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Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/net.c306
-rw-r--r--drivers/vhost/vhost.c232
-rw-r--r--drivers/vhost/vhost.h55
3 files changed, 493 insertions, 100 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index d219070fed3..29e850a7a2f 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -74,6 +74,22 @@ static int move_iovec_hdr(struct iovec *from, struct iovec *to,
}
return seg;
}
+/* Copy iovec entries for len bytes from iovec. */
+static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
+ size_t len, int iovcount)
+{
+ int seg = 0;
+ size_t size;
+ while (len && seg < iovcount) {
+ size = min(from->iov_len, len);
+ to->iov_base = from->iov_base;
+ to->iov_len = size;
+ len -= size;
+ ++from;
+ ++to;
+ ++seg;
+ }
+}
/* Caller must have TX VQ lock */
static void tx_poll_stop(struct vhost_net *net)
@@ -129,7 +145,7 @@ static void handle_tx(struct vhost_net *net)
if (wmem < sock->sk->sk_sndbuf / 2)
tx_poll_stop(net);
- hdr_size = vq->hdr_size;
+ hdr_size = vq->vhost_hlen;
for (;;) {
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
@@ -172,7 +188,7 @@ static void handle_tx(struct vhost_net *net)
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(NULL, sock, &msg, len);
if (unlikely(err < 0)) {
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
tx_poll_start(net, sock);
break;
}
@@ -191,9 +207,82 @@ static void handle_tx(struct vhost_net *net)
unuse_mm(net->dev.mm);
}
+static int peek_head_len(struct sock *sk)
+{
+ struct sk_buff *head;
+ int len = 0;
+
+ lock_sock(sk);
+ head = skb_peek(&sk->sk_receive_queue);
+ if (head)
+ len = head->len;
+ release_sock(sk);
+ return len;
+}
+
+/* This is a multi-buffer version of vhost_get_desc, that works if
+ * vq has read descriptors only.
+ * @vq - the relevant virtqueue
+ * @datalen - data length we'll be reading
+ * @iovcount - returned count of io vectors we fill
+ * @log - vhost log
+ * @log_num - log offset
+ * returns number of buffer heads allocated, negative on error
+ */
+static int get_rx_bufs(struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads,
+ int datalen,
+ unsigned *iovcount,
+ struct vhost_log *log,
+ unsigned *log_num)
+{
+ unsigned int out, in;
+ int seg = 0;
+ int headcount = 0;
+ unsigned d;
+ int r, nlogs = 0;
+
+ while (datalen > 0) {
+ if (unlikely(headcount >= VHOST_NET_MAX_SG)) {
+ r = -ENOBUFS;
+ goto err;
+ }
+ d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
+ ARRAY_SIZE(vq->iov) - seg, &out,
+ &in, log, log_num);
+ if (d == vq->num) {
+ r = 0;
+ goto err;
+ }
+ if (unlikely(out || in <= 0)) {
+ vq_err(vq, "unexpected descriptor format for RX: "
+ "out %d, in %d\n", out, in);
+ r = -EINVAL;
+ goto err;
+ }
+ if (unlikely(log)) {
+ nlogs += *log_num;
+ log += *log_num;
+ }
+ heads[headcount].id = d;
+ heads[headcount].len = iov_length(vq->iov + seg, in);
+ datalen -= heads[headcount].len;
+ ++headcount;
+ seg += in;
+ }
+ heads[headcount - 1].len += datalen;
+ *iovcount = seg;
+ if (unlikely(log))
+ *log_num = nlogs;
+ return headcount;
+err:
+ vhost_discard_vq_desc(vq, headcount);
+ return r;
+}
+
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
-static void handle_rx(struct vhost_net *net)
+static void handle_rx_big(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
unsigned out, in, log, s;
@@ -223,7 +312,7 @@ static void handle_rx(struct vhost_net *net)
use_mm(net->dev.mm);
