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Commit ea16c514 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

vhost: move acked_features to VQs 



Refactor code to make sure features are only accessed
under VQ mutex. This makes everything simpler, no need
for RCU here anymore.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 98f9ca0a

drivers/vhost/net.c

+3 −5
Original line number Diff line number Diff line
@@ -585,9 +585,9 @@ static void handle_rx(struct vhost_net *net) 
	vhost_hlen = nvq->vhost_hlen;

	sock_hlen = nvq->sock_hlen;



	vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?

	vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?

		vq->log : NULL;

	mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);

	mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);



	while ((sock_len = peek_head_len(sock->sk))) {

		sock_len += sock_hlen;
@@ -1051,15 +1051,13 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features) 
		mutex_unlock(&n->dev.mutex);

		return -EFAULT;

	}

	n->dev.acked_features = features;

	smp_wmb();

	for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {

		mutex_lock(&n->vqs[i].vq.mutex);

		n->vqs[i].vq.acked_features = features;

		n->vqs[i].vhost_hlen = vhost_hlen;

		n->vqs[i].sock_hlen = sock_hlen;

		mutex_unlock(&n->vqs[i].vq.mutex);

	}

	vhost_net_flush(n);

	mutex_unlock(&n->dev.mutex);

	return 0;

}

drivers/vhost/scsi.c

+13 −9
Original line number Diff line number Diff line
@@ -1373,6 +1373,9 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs, 


static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)

{

	struct vhost_virtqueue *vq;

	int i;



	if (features & ~VHOST_SCSI_FEATURES)

		return -EOPNOTSUPP;
@@ -1382,9 +1385,13 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features) 
		mutex_unlock(&vs->dev.mutex);

		return -EFAULT;

	}

	vs->dev.acked_features = features;

	smp_wmb();

	vhost_scsi_flush(vs);



	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {

		vq = &vs->vqs[i].vq;

		mutex_lock(&vq->mutex);

		vq->acked_features = features;

		mutex_unlock(&vq->mutex);

	}

	mutex_unlock(&vs->dev.mutex);

	return 0;

}
@@ -1591,10 +1598,6 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg, 
		return;



	mutex_lock(&vs->dev.mutex);

	if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {

		mutex_unlock(&vs->dev.mutex);

		return;

	}



	if (plug)

		reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
@@ -1603,6 +1606,7 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg, 


	vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;

	mutex_lock(&vq->mutex);

	if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))

		tcm_vhost_send_evt(vs, tpg, lun,

				   VIRTIO_SCSI_T_TRANSPORT_RESET, reason);

	mutex_unlock(&vq->mutex);

drivers/vhost/test.c

+6 −3
Original line number Diff line number Diff line
@@ -241,15 +241,18 @@ static long vhost_test_reset_owner(struct vhost_test *n) 


static int vhost_test_set_features(struct vhost_test *n, u64 features)

{

	struct vhost_virtqueue *vq;



	mutex_lock(&n->dev.mutex);

	if ((features & (1 << VHOST_F_LOG_ALL)) &&

	    !vhost_log_access_ok(&n->dev)) {

		mutex_unlock(&n->dev.mutex);

		return -EFAULT;

	}

	n->dev.acked_features = features;

	smp_wmb();

	vhost_test_flush(n);

	vq = &n->vqs[VHOST_TEST_VQ];

	mutex_lock(&vq->mutex);

	vq->acked_features = features;

	mutex_unlock(&vq->mutex);

	mutex_unlock(&n->dev.mutex);

	return 0;

}

drivers/vhost/vhost.c

+19 −17
Original line number Diff line number Diff line
@@ -191,6 +191,7 @@ static void vhost_vq_reset(struct vhost_dev *dev, 
	vq->log_used = false;

	vq->log_addr = -1ull;

	vq->private_data = NULL;

	vq->acked_features = 0;

	vq->log_base = NULL;

	vq->error_ctx = NULL;

	vq->error = NULL;
@@ -524,11 +525,13 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, 


	for (i = 0; i < d->nvqs; ++i) {

		int ok;

		bool log;



		mutex_lock(&d->vqs[i]->mutex);

		log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL);

		/* If ring is inactive, will check when it's enabled. */

		if (d->vqs[i]->private_data)

			ok = vq_memory_access_ok(d->vqs[i]->log_base, mem,

						 log_all);

			ok = vq_memory_access_ok(d->vqs[i]->log_base, mem, log);

		else

			ok = 1;

		mutex_unlock(&d->vqs[i]->mutex);
@@ -538,12 +541,12 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, 
	return 1;

}



static int vq_access_ok(struct vhost_dev *d, unsigned int num,

static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,

			struct vring_desc __user *desc,

			struct vring_avail __user *avail,

			struct vring_used __user *used)

