vhost_net_open is changed to allocate a vhost_net and return.
The remaining initializations are delayed till SET_OWNER.
SET_OWNER is changed so that the argument is used to determine
how many txqs to use. Unmodified qemu's will pass NULL, so
this is recognized and handled as numtxqs=1.
The number of vhost threads is <= #txqs. Threads handle more
than one txq when #txqs is more than MAX_VHOST_THREADS (4).
The same thread handles both RX and TX - tested with tap/bridge
so far (TBD: some changes are needed in macvtap to support the
same).
Signed-off-by: Krishna Kumar <krkumar2@xxxxxxxxxx>
---
drivers/vhost/net.c | 249 +++++++++++++++++++++++++---------------
drivers/vhost/vhost.c | 221 ++++++++++++++++++++++++-----------
drivers/vhost/vhost.h | 22 ++-
3 files changed, 332 insertions(+), 160 deletions(-)
diff -ruNp org/drivers/vhost/net.c new/drivers/vhost/net.c
--- org/drivers/vhost/net.c 2011-04-05 14:15:18.000000000 +0530
+++ new/drivers/vhost/net.c 2011-04-05 20:15:32.000000000 +0530
@@ -32,12 +32,6 @@
* Using this limit prevents one virtqueue from starving others. */
#define VHOST_NET_WEIGHT 0x80000
-enum {
- VHOST_NET_VQ_RX = 0,
- VHOST_NET_VQ_TX = 1,
- VHOST_NET_VQ_MAX = 2,
-};
-
enum vhost_net_poll_state {
VHOST_NET_POLL_DISABLED = 0,
VHOST_NET_POLL_STARTED = 1,
@@ -46,12 +40,13 @@ enum vhost_net_poll_state {
struct vhost_net {
struct vhost_dev dev;
- struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
- struct vhost_poll poll[VHOST_NET_VQ_MAX];
+ struct vhost_virtqueue *vqs;
+ struct vhost_poll *poll;
+ struct socket **socks;
/* Tells us whether we are polling a socket for TX.
* We only do this when socket buffer fills up.
* Protected by tx vq lock. */
- enum vhost_net_poll_state tx_poll_state;
+ enum vhost_net_poll_state *tx_poll_state;
};
/* Pop first len bytes from iovec. Return number of segments used. */
@@ -93,28 +88,28 @@ static void copy_iovec_hdr(const struct
}
/* Caller must have TX VQ lock */
-static void tx_poll_stop(struct vhost_net *net)
+static void tx_poll_stop(struct vhost_net *net, int qnum)
{
- if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
+ if (likely(net->tx_poll_state[qnum / 2] != VHOST_NET_POLL_STARTED))
return;
- vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
- net->tx_poll_state = VHOST_NET_POLL_STOPPED;
+ vhost_poll_stop(&net->poll[qnum]);
+ net->tx_poll_state[qnum / 2] = VHOST_NET_POLL_STOPPED;
}
/* Caller must have TX VQ lock */
-static void tx_poll_start(struct vhost_net *net, struct socket *sock)
+static void tx_poll_start(struct vhost_net *net, struct socket *sock, int qnum)
{
- if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
+ if (unlikely(net->tx_poll_state[qnum / 2] != VHOST_NET_POLL_STOPPED))
return;
- vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
- net->tx_poll_state = VHOST_NET_POLL_STARTED;
+ vhost_poll_start(&net->poll[qnum], sock->file);
+ net->tx_poll_state[qnum / 2] = VHOST_NET_POLL_STARTED;
}
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
-static void handle_tx(struct vhost_net *net)
