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-rw-r--r--drivers/vhost/Kconfig1
-rw-r--r--drivers/vhost/net.c22
-rw-r--r--drivers/vhost/vdpa.c183
-rw-r--r--drivers/vhost/vhost.c39
-rw-r--r--drivers/vhost/vhost.h11
5 files changed, 169 insertions, 87 deletions
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index d3688c6afb87..587fbae06182 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -65,6 +65,7 @@ config VHOST_VDPA
tristate "Vhost driver for vDPA-based backend"
depends on EVENTFD
select VHOST
+ select IRQ_BYPASS_MANAGER
depends on VDPA
help
This kernel module can be loaded in host kernel to accelerate
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index eea902b83afe..531a00d703cd 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -73,7 +73,7 @@ enum {
VHOST_NET_FEATURES = VHOST_FEATURES |
(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
(1ULL << VIRTIO_NET_F_MRG_RXBUF) |
- (1ULL << VIRTIO_F_IOMMU_PLATFORM)
+ (1ULL << VIRTIO_F_ACCESS_PLATFORM)
};
enum {
@@ -1615,21 +1615,6 @@ done:
return err;
}
-static int vhost_net_set_backend_features(struct vhost_net *n, u64 features)
-{
- int i;
-
- mutex_lock(&n->dev.mutex);
- for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
- mutex_lock(&n->vqs[i].vq.mutex);
- n->vqs[i].vq.acked_backend_features = features;
- mutex_unlock(&n->vqs[i].vq.mutex);
- }
- mutex_unlock(&n->dev.mutex);
-
- return 0;
-}
-
static int vhost_net_set_features(struct vhost_net *n, u64 features)
{
size_t vhost_hlen, sock_hlen, hdr_len;
@@ -1653,7 +1638,7 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
!vhost_log_access_ok(&n->dev))
goto out_unlock;
- if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) {
+ if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
if (vhost_init_device_iotlb(&n->dev, true))
goto out_unlock;
}
@@ -1730,7 +1715,8 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
return -EFAULT;
if (features & ~VHOST_NET_BACKEND_FEATURES)
return -EOPNOTSUPP;
- return vhost_net_set_backend_features(n, features);
+ vhost_set_backend_features(&n->dev, features);
+ return 0;
case VHOST_RESET_OWNER:
return vhost_net_reset_owner(n);
case VHOST_SET_OWNER:
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index a54b60d6623f..3fab94f88894 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -27,37 +27,11 @@
#include "vhost.h"
enum {
- VHOST_VDPA_FEATURES =
- (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
- (1ULL << VIRTIO_F_ANY_LAYOUT) |
- (1ULL << VIRTIO_F_VERSION_1) |
- (1ULL << VIRTIO_F_IOMMU_PLATFORM) |
- (1ULL << VIRTIO_F_RING_PACKED) |
- (1ULL << VIRTIO_F_ORDER_PLATFORM) |
- (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
- (1ULL << VIRTIO_RING_F_EVENT_IDX),
-
- VHOST_VDPA_NET_FEATURES = VHOST_VDPA_FEATURES |
- (1ULL << VIRTIO_NET_F_CSUM) |
- (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
- (1ULL << VIRTIO_NET_F_MTU) |
- (1ULL << VIRTIO_NET_F_MAC) |
- (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
- (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
- (1ULL << VIRTIO_NET_F_GUEST_ECN) |
- (1ULL << VIRTIO_NET_F_GUEST_UFO) |
- (1ULL << VIRTIO_NET_F_HOST_TSO4) |
- (1ULL << VIRTIO_NET_F_HOST_TSO6) |
- (1ULL << VIRTIO_NET_F_HOST_ECN) |
- (1ULL << VIRTIO_NET_F_HOST_UFO) |
- (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
- (1ULL << VIRTIO_NET_F_STATUS) |
- (1ULL << VIRTIO_NET_F_SPEED_DUPLEX),
+ VHOST_VDPA_BACKEND_FEATURES =
+ (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
+ (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
};
-/* Currently, only network backend w/o multiqueue is supported. */
-#define VHOST_VDPA_VQ_MAX 2
-
#define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
struct vhost_vdpa {
@@ -73,16 +47,13 @@ struct vhost_vdpa {
int virtio_id;
int minor;
struct eventfd_ctx *config_ctx;
+ int in_batch;
};
static DEFINE_IDA(vhost_vdpa_ida);
static dev_t vhost_vdpa_major;
-static const u64 vhost_vdpa_features[] = {
- [VIRTIO_ID_NET] = VHOST_VDPA_NET_FEATURES,
-};
-
static void handle_vq_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
@@ -96,7 +67,7 @@ static void handle_vq_kick(struct vhost_work *work)
