diff options
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 1215 |
1 files changed, 1215 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..e9851add6 --- /dev/null +++ b/drivers/vfio/pci/vfio_pci.c @@ -0,0 +1,1215 @@ +/* + * 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 "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_try_bus_reset(struct vfio_pci_device *vdev); + +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; + + vdev->reset_works = (pci_reset_function(pdev) == 0); + 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)); + + ret = vfio_config_init(vdev); + if (ret) { + kfree(vdev->pci_saved_state); + vdev->pci_saved_state = NULL; + pci_disable_device(pdev); + return ret; + } + + if (likely(!nointxmask)) + 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); + } + + msix_pos = pdev->msix_cap; + if (msix_pos) { + u16 flags; + u32 table; + + pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags); + pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table); + + vdev->msix_bar = table & PCI_MSIX_TABLE_BIR; + vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET; + vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16; + } else + vdev->msix_bar = 0xFF; + + if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev)) + vdev->has_vga = true; + + return 0; +} + +static void vfio_pci_disable(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int 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; + + 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; + } + + 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) && 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 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; + info.num_irqs = VFIO_PCI_NUM_IRQS; + + return copy_to_user((void __user *)arg, &info, minsz); + + } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { + struct pci_dev *pdev = vdev->pdev; + struct vfio_region_info info; + + 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 (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && + pci_resource_flags(pdev, info.index) & + IORESOURCE_MEM && info.size >= PAGE_SIZE) + info.flags |= VFIO_REGION_INFO_FLAG_MMAP; + 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) + 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: + return -EINVAL; + } + + return copy_to_user((void __user *)arg, &info, minsz); + + } 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); + + } else if (cmd == VFIO_DEVICE_SET_IRQS) { + struct vfio_irq_set hdr; + u8 *data = NULL; + int ret = 0; + + minsz = offsetofend(struct vfio_irq_set, count); + + if (copy_from_user(&hdr, (void __user *)arg, minsz)) + return -EFAULT; + + if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS || + hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK | + VFIO_IRQ_SET_ACTION_TYPE_MASK)) + return -EINVAL; + + if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) { + size_t size; + int max = vfio_pci_get_irq_count(vdev, hdr.index); + + if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL) + size = sizeof(uint8_t); + else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD) + size = sizeof(int32_t); + else + return -EINVAL; + + if (hdr.argsz - minsz < hdr.count * size || + hdr.start >= max || hdr.start + hdr.count > max) + return -EINVAL; + + data = memdup_user((void __user *)(arg + minsz), + hdr.count * 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) + 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); + } + + 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 (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM)) + return -EINVAL; + + phys_len = 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 (phys_len < PAGE_SIZE || req_start + req_len > phys_len) + return -EINVAL; + + if (index == vdev->msix_bar) { + /* + * Disallow mmaps overlapping the MSI-X table; users don't + * get to touch this directly. We could find somewhere + * else to map the overlap, but page granularity is only + * a recommendation, not a requirement, so the user needs + * to know which bits are real. Requiring them to mmap + * around the table makes that clear. + */ + + /* If neither entirely above nor below, then it overlaps */ + if (!(req_start >= vdev->msix_offset + vdev->msix_size || + req_start + req_len <= vdev->msix_offset)) + 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); + } + + 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 = iommu_group_get(&pdev->dev); + if (!group) + return -EINVAL; + + vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); + if (!vdev) { + iommu_group_put(group); + 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) { + iommu_group_put(group); + 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; + + iommu_group_put(pdev->dev.iommu_group); + 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 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 pci_driver *pci_drv = ACCESS_ONCE(pdev->driver); + + if (pci_drv != &vfio_pci_driver) + return -EBUSY; + + if (devs->cur_index == devs->max_index) + return -ENOSPC; + + devs->devices[devs->cur_index] = vfio_device_get_from_dev(&pdev->dev); + if (!devs->devices[devs->cur_index]) + return -EINVAL; + + devs->cur_index++; + 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); |