+static void handle_tx(struct vhost_virtqueue *vq)
{
- struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
+ struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
unsigned out, in, s;
int head;
struct msghdr msg = {
@@ -138,7 +133,7 @@ static void handle_tx(struct vhost_net *
wmem = atomic_read(&sock->sk->sk_wmem_alloc);
if (wmem >= sock->sk->sk_sndbuf) {
mutex_lock(&vq->mutex);
- tx_poll_start(net, sock);
+ tx_poll_start(net, sock, vq->qnum);
mutex_unlock(&vq->mutex);
return;
}
@@ -147,7 +142,7 @@ static void handle_tx(struct vhost_net *
vhost_disable_notify(vq);
if (wmem < sock->sk->sk_sndbuf / 2)
- tx_poll_stop(net);
+ tx_poll_stop(net, vq->qnum);
hdr_size = vq->vhost_hlen;
for (;;) {
@@ -162,7 +157,7 @@ static void handle_tx(struct vhost_net *
if (head == vq->num) {
wmem = atomic_read(&sock->sk->sk_wmem_alloc);
if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
- tx_poll_start(net, sock);
+ tx_poll_start(net, sock, vq->qnum);
set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
break;
}
@@ -192,7 +187,7 @@ static void handle_tx(struct vhost_net *
err = sock->ops->sendmsg(NULL, sock, &msg, len);
if (unlikely(err < 0)) {
vhost_discard_vq_desc(vq, 1);
- tx_poll_start(net, sock);
+ tx_poll_start(net, sock, vq->qnum);
break;
}
if (err != len)
@@ -287,9 +282,9 @@ err:
/* 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(struct vhost_virtqueue *vq)
{
- struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+ struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
unsigned uninitialized_var(in), log;
struct vhost_log *vq_log;
struct msghdr msg = {
@@ -398,87 +393,155 @@ static void handle_tx_kick(struct vhost_
{
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);
+ handle_tx(vq);
}
static void handle_rx_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_rx(net);
+ handle_rx(vq);
}
static void handle_tx_net(struct vhost_work *work)
{
- struct vhost_net *net = container_of(work, struct vhost_net,
- poll[VHOST_NET_VQ_TX].work);
- handle_tx(net);
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_poll,
+ work)->vq;
+
+ handle_tx(vq);
}
static void handle_rx_net(struct vhost_work *work)
{
- struct vhost_net *net = container_of(work, struct vhost_net,
- poll[VHOST_NET_VQ_RX].work);
- handle_rx(net);
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_poll,
+ work)->vq;
+
+ handle_rx(vq);
}
-static int vhost_net_open(struct inode *inode, struct file *f)
+void vhost_free_vqs(struct vhost_dev *dev)
{
- struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
- struct vhost_dev *dev;
- int r;
+ struct vhost_net *n = container_of(dev, struct vhost_net, dev);
- if (!n)
- return -ENOMEM;
+ if (!n->vqs)
+ return;
- 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(dev, n->vqs, VHOST_NET_VQ_MAX);
- if (r < 0) {
- kfree(n);
- return r;
+ kfree(n->socks);
+ kfree(n->tx_poll_state);
+ kfree(n->poll);
+ kfree(n->vqs);
+
+ /*
+ * Reset so that vhost_net_release (which gets called when
+ * vhost_dev_set_owner() call fails) will notice.
