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OpenCloudOS-Kernel/drivers/vfio/pci/vfio_pci.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.com>
*
* Derived from original vfio:
* Copyright 2010 Cisco Systems, Inc. All rights reserved.
* Author: Tom Lyon, pugs@cisco.com
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define dev_fmt pr_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 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 void vfio_pci_probe_power_state(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
u16 pmcsr;
if (!pdev->pm_cap)
return;
pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
}
/*
* pci_set_power_state() wrapper handling devices which perform a soft reset on
* D3->D0 transition. Save state prior to D0/1/2->D3, stash it on the vdev,
* restore when returned to D0. Saved separately from pci_saved_state for use
* by PM capability emulation and separately from pci_dev internal saved state
* to avoid it being overwritten and consumed around other resets.
*/
int vfio_pci_set_power_state(struct vfio_pci_device *vdev, pci_power_t state)
{
struct pci_dev *pdev = vdev->pdev;
bool needs_restore = false, needs_save = false;
int ret;
if (vdev->needs_pm_restore) {
if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
pci_save_state(pdev);
needs_save = true;
}
if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
needs_restore = true;
}
ret = pci_set_power_state(pdev, state);
if (!ret) {
/* D3 might be unsupported via quirk, skip unless in D3 */
if (needs_save && pdev->current_state >= PCI_D3hot) {
vdev->pm_save = pci_store_saved_state(pdev);
} else if (needs_restore) {
pci_load_and_free_saved_state(pdev, &vdev->pm_save);
pci_restore_state(pdev);
}
}
return ret;
}
static int vfio_pci_enable(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
int ret;
u16 cmd;
u8 msix_pos;
vfio_pci_set_power_state(vdev, PCI_D0);
/* Don't allow our initial saved state to include busmaster */
pci_clear_master(pdev);
ret = pci_enable_device(pdev);
if (ret)
return ret;
/* If reset fails because of the device lock, fail this path entirely */
ret = pci_try_reset_function(pdev);
if (ret == -EAGAIN) {
pci_disable_device(pdev);
return ret;
}
vdev->reset_works = !ret;
pci_save_state(pdev);
vdev->pci_saved_state = pci_store_saved_state(pdev);
if (!vdev->pci_saved_state)
pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
if (likely(!nointxmask)) {
if (vfio_pci_nointx(pdev)) {
pci_info(pdev, "Masking broken INTx support\n");
vdev->nointx = true;
pci_intx(pdev, 0);
} else
vdev->pci_2_3 = pci_intx_mask_supported(pdev);
}
pci_read_config_word(pdev, PCI_COMMAND, &cmd);
if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
cmd &= ~PCI_COMMAND_INTX_DISABLE;
pci_write_config_word(pdev, PCI_COMMAND, cmd);
}
ret = vfio_config_init(vdev);
if (ret) {
kfree(vdev->pci_saved_state);
vdev->pci_saved_state = NULL;
pci_disable_device(pdev);
return ret;
}
msix_pos = pdev->msix_cap;
if (msix_pos) {
u16 flags;
u32 table;
pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
} else
vdev->msix_bar = 0xFF;
if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
vdev->has_vga = true;
if (vfio_pci_is_vga(pdev) &&
pdev->vendor == PCI_VENDOR_ID_INTEL &&
IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
ret = vfio_pci_igd_init(vdev);
if (ret && ret != -ENODEV) {
pci_warn(pdev, "Failed to setup Intel IGD regions\n");
goto disable_exit;
}
}
if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
ret = vfio_pci_nvdia_v100_nvlink2_init(vdev);
if (ret && ret != -ENODEV) {
pci_warn(pdev, "Failed to setup NVIDIA NV2 RAM region\n");
goto disable_exit;
}
}
if (pdev->vendor == PCI_VENDOR_ID_IBM &&
IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
ret = vfio_pci_ibm_npu2_init(vdev);
if (ret && ret != -ENODEV) {
pci_warn(pdev, "Failed to setup NVIDIA NV2 ATSD region\n");
goto disable_exit;
}
}
vfio_pci_probe_mmaps(vdev);
return 0;
disable_exit:
vfio_pci_disable(vdev);
return ret;
}
static void vfio_pci_disable(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
struct vfio_pci_dummy_resource *dummy_res, *tmp;
struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
int i, bar;
/* Stop the device from further DMA */
pci_clear_master(pdev);
vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
VFIO_IRQ_SET_ACTION_TRIGGER,
vdev->irq_type, 0, 0, NULL);
/* Device closed, don't need mutex here */
list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
&vdev->ioeventfds_list, next) {
vfio_virqfd_disable(&ioeventfd->virqfd);
list_del(&ioeventfd->next);
kfree(ioeventfd);
}
vdev->ioeventfds_nr = 0;
vdev->virq_disabled = false;
for (i = 0; i < vdev->num_regions; i++)
vdev->region[i].ops->release(vdev, &vdev->region[i]);
vdev->num_regions = 0;
kfree(vdev->region);
vdev->region = NULL; /* don't krealloc a freed pointer */
vfio_config_free(vdev);
for (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)) {
pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
if (!vdev->reset_works)
goto out;
pci_save_state(pdev);
}
/*
* Disable INTx and MSI, presumably to avoid spurious interrupts
* during reset. Stolen from pci_reset_function()
*/
pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
/*
* Try to get the locks ourselves to prevent a deadlock. The
* success of this is dependent on being able to lock the device,
* which is not always possible.