mutex_lock(&vq->mutex);
vhost_disable_notify(vq);
- hdr_size = vq->hdr_size;
+ hdr_size = vq->vhost_hlen;
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
@@ -270,14 +359,14 @@ static void handle_rx(struct vhost_net *net)
len, MSG_DONTWAIT | MSG_TRUNC);
/* TODO: Check specific error and bomb out unless EAGAIN? */
if (err < 0) {
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
break;
}
/* TODO: Should check and handle checksum. */
if (err > len) {
pr_debug("Discarded truncated rx packet: "
" len %d > %zd\n", err, len);
- vhost_discard_vq_desc(vq);
+ vhost_discard_vq_desc(vq, 1);
continue;
}
len = err;
@@ -302,54 +391,175 @@ static void handle_rx(struct vhost_net *net)
unuse_mm(net->dev.mm);
}
-static void handle_tx_kick(struct work_struct *work)
+/* Expects to be always run from workqueue - which acts as
+ * read-size critical section for our kind of RCU. */
+static void handle_rx_mergeable(struct vhost_net *net)
{
- struct vhost_virtqueue *vq;
- struct vhost_net *net;
- vq = container_of(work, struct vhost_virtqueue, poll.work);
- net = container_of(vq->dev, struct vhost_net, dev);
+ struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+ unsigned uninitialized_var(in), log;
+ struct vhost_log *vq_log;
+ struct msghdr msg = {
+ .msg_name = NULL,
+ .msg_namelen = 0,
+ .msg_control = NULL, /* FIXME: get and handle RX aux data. */
+ .msg_controllen = 0,
+ .msg_iov = vq->iov,
+ .msg_flags = MSG_DONTWAIT,
+ };
+
+ struct virtio_net_hdr_mrg_rxbuf hdr = {
+ .hdr.flags = 0,
+ .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
+ };
+
+ size_t total_len = 0;
+ int err, headcount;
+ size_t vhost_hlen, sock_hlen;
+ size_t vhost_len, sock_len;
+ struct socket *sock = rcu_dereference(vq->private_data);
+ if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
+ return;
+
+ use_mm(net->dev.mm);
+ mutex_lock(&vq->mutex);
+ vhost_disable_notify(vq);
+ vhost_hlen = vq->vhost_hlen;
+ sock_hlen = vq->sock_hlen;
+
+ vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
+ vq->log : NULL;
+
+ while ((sock_len = peek_head_len(sock->sk))) {
+ sock_len += sock_hlen;
+ vhost_len = sock_len + vhost_hlen;
+ headcount = get_rx_bufs(vq, vq->heads, vhost_len,
+ &in, vq_log, &log);
+ /* On error, stop handling until the next kick. */
+ if (unlikely(headcount < 0))
+ break;
+ /* OK, now we need to know about added descriptors. */
+ if (!headcount) {
+ if (unlikely(vhost_enable_notify(vq))) {
+ /* They have slipped one in as we were
+ * doing that: check again. */
+ vhost_disable_notify(vq);
+ continue;
+ }
+ /* Nothing new? Wait for eventfd to tell us
+ * they refilled. */
+ break;
+ }
+ /* We don't need to be notified again. */
+ if (unlikely((vhost_hlen)))
+ /* Skip header. TODO: support TSO. */
+ move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
+ else
+ /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
+ * needed because sendmsg can modify msg_iov. */
+ copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
+ msg.msg_iovlen = in;
+ err = sock->ops->recvmsg(NULL, sock, &msg,
+ sock_len, MSG_DONTWAIT | MSG_TRUNC);
+ /* Userspace might have consumed the packet meanwhile:
+ * it's not supposed to do this usually, but might be hard
+ * to prevent. Discard data we got (if any) and keep going. */
+ if (unlikely(err != sock_len)) {
+ pr_debug("Discarded rx packet: "
+ " len %d, expected %zd\n", err, sock_len);
+ vhost_discard_vq_desc(vq, headcount);