+ */
+ n->vqs = NULL;
+}
+
+int vhost_setup_vqs(struct vhost_dev *dev, int numtxqs)
+{
+ struct vhost_net *n = container_of(dev, struct vhost_net, dev);
+ int i, nvqs;
+ int ret = -ENOMEM;
+
+ if (numtxqs < 0)
+ return -EINVAL;
+
+ if (numtxqs == 0) {
+ /* Old qemu doesn't pass arguments to set_owner, use 1 txq */
+ numtxqs = 1;
+ }
+
+ /* Get total number of virtqueues */
+ nvqs = numtxqs * 2;
+
+ n->vqs = kmalloc(nvqs * sizeof(*n->vqs), GFP_KERNEL);
+ n->poll = kmalloc(nvqs * sizeof(*n->poll), GFP_KERNEL);
+ n->socks = kmalloc(nvqs * sizeof(*n->socks), GFP_KERNEL);
+ n->tx_poll_state = kmalloc(numtxqs * sizeof(*n->tx_poll_state),
+ GFP_KERNEL);
+ if (!n->vqs || !n->poll || !n->socks || !n->tx_poll_state)
+ goto err;
+
+ /* RX followed by TX queues */
+ for (i = 0; i < nvqs; i += 2) {
+ n->vqs[i].handle_kick = handle_rx_kick;
+ n->vqs[i + 1].handle_kick = handle_tx_kick;
}
- 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;
+ ret = vhost_dev_init(dev, n->vqs, nvqs);
+ if (ret < 0)
+ goto err;
- f->private_data = n;
+ for (i = 0; i < nvqs; i += 2) {
+ vhost_poll_init(&n->poll[i], handle_rx_net, POLLIN,
+ &n->vqs[i]);
+ vhost_poll_init(&n->poll[i+1], handle_tx_net, POLLOUT,
+ &n->vqs[i+1]);
+ if (i / 2 < numtxqs)
+ n->tx_poll_state[i/2] = VHOST_NET_POLL_DISABLED;
+ }
return 0;
+
+err:
+ /* Free all pointers that may have been allocated */
+ vhost_free_vqs(dev);
+
+ return ret;
+}
+
+static int vhost_net_open(struct inode *inode, struct file *f)
+{
+ struct vhost_net *n = kzalloc(sizeof *n, GFP_KERNEL);
+ int ret = -ENOMEM;
+
+ if (n) {
+ struct vhost_dev *dev = &n->dev;
+
+ f->private_data = n;
+ mutex_init(&dev->mutex);
+
+ /* Defer all other initialization till user does SET_OWNER */
+ ret = 0;
+ }
+
+ return ret;
}
static void vhost_net_disable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
+ int qnum = vq->qnum;
+
if (!vq->private_data)
return;
- if (vq == n->vqs + VHOST_NET_VQ_TX) {
- tx_poll_stop(n);
- n->tx_poll_state = VHOST_NET_POLL_DISABLED;
- } else
- vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
+ if (qnum & 1) { /* Odd qnum -> TX */
+ tx_poll_stop(n, qnum);
+ n->tx_poll_state[qnum / 2] = VHOST_NET_POLL_DISABLED;
+ } else { /* Even qnum -> RX */
+ vhost_poll_stop(&n->poll[qnum]);
+ }
}
static void vhost_net_enable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
struct socket *sock;
+ int qnum = vq->qnum;
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (!sock)
return;
- if (vq == n->vqs + VHOST_NET_VQ_TX) {
- n->tx_poll_state = VHOST_NET_POLL_STOPPED;
- tx_poll_start(n, sock);
- } else
- vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
+ if (qnum & 1) { /* Odd qnum -> TX */
+ n->tx_poll_state[qnum / 2] = VHOST_NET_POLL_STOPPED;
+ tx_poll_start(n, sock, qnum);
+ } else { /* Even qnum -> RX */
+ vhost_poll_start(&n->poll[qnum], sock->file);
+ }
}
static struct socket *vhost_net_stop_vq(struct vhost_net *n,
@@ -495,11 +558,12 @@ static struct socket *vhost_net_stop_vq(
return sock;
}
-static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
- struct socket **rx_sock)
+static void vhost_net_stop(struct vhost_net *n)
{
- *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
- *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
