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path: root/drivers/vfio/pci/vfio_pci.c
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Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
-rw-r--r--drivers/vfio/pci/vfio_pci.c1215
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);