vhost: introduce vhost_vring_call

This commit introduces struct vhost_vring_call which replaced
raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue.
Besides eventfd_ctx, it contains a spin lock and an
irq_bypass_producer in its structure.

Signed-off-by: Zhu Lingshan <[email protected]>
Suggested-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index c8e96a09..38eb1aa 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -13,6 +13,7 @@
 #include <linux/virtio_ring.h>
 #include <linux/atomic.h>
 #include <linux/vhost_iotlb.h>
+#include <linux/irqbypass.h>
 
 struct vhost_work;
 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
@@ -60,6 +61,12 @@ enum vhost_uaddr_type {
 	VHOST_NUM_ADDRS = 3,
 };
 
+struct vhost_vring_call {
+	struct eventfd_ctx *ctx;
+	struct irq_bypass_producer producer;
+	spinlock_t ctx_lock;
+};
+
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;
@@ -72,7 +79,7 @@ struct vhost_virtqueue {
 	vring_used_t __user *used;
 	const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
 	struct file *kick;
-	struct eventfd_ctx *call_ctx;
+	struct vhost_vring_call call_ctx;
 	struct eventfd_ctx *error_ctx;
 	struct eventfd_ctx *log_ctx;