+ int i;
+
+ for (i = 0; i < n->dev.nvqs; i++)
+ n->socks[i] = vhost_net_stop_vq(n, &n->vqs[i]);
}
static void vhost_net_flush_vq(struct vhost_net *n, int index)
@@ -510,26 +574,33 @@ static void vhost_net_flush_vq(struct vh
static void vhost_net_flush(struct vhost_net *n)
{
- vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
- vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
+ int i;
+
+ for (i = 0; i < n->dev.nvqs; i++)
+ vhost_net_flush_vq(n, i);
}
static int vhost_net_release(struct inode *inode, struct file *f)
{
struct vhost_net *n = f->private_data;
- struct socket *tx_sock;
- struct socket *rx_sock;
+ struct vhost_dev *dev = &n->dev;
+ int i;
- vhost_net_stop(n, &tx_sock, &rx_sock);
+ vhost_net_stop(n);
vhost_net_flush(n);
- vhost_dev_cleanup(&n->dev);
- if (tx_sock)
- fput(tx_sock->file);
- if (rx_sock)
- fput(rx_sock->file);
+ vhost_dev_cleanup(dev);
+
+ for (i = 0; i < n->dev.nvqs; i++)
+ if (n->socks[i])
+ fput(n->socks[i]->file);
+
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
+
+ /* Free all old pointers */
+ vhost_free_vqs(dev);
+
kfree(n);
return 0;
}
@@ -610,7 +681,7 @@ static long vhost_net_set_backend(struct
if (r)
goto err;
- if (index >= VHOST_NET_VQ_MAX) {
+ if (index >= n->dev.nvqs) {
r = -ENOBUFS;
goto err;
}
@@ -656,23 +727,25 @@ err:
static long vhost_net_reset_owner(struct vhost_net *n)
{
- struct socket *tx_sock = NULL;
- struct socket *rx_sock = NULL;
long err;
+ int i;
mutex_lock(&n->dev.mutex);
err = vhost_dev_check_owner(&n->dev);
- if (err)
- goto done;
- vhost_net_stop(n, &tx_sock, &rx_sock);
+ if (err) {
+ mutex_unlock(&n->dev.mutex);
+ return err;
+ }
+
+ vhost_net_stop(n);
vhost_net_flush(n);
err = vhost_dev_reset_owner(&n->dev);
-done:
mutex_unlock(&n->dev.mutex);
- if (tx_sock)
- fput(tx_sock->file);
- if (rx_sock)
- fput(rx_sock->file);
+
+ for (i = 0; i < n->dev.nvqs; i++)
+ if (n->socks[i])
+ fput(n->socks[i]->file);
+
return err;
}
@@ -701,7 +774,7 @@ static int vhost_net_set_features(struct
}
n->dev.acked_features = features;
smp_wmb();
- for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
+ for (i = 0; i < n->dev.nvqs; ++i) {
mutex_lock(&n->vqs[i].mutex);
n->vqs[i].vhost_hlen = vhost_hlen;
n->vqs[i].sock_hlen = sock_hlen;
diff -ruNp org/drivers/vhost/vhost.c new/drivers/vhost/vhost.c
--- org/drivers/vhost/vhost.c 2011-04-05 14:15:18.000000000 +0530
+++ new/drivers/vhost/vhost.c 2011-04-05 20:06:11.000000000 +0530
@@ -70,12 +70,12 @@ static void vhost_work_init(struct vhost
/* Init poll structure */
void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
- unsigned long mask, struct vhost_dev *dev)
+ unsigned long mask, struct vhost_virtqueue *vq)
{
init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
init_poll_funcptr(&poll->table, vhost_poll_func);
poll->mask = mask;
- poll->dev = dev;
+ poll->vq = vq;
vhost_work_init(&poll->work, fn);
}
@@ -98,30 +98,31 @@ void vhost_poll_stop(struct vhost_poll *
remove_wait_queue(poll->wqh, &poll->wait);
}
-static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work,
- unsigned seq)
+static bool vhost_work_seq_done(struct vhost_virtqueue *vq,
+ struct vhost_work *work, unsigned seq)
{
int left;
- spin_lock_irq(&dev->work_lock);