static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
{
struct vhost_virtqueue *vq = private;
- struct eventfd_ctx *call_ctx = vq->call_ctx;
+ struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
if (call_ctx)
eventfd_signal(call_ctx, 1);
@@ -115,12 +86,45 @@ static irqreturn_t vhost_vdpa_config_cb(void *private)
return IRQ_HANDLED;
}
+static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
+{
+ struct vhost_virtqueue *vq = &v->vqs[qid];
+ const struct vdpa_config_ops *ops = v->vdpa->config;
+ struct vdpa_device *vdpa = v->vdpa;
+ int ret, irq;
+
+ if (!ops->get_vq_irq)
+ return;
+
+ irq = ops->get_vq_irq(vdpa, qid);
+ spin_lock(&vq->call_ctx.ctx_lock);
+ irq_bypass_unregister_producer(&vq->call_ctx.producer);
+ if (!vq->call_ctx.ctx || irq < 0) {
+ spin_unlock(&vq->call_ctx.ctx_lock);
+ return;
+ }
+
+ vq->call_ctx.producer.token = vq->call_ctx.ctx;
+ vq->call_ctx.producer.irq = irq;
+ ret = irq_bypass_register_producer(&vq->call_ctx.producer);
+ spin_unlock(&vq->call_ctx.ctx_lock);
+}
+
+static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
+{
+ struct vhost_virtqueue *vq = &v->vqs[qid];
+
+ spin_lock(&vq->call_ctx.ctx_lock);
+ irq_bypass_unregister_producer(&vq->call_ctx.producer);
+ spin_unlock(&vq->call_ctx.ctx_lock);
+}
+
static void vhost_vdpa_reset(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
- const struct vdpa_config_ops *ops = vdpa->config;
- ops->set_status(vdpa, 0);
+ vdpa_reset(vdpa);
+ v->in_batch = 0;
}
static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
@@ -155,11 +159,15 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
- u8 status;
+ u8 status, status_old;
+ int nvqs = v->nvqs;
+ u16 i;
if (copy_from_user(&status, statusp, sizeof(status)))
return -EFAULT;
+ status_old = ops->get_status(vdpa);
+
/*
* Userspace shouldn't remove status bits unless reset the
* status to 0.
@@ -169,6 +177,14 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
ops->set_status(vdpa, status);
+ if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
+ for (i = 0; i < nvqs; i++)
+ vhost_vdpa_setup_vq_irq(v, i);
+
+ if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
+ for (i = 0; i < nvqs; i++)
+ vhost_vdpa_unsetup_vq_irq(v, i);
+
return 0;
}
@@ -196,7 +212,6 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v,
struct vhost_vdpa_config __user *c)
{
struct vdpa_device *vdpa = v->vdpa;
- const struct vdpa_config_ops *ops = vdpa->config;
struct vhost_vdpa_config config;
unsigned long size = offsetof(struct vhost_vdpa_config, buf);
u8 *buf;
@@ -209,7 +224,7 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v,
if (!buf)
return -ENOMEM;
- ops->get_config(vdpa, config.off, buf, config.len);
+ vdpa_get_config(vdpa, config.off, buf, config.len);
if (copy_to_user(c->buf, buf, config.len)) {
kvfree(buf);
@@ -255,7 +270,6 @@ static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
u64 features;
features = ops->get_features(vdpa);
- features &= vhost_vdpa_features[v->virtio_id];
if (copy_to_user(featurep, &features, sizeof(features)))
return -EFAULT;
@@ -279,10 +293,7 @@ static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
if (copy_from_user(&features, featurep, sizeof(features)))
return -EFAULT;
- if (features & ~vhost_vdpa_features[v->virtio_id])
- return -EINVAL;
-
- if (ops->set_features(vdpa, features))
+ if (vdpa_set_features(vdpa, features))
return -EINVAL;
return 0;
@@ -332,14 +343,18 @@ static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
return 0;
}
+
static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
void __user *argp)
{
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
+ struct vdpa_vq_state vq_state;
struct vdpa_callback cb;
struct vhost_virtqueue *vq;
struct vhost_vring_state s;
+ u64 __user *featurep = argp;
+ u64 features;
u32 idx;
long r;
@@ -353,15 +368,32 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
idx = array_index_nospec(idx, v->nvqs);
vq = &v->vqs[idx];
- if (cmd == VHOST_VDPA_SET_VRING_ENABLE) {
+ switch (cmd) {
+ case VHOST_VDPA_SET_VRING_ENABLE:
if (copy_from_user(&s, argp, sizeof(s)))
return -EFAULT;
