qemu/hw/virtio/vhost-vdpa.c
Eugenio Pérez e6db5df7e2 vhost-vdpa: Do not send empty IOTLB update batches
With the introduction of the batch hinting, meaningless batches can be
created with no IOTLB updates if the memory region was skipped by
vhost_vdpa_listener_skipped_section. This is the case of host notifiers
memory regions, device un/realize, and others. This causes the vdpa
device to receive dma mapping settings with no changes, a possibly
expensive operation for nothing.

To avoid that, VHOST_IOTLB_BATCH_BEGIN hint is delayed until we have a
meaningful (not skipped section) mapping or unmapping operation, and
VHOST_IOTLB_BATCH_END is not written unless at least one of _UPDATE /
_INVALIDATE has been issued.

v3:
  * Use a bool instead of a counter avoiding potential number wrapping
  * Fix bad check on _commit
  * Move VHOST_BACKEND_F_IOTLB_BATCH check to
    vhost_vdpa_iotlb_batch_begin_once

v2 (from RFC):
  * Rename misleading name
  * Abstract start batching function for listener_add/del

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20210812140933.226288-1-eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 09:07:45 -04:00

703 lines
21 KiB
C

/*
* vhost-vdpa
*
* Copyright(c) 2017-2018 Intel Corporation.
* Copyright(c) 2020 Red Hat, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include <linux/vhost.h>
#include <linux/vfio.h>
#include <sys/eventfd.h>
#include <sys/ioctl.h>
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-backend.h"
#include "hw/virtio/virtio-net.h"
#include "hw/virtio/vhost-vdpa.h"
#include "exec/address-spaces.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "trace.h"
#include "qemu-common.h"
static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
{
return (!memory_region_is_ram(section->mr) &&
!memory_region_is_iommu(section->mr)) ||
/* vhost-vDPA doesn't allow MMIO to be mapped */
memory_region_is_ram_device(section->mr) ||
/*
* Sizing an enabled 64-bit BAR can cause spurious mappings to
* addresses in the upper part of the 64-bit address space. These
* are never accessed by the CPU and beyond the address width of
* some IOMMU hardware. TODO: VDPA should tell us the IOMMU width.
*/
section->offset_within_address_space & (1ULL << 63);
}
static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
void *vaddr, bool readonly)
{
struct vhost_msg_v2 msg = {};
int fd = v->device_fd;
int ret = 0;
msg.type = v->msg_type;
msg.iotlb.iova = iova;
msg.iotlb.size = size;
msg.iotlb.uaddr = (uint64_t)(uintptr_t)vaddr;
msg.iotlb.perm = readonly ? VHOST_ACCESS_RO : VHOST_ACCESS_RW;
msg.iotlb.type = VHOST_IOTLB_UPDATE;
trace_vhost_vdpa_dma_map(v, fd, msg.type, msg.iotlb.iova, msg.iotlb.size,
msg.iotlb.uaddr, msg.iotlb.perm, msg.iotlb.type);
if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
error_report("failed to write, fd=%d, errno=%d (%s)",
fd, errno, strerror(errno));
return -EIO ;
}
return ret;
}
static int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova,
hwaddr size)
{
struct vhost_msg_v2 msg = {};
int fd = v->device_fd;
int ret = 0;
msg.type = v->msg_type;
msg.iotlb.iova = iova;
msg.iotlb.size = size;
msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
trace_vhost_vdpa_dma_unmap(v, fd, msg.type, msg.iotlb.iova,
msg.iotlb.size, msg.iotlb.type);
if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
error_report("failed to write, fd=%d, errno=%d (%s)",
fd, errno, strerror(errno));
return -EIO ;
}
return ret;
}
static void vhost_vdpa_listener_begin_batch(struct vhost_vdpa *v)
{
int fd = v->device_fd;
struct vhost_msg_v2 msg = {
.type = v->msg_type,
.iotlb.type = VHOST_IOTLB_BATCH_BEGIN,
};
if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