+ spin_lock_irq(vq->work_lock);
left = seq - work->done_seq;
- spin_unlock_irq(&dev->work_lock);
+ spin_unlock_irq(vq->work_lock);
return left <= 0;
}
-static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
+static void vhost_work_flush(struct vhost_virtqueue *vq,
+ struct vhost_work *work)
{
unsigned seq;
int flushing;
- spin_lock_irq(&dev->work_lock);
+ spin_lock_irq(vq->work_lock);
seq = work->queue_seq;
work->flushing++;
- spin_unlock_irq(&dev->work_lock);
- wait_event(work->done, vhost_work_seq_done(dev, work, seq));
- spin_lock_irq(&dev->work_lock);
+ spin_unlock_irq(vq->work_lock);
+ wait_event(work->done, vhost_work_seq_done(vq, work, seq));
+ spin_lock_irq(vq->work_lock);
flushing = --work->flushing;
- spin_unlock_irq(&dev->work_lock);
+ spin_unlock_irq(vq->work_lock);
BUG_ON(flushing < 0);
}
@@ -129,26 +130,26 @@ static void vhost_work_flush(struct vhos
* locks that are also used by the callback. */
void vhost_poll_flush(struct vhost_poll *poll)
{
- vhost_work_flush(poll->dev, &poll->work);
+ vhost_work_flush(poll->vq, &poll->work);
}
-static inline void vhost_work_queue(struct vhost_dev *dev,
+static inline void vhost_work_queue(struct vhost_virtqueue *vq,
struct vhost_work *work)
{
unsigned long flags;
- spin_lock_irqsave(&dev->work_lock, flags);
+ spin_lock_irqsave(vq->work_lock, flags);
if (list_empty(&work->node)) {
- list_add_tail(&work->node, &dev->work_list);
+ list_add_tail(&work->node, vq->work_list);
work->queue_seq++;
- wake_up_process(dev->worker);
+ wake_up_process(vq->worker);
}
- spin_unlock_irqrestore(&dev->work_lock, flags);
+ spin_unlock_irqrestore(vq->work_lock, flags);
}
void vhost_poll_queue(struct vhost_poll *poll)
{
- vhost_work_queue(poll->dev, &poll->work);
+ vhost_work_queue(poll->vq, &poll->work);
}
static void vhost_vq_reset(struct vhost_dev *dev,
@@ -178,17 +179,17 @@ static void vhost_vq_reset(struct vhost_
static int vhost_worker(void *data)
{
- struct vhost_dev *dev = data;
+ struct vhost_virtqueue *vq = data;
struct vhost_work *work = NULL;
unsigned uninitialized_var(seq);
- use_mm(dev->mm);
+ use_mm(vq->dev->mm);
for (;;) {
/* mb paired w/ kthread_stop */
set_current_state(TASK_INTERRUPTIBLE);
- spin_lock_irq(&dev->work_lock);
+ spin_lock_irq(vq->work_lock);
if (work) {
work->done_seq = seq;
if (work->flushing)
@@ -196,18 +197,18 @@ static int vhost_worker(void *data)
}
if (kthread_should_stop()) {
- spin_unlock_irq(&dev->work_lock);
+ spin_unlock_irq(vq->work_lock);
__set_current_state(TASK_RUNNING);
break;
}
- if (!list_empty(&dev->work_list)) {
- work = list_first_entry(&dev->work_list,
+ if (!list_empty(vq->work_list)) {
+ work = list_first_entry(vq->work_list,
struct vhost_work, node);
list_del_init(&work->node);
seq = work->queue_seq;
} else
work = NULL;
- spin_unlock_irq(&dev->work_lock);
+ spin_unlock_irq(vq->work_lock);
if (work) {
__set_current_state(TASK_RUNNING);
@@ -216,7 +217,7 @@ static int vhost_worker(void *data)
schedule();
}
- unuse_mm(dev->mm);
+ unuse_mm(vq->dev->mm);
return 0;
}
@@ -262,6 +263,30 @@ static void vhost_dev_free_iovecs(struct
}
}
+/*
+ * Get index of an existing thread that will handle this rx/tx queue pair.
+ * The same thread handles both rx and tx.
