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kern_vfio.go
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kern_vfio.go
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// Copyright 2016 Platina Systems, Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !novfio
package pci
import (
"github.com/platinasystems/elib"
"github.com/platinasystems/elib/hw"
"github.com/platinasystems/elib/iomux"
"errors"
"fmt"
"os"
"path"
"strconv"
"sync"
"syscall"
"unsafe"
)
type vfio_group struct {
// Group number.
number uint
// /dev/vfio/GROUP_NUMBER
fd int
status vfio_group_status
devices []*vfio_pci_device
}
type vfio_device_region_info struct {
vfio_region_info
mapped_mem []byte
sparse_areas []vfio_region_sparse_mmap_area
cap_type vfio_region_info_cap_type
msix_mappable bool
}
type vfio_pci_device struct {
Device
m *vfio_main
group *vfio_group
info vfio_device_info
region_infos []vfio_device_region_info
irq_index uint32
irq_infos []vfio_irq_info
// device fd from VFIO_GROUP_GET_DEVICE_FD
device_fd int
interrupt_event_fd int
iomux.File
}
type vfio_main struct {
busCommon
api_version int
// /dev/vfio/vfio
container_fd int
iommu_info vfio_iommu_type1_info
dma_map vfio_iommu_type1_dma_map
// Groups indexed by iommu group number.
group_by_number map[uint]*vfio_group
devices []*vfio_pci_device
// Chunks are 2^log2LinesPerChunk cache lines long.
// Kernel gives us memory in "Chunks" which are physically contiguous.
log2LinesPerChunk, log2BytesPerChunk uint8
container_init_once, dma_init_once sync.Once
}
func vfio_ioctl(fd int, kind vfio_ioctl_kind, arg uintptr) (r uintptr, err error) {
r, _, e := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(fd), uintptr(kind), arg)
if e != 0 {
err = os.NewSyscallError("ioctl "+kind.String(), e)
}
return
}
func (m *vfio_main) ioctl(kind vfio_ioctl_kind, arg uintptr) (uintptr, error) {
return vfio_ioctl(m.container_fd, kind, arg)
}
func (x *vfio_group) ioctl(kind vfio_ioctl_kind, arg uintptr) (uintptr, error) {
return vfio_ioctl(x.fd, kind, arg)
}
func (x *vfio_pci_device) ioctl(kind vfio_ioctl_kind, arg uintptr) (uintptr, error) {
return vfio_ioctl(x.device_fd, kind, arg)
}
func (m *vfio_main) container_init() (err error) {
m.container_fd, err = syscall.Open("/dev/vfio/vfio", syscall.O_RDWR, 0)
if err != nil {
return
}
defer func() {
if err != nil && m.container_fd != 0 {
syscall.Close(m.container_fd)
}
}()
{
var v uintptr
if v, err = m.ioctl(vfio_get_api_version, 0); err != nil {
return
}
m.api_version = int(v)
if v, err = m.ioctl(vfio_check_extension, vfio_type1v2_iommu); v == 0 || err != nil {
if err == nil && v == 0 {
err = errors.New("vfio type 1 version 2 iommu not supported by kernel")
}
return
}
}
return
}
func (m *vfio_main) dma_init(log2_dma_heap_bytes uint) (err error) {
// Enable the IOMMU model we want.
if _, err = m.ioctl(vfio_set_iommu, vfio_type1v2_iommu); err != nil {
return
}
// Fetch iommu info. Supported page sizes.
m.iommu_info.set_size(unsafe.Sizeof(m.iommu_info))
if _, err = m.ioctl(vfio_iommu_get_info, uintptr(unsafe.Pointer(&m.iommu_info))); err != nil {
return
}
addr, data, e := elib.MmapSliceAligned(log2_dma_heap_bytes, hw.PhysmemLog2AddressAlign,
syscall.MAP_SHARED|syscall.MAP_ANONYMOUS,
syscall.PROT_READ|syscall.PROT_WRITE)
if e != nil {
err = e
return
}
m.dma_map = vfio_iommu_type1_dma_map{
vaddr: uint64(addr),
iova: uint64(hw.DmaPhysAddress(addr)),
size: uint64(1) << log2_dma_heap_bytes,
}
m.dma_map.set(unsafe.Sizeof(m.dma_map), vfio_dma_map_flag_read|vfio_dma_map_flag_write)
if _, err = m.ioctl(vfio_iommu_map_dma, uintptr(unsafe.Pointer(&m.dma_map))); err != nil {
return
}
hw.DmaInit(data)
return
}
func sysfsWrite(path, format string, args ...interface{}) error {
fn := "/sys/bus/pci/drivers/vfio-pci/" + path
f, err := os.OpenFile(fn, os.O_WRONLY, 0)
if err != nil {
return err
}
defer f.Close()
fmt.Fprintf(f, format, args...)