ops->set_vq_ready(vdpa, idx, s.num);
return 0;
- }
+ case VHOST_GET_VRING_BASE:
+ r = ops->get_vq_state(v->vdpa, idx, &vq_state);
+ if (r)
+ return r;
- if (cmd == VHOST_GET_VRING_BASE)
- vq->last_avail_idx = ops->get_vq_state(v->vdpa, idx);
+ vq->last_avail_idx = vq_state.avail_index;
+ break;
+ case VHOST_GET_BACKEND_FEATURES:
+ features = VHOST_VDPA_BACKEND_FEATURES;
+ if (copy_to_user(featurep, &features, sizeof(features)))
+ return -EFAULT;
+ return 0;
+ case VHOST_SET_BACKEND_FEATURES:
+ if (copy_from_user(&features, featurep, sizeof(features)))
+ return -EFAULT;
+ if (features & ~VHOST_VDPA_BACKEND_FEATURES)
+ return -EOPNOTSUPP;
+ vhost_set_backend_features(&v->vdev, features);
+ return 0;
+ }
r = vhost_vring_ioctl(&v->vdev, cmd, argp);
if (r)
@@ -377,12 +409,13 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
break;
case VHOST_SET_VRING_BASE:
- if (ops->set_vq_state(vdpa, idx, vq->last_avail_idx))
+ vq_state.avail_index = vq->last_avail_idx;
+ if (ops->set_vq_state(vdpa, idx, &vq_state))
r = -EINVAL;
break;
case VHOST_SET_VRING_CALL:
- if (vq->call_ctx) {
+ if (vq->call_ctx.ctx) {
cb.callback = vhost_vdpa_virtqueue_cb;
cb.private = vq;
} else {
@@ -390,6 +423,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
cb.private = NULL;
}
ops->set_vq_cb(vdpa, idx, &cb);
+ vhost_vdpa_setup_vq_irq(v, idx);
break;
case VHOST_SET_VRING_NUM:
@@ -519,13 +553,15 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
if (r)
return r;
- if (ops->dma_map)
+ if (ops->dma_map) {
r = ops->dma_map(vdpa, iova, size, pa, perm);
- else if (ops->set_map)
- r = ops->set_map(vdpa, dev->iotlb);
- else
+ } else if (ops->set_map) {
+ if (!v->in_batch)
+ r = ops->set_map(vdpa, dev->iotlb);
+ } else {
r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm));
+ }
return r;
}
@@ -538,12 +574,14 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
- if (ops->dma_map)
+ if (ops->dma_map) {
ops->dma_unmap(vdpa, iova, size);
- else if (ops->set_map)
- ops->set_map(vdpa, dev->iotlb);
- else
+ } else if (ops->set_map) {
+ if (!v->in_batch)
+ ops->set_map(vdpa, dev->iotlb);
+ } else {
iommu_unmap(v->domain, iova, size);
+ }
}
static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
@@ -636,6 +674,8 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
struct vhost_iotlb_msg *msg)
{
struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
int r = 0;
r = vhost_dev_check_owner(dev);
@@ -649,6 +689,14 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
case VHOST_IOTLB_INVALIDATE:
vhost_vdpa_unmap(v, msg->iova, msg->size);
break;
+ case VHOST_IOTLB_BATCH_BEGIN:
+ v->in_batch = true;
+ break;
+ case VHOST_IOTLB_BATCH_END:
+ if (v->in_batch && ops->set_map)
+ ops->set_map(vdpa, dev->iotlb);
+ v->in_batch = false;
+ break;
default:
r = -EINVAL;
break;
@@ -765,6 +813,18 @@ err:
return r;
}
+static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
+{
+ struct vhost_virtqueue *vq;
+ int i;
+
+ for (i = 0; i < v->nvqs; i++) {
+ vq = &v->vqs[i];
+ if (vq->call_ctx.producer.irq)
+ irq_bypass_unregister_producer(&vq->call_ctx.producer);
+ }
+}
+
static int vhost_vdpa_release(struct inode *inode, struct file *filep)
{
struct vhost_vdpa *v = filep->private_data;
@@ -777,6 +837,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
vhost_vdpa_iotlb_free(v);
vhost_vdpa_free_domain(v);
vhost_vdpa_config_put(v);
+ vhost_vdpa_clean_irq(v);
vhost_dev_cleanup(&v->vdev);
kfree(v->vdev.vqs);
mutex_unlock(&d->mutex);
@@ -872,7 +933,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
{
const struct vdpa_config_ops *ops = vdpa->config;
struct vhost_vdpa *v;
- int minor, nvqs = VHOST_VDPA_VQ_MAX;
+ int minor;
int r;
/* Currently, we only accept the network devices. */
@@ -893,14 +954,14 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
atomic_set(&v->opened, 0);
v->minor = minor;
v->vdpa = vdpa;
- v->nvqs = nvqs;
+ v->nvqs = vdpa->nvqs;
v->virtio_id = ops->get_device_id(vdpa);
device_initialize(&v->dev);
v->dev.release = vhost_vdpa_release_dev;
v->dev.parent = &vdpa->dev;
v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
- v->vqs = kmalloc_array(nvqs, sizeof(struct vhost_virtqueue),