+ continue;
+ }
+ if (unlikely(vhost_hlen) &&
+ memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
+ vhost_hlen)) {
+ vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
+ vq->iov->iov_base);
+ break;
+ }
+ /* TODO: Should check and handle checksum. */
+ if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF) &&
+ memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
+ offsetof(typeof(hdr), num_buffers),
+ sizeof hdr.num_buffers)) {
+ vq_err(vq, "Failed num_buffers write");
+ vhost_discard_vq_desc(vq, headcount);
+ break;
+ }
+ vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
+ headcount);
+ if (unlikely(vq_log))
+ vhost_log_write(vq, vq_log, log, vhost_len);
+ total_len += vhost_len;
+ if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
+ vhost_poll_queue(&vq->poll);
+ break;
+ }
+ }
+
+ mutex_unlock(&vq->mutex);
+ unuse_mm(net->dev.mm);
+}
+
+static void handle_rx(struct vhost_net *net)
+{
+ if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF))
+ handle_rx_mergeable(net);
+ else
+ handle_rx_big(net);
+}
+
+static void handle_tx_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
+
handle_tx(net);
}
-static void handle_rx_kick(struct work_struct *work)
+static void handle_rx_kick(struct vhost_work *work)
{
- struct vhost_virtqueue *vq;
- struct vhost_net *net;
- vq = container_of(work, struct vhost_virtqueue, poll.work);
- net = container_of(vq->dev, struct vhost_net, dev);
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
+
handle_rx(net);
}
-static void handle_tx_net(struct work_struct *work)
+static void handle_tx_net(struct vhost_work *work)
{
- struct vhost_net *net;
- net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_TX].work);
+ struct vhost_net *net = container_of(work, struct vhost_net,
+ poll[VHOST_NET_VQ_TX].work);
handle_tx(net);
}
-static void handle_rx_net(struct work_struct *work)
+static void handle_rx_net(struct vhost_work *work)
{
- struct vhost_net *net;
- net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_RX].work);
+ struct vhost_net *net = container_of(work, struct vhost_net,
+ poll[VHOST_NET_VQ_RX].work);
handle_rx(net);
}
static int vhost_net_open(struct inode *inode, struct file *f)
{
struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
+ struct vhost_dev *dev;
int r;
+
if (!n)
return -ENOMEM;
+
+ dev = &n->dev;
n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
- r = vhost_dev_init(&n->dev, n->vqs, VHOST_NET_VQ_MAX);
+ r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
if (r < 0) {
kfree(n);
return r;
}
- vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT);
- vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN);
+ vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
+ vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
f->private_data = n;
@@ -527,13 +737,12 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
/* start polling new socket */
oldsock = vq->private_data;
- if (sock == oldsock)
- goto done;
+ if (sock != oldsock) {
+ vhost_net_disable_vq(n, vq);
+ rcu_assign_pointer(vq->private_data, sock);
+ vhost_net_enable_vq(n, vq);
+ }
- vhost_net_disable_vq(n, vq);
- rcu_assign_pointer(vq->private_data, sock);
- vhost_net_enable_vq(n, vq);
-done:
mutex_unlock(&vq->mutex);
if (oldsock) {
@@ -574,9 +783,21 @@ done:
static int vhost_net_set_features(struct vhost_net *n, u64 features)
{
- size_t hdr_size = features & (1 << VHOST_NET_F_VIRTIO_NET_HDR) ?