error_report("failed to write, fd=%d, errno=%d (%s)",
fd, errno, strerror(errno));
}
}
static void vhost_vdpa_iotlb_batch_begin_once(struct vhost_vdpa *v)
{
if (v->dev->backend_cap & (0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH) &&
!v->iotlb_batch_begin_sent) {
vhost_vdpa_listener_begin_batch(v);
}
v->iotlb_batch_begin_sent = true;
}
static void vhost_vdpa_listener_commit(MemoryListener *listener)
{
struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
struct vhost_dev *dev = v->dev;
struct vhost_msg_v2 msg = {};
int fd = v->device_fd;
if (!(dev->backend_cap & (0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH))) {
return;
}
if (!v->iotlb_batch_begin_sent) {
return;
}
msg.type = v->msg_type;
msg.iotlb.type = VHOST_IOTLB_BATCH_END;
if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
error_report("failed to write, fd=%d, errno=%d (%s)",
fd, errno, strerror(errno));
}
v->iotlb_batch_begin_sent = false;
}
static void vhost_vdpa_listener_region_add(MemoryListener *listener,
MemoryRegionSection *section)
{
struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
hwaddr iova;
Int128 llend, llsize;
void *vaddr;
int ret;
if (vhost_vdpa_listener_skipped_section(section)) {
return;
}
if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
(section->offset_within_region & ~TARGET_PAGE_MASK))) {
error_report("%s received unaligned region", __func__);
return;
}
iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
llend = int128_make64(section->offset_within_address_space);
llend = int128_add(llend, section->size);
llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
if (int128_ge(int128_make64(iova), llend)) {
return;
}
memory_region_ref(section->mr);
/* Here we assume that memory_region_is_ram(section->mr)==true */
vaddr = memory_region_get_ram_ptr(section->mr) +
section->offset_within_region +
(iova - section->offset_within_address_space);
trace_vhost_vdpa_listener_region_add(v, iova, int128_get64(llend),
vaddr, section->readonly);
llsize = int128_sub(llend, int128_make64(iova));
vhost_vdpa_iotlb_batch_begin_once(v);
ret = vhost_vdpa_dma_map(v, iova, int128_get64(llsize),
vaddr, section->readonly);
if (ret) {
error_report("vhost vdpa map fail!");
goto fail;
}
return;
fail:
/*
* On the initfn path, store the first error in the container so we
* can gracefully fail. Runtime, there's not much we can do other
* than throw a hardware error.
*/
error_report("vhost-vdpa: DMA mapping failed, unable to continue");
return;
}
static void vhost_vdpa_listener_region_del(MemoryListener *listener,
MemoryRegionSection *section)
{
struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
hwaddr iova;
Int128 llend, llsize;
int ret;
if (vhost_vdpa_listener_skipped_section(section)) {
return;
}
if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
(section->offset_within_region & ~TARGET_PAGE_MASK))) {
error_report("%s received unaligned region", __func__);
return;
}
iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
llend = int128_make64(section->offset_within_address_space);
llend = int128_add(llend, section->size);
llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
trace_vhost_vdpa_listener_region_del(v, iova, int128_get64(llend));
if (int128_ge(int128_make64(iova), llend)) {
return;
}
llsize = int128_sub(llend, int128_make64(iova));
vhost_vdpa_iotlb_batch_begin_once(v);
ret = vhost_vdpa_dma_unmap(v, iova, int128_get64(llsize));
if (ret) {
error_report("vhost_vdpa dma unmap error!");
}
memory_region_unref(section->mr);
}
/*
* IOTLB API is used by vhost-vpda which requires incremental updating
* of the mapping. So we can not use generic vhost memory listener which
* depends on the addnop().
