| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Alex Williamson | 9292 | 88.85% | 49 | 58.33% |
| Yongji Xie | 312 | 2.98% | 1 | 1.19% |
| Alexey Kardashevskiy | 219 | 2.09% | 4 | 4.76% |
| Giovanni Cabiddu | 162 | 1.55% | 2 | 2.38% |
| Vijay Mohan Pandarathil | 136 | 1.30% | 1 | 1.19% |
| Kirti Wankhede | 47 | 0.45% | 2 | 2.38% |
| hexin | 36 | 0.34% | 1 | 1.19% |
| Gavin Shan | 35 | 0.33% | 2 | 2.38% |
| Björn Helgaas | 31 | 0.30% | 3 | 3.57% |
| Denis Efremov | 29 | 0.28% | 1 | 1.19% |
| Qian Cai | 26 | 0.25% | 1 | 1.19% |
| Arvind Yadav | 25 | 0.24% | 1 | 1.19% |
| Gustavo A. R. Silva | 22 | 0.21% | 2 | 2.38% |
| Eric Auger | 18 | 0.17% | 1 | 1.19% |
| Zeng Tao | 16 | 0.15% | 1 | 1.19% |
| Michael S. Tsirkin | 15 | 0.14% | 1 | 1.19% |
| Vlad Tsyrklevich | 9 | 0.09% | 1 | 1.19% |
| Fengguang Wu | 8 | 0.08% | 1 | 1.19% |
| Michel Lespinasse | 6 | 0.06% | 2 | 2.38% |
| Dan Carpenter | 4 | 0.04% | 1 | 1.19% |
| Wei Yang | 3 | 0.03% | 1 | 1.19% |
| Thomas Gleixner | 2 | 0.02% | 1 | 1.19% |
| Louis Taylor | 2 | 0.02% | 1 | 1.19% |
| Jiang Liu | 1 | 0.01% | 1 | 1.19% |
| Julia Lawall | 1 | 0.01% | 1 | 1.19% |
| Sinan Kaya | 1 | 0.01% | 1 | 1.19% |
| Total | 10458 | 84 |
// 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/vfio.h> #include <linux/vgaarb.h> #include <linux/nospec.h> #include <linux/sched/mm.h> #include "vfio_pci_private.h" #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" #define DRIVER_DESC "VFIO PCI - User Level meta-driver" static char ids[1024] __initdata; module_param_string(ids, ids, sizeof(ids), 0); MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified"); static bool nointxmask; module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(nointxmask, "Disable support for PCI 2.3 style INTx masking. If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag."); #ifdef CONFIG_VFIO_PCI_VGA static bool disable_vga; module_param(disable_vga, bool, S_IRUGO); MODULE_PARM_DESC(disable_vga, "Disable VGA resource access through vfio-pci"); #endif static bool disable_idle_d3; module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(disable_idle_d3, "Disable using the PCI D3 low power state for idle, unused devices"); static bool enable_sriov; #ifdef CONFIG_PCI_IOV module_param(enable_sriov, bool, 0644); MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration. Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF."); #endif static bool disable_denylist; module_param(disable_denylist, bool, 0444); MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling the denylist allows binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users."); static inline bool vfio_vga_disabled(void) { #ifdef CONFIG_VFIO_PCI_VGA return disable_vga; #else return true; #endif } static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev) { switch (pdev->vendor) { case PCI_VENDOR_ID_INTEL: switch (pdev->device) { case PCI_DEVICE_ID_INTEL_QAT_C3XXX: case PCI_DEVICE_ID_INTEL_QAT_C3XXX_VF: case PCI_DEVICE_ID_INTEL_QAT_C62X: case PCI_DEVICE_ID_INTEL_QAT_C62X_VF: case PCI_DEVICE_ID_INTEL_QAT_DH895XCC: case PCI_DEVICE_ID_INTEL_QAT_DH895XCC_VF: return true; default: return false; } } return false; } static bool vfio_pci_is_denylisted(struct pci_dev *pdev) { if (!vfio_pci_dev_in_denylist(pdev)) return false; if (disable_denylist) { pci_warn(pdev, "device denylist disabled - allowing device %04x:%04x.\n", pdev->vendor, pdev->device); return false; } pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n", pdev->vendor, pdev->device); return true; } /* * Our VGA arbiter participation is limited since we don't know anything * about the device itself. However, if the device is the only VGA device * downstream of a bridge and VFIO VGA support is disabled, then we can * safely return legacy VGA IO and memory as not decoded since the user * has no way to get to it and routing can be disabled externally at the * bridge. */ static unsigned int vfio_pci_set_vga_decode(void *opaque, bool single_vga) { struct vfio_pci_device *vdev = opaque; struct pci_dev *tmp = NULL, *pdev = vdev->pdev; unsigned char max_busnr; unsigned int decodes; if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus)) return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM | VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; max_busnr = pci_bus_max_busnr(pdev->bus); decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) { if (tmp == pdev || pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) || pci_is_root_bus(tmp->bus)) continue; if (tmp->bus->number >= pdev->bus->number && tmp->bus->number <= max_busnr) { pci_dev_put(tmp); decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; break; } } return decodes; } static inline bool vfio_pci_is_vga(struct pci_dev *pdev) { return (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA; } static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev) { struct resource *res; int i; struct vfio_pci_dummy_resource *dummy_res; INIT_LIST_HEAD(&vdev->dummy_resources_list); 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; } } static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev); static void vfio_pci_disable(struct vfio_pci_device *vdev); static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data); /* * 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_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_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; } static int vfio_pci_enable(struct vfio_pci_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; if (vfio_pci_is_vga(pdev) && pdev->vendor == PCI_VENDOR_ID_INTEL && IS_ENABLED(CONFIG_VFIO_PCI_IGD)) { ret = vfio_pci_igd_init(vdev); if (ret) { pci_warn(pdev, "Failed to setup Intel IGD regions\n"); goto disable_exit; } } if (pdev->vendor == PCI_VENDOR_ID_NVIDIA && IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) { ret = vfio_pci_nvdia_v100_nvlink2_init(vdev); if (ret && ret != -ENODEV) { pci_warn(pdev, "Failed to setup NVIDIA NV2 RAM region\n"); goto disable_exit; } } if (pdev->vendor == PCI_VENDOR_ID_IBM && IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) { ret = vfio_pci_ibm_npu2_init(vdev); if (ret && ret != -ENODEV) { pci_warn(pdev, "Failed to setup NVIDIA NV2 ATSD region\n"); goto disable_exit; } } vfio_pci_probe_mmaps(vdev); return 0; disable_exit: vfio_pci_disable(vdev); return ret; } static void vfio_pci_disable(struct vfio_pci_device *vdev) { struct pci_dev *pdev = vdev->pdev; struct vfio_pci_dummy_resource *dummy_res, *tmp; struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp; int i, bar; /* Stop the device from further DMA */ pci_clear_master(pdev); vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER, vdev->irq_type, 0, 0, NULL); /* Device closed, don't need mutex here */ list_for_each_entry_safe(ioeventfd, ioeventfd_tmp, &vdev->ioeventfds_list, next) { vfio_virqfd_disable(&ioeventfd->virqfd); list_del(&ioeventfd->next); kfree(ioeventfd); } vdev->ioeventfds_nr = 0; vdev->virq_disabled = false; for (i = 0; i < vdev->num_regions; i++) vdev->region[i].ops->release(vdev, &vdev->region[i]); vdev->num_regions = 0; kfree(vdev->region); vdev->region = NULL; /* don't krealloc a freed pointer */ vfio_config_free(vdev); for (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_cfg_access_trylock(pdev)) { if (device_trylock(&pdev->dev)) { if (!__pci_reset_function_locked(pdev)) vdev->needs_reset = false; device_unlock(&pdev->dev); } pci_cfg_access_unlock(pdev); } pci_restore_state(pdev); out: pci_disable_device(pdev); vfio_pci_try_bus_reset(vdev); if (!disable_idle_d3) vfio_pci_set_power_state(vdev, PCI_D3hot); } static struct pci_driver vfio_pci_driver; static struct vfio_pci_device *get_pf_vdev(struct vfio_pci_device *vdev, struct vfio_device **pf_dev) { struct pci_dev *physfn = pci_physfn(vdev->pdev); 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) != &vfio_pci_driver) { vfio_device_put(*pf_dev); return NULL; } return vfio_device_data(*pf_dev); } static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val) { struct vfio_device *pf_dev; struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev); 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_dev); } static void vfio_pci_release(void *device_data) { struct vfio_pci_device *vdev = device_data; mutex_lock(&vdev->reflck->lock); if (!