+ v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
GFP_KERNEL);
if (!v->vqs) {
r = -ENOMEM;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 74d135ee7e26..5857d4eec9d7 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -298,6 +298,13 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
__vhost_vq_meta_reset(d->vqs[i]);
}
+static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx)
+{
+ call_ctx->ctx = NULL;
+ memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer));
+ spin_lock_init(&call_ctx->ctx_lock);
+}
+
static void vhost_vq_reset(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
{
@@ -319,13 +326,13 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->log_base = NULL;
vq->error_ctx = NULL;
vq->kick = NULL;
- vq->call_ctx = NULL;
vq->log_ctx = NULL;
vhost_reset_is_le(vq);
vhost_disable_cross_endian(vq);
vq->busyloop_timeout = 0;
vq->umem = NULL;
vq->iotlb = NULL;
+ vhost_vring_call_reset(&vq->call_ctx);
__vhost_vq_meta_reset(vq);
}
@@ -685,8 +692,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
eventfd_ctx_put(dev->vqs[i]->error_ctx);
if (dev->vqs[i]->kick)
fput(dev->vqs[i]->kick);
- if (dev->vqs[i]->call_ctx)
- eventfd_ctx_put(dev->vqs[i]->call_ctx);
+ if (dev->vqs[i]->call_ctx.ctx)
+ eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx);
vhost_vq_reset(dev, dev->vqs[i]);
}
vhost_dev_free_iovecs(dev);
@@ -1405,7 +1412,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
memcpy(newmem, &mem, size);
if (copy_from_user(newmem->regions, m->regions,
- mem.nregions * sizeof *m->regions)) {
+ flex_array_size(newmem, regions, mem.nregions))) {
kvfree(newmem);
return -EFAULT;
}
@@ -1629,7 +1636,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
r = PTR_ERR(ctx);
break;
}
- swap(ctx, vq->call_ctx);
+
+ spin_lock(&vq->call_ctx.ctx_lock);
+ swap(ctx, vq->call_ctx.ctx);
+ spin_unlock(&vq->call_ctx.ctx_lock);
break;
case VHOST_SET_VRING_ERR:
if (copy_from_user(&f, argp, sizeof f)) {
@@ -2435,8 +2445,8 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
/* Signal the Guest tell them we used something up. */
- if (vq->call_ctx && vhost_notify(dev, vq))
- eventfd_signal(vq->call_ctx, 1);
+ if (vq->call_ctx.ctx && vhost_notify(dev, vq))
+ eventfd_signal(vq->call_ctx.ctx, 1);
}
EXPORT_SYMBOL_GPL(vhost_signal);
@@ -2576,6 +2586,21 @@ struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
}
EXPORT_SYMBOL_GPL(vhost_dequeue_msg);
+void vhost_set_backend_features(struct vhost_dev *dev, u64 features)
+{
+ struct vhost_virtqueue *vq;
+ int i;
+
+ mutex_lock(&dev->mutex);
+ for (i = 0; i < dev->nvqs; ++i) {
+ vq = dev->vqs[i];
+ mutex_lock(&vq->mutex);
+ vq->acked_backend_features = features;
+ mutex_unlock(&vq->mutex);
+ }
+ mutex_unlock(&dev->mutex);
+}
+EXPORT_SYMBOL_GPL(vhost_set_backend_features);
static int __init vhost_init(void)
{
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index c8e96a095d3b..9032d3c2a9f4 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -13,6 +13,7 @@
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
#include <linux/vhost_iotlb.h>
+#include <linux/irqbypass.h>
struct vhost_work;
typedef void (*vhost_work_fn_t)(struct vhost_work *work);
@@ -60,6 +61,12 @@ enum vhost_uaddr_type {
VHOST_NUM_ADDRS = 3,
};
+struct vhost_vring_call {
+ struct eventfd_ctx *ctx;
+ struct irq_bypass_producer producer;
+ spinlock_t ctx_lock;
+};
+
/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
struct vhost_dev *dev;
@@ -72,7 +79,7 @@ struct vhost_virtqueue {
vring_used_t __user *used;
const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
struct file *kick;
- struct eventfd_ctx *call_ctx;
+ struct vhost_vring_call call_ctx;
struct eventfd_ctx *error_ctx;
struct eventfd_ctx *log_ctx;
@@ -207,6 +214,8 @@ void vhost_enqueue_msg(struct vhost_dev *dev,
struct vhost_msg_node *node);
struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
struct list_head *head);
+void vhost_set_backend_features(struct vhost_dev *dev, u64 features);
+
__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
poll_table *wait);
ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,