return err
}
func (d *vfio_pci_device) sysfsWriteID(name string) (err error) {
err = sysfsWrite(name, "%04x %04x", int(d.VendorID()), int(d.DeviceID()))
return
}
func (d *vfio_pci_device) sysfsWriteAddr(name string) (err error) {
err = sysfsWrite(name, "%v", &d.Device.Addr)
return
}
func (d *vfio_pci_device) new_id() error { return d.sysfsWriteID("new_id") }
func (d *vfio_pci_device) remove_id() error { return d.sysfsWriteID("remove_id") }
func (d *vfio_pci_device) bind() error { return d.sysfsWriteAddr("bind") }
func (d *vfio_pci_device) unbind() error { return d.sysfsWriteAddr("unbind") }
var DefaultBus = &vfio_main{}
func (d *vfio_main) NewDevice() BusDevice { return &vfio_pci_device{m: d} }
// fixme should check that all iommu groups are fully populated.
func (d *vfio_main) Validate() (err error) { return }
func (d *vfio_pci_device) GetDevice() *Device { return &d.Device }
func (d *vfio_pci_device) sysfs_get_group_number() (uint, error) {
s, err := os.Readlink("/sys/bus/pci/devices/" + d.Device.Addr.String() + "/iommu_group")
if err != nil {
return 0, err
}
n, err := strconv.ParseUint(path.Base(s), 10, 0)
return uint(n), err
}
func (d *vfio_pci_device) new_group(group_number uint) (g *vfio_group, err error) {
m := d.m
group_path := fmt.Sprintf("/dev/vfio/%d", group_number)
var fd int
fd, err = syscall.Open(group_path, syscall.O_RDWR, 0)
if err != nil {
err = os.NewSyscallError("open "+group_path, err)
return
}
defer func() {
if err != nil && fd >= 0 {
syscall.Close(fd)
g = nil
}
}()
g = &vfio_group{number: group_number, fd: fd}
g.status.set_size(unsafe.Sizeof(g.status))
if _, err = g.ioctl(vfio_group_get_status, uintptr(unsafe.Pointer(&g.status.vfio_ioctl_common))); err != nil {
return
}
// Group must be viable.
if g.status.flags&vfio_group_flags_viable == 0 {
err = fmt.Errorf("vfio group %d is not viable (not all devices are bound for vfio)", g.number)
return
}
if m.group_by_number == nil {
m.group_by_number = make(map[uint]*vfio_group)
}
m.group_by_number[group_number] = g
return
}
func (d *vfio_pci_device) find_group() (g *vfio_group, err error) {
var (
n uint
ok bool
)
g = d.group
if g != nil {
return
}
if n, err = d.sysfs_get_group_number(); err != nil {
return
}
if g, ok = d.m.group_by_number[n]; !ok {
g, err = d.new_group(n)
if err != nil {
return
}
}
d.group = g
g.devices = append(g.devices, d)
d.m.devices = append(d.m.devices, d)
return
}
func (d *vfio_pci_device) Open() (err error) {
// Wrap error with device.
defer func() {
if err != nil {
err = fmt.Errorf("pci %s: %s", d.Device.String(), err)
}
}()
err = d.new_id()
if err != nil {
return
}
// Make sure group exists and is viable.
if _, err = d.find_group(); err != nil {
return
}
// Initialize DMA heap once device is open.
d.m.container_init_once.Do(func() {
err = d.m.container_init()
})
if err != nil {
return
}
// Set group container.
if d.group.status.flags&vfio_group_flags_container_set == 0 {
if _, err = vfio_ioctl(d.group.fd, vfio_group_set_container, uintptr(unsafe.Pointer(&d.m.container_fd))); err != nil {
return
}
d.group.status.flags |= vfio_group_flags_container_set
}
// Initialize DMA heap once at least one group has been added to container.
d.m.dma_init_once.Do(func() {
err = d.m.dma_init(28)
})
if err != nil {
return
}
// Get device fd.
{
tmp := []byte(d.Device.Addr.String())
var fd uintptr
if fd, err = d.group.ioctl(vfio_group_get_device_fd, uintptr(unsafe.Pointer(&tmp[0]))); err != nil {
return
}
d.device_fd = int(fd)
}
// Fetch device info.
d.info.set_size(unsafe.Sizeof(d.info))
if _, err = d.ioctl(vfio_device_get_info, uintptr(unsafe.Pointer(&d.info))); err != nil {
return
}
// Fetch regions.
