 0; size_t data_size = 0; if (copy_from_user(&hdr, 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(&arg->data, 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; } static int vfio_pci_ioctl_reset(struct vfio_pci_core_device *vdev, void __user *arg) { int ret; if (!vdev->reset_works) return -EINVAL; vfio_pci_zap_and_down_write_memory_lock(vdev); /* * This function can be invoked while the power state is non-D0. If * pci_try_reset_function() has been called while the power state is * non-D0, then pci_try_reset_function() will internally set the power * state to D0 without vfio driver involvement. For the devices which * have NoSoftRst-, the reset function can cause the PCI config space * reset without restoring the original state (saved locally in * 'vdev->pm_save'). */ vfio_pci_set_power_state(vdev, PCI_D0); ret = pci_try_reset_function(vdev->pdev); up_write(&vdev->memory_lock); return ret; } static int vfio_pci_ioctl_get_pci_hot_reset_info( struct vfio_pci_core_device *vdev, struct vfio_pci_hot_reset_info __user *arg) { unsigned long minsz = offsetofend(struct vfio_pci_hot_reset_info, count); struct vfio_pci_dependent_device *devices = NULL; struct vfio_pci_hot_reset_info hdr; struct vfio_pci_fill_info fill = {}; bool slot = false; int ret, count; if (copy_from_user(&hdr, 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; ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs, &count, slot); if (ret) return ret; if (count > (hdr.argsz - sizeof(hdr)) / sizeof(*devices)) { hdr.count = count; ret = -ENOSPC; goto header; } devices = kcalloc(count, sizeof(*devices), GFP_KERNEL); if (!devices) return -ENOMEM; fill.devices = devices; fill.nr_devices = count; fill.vdev = &vdev->vdev; if (vfio_device_cdev_opened(&vdev->vdev)) fill.flags |= VFIO_PCI_HOT_RESET_FLAG_DEV_ID | VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; mutex_lock(&vdev->vdev.dev_set->lock); ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs, &fill, slot); mutex_unlock(&vdev->vdev.dev_set->lock); if (ret) goto out; if (copy_to_user(arg->devices, devices, sizeof(*devices) * fill.count)) { ret = -EFAULT; goto out; } hdr.count = fill.count; hdr.flags = fill.flags; header: if (copy_to_user(arg, &hdr, minsz)) ret = -EFAULT; out: kfree(devices); return ret; } static int vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev, int array_count, bool slot, struct vfio_pci_hot_reset __user *arg) { int32_t *group_fds; struct file **files; struct vfio_pci_group_info info; int file_idx, count = 0, ret = 0; /* * 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; if (array_count > count) return -EINVAL; group_fds = kcalloc(array_count, sizeof(*group_fds), GFP_KERNEL); files = kcalloc(array_count, sizeof(*files), GFP_KERNEL); if (!group_fds || !files) { kfree(group_fds); kfree(files); return -ENOMEM; } if (copy_from_user(group_fds, arg->group_fds, array_count * sizeof(*group_fds))) { kfree(group_fds); kfree(files); return -EFAULT; } /* * Get the group file for each fd to ensure the group is held across * the reset */ for (file_idx = 0; file_idx < array_count; file_idx++) { struct file *file = fget(group_fds[file_idx]); if (!file) { ret = -EBADF; break; } /* Ensure the FD is a vfio group FD.*/ if (!vfio_file_is_group(file)) { fput(file); ret = -EINVAL; break; } files[file_idx] = file; } kfree(group_fds); /* release reference to groups on error */ if (ret) goto hot_reset_release; info.count = array_count; info.files = files; ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info, NULL); hot_reset_release: for (file_idx--; file_idx >= 0; file_idx--) fput(files[file_idx]); kfree(files); return ret; } static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev, struct vfio_pci_hot_reset __user *arg) { unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count); struct vfio_pci_hot_reset hdr; bool slot = false; if (copy_from_user(&hdr, arg, minsz)) return -EFAULT; if (hdr.argsz < minsz || hdr.flags) return -EINVAL; /* zero-length array is only for cdev opened devices */ if (!!hdr.count == vfio_device_cdev_opened(&vdev->vdev)) 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; if (hdr.count) return vfio_pci_ioctl_pci_hot_reset_groups(vdev, hdr.count, slot, arg); return vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, NULL, vfio_iommufd_device_ictx(&vdev->vdev)); } static int vfio_pci_ioctl_ioeventfd(struct vfio_pci_core_device *vdev, struct vfio_device_ioeventfd __user *arg) { unsigned long minsz = offsetofend(struct