+ */
+static int vhost_get_thread_index(int index)
+{
+ return (index / 2) % MAX_VHOST_THREADS;
+}
+
+/* Get index into the an earlier vq that we can share with */
+static int vhost_get_vq_index(int index)
+{
+ return vhost_get_thread_index(index) * 2;
+}
+
+/*
+ * This is needed to initialize work_list/work_lock or start a new
+ * worker thread. Since a single rx/tx is handled by a single worker,
+ */
+static int vhost_needs_init(int i, int j)
+{
+ return i == j * 2;
+}
+
long vhost_dev_init(struct vhost_dev *dev,
struct vhost_virtqueue *vqs, int nvqs)
{
@@ -274,20 +299,30 @@ long vhost_dev_init(struct vhost_dev *de
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].log = NULL;
- dev->vqs[i].indirect = NULL;
- dev->vqs[i].heads = NULL;
- dev->vqs[i].dev = dev;
- mutex_init(&dev->vqs[i].mutex);
+ struct vhost_virtqueue *vq = &dev->vqs[i];
+ int j = vhost_get_thread_index(i);
+
+ if (vhost_needs_init(i, j)) {
+ spin_lock_init(&dev->work[j].work_lock);
+ INIT_LIST_HEAD(&dev->work[j].work_list);
+ }
+
+ vq->work_lock = &dev->work[j].work_lock;
+ vq->work_list = &dev->work[j].work_list;
+
+ vq->worker = NULL;
+ vq->qnum = i;
+ vq->log = NULL;
+ vq->indirect = NULL;
+ vq->heads = NULL;
+ vq->dev = dev;
+ mutex_init(&vq->mutex);
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);
+ if (vq->handle_kick)
+ vhost_poll_init(&vq->poll,
+ vq->handle_kick, POLLIN, vq);
}
return 0;
@@ -314,21 +349,83 @@ static void vhost_attach_cgroups_work(st
s->ret = cgroup_attach_task_all(s->owner, current);
}
-static int vhost_attach_cgroups(struct vhost_dev *dev)
+static int vhost_attach_cgroups(struct vhost_virtqueue *vq)
{
struct vhost_attach_cgroups_struct attach;
attach.owner = current;
vhost_work_init(&attach.work, vhost_attach_cgroups_work);
- vhost_work_queue(dev, &attach.work);
- vhost_work_flush(dev, &attach.work);
+ vhost_work_queue(vq, &attach.work);
+ vhost_work_flush(vq, &attach.work);
return attach.ret;
}
+static void __vhost_stop_workers(struct vhost_dev *dev, int nvhosts)
+{
+ int i;
+
+ for (i = 0; i < dev->nvqs; i++) {
+ if (i < nvhosts) {
+ WARN_ON(!list_empty(dev->vqs[i * 2].work_list));
+ if (dev->vqs[i * 2].worker)
+ kthread_stop(dev->vqs[i * 2].worker);
+ }
+ dev->vqs[i].worker = NULL;
+ }
+
+ if (dev->mm)
+ mmput(dev->mm);
+ dev->mm = NULL;
+}
+
+static void vhost_stop_workers(struct vhost_dev *dev)
+{
+ int nthreads = min_t(int, dev->nvqs / 2, MAX_VHOST_THREADS);
+
+ __vhost_stop_workers(dev, nthreads);
+}
+
+static int vhost_start_workers(struct vhost_dev *dev)
+{
+ int i, err;
+
+ for (i = 0; i < dev->nvqs; ++i) {
+ struct vhost_virtqueue *vq = &dev->vqs[i];
+ int j = vhost_get_thread_index(i);
+
+ if (vhost_needs_init(i, j)) {
+ /* Start a new thread */
+ vq->worker = kthread_create(vhost_worker, vq,
+ "vhost-%d-%d",
+ current->pid, j);
+ if (IS_ERR(vq->worker)) {
+ err = PTR_ERR(vq->worker);
+ goto err;
+ }
+
+ wake_up_process(vq->worker);
+
+ /* avoid contributing to loadavg */
+ err = vhost_attach_cgroups(vq);
+ if (err)
+ goto err;
+ } else {
+ /* Share work with an existing thread */
+ int j = vhost_get_vq_index(i);
+
+ vq->worker = dev->vqs[j].worker;
+ }
+ }
+ return 0;
+
+err:
+ __vhost_stop_workers(dev, i / 2);
+ return err;
+}
+
/* Caller should have device mutex */