*/
static const MemoryListener vhost_vdpa_memory_listener = {
.commit = vhost_vdpa_listener_commit,
.region_add = vhost_vdpa_listener_region_add,
.region_del = vhost_vdpa_listener_region_del,
};
static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request,
void *arg)
{
struct vhost_vdpa *v = dev->opaque;
int fd = v->device_fd;
int ret;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
ret = ioctl(fd, request, arg);
return ret < 0 ? -errno : ret;
}
static void vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status)
{
uint8_t s;
trace_vhost_vdpa_add_status(dev, status);
if (vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &s)) {
return;
}
s |= status;
vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &s);
}
static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
{
struct vhost_vdpa *v;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
trace_vhost_vdpa_init(dev, opaque);
v = opaque;
v->dev = dev;
dev->opaque = opaque ;
v->listener = vhost_vdpa_memory_listener;
v->msg_type = VHOST_IOTLB_MSG_V2;
vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
VIRTIO_CONFIG_S_DRIVER);
return 0;
}
static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev,
int queue_index)
{
size_t page_size = qemu_real_host_page_size;
struct vhost_vdpa *v = dev->opaque;
VirtIODevice *vdev = dev->vdev;
VhostVDPAHostNotifier *n;
n = &v->notifier[queue_index];
if (n->addr) {
virtio_queue_set_host_notifier_mr(vdev, queue_index, &n->mr, false);
object_unparent(OBJECT(&n->mr));
munmap(n->addr, page_size);
n->addr = NULL;
}
}
static void vhost_vdpa_host_notifiers_uninit(struct vhost_dev *dev, int n)
{
int i;
for (i = 0; i < n; i++) {
vhost_vdpa_host_notifier_uninit(dev, i);
}
}
static int vhost_vdpa_host_notifier_init(struct vhost_dev *dev, int queue_index)
{
size_t page_size = qemu_real_host_page_size;
struct vhost_vdpa *v = dev->opaque;
VirtIODevice *vdev = dev->vdev;
VhostVDPAHostNotifier *n;
int fd = v->device_fd;
void *addr;
char *name;
vhost_vdpa_host_notifier_uninit(dev, queue_index);
n = &v->notifier[queue_index];
addr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, fd,
queue_index * page_size);
if (addr == MAP_FAILED) {
goto err;
}
name = g_strdup_printf("vhost-vdpa/host-notifier@%p mmaps[%d]",
v, queue_index);
memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
page_size, addr);
g_free(name);
if (virtio_queue_set_host_notifier_mr(vdev, queue_index, &n->mr, true)) {
munmap(addr, page_size);
goto err;
}
n->addr = addr;
return 0;
err:
return -1;
}
static void vhost_vdpa_host_notifiers_init(struct vhost_dev *dev)
{
int i;
for (i = dev->vq_index; i < dev->vq_index + dev->nvqs; i++) {
if (vhost_vdpa_host_notifier_init(dev, i)) {
goto err;
}
}
return;
err:
vhost_vdpa_host_notifiers_uninit(dev, i);
return;
}
static int vhost_vdpa_cleanup(struct vhost_dev *dev)
{
struct vhost_vdpa *v;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
v = dev->opaque;
trace_vhost_vdpa_cleanup(dev, v);
vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
memory_listener_unregister(&v->listener);
dev->opaque = NULL;
return 0;
}
static int vhost_vdpa_memslots_limit(struct vhost_dev *dev)
{
trace_vhost_vdpa_memslots_limit(dev, INT_MAX);
return INT_MAX;
}
static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
struct vhost_memory *mem)
{
trace_vhost_vdpa_set_mem_table(dev, mem->nregions, mem->padding);
if (trace_event_get_state_backends(TRACE_VHOST_VDPA_SET_MEM_TABLE) &&
trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_REGIONS)) {
int i;
for (i = 0; i < mem->nregions; i++) {
trace_vhost_vdpa_dump_regions(dev, i,
mem->regions[i].guest_phys_addr,
mem->regions[i].memory_size,
mem->regions[i].userspace_addr,
mem->regions[i].flags_padding);
}
}
if (mem->padding) {
return -1;
}
return 0;
}
static int vhost_vdpa_set_features(struct vhost_dev *dev,