* We can not use the "try" reset interface here, which will
* overwrite the previously restored configuration information.
*/
if (vdev->reset_works && pci_cfg_access_trylock(pdev)) {
if (device_trylock(&pdev->dev)) {
if (!__pci_reset_function_locked(pdev))
vdev->needs_reset = false;
device_unlock(&pdev->dev);
}
pci_cfg_access_unlock(pdev);
}
pci_restore_state(pdev);
out:
pci_disable_device(pdev);
vfio_pci_try_bus_reset(vdev);
if (!disable_idle_d3)
vfio_pci_set_power_state(vdev, PCI_D3hot);
}
static void vfio_pci_release(void *device_data)
{
struct vfio_pci_device *vdev = device_data;
mutex_lock(&vdev->reflck->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(&vdev->reflck->lock);
module_put(THIS_MODULE);
}
static int vfio_pci_open(void *device_data)
{
struct vfio_pci_device *vdev = device_data;
int ret = 0;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
mutex_lock(&vdev->reflck->lock);
if (!vdev->refcnt) {
ret = vfio_pci_enable(vdev);
if (ret)
goto error;
vfio_spapr_pci_eeh_open(vdev->pdev);
}
vdev->refcnt++;
error:
mutex_unlock(&vdev->reflck->lock);
if (ret)
module_put(THIS_MODULE);
return ret;
}
static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
{
if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
u8 pin;
if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
vdev->nointx || vdev->pdev->is_virtfn)
return 0;
pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
return pin ? 1 : 0;
} else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
u8 pos;
u16 flags;
pos = vdev->pdev->msi_cap;
if (pos) {
pci_read_config_word(vdev->pdev,
pos + PCI_MSI_FLAGS, &flags);
return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
}
} else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
u8 pos;
u16 flags;
pos = vdev->pdev->msix_cap;
if (pos) {
pci_read_config_word(vdev->pdev,
pos + PCI_MSIX_FLAGS, &flags);
return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
}
} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
if (pci_is_pcie(vdev->pdev))
return 1;
} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
return 1;
}
return 0;
}
static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
{
(*(int *)data)++;
return 0;
}
struct vfio_pci_fill_info {
int max;
int cur;
struct vfio_pci_dependent_device *devices;
};
static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
{
struct vfio_pci_fill_info *fill = data;
struct iommu_group *iommu_group;
if (fill->cur == fill->max)
return -EAGAIN; /* Something changed, try again */
iommu_group = iommu_group_get(&pdev->dev);
if (!iommu_group)
return -EPERM; /* Cannot reset non-isolated devices */
fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
fill->devices[fill->cur].bus = pdev->bus->number;
fill->devices[fill->cur].devfn = pdev->devfn;
fill->cur++;
iommu_group_put(iommu_group);
return 0;
}
struct vfio_pci_group_entry {
struct vfio_group *group;
int id;
};
struct vfio_pci_group_info {
int count;
struct vfio_pci_group_entry *groups;
};
static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
{
struct vfio_pci_group_info *info = data;
struct iommu_group *group;
int id, i;
group = iommu_group_get(&pdev->dev);
if (!group)
return -EPERM;
id = iommu_group_id(group);
for (i = 0; i < info->count; i++)
if (info->groups[i].id == id)
break;
iommu_group_put(group);
return (i == info->count) ? -EINVAL : 0;
}
static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
{
for (; pdev; pdev = pdev->bus->self)
if (pdev->bus == slot->bus)
return (pdev->slot == slot);
return false;
}
struct vfio_pci_walk_info {
