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