vfio_device_ioeventfd, fd); struct vfio_device_ioeventfd ioeventfd; int count; if (copy_from_user(&ioeventfd, 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); } 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); void __user *uarg = (void __user *)arg; switch (cmd) { case VFIO_DEVICE_GET_INFO: return vfio_pci_ioctl_get_info(vdev, uarg); case VFIO_DEVICE_GET_IRQ_INFO: return vfio_pci_ioctl_get_irq_info(vdev, uarg); case VFIO_DEVICE_GET_PCI_HOT_RESET_INFO: return vfio_pci_ioctl_get_pci_hot_reset_info(vdev, uarg); case VFIO_DEVICE_GET_REGION_INFO: return vfio_pci_ioctl_get_region_info(vdev, uarg); case VFIO_DEVICE_IOEVENTFD: return vfio_pci_ioctl_ioeventfd(vdev, uarg); case VFIO_DEVICE_PCI_HOT_RESET: return vfio_pci_ioctl_pci_hot_reset(vdev, uarg); case VFIO_DEVICE_RESET: return vfio_pci_ioctl_reset(vdev, uarg); case VFIO_DEVICE_SET_IRQS: return vfio_pci_ioctl_set_irqs(vdev, uarg); default: return -ENOTTY; } } EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl); static int vfio_pci_core_feature_token(struct vfio_device *device, u32 flags, uuid_t __user *arg, size_t argsz) { struct vfio_pci_core_device *vdev = container_of(device, struct vfio_pci_core_device, vdev); uuid_t uuid; int ret; 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. */ ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, sizeof(uuid)); if (ret != 1) return ret; if (copy_from_user(&uuid, arg, 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; } int vfio_pci_core_ioctl_feature(struct vfio_device *device, u32 flags, void __user *arg, size_t argsz) { switch (flags & VFIO_DEVICE_FEATURE_MASK) { case VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY: return vfio_pci_core_pm_entry(device, flags, arg, argsz); case VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP: return vfio_pci_core_pm_entry_with_wakeup(device, flags, arg, argsz); case VFIO_DEVICE_FEATURE_LOW_POWER_EXIT: return vfio_pci_core_pm_exit(device, flags, arg, argsz); case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN: return vfio_pci_core_feature_token(device, flags, arg, argsz); default: return -ENOTTY; } } EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl_feature); 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); int ret; if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions) return -EINVAL; ret = pm_runtime_resume_and_get(&vdev->pdev->dev); if (ret) { pci_info_ratelimited(vdev->pdev, "runtime resume failed %d\n", ret); return -EIO; } switch (index) { case VFIO_PCI_CONFIG_REGION_INDEX: ret = vfio_pci_config_rw(vdev, buf, count, ppos, iswrite); break; case VFIO_PCI_ROM_REGION_INDEX: if (iswrite) ret = -EINVAL; else ret = vfio_pci_bar_rw(vdev, buf, count, ppos, false); break; case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: ret = vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite); break; case VFIO_PCI_VGA_REGION_INDEX: ret = vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite); break; default: index -= VFIO_PCI_NUM_REGIONS; ret = vdev->region[index].ops->rw(vdev, buf, count, ppos, iswrite); break; } pm_runtime_put(&vdev->pdev->dev); return ret; } 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_ACCOUNT); 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); /* * Memory region cannot be accessed if the low power feature is engaged * or memory access is disabled. */ if (vdev->pm_runtime_engaged || !__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. */ vm_flags_set(vma, 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) { struct vfio_pci_core_device *pf_vdev = vdev->sriov_pf_core_dev; 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) { 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); 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; struct vfio_pci_core_device *cur; struct pci_dev *physfn; int ret; if (pdev->is_virtfn) { /* * If this VF was created by our vfio_pci_core_sriov_configure() * then we can find the PF vfio_pci_core_device now, and due to * the locking in pci_disable_sriov() it cannot change until * this VF device driver is removed. */ physfn = pci_physfn(vdev->pdev); mutex_lock(&vfio_pci_sriov_pfs_mutex); list_for_each_entry(cur, &vfio_pci_sriov_pfs, sriov_pfs_item) { if (cur->pdev == physfn) { vdev->sriov_pf_core_dev = cur; break; } } mutex_unlock(&vfio_pci_sriov_pfs_mutex); return 0; } /* Not a SRIOV PF */ 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; ret = aperture_remove_conflicting_pci_devices(pdev, vdev->vdev.ops->name); if (ret) return