uint64_t features)
{
int ret;
trace_vhost_vdpa_set_features(dev, features);
ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
uint8_t status = 0;
if (ret) {
return ret;
}
vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
return !(status & VIRTIO_CONFIG_S_FEATURES_OK);
}
static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
{
uint64_t features;
uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2 |
0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH;
int r;
if (vhost_vdpa_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) {
return 0;
}
features &= f;
r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features);
if (r) {
return 0;
}
dev->backend_cap = features;
return 0;
}
static int vhost_vdpa_get_device_id(struct vhost_dev *dev,
uint32_t *device_id)
{
int ret;
ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_DEVICE_ID, device_id);
trace_vhost_vdpa_get_device_id(dev, *device_id);
return ret;
}
static int vhost_vdpa_reset_device(struct vhost_dev *dev)
{
int ret;
uint8_t status = 0;
ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
trace_vhost_vdpa_reset_device(dev, status);
return ret;
}
static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
{
assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
trace_vhost_vdpa_get_vq_index(dev, idx, idx - dev->vq_index);
return idx - dev->vq_index;
}
static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
{
int i;
trace_vhost_vdpa_set_vring_ready(dev);
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_vring_state state = {
.index = dev->vq_index + i,
.num = 1,
};
vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
}
return 0;
}
static void vhost_vdpa_dump_config(struct vhost_dev *dev, const uint8_t *config,
uint32_t config_len)
{
int b, len;
char line[QEMU_HEXDUMP_LINE_LEN];
for (b = 0; b < config_len; b += 16) {
len = config_len - b;
qemu_hexdump_line(line, b, config, len, false);
trace_vhost_vdpa_dump_config(dev, line);
}
}
static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data,
uint32_t offset, uint32_t size,
uint32_t flags)
{
struct vhost_vdpa_config *config;
int ret;
unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
trace_vhost_vdpa_set_config(dev, offset, size, flags);
config = g_malloc(size + config_size);
config->off = offset;
config->len = size;
memcpy(config->buf, data, size);
if (trace_event_get_state_backends(TRACE_VHOST_VDPA_SET_CONFIG) &&
trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_CONFIG)) {
vhost_vdpa_dump_config(dev, data, size);
}
ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_CONFIG, config);
g_free(config);
return ret;
}
static int vhost_vdpa_get_config(struct vhost_dev *dev, uint8_t *config,
uint32_t config_len, Error **errp)
{
struct vhost_vdpa_config *v_config;
unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
int ret;
trace_vhost_vdpa_get_config(dev, config, config_len);
v_config = g_malloc(config_len + config_size);
v_config->len = config_len;
v_config->off = 0;
ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_CONFIG, v_config);
memcpy(config, v_config->buf, config_len);
g_free(v_config);
if (trace_event_get_state_backends(TRACE_VHOST_VDPA_GET_CONFIG) &&
trace_event_get_state_backends(TRACE_VHOST_VDPA_DUMP_CONFIG)) {
vhost_vdpa_dump_config(dev, config, config_len);
}
return ret;
}
static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
{
struct vhost_vdpa *v = dev->opaque;
trace_vhost_vdpa_dev_start(dev, started);
if (started) {
uint8_t status = 0;
memory_listener_register(&v->listener, &address_space_memory);
vhost_vdpa_host_notifiers_init(dev);
vhost_vdpa_set_vring_ready(dev);
vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
} else {
vhost_vdpa_reset_device(dev);
vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
VIRTIO_CONFIG_S_DRIVER);
vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
memory_listener_unregister(&v->listener);
return 0;
}
}
static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
struct vhost_log *log)
{
trace_vhost_vdpa_set_log_base(dev, base, log->size, log->refcnt, log->fd,
log->log);
return vhost_vdpa_call(dev, VHOST_SET_LOG_BASE, &base);
}
static int vhost_vdpa_set_vring_addr(struct vhost_dev *dev,
struct vhost_vring_addr *addr)
{
trace_vhost_vdpa_set_vring_addr(dev, addr->index, addr->flags,
addr->desc_user_addr, addr->used_user_addr,
addr->avail_user_addr,
addr->log_guest_addr);
return vhost_vdpa_call(dev, VHOST_SET_VRING_ADDR, addr);
}
static int vhost_vdpa_set_vring_num(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
trace_vhost_vdpa_set_vring_num(dev, ring->index, ring->num);
return vhost_vdpa_call(dev, VHOST_SET_VRING_NUM, ring);
}
static int vhost_vdpa_set_vring_base(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
trace_vhost_vdpa_set_vring_base(dev, ring->index, ring->num);
return vhost_vdpa_call(dev, VHOST_SET_VRING_BASE, ring);
}
static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
int ret;
ret = vhost_vdpa_call(dev, VHOST_GET_VRING_BASE, ring);
trace_vhost_vdpa_get_vring_base(dev, ring->index, ring->num);
return ret;
}
static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
trace_vhost_vdpa_set_vring_kick(dev, file->index, file->fd);
return vhost_vdpa_call(dev, VHOST_SET_VRING_KICK, file);
}
static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
}
static int vhost_vdpa_get_features(struct vhost_dev *dev,
uint64_t *features)
{
int ret;
ret = vhost_vdpa_call(dev, VHOST_GET_FEATURES, features);
trace_vhost_vdpa_get_features(dev, *features);
return ret;
}
static int vhost_vdpa_set_owner(struct vhost_dev *dev)
{
trace_vhost_vdpa_set_owner(dev);
return vhost_vdpa_call(dev, VHOST_SET_OWNER, NULL);
}
static int vhost_vdpa_vq_get_addr(struct vhost_dev *dev,
struct vhost_vring_addr *addr, struct vhost_virtqueue *vq)
{
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
addr->desc_user_addr = (uint64_t)(unsigned long)vq->desc_phys;
addr->avail_user_addr = (uint64_t)(unsigned long)vq->avail_phys;
addr->used_user_addr = (uint64_t)(unsigned long)vq->used_phys;
trace_vhost_vdpa_vq_get_addr(dev, vq, addr->desc_user_addr,
addr->avail_user_addr, addr->used_user_addr);
return 0;
}
static bool vhost_vdpa_force_iommu(struct vhost_dev *dev)
{
return true;
}
const VhostOps vdpa_ops = {
.backend_type = VHOST_BACKEND_TYPE_VDPA,
.vhost_backend_init = vhost_vdpa_init,
.vhost_backend_cleanup = vhost_vdpa_cleanup,
.vhost_set_log_base = vhost_vdpa_set_log_base,
.vhost_set_vring_addr = vhost_vdpa_set_vring_addr,
.vhost_set_vring_num = vhost_vdpa_set_vring_num,
.vhost_set_vring_base = vhost_vdpa_set_vring_base,
.vhost_get_vring_base = vhost_vdpa_get_vring_base,
.vhost_set_vring_kick = vhost_vdpa_set_vring_kick,
.vhost_set_vring_call = vhost_vdpa_set_vring_call,
.vhost_get_features = vhost_vdpa_get_features,
.vhost_set_backend_cap = vhost_vdpa_set_backend_cap,
.vhost_set_owner = vhost_vdpa_set_owner,
.vhost_set_vring_endian = NULL,
.vhost_backend_memslots_limit = vhost_vdpa_memslots_limit,
.vhost_set_mem_table = vhost_vdpa_set_mem_table,
.vhost_set_features = vhost_vdpa_set_features,
.vhost_reset_device = vhost_vdpa_reset_device,
.vhost_get_vq_index = vhost_vdpa_get_vq_index,
.vhost_get_config = vhost_vdpa_get_config,
.vhost_set_config = vhost_vdpa_set_config,
.vhost_requires_shm_log = NULL,
.vhost_migration_done = NULL,
.vhost_backend_can_merge = NULL,
.vhost_net_set_mtu = NULL,
.vhost_set_iotlb_callback = NULL,
.vhost_send_device_iotlb_msg = NULL,
.vhost_dev_start = vhost_vdpa_dev_start,
.vhost_get_device_id = vhost_vdpa_get_device_id,
.vhost_vq_get_addr = vhost_vdpa_vq_get_addr,
.vhost_force_iommu = vhost_vdpa_force_iommu,
};