- sizeof(struct virtio_net_hdr) : 0;
+ size_t vhost_hlen, sock_hlen, hdr_len;
int i;
+
+ hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
+ sizeof(struct virtio_net_hdr_mrg_rxbuf) :
+ sizeof(struct virtio_net_hdr);
+ if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
+ /* vhost provides vnet_hdr */
+ vhost_hlen = hdr_len;
+ sock_hlen = 0;
+ } else {
+ /* socket provides vnet_hdr */
+ vhost_hlen = 0;
+ sock_hlen = hdr_len;
+ }
mutex_lock(&n->dev.mutex);
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&n->dev)) {
@@ -587,7 +808,8 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
smp_wmb();
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
mutex_lock(&n->vqs[i].mutex);
- n->vqs[i].hdr_size = hdr_size;
+ n->vqs[i].vhost_hlen = vhost_hlen;
+ n->vqs[i].sock_hlen = sock_hlen;
mutex_unlock(&n->vqs[i].mutex);
}
vhost_net_flush(n);
@@ -639,7 +861,7 @@ static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
}
#endif
-const static struct file_operations vhost_net_fops = {
+static const struct file_operations vhost_net_fops = {
.owner = THIS_MODULE,
.release = vhost_net_release,
.unlocked_ioctl = vhost_net_ioctl,
@@ -657,25 +879,13 @@ static struct miscdevice vhost_net_misc = {
static int vhost_net_init(void)
{
- int r = vhost_init();
- if (r)
- goto err_init;
- r = misc_register(&vhost_net_misc);
- if (r)
- goto err_reg;
- return 0;
-err_reg:
- vhost_cleanup();
-err_init:
- return r;
-
+ return misc_register(&vhost_net_misc);
}
module_init(vhost_net_init);
static void vhost_net_exit(void)
{
misc_deregister(&vhost_net_misc);
- vhost_cleanup();
}
module_exit(vhost_net_exit);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 0b99783083f..e05557d5299 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -17,12 +17,13 @@
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
-#include <linux/workqueue.h>
#include <linux/rcupdate.h>
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/highmem.h>
#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/cgroup.h>
#include <linux/net.h>
#include <linux/if_packet.h>
@@ -37,8 +38,6 @@ enum {
VHOST_MEMORY_F_LOG = 0x1,
};
-static struct workqueue_struct *vhost_workqueue;
-
static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
{
@@ -52,23 +51,31 @@ static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync,
void *key)
{
- struct vhost_poll *poll;
- poll = container_of(wait, struct vhost_poll, wait);
+ struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait);
+
if (!((unsigned long)key & poll->mask))
return 0;
- queue_work(vhost_workqueue, &poll->work);
+ vhost_poll_queue(poll);
return 0;
}
/* Init poll structure */
-void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
- unsigned long mask)
+void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
+ unsigned long mask, struct vhost_dev *dev)
{
- INIT_WORK(&poll->work, func);
+ struct vhost_work *work = &poll->work;
+
init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
init_poll_funcptr(&poll->table, vhost_poll_func);
poll->mask = mask;
+ poll->dev = dev;
+
+ INIT_LIST_HEAD(&work->node);
+ work->fn = fn;
+ init_waitqueue_head(&work->done);
+ work->flushing = 0;
+ work->queue_seq = work->done_seq = 0;
}
/* Start polling a file. We add ourselves to file's wait queue. The caller must
@@ -92,12 +99,40 @@ void vhost_poll_stop(struct vhost_poll *poll)
* locks that are also used by the callback. */
void vhost_poll_flush(struct vhost_poll *poll)
{
- flush_work(&poll->work);
+ struct vhost_work *work = &poll->work;
+ unsigned seq;
+ int left;
+ int flushing;
+
+ spin_lock_irq(&poll->dev->work_lock);
+ seq = work->queue_seq;
+ work->flushing++;
+ spin_unlock_irq(&poll->dev->work_lock);
+ wait_event(work->done, ({
+ spin_lock_irq(&poll->dev->work_lock);
+ left = seq - work->done_seq <= 0;