int (*fn)(struct pci_dev *, void *data);
void *data;
struct pci_dev *pdev;
bool slot;
int ret;
};
static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
{
struct vfio_pci_walk_info *walk = data;
if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
walk->ret = walk->fn(pdev, walk->data);
return walk->ret;
}
static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
int (*fn)(struct pci_dev *,
void *data), void *data,
bool slot)
{
struct vfio_pci_walk_info walk = {
.fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
};
pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
return walk.ret;
}
static int msix_mmappable_cap(struct vfio_pci_device *vdev,
struct vfio_info_cap *caps)
{
struct vfio_info_cap_header header = {
.id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
.version = 1
};
return vfio_info_add_capability(caps, &header, sizeof(header));
}
int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
unsigned int type, unsigned int subtype,
const struct vfio_pci_regops *ops,
size_t size, u32 flags, void *data)
{
struct vfio_pci_region *region;
region = krealloc(vdev->region,
(vdev->num_regions + 1) * sizeof(*region),
GFP_KERNEL);
if (!region)
return -ENOMEM;
vdev->region = region;
vdev->region[vdev->num_regions].type = type;
vdev->region[vdev->num_regions].subtype = subtype;
vdev->region[vdev->num_regions].ops = ops;
vdev->region[vdev->num_regions].size = size;
vdev->region[vdev->num_regions].flags = flags;
vdev->region[vdev->num_regions].data = data;
vdev->num_regions++;
return 0;
}
struct vfio_devices {
struct vfio_device **devices;
int cur_index;
int max_index;
};
static long vfio_pci_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
struct vfio_pci_device *vdev = device_data;
unsigned long minsz;
if (cmd == VFIO_DEVICE_GET_INFO) {
struct vfio_device_info info;
minsz = offsetofend(struct vfio_device_info, num_irqs);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
info.flags = VFIO_DEVICE_FLAGS_PCI;
if (vdev->reset_works)
info.flags |= VFIO_DEVICE_FLAGS_RESET;
info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
info.num_irqs = VFIO_PCI_NUM_IRQS;
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct pci_dev *pdev = vdev->pdev;
struct vfio_region_info info;
struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
int i, ret;
minsz = offsetofend(struct vfio_region_info, offset);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
switch (info.index) {
case VFIO_PCI_CONFIG_REGION_INDEX:
info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
info.size = pdev->cfg_size;
info.flags = VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE;
break;
case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
info.size = pci_resource_len(pdev, info.index);
if (!info.size) {
info.flags = 0;
break;
}
info.flags = VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE;
if (vdev->bar_mmap_supported[info.index]) {
info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
if (info.index == vdev->msix_bar) {
ret = msix_mmappable_cap(vdev, &caps);
if (ret)
return ret;
}
}
break;
case VFIO_PCI_ROM_REGION_INDEX:
{
void __iomem *io;
size_t size;
u16 cmd;
info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
info.flags = 0;
/* Report the BAR size, not the ROM size */
info.size = pci_resource_len(pdev, info.index);
if (!info.size) {
/* Shadow ROMs appear as PCI option ROMs */
if (pdev->resource[PCI_ROM_RESOURCE].flags &
IORESOURCE_ROM_SHADOW)
info.size = 0x20000;
else
break;
}
/*
* Is it really there? Enable memory decode for
* implicit access in pci_map_rom().