(--vdev->refcnt)) { vfio_pci_vf_token_user_add(vdev, -1); vfio_spapr_pci_eeh_release(vdev->pdev); vfio_pci_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); } mutex_unlock(&vdev->reflck->lock); module_put(THIS_MODULE); } static int vfio_pci_open(void *device_data) { struct vfio_pci_device *vdev = device_data; int ret = 0; if (!try_module_get(THIS_MODULE)) return -ENODEV; mutex_lock(&vdev->reflck->lock); if (!vdev->refcnt) { ret = vfio_pci_enable(vdev); if (ret) goto error; vfio_spapr_pci_eeh_open(vdev->pdev); vfio_pci_vf_token_user_add(vdev, 1); } vdev->refcnt++; error: mutex_unlock(&vdev->reflck->lock); if (ret) module_put(THIS_MODULE); return ret; } static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type) { if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) { u8 pin; 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_entry { struct vfio_group *group; int id; }; struct vfio_pci_group_info { int count; struct vfio_pci_group_entry *groups; }; static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data) { struct vfio_pci_group_info *info = data; struct iommu_group *group; int id, i; group = iommu_group_get(&pdev->dev); if (!group) return -EPERM; id = iommu_group_id(group); for (i = 0; i < info->count; i++) if (info->groups[i].id == id) break; iommu_group_put(group); return (i == info->count) ? -EINVAL : 0; } static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot) { for (; pdev; pdev = pdev->bus->self) if (pdev->bus == slot->bus) return (pdev->slot == slot); return false; } struct vfio_pci_walk_info { int (*fn)(struct pci_dev *, void *data); void *data; struct pci_dev *pdev; bool slot; int ret; }; static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data) { struct vfio_pci_walk_info *walk = data; if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot)) walk->ret = walk->fn(pdev, walk->data); return walk->ret; } static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev, int (*fn)(struct pci_dev *, void *data), void *data, bool slot) { struct vfio_pci_walk_info walk = { .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0, }; pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk); return walk.ret; } static int msix_mmappable_cap(struct vfio_pci_device *vdev, struct vfio_info_cap *caps) { struct vfio_info_cap_header header = { .id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE, .version = 1 }; return vfio_info_add_capability(caps, &header, sizeof(header)); } int vfio_pci_register_dev_region(struct vfio_pci_device *vdev, unsigned int type, unsigned int subtype, const struct vfio_pci_regops *ops, size_t size, u32 flags, void *data) { struct vfio_pci_region *region; region = krealloc(vdev->region, (vdev->num_regions + 1) * sizeof(*region), GFP_KERNEL); if (!region) return -ENOMEM; vdev->region = region; vdev->region[vdev->num_regions].type = type; vdev->region[vdev->num_regions].subtype = subtype; vdev->region[vdev->num_regions].ops = ops; vdev->region[vdev->num_regions].size = size; vdev->region[vdev->num_regions].flags = flags; vdev->region[vdev->num_regions].data = data; vdev->num_regions++; return 0; } struct vfio_devices { struct vfio_device **devices; int cur_index; int max_index; }; static long vfio_pci_ioctl(void *device_data, unsigned int cmd, unsigned long arg) { struct vfio_pci_device *vdev = device_data; unsigned long minsz; if (cmd == VFIO_DEVICE_GET_INFO) { struct vfio_device_info info; minsz = offsetofend(struct vfio_device_info, num_irqs); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; info.flags = VFIO_DEVICE_FLAGS_PCI; if (vdev->reset_works) info.flags |= VFIO_DEVICE_FLAGS_RESET; info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions; info.num_irqs = VFIO_PCI_NUM_IRQS; return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { struct pci_dev *pdev = vdev->pdev; struct vfio_region_info info; struct vfio_info_cap caps = { .buf = NULL, .size = 0 }; int i, ret; minsz = offsetofend(struct vfio_region_info, offset); if (copy_from_user(&info, (void __user *)arg, minsz)) return -EFAULT; if (info.argsz < minsz) return -EINVAL; switch (info.index) { case VFIO_PCI_CONFIG_REGION_INDEX: info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); info.size = pdev->cfg_size; info.flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; break; case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); info.size = pci_resource_len(pdev, info.index); if (!info.size) { info.flags = 0; break; } info.flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; if (vdev->bar_mmap_supported[info.index]) { info.flags |= VFIO_REGION_INFO_FLAG_MMAP; if (info.index == vdev->msix_bar) { ret = msix_mmappable_cap(vdev, &caps); if (ret) return ret; } } break; case VFIO_PCI_ROM_REGION_INDEX: { void __iomem *io; size_t size; 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_pci_group_entry *groups; struct vfio_pci_group_info info; struct vfio_devices devs = { .cur_index = 0 }; bool slot = false; int i, group_idx, mem_idx = 0, 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 = group; groups[group_idx].id = vfio_external_user_iommu_id(group); } kfree(group_fds); /* release reference to groups on error */ if (ret) goto hot_reset_release; info.count = hdr.count; info.groups = groups; /* * Test whether all the affected devices are contained * by the set of groups provided by the user. */ ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_validate_devs, &info, slot); if (ret) goto hot_reset_release; devs.max_index = count; devs.devices = kcalloc(count, sizeof(struct vfio_device *), GFP_KERNEL); if (!devs.devices) { ret = -ENOMEM; goto hot_reset_release; } /* * 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. */ ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_try_zap_and_vma_lock_cb, &devs, slot); if (ret) goto hot_reset_release; for (; mem_idx < devs.cur_index; mem_idx++) { struct vfio_pci_device *tmp; tmp = vfio_device_data(devs.devices[mem_idx]); ret = down_write_trylock(&tmp->memory_lock); if (!ret) { ret = -EBUSY; goto hot_reset_release; } mutex_unlock(&tmp->vma_lock); } /* User has access, do the reset */ ret = pci_reset_bus(vdev->pdev); hot_reset_release: for (i = 0; i < devs.cur_index; i++) { struct vfio_device *device; struct vfio_pci_device *tmp; device = devs.devices[i]; tmp = vfio_device_data(device); if (i < mem_idx) up_write(&tmp->memory_lock); else mutex_unlock(&tmp->vma_lock); vfio_device_put(device); } kfree(devs.devices); for (group_idx--; group_idx >= 0; group_idx--) vfio_group_put_external_user(groups[group_idx].group); kfree(groups); return ret; } else if (cmd == VFIO_DEVICE_IOEVENTFD) { struct vfio_device_ioeventfd ioeventfd; int count; minsz = offsetofend(struct vfio_device_ioeventfd, fd); if (copy_from_user(&ioeventfd, (void __user *)arg, minsz)) return -EFAULT; if (ioeventfd.argsz < minsz) return -EINVAL; if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK) return -EINVAL; count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK; if (hweight8(count) != 1 || ioeventfd.fd < -1) return -EINVAL; return vfio_pci_ioeventfd(vdev, ioeventfd.offset, ioeventfd.data, count, ioeventfd.fd); } 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; } static ssize_t vfio_pci_rw(void *device_data, char __user *buf, size_t count, loff_t *ppos, bool iswrite) { unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); struct vfio_pci_device *vdev = device_data; if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions) return -EINVAL; switch (index) { case VFIO_PCI_CONFIG_REGION_INDEX: return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite); case VFIO_PCI_ROM_REGION_INDEX: if (iswrite) return -EINVAL; return vfio_pci_bar_rw(vdev, buf, count, ppos, false); case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite); case VFIO_PCI_VGA_REGION_INDEX: return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite); default: index -= VFIO_PCI_NUM_REGIONS; return vdev->region[index].ops->rw(vdev, buf, count, ppos, iswrite); } return -EINVAL; } static ssize_t vfio_pci_read(void *device_data, char __user *buf, size_t count, loff_t *ppos) { if (!count) return 0; return vfio_pci_rw(device_data, buf, count, ppos, false); } static ssize_t vfio_pci_write(void *device_data, const char __user *buf, size_t count, loff_t *ppos) { if (!count) return 0; return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true); } /* 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_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 (mmget_still_valid(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_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_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_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_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_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_device *vdev = vma->vm_private_data; 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; mutex_unlock(&vdev->vma_lock); goto up_out; } if (__vfio_pci_add_vma(vdev, vma)) { ret = VM_FAULT_OOM; mutex_unlock(&vdev->vma_lock); goto up_out; } mutex_unlock(&vdev->vma_lock); if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, vma->vm_end - vma->vm_start, vma->vm_page_prot)) ret = VM_FAULT_SIGBUS; up_out: up_read(&vdev->memory_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, }; static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) { struct vfio_pci_device *vdev = device_data; struct pci_dev *pdev = vdev->pdev; unsigned int index; u64 phys_len, req_len, pgoff, req_start; int ret; index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT); if (vma->vm_end < vma->vm_start) return -EINVAL; if ((vma->vm_flags & VM_SHARED) == 0) return -EINVAL; if (index >= VFIO_PCI_NUM_REGIONS) { int regnum = index - VFIO_PCI_NUM_REGIONS; struct vfio_pci_region *region = vdev->region + regnum; if (region && 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; } static void vfio_pci_request(void *device_data, unsigned int count) { struct vfio_pci_device *vdev = device_data; 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); } static int vfio_pci_validate_vf_token(struct vfio_pci_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_device *pf_dev; struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_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) { vfio_device_put(pf_dev); 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_dev); 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=" static int vfio_pci_match(void *device_data, char *buf) { struct vfio_pci_device *vdev = device_data; 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 */ } static const struct vfio_device_ops vfio_pci_ops = { .name = "vfio-pci", .open = vfio_pci_open, .release = vfio_pci_release, .ioctl = vfio_pci_ioctl, .read = vfio_pci_read, .write = vfio_pci_write, .mmap = vfio_pci_mmap, .request = vfio_pci_request, .match = vfio_pci_match, }; static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev); static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck); static struct pci_driver vfio_pci_driver; static int vfio_pci_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct vfio_pci_device *vdev = container_of(nb, struct vfio_pci_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", vfio_pci_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 != &vfio_pci_driver) pci_warn(vdev->pdev, "VF %s bound to driver %s while PF bound to vfio-pci\n", pci_name(pdev), drv->name); } return 0; } static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct vfio_pci_device *vdev; struct iommu_group *group; int ret; if (vfio_pci_is_denylisted(pdev)) return -EINVAL; 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; vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); if (!vdev) { ret = -ENOMEM; goto out_group_put; } vdev->pdev = pdev; vdev->irq_type = VFIO_PCI_NUM_IRQS; mutex_init(&vdev->igate); spin_lock_init(&vdev->irqlock); mutex_init(&vdev->ioeventfds_lock); INIT_LIST_HEAD(&vdev->ioeventfds_list); mutex_init(&vdev->vma_lock); INIT_LIST_HEAD(&vdev->vma_list); init_rwsem(&vdev->memory_lock); ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); if (ret) goto out_free; ret = vfio_pci_reflck_attach(vdev); if (ret) goto out_del_group_dev; if (pdev->is_physfn) { vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL); if (!vdev->vf_token) { ret = -ENOMEM; goto out_reflck; } 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) goto out_vf_token; } if (vfio_pci_is_vga(pdev)) { vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode); vga_set_legacy_decoding(pdev, vfio_pci_set_vga_decode(vdev, false)); } 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); } return ret; out_vf_token: kfree(vdev->vf_token); out_reflck: vfio_pci_reflck_put(vdev->reflck); out_del_group_dev: vfio_del_group_dev(&pdev->dev); out_free: kfree(vdev); out_group_put: vfio_iommu_group_put(group, &pdev->dev); return ret; } static void