d.region_infos = make([]vfio_device_region_info, d.info.num_regions)
for i := range d.region_infos {
type tmp struct {
vfio_region_info
caps [4 << 10]byte
}
x := &tmp{}
x.set_size(unsafe.Sizeof(*x))
x.index = uint32(i)
if _, err = d.ioctl(vfio_device_get_region_info, uintptr(unsafe.Pointer(x))); err != nil {
if i == vfio_pci_vga_region_index {
// ignore vga region missing
err = nil
} else {
return
}
}
ri := &d.region_infos[i]
ri.vfio_region_info = x.vfio_region_info
if x.flags&vfio_region_info_flag_caps != 0 {
o := x.cap_offset - uint32(unsafe.Sizeof(vfio_region_info{}))
b := x.caps[o:]
h, p := get_vfio_info_cap_header(b, 0)
for h != nil {
switch h.kind {
case vfio_region_info_cap_kind_sparse_mmap:
m := (*vfio_region_info_cap_sparse_mmap)(p)
for i := uint32(0); i < m.nr_areas; i++ {
a := m.get_area(i)
ri.sparse_areas = append(ri.sparse_areas, *a)
}
case vfio_region_info_cap_kind_type:
m := (*vfio_region_info_cap_type)(p)
ri.cap_type = *m
case vfio_region_info_cap_kind_msix_mappable:
ri.msix_mappable = true
default:
panic(fmt.Errorf("vfio region info unknown cap: %+v", h))
}
h, p = h.next(b)
}
}
}
// Fetch interrupt infos for each interrupt.
d.irq_infos = make([]vfio_irq_info, d.info.num_irqs)
for i := range d.irq_infos {
x := &d.irq_infos[i]
x.set_size(unsafe.Sizeof(*x))
x.index = uint32(i)
if _, err = d.ioctl(vfio_device_get_irq_info, uintptr(unsafe.Pointer(x))); err != nil {
return
}
}
// Set bus master in pci command register.
// Otherwise no love with device dma or msi interrupts.
d.SetMaster(true)
// Reset device.
if _, err = d.ioctl(vfio_device_reset, 0); err != nil {
err = nil // ignore error
}
return
}
func (g *vfio_group) close() (err error) {
syscall.Close(g.fd)
g.fd = -1
return
}
func (m *vfio_main) close() (err error) {
for _, g := range m.group_by_number {
if err = g.close(); err != nil {
return
}
}
{
unmap := vfio_iommu_type1_dma_unmap{
iova: m.dma_map.iova,
size: m.dma_map.size,
}
unmap.set(unsafe.Sizeof(unmap), 0)
if _, err = m.ioctl(vfio_iommu_unmap_dma, uintptr(unsafe.Pointer(&unmap))); err != nil {
return
}
}
syscall.Close(m.container_fd)
m.container_fd = -1
for i := range m.devices {
e := m.devices[i]
if err = e.unmap_resources(); err != nil {
return
}
if err = e.unbind(); err != nil {
return
}
if err = e.remove_id(); err != nil {
return
}
}
return
}
func (d *vfio_pci_device) Close() (err error) {
if d.interrupt_event_fd > 0 {
iomux.Del(d)
syscall.Close(d.interrupt_event_fd)
d.interrupt_event_fd = -1
}
if d.device_fd > 0 {
syscall.Close(d.device_fd)
d.device_fd = -1
}
found_open := false
for i := range d.m.devices {
if d.m.devices[i].device_fd > 0 {
found_open = true
break
}
}
if !found_open {
err = d.m.close()
}
return
}
func (d *vfio_pci_device) unmap_resources() (err error) {
for i := range d.region_infos {
ri := &d.region_infos[i]
if ri.mapped_mem != nil {
err = elib.Munmap(ri.mapped_mem)
if err != nil {
return
}
}
}
return
}
func (d *vfio_pci_device) MapResource(i uint) (res uintptr, err error) {
var mem uintptr
r := &d.Device.Resources[i]
if r.Index >= uint32(len(d.region_infos)) {
err = fmt.Errorf("%s: mmap unknown resource BAR %d",
d.Device.String(), r.Index)
return
}
ri := &d.region_infos[r.Index]
fmt.Printf("MapResource %s, region %d", d.Device.String(), i)
if ri.msix_mappable {
fmt.Print(", msix-mappable")
}
fmt.Printf(", sz %v, offset %v", ri.size, ri.offset)
if ri.msix_mappable || len(ri.sparse_areas) == 0 {
_, r.Mem, err = elib.MmapSlice(0,
uintptr(ri.size),
syscall.PROT_READ|syscall.PROT_WRITE,
syscall.MAP_SHARED,
uintptr(d.device_fd),
uintptr(ri.offset))
} else {
mem, r.Mem, err = elib.MmapSlice(0,
uintptr(ri.size),
syscall.PROT_NONE,
syscall.MAP_SHARED|syscall.MAP_ANONYMOUS,
0, 0)
for ai := range ri.sparse_areas {
if err != nil {
break
}
a := &ri.sparse_areas[ai]
_, _, err = elib.MmapSlice(mem+uintptr(a.offset),
uintptr(a.size),
syscall.PROT_READ|syscall.PROT_WRITE,
syscall.MAP_SHARED|syscall.MAP_FIXED,
uintptr(d.device_fd),
uintptr(ri.offset+a.offset))
fmt.Printf(".\nMapResource %s, region %d, area %d",
d.Device.String(), i, i)
fmt.Printf(", sz %v, offset %v",
mem+uintptr(a.offset), ri.offset+a.offset)
}
}
if err != nil {
fmt.Print(": ", err)
err = fmt.Errorf("%s: mmap resource %d: %s",
d.Device.String(), r.Index, err)
return
}
fmt.Println(".")