ret; ret = vga_client_register(pdev, vfio_pci_set_decode); if (ret) return ret; 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); } int vfio_pci_core_init_dev(struct vfio_device *core_vdev) { struct vfio_pci_core_device *vdev = container_of(core_vdev, struct vfio_pci_core_device, vdev); vdev->pdev = to_pci_dev(core_vdev->dev); 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_LIST_HEAD(&vdev->sriov_pfs_item); init_rwsem(&vdev->memory_lock); xa_init(&vdev->ctx); return 0; } EXPORT_SYMBOL_GPL(vfio_pci_core_init_dev); void vfio_pci_core_release_dev(struct vfio_device *core_vdev) { struct vfio_pci_core_device *vdev = container_of(core_vdev, struct vfio_pci_core_device, vdev); mutex_destroy(&vdev->igate); mutex_destroy(&vdev->ioeventfds_lock); mutex_destroy(&vdev->vma_lock); kfree(vdev->region); kfree(vdev->pm_save); } EXPORT_SYMBOL_GPL(vfio_pci_core_release_dev); int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev) { struct pci_dev *pdev = vdev->pdev; struct device *dev = &pdev->dev; int ret; /* Drivers must set the vfio_pci_core_device to their drvdata */ if (WARN_ON(vdev != dev_get_drvdata(dev))) return -EINVAL; if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL) return -EINVAL; if (vdev->vdev.mig_ops) { if (!(vdev->vdev.mig_ops->migration_get_state && vdev->vdev.mig_ops->migration_set_state && vdev->vdev.mig_ops->migration_get_data_size) || !(vdev->vdev.migration_flags & VFIO_MIGRATION_STOP_COPY)) return -EINVAL; } if (vdev->vdev.log_ops && !(vdev->vdev.log_ops->log_start && vdev->vdev.log_ops->log_stop && vdev->vdev.log_ops->log_read_and_clear)) 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; } 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) return ret; ret = vfio_pci_vf_init(vdev); if (ret) return ret; ret = vfio_pci_vga_init(vdev); if (ret) goto out_vf; vfio_pci_probe_power_state(vdev); /* * 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 enabling runtime PM. */ vfio_pci_set_power_state(vdev, PCI_D0); dev->driver->pm = &vfio_pci_core_pm_ops; pm_runtime_allow(dev); if (!disable_idle_d3) pm_runtime_put(dev); ret = vfio_register_group_dev(&vdev->vdev); if (ret) goto out_power; return 0; out_power: if (!disable_idle_d3) pm_runtime_get_noresume(dev); pm_runtime_forbid(dev); out_vf: vfio_pci_vf_uninit(vdev); return ret; } EXPORT_SYMBOL_GPL(vfio_pci_core_register_device); void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev) { vfio_pci_core_sriov_configure(vdev, 0); vfio_unregister_group_dev(&vdev->vdev); vfio_pci_vf_uninit(vdev); vfio_pci_vga_uninit(vdev); if (!disable_idle_d3) pm_runtime_get_noresume(&vdev->pdev->dev); pm_runtime_forbid(&vdev->pdev->dev); } EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device); pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev, pci_channel_state_t state) { struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev); mutex_lock(&vdev->igate); if (vdev->err_trigger) eventfd_signal(vdev->err_trigger, 1); mutex_unlock(&vdev->igate); return PCI_ERS_RESULT_CAN_RECOVER; } EXPORT_SYMBOL_GPL(vfio_pci_core_aer_err_detected); int vfio_pci_core_sriov_configure(struct vfio_pci_core_device *vdev, int nr_virtfn) { struct pci_dev *pdev = vdev->pdev; int ret = 0; device_lock_assert(&pdev->dev); if (nr_virtfn) { mutex_lock(&vfio_pci_sriov_pfs_mutex); /* * The thread that adds the vdev to the list is the only thread * that gets to call pci_enable_sriov() and we will only allow * it to be called once without going through * pci_disable_sriov() */ if (!list_empty(&vdev->sriov_pfs_item)) { ret = -EINVAL; goto out_unlock; } list_add_tail(&vdev->sriov_pfs_item, &vfio_pci_sriov_pfs); mutex_unlock(&vfio_pci_sriov_pfs_mutex); /* * The PF power state should always be higher than the VF power * state. The PF can be in low power state either with runtime * power management (when there is no user) or PCI_PM_CTRL * register write by the user. If PF is in the low power state, * then change the power state to D0 first before enabling * SR-IOV. Also, this function can be called at any time, and * userspace PCI_PM_CTRL write can race against this code path, * so protect the same with 'memory_lock'. */ ret = pm_runtime_resume_and_get(&pdev->dev); if (ret) goto out_del; down_write(&vdev->memory_lock); vfio_pci_set_power_state(vdev, PCI_D0); ret = pci_enable_sriov(pdev, nr_virtfn); up_write(&vdev->memory_lock); if (ret) { pm_runtime_put(&pdev->dev); goto out_del; } return nr_virtfn; } if (pci_num_vf(pdev)) { pci_disable_sriov(pdev); pm_runtime_put(&pdev->dev); } out_del: mutex_lock(&vfio_pci_sriov_pfs_mutex); list_del_init(&vdev->sriov_pfs_item); out_unlock: mutex_unlock(&vfio_pci_sriov_pfs_mutex); return ret; } EXPORT_SYMBOL_GPL(vfio_pci_core_sriov_configure); const struct pci_error_handlers vfio_pci_core_err_handlers = { .error_detected = vfio_pci_core_aer_err_detected, }; EXPORT_SYMBOL_GPL(vfio_pci_core_err_handlers); static bool vfio_dev_in_groups(struct vfio_device *vdev, struct vfio_pci_group_info *groups) { unsigned int i; if (!groups) return false; for (i = 0; i < groups->count; i++) if (vfio_file_has_dev(groups->files[i], vdev)) 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; return vfio_find_device_in_devset(dev_set, &pdev->dev) ? 0 : -ENODEV; } /* * 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; } static int vfio_pci_dev_set_pm_runtime_get(struct vfio_device_set *dev_set) { struct vfio_pci_core_device *cur; int ret; list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) { ret = pm_runtime_resume_and_get(&cur->pdev->dev); if (ret) goto unwind; } return 0; unwind: list_for_each_entry_continue_reverse(cur, &dev_set->device_list, vdev.dev_set_list) pm_runtime_put(&cur->pdev->dev); return ret; } /* * 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 iommufd_ctx *iommufd_ctx) { 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; } /* * Some of the devices in the dev_set can be in the runtime suspended * state. Increment the usage count for all the devices in the dev_set * before reset and decrement the same after reset. */ ret = vfio_pci_dev_set_pm_runtime_get(dev_set); if (ret) goto err_unlock; list_for_each_entry(cur_vma, &dev_set->device_list, vdev.dev_set_list) { bool owned; /* * Test whether all the affected devices can be reset by the * user. * * If called from a group opened device and the user provides * a set of groups, all the devices in the dev_set should be * contained by the set of groups provided by the user. * * If called from a cdev opened device and the user provides * a zero-length array, all the devices in the dev_set must * be bound to the same iommufd_ctx as the input iommufd_ctx. * If there is any device that has not been bound to any * iommufd_ctx yet, check if its iommu_group has any device * bound to the input iommufd_ctx. Such devices can be * considered owned by the input iommufd_ctx as the device * cannot be owned by another iommufd_ctx when its iommu_group * is owned. * * Otherwise, reset is not allowed. */ if (iommufd_ctx) { int devid = vfio_iommufd_get_dev_id(&cur_vma->vdev, iommufd_ctx); owned = (devid > 0 || devid == -ENOENT); } else { owned = vfio_dev_in_groups(&cur_vma->vdev, groups); } if (!owned) { 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; /* * The pci_reset_bus() will reset all the devices in the bus. * The power state can be non-D0 for some of the devices in the bus. * For these devices, the pci_reset_bus() will internally set * the power state to D0 without vfio driver involvement. * For the devices which have NoSoftRst-, the reset function can * cause the PCI config space reset without restoring the original * state (saved locally in 'vdev->pm_save'). */ list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) vfio_pci_set_power_state(cur, PCI_D0); 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); } list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) pm_runtime_put(&cur->pdev->dev); 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; /* No other VFIO device in the set can be open. */ if (vfio_device_set_open_count(dev_set) > 1) return false; list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) 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. */ static void vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set) { struct vfio_pci_core_device *cur; struct pci_dev *pdev; bool reset_done = false; if (!vfio_pci_dev_set_needs_reset(dev_set)) return; pdev = vfio_pci_dev_set_resettable(dev_set); if (!pdev) return; /* * Some of the devices in the bus can be in the runtime suspended * state. Increment the usage count for all the devices in the dev_set * before reset and decrement the same after reset. */ if (!disable_idle_d3 && vfio_pci_dev_set_pm_runtime_get(dev_set)) return; if (!pci_reset_bus(pdev)) reset_done = true; list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) { if (reset_done) cur->needs_reset = false; if (!disable_idle_d3) pm_runtime_put(&cur->pdev->dev); } } 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);