Commit 1cdaafa1 authored by Mike Christie's avatar Mike Christie Committed by Michael S. Tsirkin
Browse files

vhost: replace single worker pointer with xarray 



The next patch allows userspace to create multiple workers per device,
so this patch replaces the vhost_worker pointer with an xarray so we
can store mupltiple workers and look them up.

Signed-off-by: default avatarMike Christie <michael.christie@oracle.com>
Message-Id: <20230626232307.97930-15-michael.christie@oracle.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent cef25866

drivers/vhost/vhost.c

+48 −16
Original line number Diff line number Diff line
@@ -280,7 +280,11 @@ EXPORT_SYMBOL_GPL(vhost_vq_flush); 


void vhost_dev_flush(struct vhost_dev *dev)

{

	vhost_worker_flush(dev->worker);

	struct vhost_worker *worker;

	unsigned long i;



	xa_for_each(&dev->worker_xa, i, worker)

		vhost_worker_flush(worker);

}

EXPORT_SYMBOL_GPL(vhost_dev_flush);
@@ -482,7 +486,6 @@ void vhost_dev_init(struct vhost_dev *dev, 
	dev->umem = NULL;

	dev->iotlb = NULL;

	dev->mm = NULL;

	dev->worker = NULL;

	dev->iov_limit = iov_limit;

	dev->weight = weight;

	dev->byte_weight = byte_weight;
@@ -492,7 +495,7 @@ void vhost_dev_init(struct vhost_dev *dev, 
	INIT_LIST_HEAD(&dev->read_list);

	INIT_LIST_HEAD(&dev->pending_list);

	spin_lock_init(&dev->iotlb_lock);



	xa_init_flags(&dev->worker_xa, XA_FLAGS_ALLOC);



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

		vq = dev->vqs[i];
@@ -554,15 +557,35 @@ static void vhost_detach_mm(struct vhost_dev *dev) 
	dev->mm = NULL;

}



static void vhost_worker_free(struct vhost_dev *dev)

static void vhost_worker_destroy(struct vhost_dev *dev,

				 struct vhost_worker *worker)

{

	if (!dev->worker)

	if (!worker)

		return;



	WARN_ON(!llist_empty(&dev->worker->work_list));

	vhost_task_stop(dev->worker->vtsk);

	kfree(dev->worker);

	dev->worker = NULL;

	WARN_ON(!llist_empty(&worker->work_list));

	xa_erase(&dev->worker_xa, worker->id);

	vhost_task_stop(worker->vtsk);

	kfree(worker);

}



static void vhost_workers_free(struct vhost_dev *dev)

{

	struct vhost_worker *worker;

	unsigned long i;



	if (!dev->use_worker)

		return;



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

		dev->vqs[i]->worker = NULL;

	/*

	 * Free the default worker we created and cleanup workers userspace

	 * created but couldn't clean up (it forgot or crashed).

	 */

	xa_for_each(&dev->worker_xa, i, worker)

		vhost_worker_destroy(dev, worker);

	xa_destroy(&dev->worker_xa);

}



static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev)
@@ -570,6 +593,8 @@ static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) 
	struct vhost_worker *worker;

	struct vhost_task *vtsk;

	char name[TASK_COMM_LEN];

	int ret;

	u32 id;



	worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT);

	if (!worker)
@@ -584,16 +609,18 @@ static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) 
	init_llist_head(&worker->work_list);

	worker->kcov_handle = kcov_common_handle();

	worker->vtsk = vtsk;

	/*

	 * vsock can already try to queue so make sure llist and vtsk are both

	 * set before vhost_work_queue sees dev->worker is set.

	 */

	smp_wmb();

	dev->worker = worker;



	vhost_task_start(vtsk);



	ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL);

	if (ret < 0)

		goto stop_worker;

	worker->id = id;



	return worker;



stop_worker:

	vhost_task_stop(vtsk);

free_worker:

	kfree(worker);

	return NULL;
@@ -650,6 +677,11 @@ long vhost_dev_set_owner(struct vhost_dev *dev) 
			err = -ENOMEM;

			goto err_worker;

		}

		/*

		 * vsock can already try to queue so make sure the worker

		 * is setup before vhost_vq_work_queue sees vq->worker is set.

		 */

		smp_wmb();



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

			dev->vqs[i]->worker = worker;
@@ -751,7 +783,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) 
	dev->iotlb = NULL;

	vhost_clear_msg(dev);

	wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM);

	vhost_worker_free(dev);

	vhost_workers_free(dev);

	vhost_detach_mm(dev);

}

EXPORT_SYMBOL_GPL(vhost_dev_cleanup);

drivers/vhost/vhost.h

+2 −1
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ struct vhost_worker { 
	struct vhost_task	*vtsk;

	struct llist_head	work_list;

	u64			kcov_handle;

	u32			id;

};



/* Poll a file (eventfd or socket) */
@@ -159,7 +160,6 @@ struct vhost_dev { 
	struct vhost_virtqueue **vqs;

	int nvqs;

	struct eventfd_ctx *log_ctx;

	struct vhost_worker *worker;

	struct vhost_iotlb *umem;

	struct vhost_iotlb *iotlb;

	spinlock_t iotlb_lock;
@@ -169,6 +169,7 @@ struct vhost_dev { 
	int iov_limit;

	int weight;

	int byte_weight;

	struct xarray worker_xa;

	bool use_worker;

	int (*msg_handler)(struct vhost_dev *dev, u32 asid,

			   struct vhost_iotlb_msg *msg);