diff options
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 1829 |
1 files changed, 1829 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c new file mode 100644 index 000000000..51b791c75 --- /dev/null +++ b/drivers/vfio/pci/vfio_pci.c @@ -0,0 +1,1829 @@ +/* + * Copyright (C) 2012 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson <alex.williamson@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Derived from original vfio: + * Copyright 2010 Cisco Systems, Inc. All rights reserved. + * Author: Tom Lyon, pugs@cisco.com + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/device.h> +#include <linux/eventfd.h> +#include <linux/file.h> +#include <linux/interrupt.h> +#include <linux/iommu.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/notifier.h> +#include <linux/pci.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/vfio.h> +#include <linux/vgaarb.h> +#include <linux/nospec.h> +#include <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 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; + + 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); +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: + return true; + default: + return false; + } + } + + return false; +} + +static int vfio_pci_enable(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int ret; + u16 cmd; + u8 msix_pos; + + pci_set_power_state(pdev, PCI_D0); + + /* Don't allow our initial saved state to include busmaster */ + pci_clear_master(pdev); + + ret = pci_enable_device(pdev); + if (ret) + return ret; + + /* If reset fails because of the device lock, fail this path entirely */ + ret = pci_try_reset_function(pdev); + if (ret == -EAGAIN) { + pci_disable_device(pdev); + return ret; + } + + vdev->reset_works = !ret; + pci_save_state(pdev); + vdev->pci_saved_state = pci_store_saved_state(pdev); + if (!vdev->pci_saved_state) + pr_debug("%s: Couldn't store %s saved state\n", + __func__, dev_name(&pdev->dev)); + + if (likely(!nointxmask)) { + if (vfio_pci_nointx(pdev)) { + dev_info(&pdev->dev, "Masking broken INTx support\n"); + vdev->nointx = true; + pci_intx(pdev, 0); + } else + vdev->pci_2_3 = pci_intx_mask_supported(pdev); + } + + pci_read_config_word(pdev, PCI_COMMAND, &cmd); + if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) { + cmd &= ~PCI_COMMAND_INTX_DISABLE; + pci_write_config_word(pdev, PCI_COMMAND, cmd); + } + + ret = vfio_config_init(vdev); + if (ret) { + kfree(vdev->pci_saved_state); + vdev->pci_saved_state = NULL; + pci_disable_device(pdev); + return ret; + } + + msix_pos = pdev->msix_cap; + if (msix_pos) { + u16 flags; + u32 table; + + pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags); + pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table); + + vdev->msix_bar = table & PCI_MSIX_TABLE_BIR; + vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET; + vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16; + } else + vdev->msix_bar = 0xFF; + + if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev)) + vdev->has_vga = true; + + + if (vfio_pci_is_vga(pdev) && + pdev->vendor == PCI_VENDOR_ID_INTEL && + IS_ENABLED(CONFIG_VFIO_PCI_IGD)) { + ret = vfio_pci_igd_init(vdev); + if (ret) { + dev_warn(&vdev->pdev->dev, + "Failed to setup Intel IGD regions\n"); + vfio_pci_disable(vdev); + return ret; + } + } + + vfio_pci_probe_mmaps(vdev); + + return 0; +} + +static void vfio_pci_disable(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + struct vfio_pci_dummy_resource *dummy_res, *tmp; + struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp; + int i, bar; + + /* Stop the device from further DMA */ + pci_clear_master(pdev); + + vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE | + VFIO_IRQ_SET_ACTION_TRIGGER, + vdev->irq_type, 0, 0, NULL); + + /* Device closed, don't need mutex here */ + list_for_each_entry_safe(ioeventfd, ioeventfd_tmp, + &vdev->ioeventfds_list, next) { + vfio_virqfd_disable(&ioeventfd->virqfd); + list_del(&ioeventfd->next); + kfree(ioeventfd); + } + vdev->ioeventfds_nr = 0; + + vdev->virq_disabled = false; + + for (i = 0; i < vdev->num_regions; i++) + vdev->region[i].ops->release(vdev, &vdev->region[i]); + + vdev->num_regions = 0; + kfree(vdev->region); + vdev->region = NULL; /* don't krealloc a freed pointer */ + + vfio_config_free(vdev); + + for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) { + if (!vdev->barmap[bar]) + continue; + pci_iounmap(pdev, vdev->barmap[bar]); + pci_release_selected_regions(pdev, 