+ spin_unlock_irq(&poll->dev->work_lock);
+ left;
+ }));
+ spin_lock_irq(&poll->dev->work_lock);
+ flushing = --work->flushing;
+ spin_unlock_irq(&poll->dev->work_lock);
+ BUG_ON(flushing < 0);
}
void vhost_poll_queue(struct vhost_poll *poll)
{
- queue_work(vhost_workqueue, &poll->work);
+ struct vhost_dev *dev = poll->dev;
+ struct vhost_work *work = &poll->work;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->work_lock, flags);
+ if (list_empty(&work->node)) {
+ list_add_tail(&work->node, &dev->work_list);
+ work->queue_seq++;
+ wake_up_process(dev->worker);
+ }
+ spin_unlock_irqrestore(&dev->work_lock, flags);
}
static void vhost_vq_reset(struct vhost_dev *dev,
@@ -114,7 +149,8 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->used_flags = 0;
vq->log_used = false;
vq->log_addr = -1ull;
- vq->hdr_size = 0;
+ vq->vhost_hlen = 0;
+ vq->sock_hlen = 0;
vq->private_data = NULL;
vq->log_base = NULL;
vq->error_ctx = NULL;
@@ -125,10 +161,51 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->log_ctx = NULL;
}
+static int vhost_worker(void *data)
+{
+ struct vhost_dev *dev = data;
+ struct vhost_work *work = NULL;
+ unsigned uninitialized_var(seq);
+
+ for (;;) {
+ /* mb paired w/ kthread_stop */
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_lock_irq(&dev->work_lock);
+ if (work) {
+ work->done_seq = seq;
+ if (work->flushing)
+ wake_up_all(&work->done);
+ }
+
+ if (kthread_should_stop()) {
+ spin_unlock_irq(&dev->work_lock);
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+ if (!list_empty(&dev->work_list)) {
+ work = list_first_entry(&dev->work_list,
+ struct vhost_work, node);
+ list_del_init(&work->node);
+ seq = work->queue_seq;
+ } else
+ work = NULL;
+ spin_unlock_irq(&dev->work_lock);
+
+ if (work) {
+ __set_current_state(TASK_RUNNING);
+ work->fn(work);
+ } else
+ schedule();
+
+ }
+}
+
long vhost_dev_init(struct vhost_dev *dev,
struct vhost_virtqueue *vqs, int nvqs)
{
int i;
+
dev->vqs = vqs;
dev->nvqs = nvqs;
mutex_init(&dev->mutex);
@@ -136,6 +213,9 @@ long vhost_dev_init(struct vhost_dev *dev,
dev->log_file = NULL;
dev->memory = NULL;
dev->mm = NULL;
+ spin_lock_init(&dev->work_lock);
+ INIT_LIST_HEAD(&dev->work_list);
+ dev->worker = NULL;
for (i = 0; i < dev->nvqs; ++i) {
dev->vqs[i].dev = dev;
@@ -143,9 +223,9 @@ long vhost_dev_init(struct vhost_dev *dev,
vhost_vq_reset(dev, dev->vqs + i);
if (dev->vqs[i].handle_kick)
vhost_poll_init(&dev->vqs[i].poll,
- dev->vqs[i].handle_kick,
- POLLIN);
+ dev->vqs[i].handle_kick, POLLIN, dev);
}
+
return 0;
}
@@ -159,12 +239,36 @@ long vhost_dev_check_owner(struct vhost_dev *dev)
/* Caller should have device mutex */
static long vhost_dev_set_owner(struct vhost_dev *dev)
{
+ struct task_struct *worker;
+ int err;
/* Is there an owner already? */
- if (dev->mm)
- return -EBUSY;
+ if (dev->mm) {
+ err = -EBUSY;
+ goto err_mm;
+ }
/* No owner, become one */
dev->mm = get_task_mm(current);
+ worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid);
+ if (IS_ERR(worker)) {
+ err = PTR_ERR(worker);
+ goto err_worker;
+ }
+
+ dev->worker = worker;
+ err = cgroup_attach_task_current_cg(worker);
+ if (err)
+ goto err_cgroup;
+ wake_up_process(worker); /* avoid contributing to loadavg */
+
return 0;
+err_cgroup:
+ kthread_stop(worker);
+err_worker:
+ if (dev->mm)
+ mmput(dev->mm);
+ dev->mm = NULL;
+err_mm:
+ return err;
}
/* Caller should have device mutex */
@@ -217,6 +321,9 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
if (dev->mm)
mmput(dev->mm);
dev->mm = NULL;
+
+ WARN_ON(!list_empty(&dev->work_list));
+ kthread_stop(dev->worker);
}
static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
@@ -237,8 +344,8 @@ static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem,
{
int i;
- if (!mem)
- return 0;