*/
cmd = vfio_pci_memory_lock_and_enable(vdev);
io = pci_map_rom(pdev, &size);
if (io) {
info.flags = VFIO_REGION_INFO_FLAG_READ;
pci_unmap_rom(pdev, io);
} else {
info.size = 0;
}
vfio_pci_memory_unlock_and_restore(vdev, cmd);
break;
}
case VFIO_PCI_VGA_REGION_INDEX:
if (!vdev->has_vga)
return -EINVAL;
info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
info.size = 0xc0000;
info.flags = VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE;
break;
default:
{
struct vfio_region_info_cap_type cap_type = {
.header.id = VFIO_REGION_INFO_CAP_TYPE,
.header.version = 1 };
if (info.index >=
VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
info.index = array_index_nospec(info.index,
VFIO_PCI_NUM_REGIONS +
vdev->num_regions);
i = info.index - VFIO_PCI_NUM_REGIONS;
info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
info.size = vdev->region[i].size;
info.flags = vdev->region[i].flags;
cap_type.type = vdev->region[i].type;
cap_type.subtype = vdev->region[i].subtype;
ret = vfio_info_add_capability(&caps, &cap_type.header,
sizeof(cap_type));
if (ret)
return ret;
if (vdev->region[i].ops->add_capability) {
ret = vdev->region[i].ops->add_capability(vdev,
&vdev->region[i], &caps);
if (ret)
return ret;
}
}
}
if (caps.size) {
info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
if (info.argsz < sizeof(info) + caps.size) {
info.argsz = sizeof(info) + caps.size;
info.cap_offset = 0;
} else {
vfio_info_cap_shift(&caps, sizeof(info));
if (copy_to_user((void __user *)arg +
sizeof(info), caps.buf,
caps.size)) {
kfree(caps.buf);
return -EFAULT;
}
info.cap_offset = sizeof(info);
}
kfree(caps.buf);
}
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
minsz = offsetofend(struct vfio_irq_info, count);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
return -EINVAL;
switch (info.index) {
case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
case VFIO_PCI_REQ_IRQ_INDEX:
break;
case VFIO_PCI_ERR_IRQ_INDEX:
if (pci_is_pcie(vdev->pdev))
break;
/* 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 (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
if ((vma->vm_flags & VM_SHARED) == 0)
return -EINVAL;
if (index >= VFIO_PCI_NUM_REGIONS) {
int regnum = index - VFIO_PCI_NUM_REGIONS;
struct vfio_pci_region *region = vdev->region + regnum;
if (region->ops && region->ops->mmap &&
(region->flags & VFIO_REGION_INFO_FLAG_MMAP))
return region->ops->mmap(vdev, region, vma);
return -EINVAL;
}
if (index >= VFIO_PCI_ROM_REGION_INDEX)
return -EINVAL;
if (!vdev->bar_mmap_supported[index])
return -EINVAL;
phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
req_len = vma->vm_end - vma->vm_start;
pgoff = vma->vm_pgoff &
((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
req_start = pgoff << PAGE_SHIFT;
if (req_start + req_len > phys_len)
return -EINVAL;
/*
* Even though we don't make use of the barmap for the mmap,
* we need to request the region and the barmap tracks that.
*/
if (!vdev->barmap[index]) {
ret = pci_request_selected_regions(pdev,
1 << index, "vfio-pci");
if (ret)
return ret;
vdev->barmap[index] = pci_iomap(pdev, index, 0);
if (!vdev->barmap[index]) {
pci_release_selected_regions(pdev, 1 << index);
return -ENOMEM;
}
}
vma->vm_private_data = vdev;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
/*
* See remap_pfn_range(), called from vfio_pci_fault() but we can't
* change vm_flags within the fault handler. Set them now.
*/
vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &vfio_pci_mmap_ops;
return 0;
}
static void vfio_pci_request(void *device_data, unsigned int count)
{
struct vfio_pci_device *vdev = device_data;
struct pci_dev *pdev = vdev->pdev;
mutex_lock(&vdev->igate);
if (vdev->req_trigger) {
if (!(count % 10))
pci_notice_ratelimited(pdev,
"Relaying device request to user (#%u)\n",
count);
eventfd_signal(vdev->req_trigger, 1);
} else if (count == 0) {
pci_warn(pdev,
"No device request channel registered, blocked until released by user\n");
}
mutex_unlock(&vdev->igate);
}
static 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_reflck_attach(struct vfio_pci_device *vdev);
static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck);
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;
}
ret = vfio_pci_reflck_attach(vdev);
if (ret) {
vfio_del_group_dev(&pdev->dev);
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));
}
vfio_pci_probe_power_state(vdev);
if (!disable_idle_d3) {
/*
* pci-core sets the device power state to an unknown value at
* bootup and after being removed from a driver. The only
* transition it allows from this unknown state is to D0, which
* typically happens when a driver calls pci_enable_device().
