[PATCH 4/9] vhost: allow vhost_polls to use different vhost_workers

Mike Christie
Tue, 25 May 2021 18:05:55 -0000

This allows vhost_polls to use the worker the vq the poll is associated
with.

This also exports a helper vhost_vq_work_queue which is used here
internally, and will be used in the vhost-scsi patches.

Signed-off-by: Mike Christie <michael.christie at oracle.com>
---
 drivers/vhost/net.c   |  6 ++++--
 drivers/vhost/vhost.c | 19 ++++++++++++++++---
 drivers/vhost/vhost.h |  6 +++++-
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index df82b124170e..948bc3d361ab 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1334,8 +1334,10 @@ static int vhost_net_open(struct inode *inode, struct
file *f)
 		       VHOST_NET_PKT_WEIGHT, VHOST_NET_WEIGHT, true,
 		       NULL);

-	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev);
-	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev);
+	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev,
+			vqs[VHOST_NET_VQ_TX]);
+	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev,
+			vqs[VHOST_NET_VQ_RX]);

 	f->private_data = n;
 	n->page_frag.page = NULL;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 4bfa9a7a51bb..3cc1196d465b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -187,13 +187,15 @@ EXPORT_SYMBOL_GPL(vhost_work_init);

 /* Init poll structure */
 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
-		     __poll_t mask, struct vhost_dev *dev)
+		     __poll_t mask, struct vhost_dev *dev,
+		     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->wqh = NULL;
+	poll->vq = vq;

 	vhost_work_init(&poll->work, fn);
 }
@@ -298,9 +300,15 @@ bool vhost_has_work(struct vhost_dev *dev)
 }
 EXPORT_SYMBOL_GPL(vhost_has_work);

+void vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work)
+{
+	vhost_work_queue_on(work, vq->worker);
+}
+EXPORT_SYMBOL_GPL(vhost_vq_work_queue);
+
 void vhost_poll_queue(struct vhost_poll *poll)
 {
-	vhost_work_queue(poll->dev, &poll->work);
+	vhost_vq_work_queue(poll->vq, &poll->work);
 }
 EXPORT_SYMBOL_GPL(vhost_poll_queue);

@@ -359,6 +367,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->busyloop_timeout = 0;
 	vq->umem = NULL;
 	vq->iotlb = NULL;
+	vq->worker = NULL;
 	vhost_vring_call_reset(&vq->call_ctx);
 	__vhost_vq_meta_reset(vq);
 }
@@ -527,7 +536,7 @@ void vhost_dev_init(struct vhost_dev *dev,
 		vhost_vq_reset(dev, vq);
 		if (vq->handle_kick)
 			vhost_poll_init(&vq->poll, vq->handle_kick,
-					EPOLLIN, dev);
+					EPOLLIN, dev, vq);
 	}
 }
 EXPORT_SYMBOL_GPL(vhost_dev_init);
@@ -662,6 +671,7 @@ static struct vhost_worker *vhost_worker_create(struct
vhost_dev *dev)
 static int vhost_worker_try_create_def(struct vhost_dev *dev)
 {
 	struct vhost_worker *worker;
+	int i;

 	if (!dev->use_worker || dev->workers)
 		return 0;
@@ -674,6 +684,9 @@ static int vhost_worker_try_create_def(struct vhost_dev
*dev)
 	if (!worker)
 		goto free_workers;

+	for (i = 0; i < dev->nvqs; i++)
+		dev->vqs[i]->worker = worker;
+
 	dev->workers[worker->id] = worker;
 	dev->num_workers++;
 	return 0;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index fa1af4106755..6880e7a29872 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -41,14 +41,17 @@ struct vhost_poll {
 	struct vhost_work	work;
 	__poll_t		mask;
 	struct vhost_dev	*dev;
+	struct vhost_virtqueue	*vq;
 };

 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
 bool vhost_has_work(struct vhost_dev *dev);
+void vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);

 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
-		     __poll_t mask, struct vhost_dev *dev);
+		     __poll_t mask, struct vhost_dev *dev,
+		     struct vhost_virtqueue *vq);
 int 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);
@@ -76,6 +79,7 @@ struct vhost_vring_call {
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;
+	struct vhost_worker *worker;

 	/* The actual ring of buffers. */
 	struct mutex mutex;
--
2.25.1