1 << bar); + vdev->barmap[bar] = NULL; + } + + list_for_each_entry_safe(dummy_res, tmp, + &vdev->dummy_resources_list, res_next) { + list_del(&dummy_res->res_next); + release_resource(&dummy_res->resource); + kfree(dummy_res); + } + + vdev->needs_reset = true; + + /* + * If we have saved state, restore it. If we can reset the device, + * even better. Resetting with current state seems better than + * nothing, but saving and restoring current state without reset + * is just busy work. + */ + if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) { + pr_info("%s: Couldn't reload %s saved state\n", + __func__, dev_name(&pdev->dev)); + + if (!vdev->reset_works) + goto out; + + pci_save_state(pdev); + } + + /* + * Disable INTx and MSI, presumably to avoid spurious interrupts + * during reset. Stolen from pci_reset_function() + */ + pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); + + /* + * Try to 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) + 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_lock(&vdev->igate); + if (vdev->err_trigger) { + eventfd_ctx_put(vdev->err_trigger); + vdev->err_trigger = NULL; + } + mutex_unlock(&vdev->igate); + + mutex_lock(&vdev->igate); + if (vdev->req_trigger) { + eventfd_ctx_put(vdev->req_trigger); + vdev->req_trigger = NULL; + } + mutex_unlock(&vdev->igate); + } + + 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; + + 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 (caps.size) { + info.flags |= VFIO_REGION_INFO_FLAG_CAPS; + if (info.argsz < sizeof(info) + caps.size) { + info.argsz = sizeof(info) + caps.size; + info.cap_offset = 0; + } else { + vfio_info_cap_shift(&caps, sizeof(info)); + if (copy_to_user((void __user *)arg + + sizeof(info), caps.buf, + caps.size)) { + kfree(caps.buf); + return -EFAULT; + } + info.cap_offset = sizeof(info); + } + + kfree(caps.buf); + } + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + + } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { + struct vfio_irq_info info; + + minsz = offsetofend(struct vfio_irq_info, count); + + if (copy_from_user(&info, (void __user *)arg, minsz)) + return -EFAULT; + + if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS) + return -EINVAL; + + switch (info.index) { + case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX: + case VFIO_PCI_REQ_IRQ_INDEX: + break; + case VFIO_PCI_ERR_IRQ_INDEX: + if (pci_is_pcie(vdev->pdev)) + break; + /* fall through */ + default: + return -EINVAL; + } + + info.flags = VFIO_IRQ_INFO_EVENTFD; + + info.count = vfio_pci_get_irq_count(vdev, info.index); + + if (info.index == VFIO_PCI_INTX_IRQ_INDEX) + info.flags |= (VFIO_IRQ_INFO_MASKABLE | + VFIO_IRQ_INFO_AUTOMASKED); + else + info.flags |= VFIO_IRQ_INFO_NORESIZE; + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + + } else if (cmd == VFIO_DEVICE_SET_IRQS) { + struct vfio_irq_set hdr; + u8 *data = NULL; + int max, ret = 0; + size_t data_size = 0; + + minsz = offsetofend(struct vfio_irq_set, count); + + if (copy_from_user(&hdr, (void __user *)arg, minsz)) + return -EFAULT; + + max = vfio_pci_get_irq_count(vdev, hdr.index); + + ret = vfio_set_irqs_validate_and_prepare(&hdr, max, + VFIO_PCI_NUM_IRQS, &data_size); + if (ret) + return ret; + + if (data_size) { + data = memdup_user((void __user *)(arg + minsz), + data_size); + if (IS_ERR(data)) + return PTR_ERR(data); + } + + mutex_lock(&vdev->igate); + + ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index, + hdr.start, hdr.count, data); + + mutex_unlock(&vdev->igate); + kfree(data); + + return ret; + + } else if (cmd == VFIO_DEVICE_RESET) { + 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_sem, 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); + } + + 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_sem 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_sem => vma_lock + * ordering, which requires using vma_lock to walk vma_list to + * acquire an mm, then dropping vma_lock to get the mmap_sem and + * reacquiring vma_lock. This logic is derived from similar + * requirements in uverbs_user_mmap_disassociate(). + * + * mmap_sem 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_sem 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_sem 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 (!down_read_trylock(&mm->mmap_sem)) { + mmput(mm); + return 0; + } + } else { + down_read(&mm->mmap_sem); + } + if (mmget_still_valid(mm)) { + if (try) { + if (!mutex_trylock(&vdev->vma_lock)) { + up_read(&mm->mmap_sem); + 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); + } + up_read(&mm->mmap_sem); + 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; + struct vfio_pci_mmap_vma *mmap_vma; + vm_fault_t ret = VM_FAULT_NOPAGE; + + mutex_lock(&vdev->vma_lock); + down_read(&vdev->memory_lock); + + if (!