* We're not ready to enable the device yet, but we do want to
* be able to get to D3. Therefore first do a D0 transition
* before going to D3.
*/
vfio_pci_set_power_state(vdev, PCI_D0);
vfio_pci_set_power_state(vdev, PCI_D3hot);
}
return ret;
}
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_pci_reflck_put(vdev->reflck);
vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
kfree(vdev->region);
mutex_destroy(&vdev->ioeventfds_lock);
if (!disable_idle_d3)
vfio_pci_set_power_state(vdev, PCI_D0);
kfree(vdev->pm_save);
kfree(vdev);
if (vfio_pci_is_vga(pdev)) {
vga_client_register(pdev, NULL, NULL, NULL);
vga_set_legacy_decoding(pdev,
VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM);
}
}
static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
pci_channel_state_t state)
{
struct vfio_pci_device *vdev;
struct vfio_device *device;
device = vfio_device_get_from_dev(&pdev->dev);
if (device == NULL)
return PCI_ERS_RESULT_DISCONNECT;
vdev = vfio_device_data(device);
if (vdev == NULL) {
vfio_device_put(device);
return PCI_ERS_RESULT_DISCONNECT;
}
mutex_lock(&vdev->igate);
if (vdev->err_trigger)
eventfd_signal(vdev->err_trigger, 1);
mutex_unlock(&vdev->igate);
vfio_device_put(device);
return PCI_ERS_RESULT_CAN_RECOVER;
}
static 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 DEFINE_MUTEX(reflck_lock);
static struct vfio_pci_reflck *vfio_pci_reflck_alloc(void)
{
struct vfio_pci_reflck *reflck;
reflck = kzalloc(sizeof(*reflck), GFP_KERNEL);
if (!reflck)
return ERR_PTR(-ENOMEM);
kref_init(&reflck->kref);
mutex_init(&reflck->lock);
return reflck;
}
static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck)
{
kref_get(&reflck->kref);
}
static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
{
struct vfio_pci_reflck **preflck = data;
struct vfio_device *device;
struct vfio_pci_device *vdev;
device = vfio_device_get_from_dev(&pdev->dev);
if (!device)
return 0;
if (pci_dev_driver(pdev) != &vfio_pci_driver) {
vfio_device_put(device);
return 0;
}
vdev = vfio_device_data(device);
if (vdev->reflck) {
vfio_pci_reflck_get(vdev->reflck);
*preflck = vdev->reflck;
vfio_device_put(device);
return 1;
}
vfio_device_put(device);
return 0;
}
static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev)
{
bool slot = !pci_probe_reset_slot(vdev->pdev->slot);
mutex_lock(&reflck_lock);
if (pci_is_root_bus(vdev->pdev->bus) ||
vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find,
&vdev->reflck, slot) <= 0)
vdev->reflck = vfio_pci_reflck_alloc();
mutex_unlock(&reflck_lock);
return PTR_ERR_OR_ZERO(vdev->reflck);
}
static void vfio_pci_reflck_release(struct kref *kref)
{
struct vfio_pci_reflck *reflck = container_of(kref,
struct vfio_pci_reflck,
kref);
kfree(reflck);
mutex_unlock(&reflck_lock);
}
static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck)
{
kref_put_mutex(&reflck->kref, vfio_pci_reflck_release, &reflck_lock);
}
static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
{
struct vfio_devices *devs = data;
struct vfio_device *device;
struct vfio_pci_device *vdev;
if (devs->cur_index == devs->max_index)
return -ENOSPC;
device = vfio_device_get_from_dev(&pdev->dev);
if (!device)
return -EINVAL;
if (pci_dev_driver(pdev) != &vfio_pci_driver) {
vfio_device_put(device);
return -EBUSY;
}
vdev = vfio_device_data(device);
/* Fault if the device is not unused */
if (vdev->refcnt) {
vfio_device_put(device);
return -EBUSY;
}
devs->devices[devs->cur_index++] = device;
return 0;
}
static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data)
{
struct vfio_devices *devs = data;
struct vfio_device *device;
struct vfio_pci_device *vdev;
if (devs->cur_index == devs->max_index)
return -ENOSPC;
device = vfio_device_get_from_dev(&pdev->dev);
if (!device)
return -EINVAL;
if (pci_dev_driver(pdev) != &vfio_pci_driver) {
vfio_device_put(device);
return -EBUSY;
}
vdev = vfio_device_data(device);
/*
* Locking multiple devices is prone to deadlock, runaway and
* unwind if we hit contention.