+ if (!mem)
+ return 0;
for (i = 0; i < mem->nregions; ++i) {
struct vhost_memory_region *m = mem->regions + i;
@@ -995,9 +1102,9 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
}
/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
-void vhost_discard_vq_desc(struct vhost_virtqueue *vq)
+void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
{
- vq->last_avail_idx--;
+ vq->last_avail_idx -= n;
}
/* After we've used one of their buffers, we tell them about it. We'll then
@@ -1042,6 +1149,67 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
return 0;
}
+static int __vhost_add_used_n(struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads,
+ unsigned count)
+{
+ struct vring_used_elem __user *used;
+ int start;
+
+ start = vq->last_used_idx % vq->num;
+ used = vq->used->ring + start;
+ if (copy_to_user(used, heads, count * sizeof *used)) {
+ vq_err(vq, "Failed to write used");
+ return -EFAULT;
+ }
+ if (unlikely(vq->log_used)) {
+ /* Make sure data is seen before log. */
+ smp_wmb();
+ /* Log used ring entry write. */
+ log_write(vq->log_base,
+ vq->log_addr +
+ ((void __user *)used - (void __user *)vq->used),
+ count * sizeof *used);
+ }
+ vq->last_used_idx += count;
+ return 0;
+}
+
+/* After we've used one of their buffers, we tell them about it. We'll then
+ * want to notify the guest, using eventfd. */
+int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
+ unsigned count)
+{
+ int start, n, r;
+
+ start = vq->last_used_idx % vq->num;
+ n = vq->num - start;
+ if (n < count) {
+ r = __vhost_add_used_n(vq, heads, n);
+ if (r < 0)
+ return r;
+ heads += n;
+ count -= n;
+ }
+ r = __vhost_add_used_n(vq, heads, count);
+
+ /* Make sure buffer is written before we update index. */
+ smp_wmb();
+ if (put_user(vq->last_used_idx, &vq->used->idx)) {
+ vq_err(vq, "Failed to increment used idx");
+ return -EFAULT;
+ }
+ if (unlikely(vq->log_used)) {
+ /* Log used index update. */
+ log_write(vq->log_base,
+ vq->log_addr + offsetof(struct vring_used, idx),
+ sizeof vq->used->idx);
+ if (vq->log_ctx)
+ eventfd_signal(vq->log_ctx, 1);
+ }
+ return r;
+}
+
/* This actually signals the guest, using eventfd. */
void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
@@ -1076,6 +1244,15 @@ void vhost_add_used_and_signal(struct vhost_dev *dev,
vhost_signal(dev, vq);
}
+/* multi-buffer version of vhost_add_used_and_signal */
+void vhost_add_used_and_signal_n(struct vhost_dev *dev,
+ struct vhost_virtqueue *vq,
+ struct vring_used_elem *heads, unsigned count)
+{
+ vhost_add_used_n(vq, heads, count);
+ vhost_signal(dev, vq);
+}
+
/* OK, now we need to know about added descriptors. */
bool vhost_enable_notify(struct vhost_virtqueue *vq)
{
@@ -1100,7 +1277,7 @@ bool vhost_enable_notify(struct vhost_virtqueue *vq)
return false;
}
- return avail_idx != vq->last_avail_idx;
+ return avail_idx != vq->avail_idx;
}
/* We don't need to be notified again. */
@@ -1115,16 +1292,3 @@ void vhost_disable_notify(struct vhost_virtqueue *vq)
vq_err(vq, "Failed to enable notification at %p: %d\n",
&vq->used->flags, r);
}
-
-int vhost_init(void)
-{
- vhost_workqueue = create_singlethread_workqueue("vhost");
- if (!vhost_workqueue)
- return -ENOMEM;
- return 0;
-}
-
-void vhost_cleanup(void)
-{
- destroy_workqueue(vhost_workqueue);
-}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 11ee13dba0f..afd77295971 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -5,13 +5,13 @@
#include <linux/vhost.h>
#include <linux/mm.h>
#include <linux/mutex.h>
-#include <linux/workqueue.h>
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/skbuff.h>
#include <linux/uio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
+#include <asm/atomic.h>
struct vhost_device;
@@ -20,19 +20,31 @@ enum {
VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2,
};
+struct vhost_work;
+typedef void (*vhost_work_fn_t)(struct vhost_work *work);
+
+struct vhost_work {
+ struct list_head node;
+ vhost_work_fn_t fn;
+ wait_queue_head_t done;
+ int flushing;
+ unsigned queue_seq;
+ unsigned done_seq;
+};
+
/* Poll a file (eventfd or socket) */
/* Note: there's nothing vhost specific about this structure. */
struct vhost_poll {
poll_table table;
wait_queue_head_t *wqh;
wait_queue_t wait;
- /* struct which will handle all actual work. */
- struct work_struct work;
+ struct vhost_work work;
unsigned long mask;
+ struct vhost_dev *dev;
};
-void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
- unsigned long mask);
+void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
+ unsigned long mask, struct vhost_dev *dev);
void vhost_poll_start(struct vhost_poll *poll, struct file *file);
void vhost_poll_stop(struct vhost_poll *poll);
void vhost_poll_flush(struct vhost_poll *poll);
@@ -63,7 +75,7 @@ struct vhost_virtqueue {
struct vhost_poll poll;
/* The routine to call when the Guest pings us, or timeout. */
- work_func_t handle_kick;
+ vhost_work_fn_t handle_kick;
/* Last available index we saw. */
u16 last_avail_idx;
@@ -84,13 +96,15 @@ struct vhost_virtqueue {
struct iovec indirect[VHOST_NET_MAX_SG];
struct iovec iov[VHOST_NET_MAX_SG];
struct iovec hdr[VHOST_NET_MAX_SG];
- size_t hdr_size;
+ size_t vhost_hlen;
+ size_t sock_hlen;
+ struct vring_used_elem heads[VHOST_NET_MAX_SG];
/* We use a kind of RCU to access private pointer.
- * All readers access it from workqueue, which makes it possible to
- * flush the workqueue instead of synchronize_rcu. Therefore readers do
+ * All readers access it from worker, which makes it possible to
+ * flush the vhost_work instead of synchronize_rcu. Therefore readers do
* not need to call rcu_read_lock/rcu_read_unlock: the beginning of
- * work item execution acts instead of rcu_read_lock() and the end of
- * work item execution acts instead of rcu_read_lock().
+ * vhost_work execution acts instead of rcu_read_lock() and the end of
+ * vhost_work execution acts instead of rcu_read_lock().
* Writers use virtqueue mutex. */
void *private_data;
/* Log write descriptors */
@@ -110,6 +124,9 @@ struct vhost_dev {
int nvqs;
struct file *log_file;
struct eventfd_ctx *log_ctx;
+ spinlock_t work_lock;
+ struct list_head work_list;
+ struct task_struct *worker;
};
long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
@@ -124,21 +141,22 @@ int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num);
-void vhost_discard_vq_desc(struct vhost_virtqueue *);
+void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
-void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
+int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
+ unsigned count);
void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
- unsigned int head, int len);
+ unsigned int id, int len);
+void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
+ struct vring_used_elem *heads, unsigned count);
+void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
void vhost_disable_notify(struct vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_virtqueue *);
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
unsigned int log_num, u64 len);
-int vhost_init(void);
-void vhost_cleanup(void);
-
#define vq_err(vq, fmt, ...) do { \
pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
if ((vq)->error_ctx) \
@@ -149,7 +167,8 @@ enum {
VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) |
(1 << VIRTIO_RING_F_INDIRECT_DESC) |
(1 << VHOST_F_LOG_ALL) |
- (1 << VHOST_NET_F_VIRTIO_NET_HDR),
+ (1 << VHOST_NET_F_VIRTIO_NET_HDR) |
+ (1 << VIRTIO_NET_F_MRG_RXBUF),
};
static inline int vhost_has_feature(struct vhost_dev *dev, int bit)