vfio_pci_remove(struct pci_dev *pdev) { struct vfio_pci_device *vdev; pci_disable_sriov(pdev); vdev = vfio_del_group_dev(&pdev->dev); if (!vdev) return; if (vdev->vf_token) { WARN_ON(vdev->vf_token->users); mutex_destroy(&vdev->vf_token->lock); kfree(vdev->vf_token); } if (vdev->nb.notifier_call) bus_unregister_notifier(&pci_bus_type, &vdev->nb); vfio_pci_reflck_put(vdev->reflck); vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev); kfree(vdev->region); mutex_destroy(&vdev->ioeventfds_lock); if (!disable_idle_d3) vfio_pci_set_power_state(vdev, PCI_D0); kfree(vdev->pm_save); kfree(vdev); if (vfio_pci_is_vga(pdev)) { vga_client_register(pdev, NULL, NULL, NULL); vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM | VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM); } } static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev, pci_channel_state_t state) { struct vfio_pci_device *vdev; struct vfio_device *device; device = vfio_device_get_from_dev(&pdev->dev); if (device == NULL) return PCI_ERS_RESULT_DISCONNECT; vdev = vfio_device_data(device); if (vdev == NULL) { vfio_device_put(device); return PCI_ERS_RESULT_DISCONNECT; } mutex_lock(&vdev->igate); if (vdev->err_trigger) eventfd_signal(vdev->err_trigger, 1); mutex_unlock(&vdev->igate); vfio_device_put(device); return PCI_ERS_RESULT_CAN_RECOVER; } static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn) { struct vfio_pci_device *vdev; struct vfio_device *device; int ret = 0; might_sleep(); if (!enable_sriov) return -ENOENT; device = vfio_device_get_from_dev(&pdev->dev); if (!device) return -ENODEV; vdev = vfio_device_data(device); if (!vdev) { vfio_device_put(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; } static const struct pci_error_handlers vfio_err_handlers = { .error_detected = vfio_pci_aer_err_detected, }; static struct pci_driver vfio_pci_driver = { .name = "vfio-pci", .id_table = NULL, /* only dynamic ids */ .probe = vfio_pci_probe, .remove = vfio_pci_remove, .sriov_configure = vfio_pci_sriov_configure, .err_handler = &vfio_err_handlers, }; static DEFINE_MUTEX(reflck_lock); static struct vfio_pci_reflck *vfio_pci_reflck_alloc(void) { struct vfio_pci_reflck *reflck; reflck = kzalloc(sizeof(*reflck), GFP_KERNEL); if (!reflck) return ERR_PTR(-ENOMEM); kref_init(&reflck->kref); mutex_init(&reflck->lock); return reflck; } static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck) { kref_get(&reflck->kref); } static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data) { struct vfio_pci_reflck **preflck = data; struct vfio_device *device; struct vfio_pci_device *vdev; device = vfio_device_get_from_dev(&pdev->dev); if (!device) return 0; if (pci_dev_driver(pdev) != &vfio_pci_driver) { vfio_device_put(device); return 0; } vdev = vfio_device_data(device); if (vdev->reflck) { vfio_pci_reflck_get(vdev->reflck); *preflck = vdev->reflck; vfio_device_put(device); return 1; } vfio_device_put(device); return 0; } static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev) { bool slot = !pci_probe_reset_slot(vdev->pdev->slot); mutex_lock(&reflck_lock); if (pci_is_root_bus(vdev->pdev->bus) || vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find, &vdev->reflck, slot) <= 0) vdev->reflck = vfio_pci_reflck_alloc(); mutex_unlock(&reflck_lock); return PTR_ERR_OR_ZERO(vdev->reflck); } static void vfio_pci_reflck_release(struct kref *kref) { struct vfio_pci_reflck *reflck = container_of(kref, struct vfio_pci_reflck, kref); kfree(reflck); mutex_unlock(&reflck_lock); } static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck) { kref_put_mutex(&reflck->kref, vfio_pci_reflck_release, &reflck_lock); } static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data) { struct vfio_devices *devs = data; struct vfio_device *device; struct vfio_pci_device *vdev; if (devs->cur_index == devs->max_index) return -ENOSPC; device = vfio_device_get_from_dev(&pdev->dev); if (!device) return -EINVAL; if (pci_dev_driver(pdev) != &vfio_pci_driver) { vfio_device_put(device); return -EBUSY; } vdev = vfio_device_data(device); /* Fault if the device is not unused */ if (vdev->refcnt) { vfio_device_put(device); return -EBUSY; } devs->devices[devs->cur_index++] = device; return 