{

	size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;

	size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;

	return access_ok(VERIFY_READ, desc, num * sizeof *desc) &&

	       access_ok(VERIFY_READ, avail,

			 sizeof *avail + num * sizeof *avail->ring + s) &&
@@ -565,16 +568,16 @@ EXPORT_SYMBOL_GPL(vhost_log_access_ok); 


/* Verify access for write logging. */

/* Caller should have vq mutex and device mutex */

static int vq_log_access_ok(struct vhost_dev *d, struct vhost_virtqueue *vq,

static int vq_log_access_ok(struct vhost_virtqueue *vq,

			    void __user *log_base)

{

	struct vhost_memory *mp;

	size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;

	size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;



	mp = rcu_dereference_protected(vq->dev->memory,

				       lockdep_is_held(&vq->mutex));

	return vq_memory_access_ok(log_base, mp,

			    vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) &&

				   vhost_has_feature(vq, VHOST_F_LOG_ALL)) &&

		(!vq->log_used || log_access_ok(log_base, vq->log_addr,

					sizeof *vq->used +

					vq->num * sizeof *vq->used->ring + s));
@@ -584,8 +587,8 @@ static int vq_log_access_ok(struct vhost_dev *d, struct vhost_virtqueue *vq, 
/* Caller should have vq mutex and device mutex */

int vhost_vq_access_ok(struct vhost_virtqueue *vq)

{

	return vq_access_ok(vq->dev, vq->num, vq->desc, vq->avail, vq->used) &&

		vq_log_access_ok(vq->dev, vq, vq->log_base);

	return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) &&

		vq_log_access_ok(vq, vq->log_base);

}

EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
@@ -612,8 +615,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) 
		return -EFAULT;

	}



	if (!memory_access_ok(d, newmem,

			      vhost_has_feature(d, VHOST_F_LOG_ALL))) {

	if (!memory_access_ok(d, newmem, 0)) {

		kfree(newmem);

		return -EFAULT;

	}
@@ -726,7 +728,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) 
		 * If it is not, we don't as size might not have been setup.

		 * We will verify when backend is configured. */

		if (vq->private_data) {

			if (!vq_access_ok(d, vq->num,

			if (!vq_access_ok(vq, vq->num,

				(void __user *)(unsigned long)a.desc_user_addr,

				(void __user *)(unsigned long)a.avail_user_addr,

				(void __user *)(unsigned long)a.used_user_addr)) {
@@ -866,7 +868,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) 
			vq = d->vqs[i];

			mutex_lock(&vq->mutex);

			/* If ring is inactive, will check when it's enabled. */

			if (vq->private_data && !vq_log_access_ok(d, vq, base))

			if (vq->private_data && !vq_log_access_ok(vq, base))

				r = -EFAULT;

			else

				vq->log_base = base;
@@ -1434,11 +1436,11 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	 * interrupts. */

	smp_mb();



	if (vhost_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&

	if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) &&

	    unlikely(vq->avail_idx == vq->last_avail_idx))

		return true;



	if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {

	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {

		__u16 flags;

		if (__get_user(flags, &vq->avail->flags)) {

			vq_err(vq, "Failed to get flags");
@@ -1499,7 +1501,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))

		return false;

	vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;

	if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {

	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {

		r = vhost_update_used_flags(vq);

		if (r) {

			vq_err(vq, "Failed to enable notification at %p: %d\n",
@@ -1536,7 +1538,7 @@ void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) 
	if (vq->used_flags & VRING_USED_F_NO_NOTIFY)

		return;

	vq->used_flags |= VRING_USED_F_NO_NOTIFY;

	if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {

	if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {

		r = vhost_update_used_flags(vq);

		if (r)

			vq_err(vq, "Failed to enable notification at %p: %d\n",

drivers/vhost/vhost.h

+3 −8
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ struct vhost_virtqueue { 
	struct vring_used_elem *heads;

	/* Protected by virtqueue mutex. */

	void *private_data;

	unsigned acked_features;

	/* Log write descriptors */

	void __user *log_base;

	struct vhost_log *log;
@@ -117,7 +118,6 @@ struct vhost_dev { 
	struct vhost_memory __rcu *memory;

	struct mm_struct *mm;

	struct mutex mutex;

	unsigned acked_features;

	struct vhost_virtqueue **vqs;

	int nvqs;

	struct file *log_file;
@@ -174,13 +174,8 @@ enum { 
			 (1ULL << VHOST_F_LOG_ALL),

};



static inline int vhost_has_feature(struct vhost_dev *dev, int bit)

static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)

{

	unsigned acked_features;



	/* TODO: check that we are running from vhost_worker or dev mutex is

	 * held? */

	acked_features = rcu_dereference_index_check(dev->acked_features, 1);

	return acked_features & (1 << bit);

	return vq->acked_features & (1 << bit);

}

#endif