__vfio_pci_memory_enabled(vdev)) { + ret = VM_FAULT_SIGBUS; + goto up_out; + } + + /* + * We populate the whole vma on fault, so we need to test whether + * the vma has already been mapped, such as for concurrent faults + * to the same vma. io_remap_pfn_range() will trigger a BUG_ON if + * we ask it to fill the same range again. + */ + list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) { + if (mmap_vma->vma == vma) + goto up_out; + } + + if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + vma->vm_end - vma->vm_start, + vma->vm_page_prot)) { + ret = VM_FAULT_SIGBUS; + zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start); + goto up_out; + } + + if (__vfio_pci_add_vma(vdev, vma)) { + ret = VM_FAULT_OOM; + zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start); + } + +up_out: + up_read(&vdev->memory_lock); + mutex_unlock(&vdev->vma_lock); + return ret; +} + +static const struct vm_operations_struct vfio_pci_mmap_ops = { + .open = vfio_pci_mmap_open, + .close = vfio_pci_mmap_close, + .fault = vfio_pci_mmap_fault, +}; + +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; + + /* + * 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; + + mutex_lock(&vdev->igate); + + if (vdev->req_trigger) { + if (!(count % 10)) + dev_notice_ratelimited(&vdev->pdev->dev, + "Relaying device request to user (#%u)\n", + count); + eventfd_signal(vdev->req_trigger, 1); + } else if (count == 0) { + dev_warn(&vdev->pdev->dev, + "No device request channel registered, blocked until released by user\n"); + } + + mutex_unlock(&vdev->igate); +} + +static const struct vfio_device_ops vfio_pci_ops = { + .name = "vfio-pci", + .open = vfio_pci_open, + .release = vfio_pci_release, + .ioctl = vfio_pci_ioctl, + .read = vfio_pci_read, + .write = vfio_pci_write, + .mmap = vfio_pci_mmap, + .request = vfio_pci_request, +}; + +static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct vfio_pci_device *vdev; + struct iommu_group *group; + int ret; + + if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL) + return -EINVAL; + + /* + * Prevent binding to PFs with VFs enabled, this too easily allows + * userspace instance with VFs and PFs from the same device, which + * cannot work. Disabling SR-IOV here would initiate removing the + * VFs, which would unbind the driver, which is prone to blocking + * if that VF is also in use by vfio-pci. Just reject these PFs + * and let the user sort it out. + */ + if (pci_num_vf(pdev)) { + pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n"); + return -EBUSY; + } + + group = vfio_iommu_group_get(&pdev->dev); + if (!group) + return -EINVAL; + + vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); + if (!vdev) { + vfio_iommu_group_put(group, &pdev->dev); + return -ENOMEM; + } + + vdev->pdev = pdev; + vdev->irq_type = VFIO_PCI_NUM_IRQS; + mutex_init(&vdev->igate); + spin_lock_init(&vdev->irqlock); + mutex_init(&vdev->ioeventfds_lock); + INIT_LIST_HEAD(&vdev->dummy_resources_list); + INIT_LIST_HEAD(&vdev->ioeventfds_list); + mutex_init(&vdev->vma_lock); + INIT_LIST_HEAD(&vdev->vma_list); + init_rwsem(&vdev->memory_lock); + + ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); + if (ret) { + vfio_iommu_group_put(group, &pdev->dev); + kfree(vdev); + return ret; + } + + if (vfio_pci_is_vga(pdev)) { + vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode); + vga_set_legacy_decoding(pdev, + vfio_pci_set_vga_decode(vdev, false)); + } + + if (!disable_idle_d3) { + /* + * pci-core sets the device power state to an unknown value at + * bootup and after being removed from a driver. The only + * transition it allows from this unknown state is to D0, which + * typically happens when a driver calls pci_enable_device(). + * We're not ready to enable the device yet, but we do want to + * be able to get to D3. Therefore first do a D0 transition + * before going to D3. + */ + pci_set_power_state(pdev, PCI_D0); + pci_set_power_state(pdev, PCI_D3hot); + } + + return ret; +} + +static void