-static long vhost_dev_set_owner(struct vhost_dev *dev)
+static long vhost_dev_set_owner(struct vhost_dev *dev, int numtxqs)
{
- struct task_struct *worker;
int err;
/* Is there an owner already? */
@@ -337,33 +434,30 @@ static long vhost_dev_set_owner(struct v
goto err_mm;
}
+ err = vhost_setup_vqs(dev, numtxqs);
+ if (err)
+ 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;
- wake_up_process(worker); /* avoid contributing to loadavg */
- err = vhost_attach_cgroups(dev);
+ /* Start threads */
+ err = vhost_start_workers(dev);
if (err)
- goto err_cgroup;
+ goto free_vqs;
err = vhost_dev_alloc_iovecs(dev);
if (err)
- goto err_cgroup;
+ goto clean_workers;
return 0;
-err_cgroup:
- kthread_stop(worker);
- dev->worker = NULL;
-err_worker:
+clean_workers:
+ vhost_stop_workers(dev);
+free_vqs:
if (dev->mm)
mmput(dev->mm);
dev->mm = NULL;
+ vhost_free_vqs(dev);
err_mm:
return err;
}
@@ -418,14 +512,7 @@ void vhost_dev_cleanup(struct vhost_dev
kfree(rcu_dereference_protected(dev->memory,
lockdep_is_held(&dev->mutex)));
RCU_INIT_POINTER(dev->memory, NULL);
- WARN_ON(!list_empty(&dev->work_list));
- if (dev->worker) {
- kthread_stop(dev->worker);
- dev->worker = NULL;
- }
- if (dev->mm)
- mmput(dev->mm);
- dev->mm = NULL;
+ vhost_stop_workers(dev);
}
static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
@@ -790,7 +877,7 @@ long vhost_dev_ioctl(struct vhost_dev *d
/* If you are not the owner, you can become one */
if (ioctl == VHOST_SET_OWNER) {
- r = vhost_dev_set_owner(d);
+ r = vhost_dev_set_owner(d, arg);
goto done;
}
diff -ruNp org/drivers/vhost/vhost.h new/drivers/vhost/vhost.h
--- org/drivers/vhost/vhost.h 2011-04-05 14:15:18.000000000 +0530
+++ new/drivers/vhost/vhost.h 2011-04-05 14:15:18.000000000 +0530
@@ -35,11 +35,11 @@ struct vhost_poll {
wait_queue_t wait;
struct vhost_work work;
unsigned long mask;
- struct vhost_dev *dev;
+ struct vhost_virtqueue *vq; /* points back to vq */
};
void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
- unsigned long mask, struct vhost_dev *dev);
+ unsigned long mask, struct vhost_virtqueue *vq);
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);
@@ -108,8 +108,20 @@ struct vhost_virtqueue {
/* Log write descriptors */
void __user *log_base;
struct vhost_log *log;
+ struct task_struct *worker; /* worker for this vq */
+ spinlock_t *work_lock; /* points to a dev->work_lock[] entry */
+ struct list_head *work_list; /* points to a dev->work_list[] entry */
+ int qnum; /* 0 for RX, 1 for TX, and so on alternatively */
};
+/* work entry and the lock */
+struct work_lock_list {
+ spinlock_t work_lock;
+ struct list_head work_list;
+} ____cacheline_aligned_in_smp;
+
+#define MAX_VHOST_THREADS 4
+
struct vhost_dev {
/* Readers use RCU to access memory table pointer
* log base pointer and features.
@@ -122,11 +134,11 @@ 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;
+ struct work_lock_list work[MAX_VHOST_THREADS];
};
+int vhost_setup_vqs(struct vhost_dev *dev, int numtxqs);
+void vhost_free_vqs(struct vhost_dev *dev);
long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
long vhost_dev_check_owner(struct vhost_dev *);
long vhost_dev_reset_owner(struct vhost_dev *);
--
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