0; } static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data) { struct vfio_devices *devs = data; struct vfio_device *device; struct vfio_pci_device *vdev; if (devs->cur_index == devs->max_index) return -ENOSPC; device = vfio_device_get_from_dev(&pdev->dev); if (!device) return -EINVAL; if (pci_dev_driver(pdev) != &vfio_pci_driver) { vfio_device_put(device); return -EBUSY; } vdev = vfio_device_data(device); /* * Locking multiple devices is prone to deadlock, runaway and * unwind if we hit contention. */ if (!vfio_pci_zap_and_vma_lock(vdev, true)) { vfio_device_put(device); return -EBUSY; } devs->devices[devs->cur_index++] = device; return 0; } /* * If a bus or slot reset is available for the provided device and: * - All of the devices affected by that bus or slot reset are unused * (!refcnt) * - 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. Callers are required * to hold vdev->reflck->lock, protecting the bus/slot reset group from * concurrent opens. A vfio_device reference is acquired for each device * to prevent unbinds during the reset operation. * * NB: vfio-core considers a group to be viable even if some devices are * bound to drivers like pci-stub or pcieport. Here we require all devices * to be bound to vfio_pci since that's the only way we can be sure they * stay put. */ static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev) { struct vfio_devices devs = { .cur_index = 0 }; int i = 0, ret = -EINVAL; bool slot = false; struct vfio_pci_device *tmp; if (!pci_probe_reset_slot(vdev->pdev->slot)) slot = true; else if (pci_probe_reset_bus(vdev->pdev->bus)) return; if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs, &i, slot) || !i) return; devs.max_index = i; devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL); if (!devs.devices) return; if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_get_unused_devs, &devs, slot)) goto put_devs; /* Does at least one need a reset? */ for (i = 0; i < devs.cur_index; i++) { tmp = vfio_device_data(devs.devices[i]); if (tmp->needs_reset) { ret = pci_reset_bus(vdev->pdev); break; } } put_devs: for (i = 0; i < devs.cur_index; i++) { tmp = vfio_device_data(devs.devices[i]); /* * If reset was successful, affected devices no longer need * a reset and we should return all the collateral devices * to low power. If not successful, we either didn't reset * the bus or timed out waiting for it, so let's not touch * the power state. */ if (!ret) { tmp->needs_reset = false; if (tmp != vdev && !disable_idle_d3) vfio_pci_set_power_state(tmp, PCI_D3hot); } vfio_device_put(devs.devices[i]); } kfree(devs.devices); } static void __exit vfio_pci_cleanup(void) { pci_unregister_driver(&vfio_pci_driver); vfio_pci_uninit_perm_bits(); } static void __init vfio_pci_fill_ids(void) { char *p, *id; int rc; /* no ids passed actually */ if (ids[0] == '\0') return; /* add ids specified in the module parameter */ p = ids; while ((id = strsep(&p, ","))) { unsigned int vendor, device, subvendor = PCI_ANY_ID, subdevice = PCI_ANY_ID, class = 0, class_mask = 0; int fields; if (!strlen(id)) continue; fields = sscanf(id, "%x:%x:%x:%x:%x:%x", &vendor, &device, &subvendor, &subdevice, &class, &class_mask); if (fields < 2) { pr_warn("invalid id string \"%s\"\n", id); continue; } rc = pci_add_dynid(&vfio_pci_driver, vendor, device, subvendor, subdevice, class, class_mask, 0); if (rc) pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n", vendor, device, subvendor, subdevice, class, class_mask, rc); else pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n", vendor, device, subvendor, subdevice, class, class_mask); } } static int __init vfio_pci_init(void) { int ret; /* Allocate shared config space permision data used by all devices */ ret = vfio_pci_init_perm_bits(); if (ret) return ret; /* Register and scan for devices */ ret = pci_register_driver(&vfio_pci_driver); if (ret) goto out_driver; vfio_pci_fill_ids(); if (disable_denylist) pr_warn("device denylist disabled.\n"); return 0; out_driver: vfio_pci_uninit_perm_bits(); return ret; } module_init(vfio_pci_init); module_exit(vfio_pci_cleanup); MODULE_VERSION(DRIVER_VERSION); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC);
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