vfio_pci_remove(struct pci_dev *pdev) +{ + struct vfio_pci_device *vdev; + + vdev = vfio_del_group_dev(&pdev->dev); + if (!vdev) + return; + + vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev); + kfree(vdev->region); + mutex_destroy(&vdev->ioeventfds_lock); + kfree(vdev); + + if (vfio_pci_is_vga(pdev)) { + vga_client_register(pdev, NULL, NULL, NULL); + vga_set_legacy_decoding(pdev, + VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM | + VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM); + } + + if (!disable_idle_d3) + pci_set_power_state(pdev, PCI_D0); +} + +static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev, + pci_channel_state_t state) +{ + struct vfio_pci_device *vdev; + struct vfio_device *device; + + device = vfio_device_get_from_dev(&pdev->dev); + if (device == NULL) + return PCI_ERS_RESULT_DISCONNECT; + + vdev = vfio_device_data(device); + if (vdev == NULL) { + vfio_device_put(device); + return PCI_ERS_RESULT_DISCONNECT; + } + + mutex_lock(&vdev->igate); + + if (vdev->err_trigger) + eventfd_signal(vdev->err_trigger, 1); + + mutex_unlock(&vdev->igate); + + vfio_device_put(device); + + return PCI_ERS_RESULT_CAN_RECOVER; +} + +static const struct pci_error_handlers vfio_err_handlers = { + .error_detected = vfio_pci_aer_err_detected, +}; + +static struct pci_driver vfio_pci_driver = { + .name = "vfio-pci", + .id_table = NULL, /* only dynamic ids */ + .probe = vfio_pci_probe, + .remove = vfio_pci_remove, + .err_handler = &vfio_err_handlers, +}; + +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; +} + +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; +} + +/* + * Attempt to do a bus/slot reset if there are devices affected by a reset for + * this device that are needs_reset and all of the affected devices are unused + * (!refcnt). Callers are required to hold driver_lock when calling this to + * prevent device opens and concurrent bus reset attempts. We prevent device + * unbinds by acquiring and holding a reference to the vfio_device. + * + * NB: vfio-core considers a group to be viable even if some devices are + * bound to drivers like pci-stub or pcieport. Here we require all devices + * to be bound to vfio_pci since that's the only way we can be sure they + * stay put. + */ +static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev) +{ + struct vfio_devices devs = { .cur_index = 0 }; + int i = 0, ret = -EINVAL; + bool needs_reset = false, slot = false; + struct vfio_pci_device *tmp; + + if (!pci_probe_reset_slot(vdev->pdev->slot)) + slot = true; + else if (pci_probe_reset_bus(vdev->pdev->bus)) + return; + + if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs, + &i, slot) || !i) + return; + + devs.max_index = i; + devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL); + if (!devs.devices) + return; + + if (vfio_pci_for_each_slot_or_bus(vdev->pdev, + vfio_pci_get_devs, &devs, slot)) + goto put_devs; + + for (i = 0; i < devs.cur_index; i++) { + tmp = vfio_device_data(devs.devices[i]); + if (tmp->needs_reset) + needs_reset = true; + if (tmp->refcnt) + goto put_devs; + } + + if (needs_reset) + ret = pci_reset_bus(vdev->pdev); + +put_devs: + for (i = 0; i < devs.cur_index; i++) { + tmp = vfio_device_data(devs.devices[i]); + if (!ret) + tmp->needs_reset = false; + + if (!tmp->refcnt && !disable_idle_d3) + pci_set_power_state(tmp->pdev, PCI_D3hot); + + vfio_device_put(devs.devices[i]); + } + + kfree(devs.devices); +} + +static void __exit vfio_pci_cleanup(void) +{ + pci_unregister_driver(&vfio_pci_driver); + vfio_pci_uninit_perm_bits(); +} + +static void __init vfio_pci_fill_ids(void) +{ + char *p, *id; + int rc; + + /* no ids passed actually */ + if (ids[0] == '\0') + return; + + /* add ids specified in the module parameter */ + p = ids; + while ((id = strsep(&p, ","))) { + unsigned int vendor, device, subvendor = PCI_ANY_ID, + subdevice = PCI_ANY_ID, class = 0, class_mask = 0; + int fields; + + if (!strlen(id)) + continue; + + fields = sscanf(id, "%x:%x:%x:%x:%x:%x", + &vendor, &device, &subvendor, &subdevice, + &class, &class_mask); + + if (fields < 2) { + pr_warn("invalid id string \"%s\"\n", id); + continue; + } + + rc = pci_add_dynid(&vfio_pci_driver, vendor, device, + subvendor, subdevice, class, class_mask, 0); + if (rc) + pr_warn("failed to add dynamic id [%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(); + + 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); |