[RFC v4 08/11] vduse: Add config interrupt support

[Xie Yongji]

This patch introduces a new ioctl VDUSE_INJECT_CONFIG_IRQ
to support injecting config interrupt.

Signed-off-by: Xie Yongji <xieyon...@bytedance.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 24 +++++++++++++++++++++++-
 include/uapi/linux/vduse.h         |  3 +++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c 
b/drivers/vdpa/vdpa_user/vduse_dev.c
index 393bf99c48be..8042d3fa57f1 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -66,6 +66,8 @@ struct vduse_dev {
        struct list_head send_list;
        struct list_head recv_list;
        struct list_head list;
+       struct vdpa_callback config_cb;
+       spinlock_t irq_lock;
        bool connected;
        int minor;
        u16 vq_size_max;
@@ -483,6 +485,11 @@ static void vduse_dev_reset(struct vduse_dev *dev)
        vduse_iotlb_del_range(dev, 0ULL, ULLONG_MAX);
        vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX);
 
+       spin_lock(&dev->irq_lock);
+       dev->config_cb.callback = NULL;
+       dev->config_cb.private = NULL;
+       spin_unlock(&dev->irq_lock);
+
        for (i = 0; i < dev->vq_num; i++) {
                struct vduse_virtqueue *vq = &dev->vqs[i];
 
@@ -599,7 +606,12 @@ static int vduse_vdpa_set_features(struct vdpa_device 
*vdpa, u64 features)
 static void vduse_vdpa_set_config_cb(struct vdpa_device *vdpa,
                                  struct vdpa_callback *cb)
 {
-       /* We don't support config interrupt */
+       struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+
+       spin_lock(&dev->irq_lock);
+       dev->config_cb.callback = cb->callback;
+       dev->config_cb.private = cb->private;
+       spin_unlock(&dev->irq_lock);
 }
 
 static u16 vduse_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
@@ -913,6 +925,15 @@ static long vduse_dev_ioctl(struct file *file, unsigned 
int cmd,
                spin_unlock_irq(&vq->irq_lock);
                break;
        }
+       case VDUSE_INJECT_CONFIG_IRQ:
+               ret = -EINVAL;
+               spin_lock_irq(&dev->irq_lock);
+               if (dev->config_cb.callback) {
+                       dev->config_cb.callback(dev->config_cb.private);
+                       ret = 0;
+               }
+               spin_unlock_irq(&dev->irq_lock);
+               break;
        default:
                ret = -ENOIOCTLCMD;
                break;
@@ -996,6 +1017,7 @@ static struct vduse_dev *vduse_dev_create(void)
        INIT_LIST_HEAD(&dev->recv_list);
        atomic64_set(&dev->msg_unique, 0);
        spin_lock_init(&dev->iommu_lock);
+       spin_lock_init(&dev->irq_lock);
        atomic_set(&dev->bounce_map, 0);
 
        init_waitqueue_head(&dev->waitq);
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index 9391c4acfa53..9070cd512cb4 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -133,4 +133,7 @@ struct vduse_vq_eventfd {
 /* Inject an interrupt for specific virtqueue */
 #define VDUSE_INJECT_VQ_IRQ    _IO(VDUSE_BASE, 0x05)
 
+/* Inject a config interrupt */
+#define VDUSE_INJECT_CONFIG_IRQ        _IO(VDUSE_BASE, 0x06)
+
 #endif /* _UAPI_VDUSE_H_ */
-- 
2.11.0