*/
if (!vfio_pci_zap_and_vma_lock(vdev, true)) {
vfio_device_put(device);
return -EBUSY;
}
devs->devices[devs->cur_index++] = device;
return 0;
}
/*
* If a bus or slot reset is available for the provided device and:
* - All of the devices affected by that bus or slot reset are unused
* (!refcnt)
* - At least one of the affected devices is marked dirty via
* needs_reset (such as by lack of FLR support)
* Then attempt to perform that bus or slot reset. Callers are required
* to hold vdev->reflck->lock, protecting the bus/slot reset group from
* concurrent opens. A vfio_device reference is acquired for each device
* to prevent unbinds during the reset operation.
*
* NB: vfio-core considers a group to be viable even if some devices are
* bound to drivers like pci-stub or pcieport. Here we require all devices
* to be bound to vfio_pci since that's the only way we can be sure they
* stay put.
*/
static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
{
struct vfio_devices devs = { .cur_index = 0 };
int i = 0, ret = -EINVAL;
bool slot = false;
struct vfio_pci_device *tmp;
if (!pci_probe_reset_slot(vdev->pdev->slot))
slot = true;
else if (pci_probe_reset_bus(vdev->pdev->bus))
return;
if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
&i, slot) || !i)
return;
devs.max_index = i;
devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL);
if (!devs.devices)
return;
if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
vfio_pci_get_unused_devs,
&devs, slot))
goto put_devs;
/* Does at least one need a reset? */
for (i = 0; i < devs.cur_index; i++) {
tmp = vfio_device_data(devs.devices[i]);
if (tmp->needs_reset) {
ret = pci_reset_bus(vdev->pdev);
break;
}
}
put_devs:
for (i = 0; i < devs.cur_index; i++) {
tmp = vfio_device_data(devs.devices[i]);
/*
* If reset was successful, affected devices no longer need
* a reset and we should return all the collateral devices
* to low power. If not successful, we either didn't reset
* the bus or timed out waiting for it, so let's not touch
* the power state.
*/
if (!ret) {
tmp->needs_reset = false;
if (tmp != vdev && !disable_idle_d3)
vfio_pci_set_power_state(tmp, PCI_D3hot);
}
vfio_device_put(devs.devices[i]);
}
kfree(devs.devices);
}
static void __exit vfio_pci_cleanup(void)
{
pci_unregister_driver(&vfio_pci_driver);
vfio_pci_uninit_perm_bits();
}
static void __init vfio_pci_fill_ids(void)
{
char *p, *id;
int rc;
/* no ids passed actually */
if (ids[0] == '\0')
return;
/* add ids specified in the module parameter */
p = ids;
while ((id = strsep(&p, ","))) {
unsigned int vendor, device, subvendor = PCI_ANY_ID,
subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
int fields;
if (!strlen(id))
continue;
fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
&vendor, &device, &subvendor, &subdevice,
&class, &class_mask);
if (fields < 2) {
pr_warn("invalid id string \"%s\"\n", id);
continue;
}
rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
subvendor, subdevice, class, class_mask, 0);
if (rc)
pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
vendor, device, subvendor, subdevice,
class, class_mask, rc);
else
pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
vendor, device, subvendor, subdevice,
class, class_mask);
}
}
static int __init vfio_pci_init(void)
{
int ret;
/* Allocate shared config space permision data used by all devices */
ret = vfio_pci_init_perm_bits();
if (ret)
return ret;
/* Register and scan for devices */
ret = pci_register_driver(&vfio_pci_driver);
if (ret)
goto out_driver;
vfio_pci_fill_ids();
return 0;
out_driver:
vfio_pci_uninit_perm_bits();
return ret;
}
module_init(vfio_pci_init);
module_exit(vfio_pci_cleanup);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
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