res = uintptr(unsafe.Pointer(&r.Mem[0]))
ri.mapped_mem = r.Mem
return
}
func (d *vfio_pci_device) region_rw(region, offset, vʹ, nBytes uint, isWrite bool) (v uint, err error) {
var b [4]byte
fd := d.device_fd
o := int64(region)<<40 + int64(offset)
if isWrite {
for i := range b {
b[i] = byte((vʹ >> uint(8*i)) & 0xff)
}
_, err = syscall.Pwrite(fd, b[:nBytes], o)
v = vʹ
} else {
_, err = syscall.Pread(fd, b[:nBytes], o)
if err == nil {
for i := range b {
v |= uint(b[i]) << (8 * uint(i))
}
}
}
return
}
func (d *vfio_pci_device) ConfigRw(offset, v, nBytes uint, isWrite bool) uint {
// Before Open() is called; rely on /sys based config space read/write.
if d.device_fd == 0 {
return d.Device.ConfigRw(offset, v, nBytes, isWrite)
}
v, err := d.region_rw(vfio_pci_config_region_index, offset, v, nBytes, isWrite)
if err != nil {
panic(err)
}
return v
}
var errShouldNeverHappen = errors.New("should never happen")
func (d *vfio_pci_device) ErrorReady() error { return errShouldNeverHappen }
func (d *vfio_pci_device) WriteReady() error { return errShouldNeverHappen }
func (d *vfio_pci_device) WriteAvailable() bool { return false }
func (d *vfio_pci_device) String() string { return "pci " + d.Device.String() }
func (d *vfio_pci_device) InterruptEnable(EnableMsi bool) (err error) {
// Get eventfd for interrupt.
{
r, _, e := syscall.RawSyscall(syscall.SYS_EVENTFD, 0, syscall.O_CLOEXEC|syscall.O_NONBLOCK, 0)
if e != 0 {
err = os.NewSyscallError("eventfd", e)
return
}
d.interrupt_event_fd = int(r)
}
// Enable interrupt.
{
var ii *vfio_irq_info
if ii = &d.irq_infos[vfio_pci_msi_irq_index]; ii.count == 0 || !EnableMsi {
// No MSI? Choose first one.
for i := range d.irq_infos {
if d.irq_infos[i].count > 0 {
ii = &d.irq_infos[i]
break
}
}
}
if ii.count == 0 {
panic("no irq")
}
d.irq_index = ii.index
type set struct {
vfio_irq_set
data [1]int32 // event fds
}
var s set
s.set(unsafe.Sizeof(s), vfio_irq_set_data_eventfd|vfio_irq_set_action_trigger)
s.index = ii.index
s.start = uint32(0)
s.count = uint32(len(s.data))
s.data[0] = int32(d.interrupt_event_fd)
if _, err = d.ioctl(vfio_device_set_irqs, uintptr(unsafe.Pointer(&s))); err != nil {
return
}
}
// Listen for interrupts.
{
d.Fd = int(d.interrupt_event_fd)
iomux.Add(d)
}
return
}
func (d *vfio_pci_device) enableDisableInterrupts(enable bool) (err error) {
var s vfio_irq_set
action := uint(vfio_irq_set_action_mask)
if enable {
action = vfio_irq_set_action_unmask
}
s.set(unsafe.Sizeof(s), vfio_irq_set_data_none|action)
s.index = d.irq_index
s.start = 0
s.count = 1
if _, err = d.ioctl(vfio_device_set_irqs, uintptr(unsafe.Pointer(&s))); err != nil {
return
}
return
}
// UIO file is ready when interrupt occurs.
func (d *vfio_pci_device) ReadReady() (err error) {
var b [8]byte
if _, err = syscall.Read(d.interrupt_event_fd, b[:]); err != nil {
return
}
if d.irq_index == vfio_pci_intx_irq_index {
err = d.enableDisableInterrupts(false)
if err != nil {
return
}
}
d.DriverDevice.Interrupt()
if d.irq_index == vfio_pci_intx_irq_index {
err = d.enableDisableInterrupts(true)
if err != nil {
return
}
}
return
}