[PATCH RESEND 3/5] vhost_vdpa: Support config interrupt in vdpa

[Zhu Lingshan]

This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan <lingshan....@intel.com>
Acked-by: Jason Wang <jasow...@redhat.com>
---
 drivers/vhost/vdpa.c       | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/vhost.h |  4 ++++
 2 files changed, 51 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 0968361..ffb41cf 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -21,6 +21,7 @@
 #include <linux/nospec.h>
 #include <linux/vhost.h>
 #include <linux/virtio_net.h>
+#include <linux/kernel.h>
 
 #include "vhost.h"
 
@@ -70,6 +71,7 @@ struct vhost_vdpa {
        int nvqs;
        int virtio_id;
        int minor;
+       struct eventfd_ctx *config_ctx;
 };
 
 static DEFINE_IDA(vhost_vdpa_ida);
@@ -101,6 +103,17 @@ static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
        return IRQ_HANDLED;
 }
 
+static irqreturn_t vhost_vdpa_config_cb(void *private)
+{
+       struct vhost_vdpa *v = private;
+       struct eventfd_ctx *config_ctx = v->config_ctx;
+
+       if (config_ctx)
+               eventfd_signal(config_ctx, 1);
+
+       return IRQ_HANDLED;
+}
+
 static void vhost_vdpa_reset(struct vhost_vdpa *v)
 {
        struct vdpa_device *vdpa = v->vdpa;
@@ -288,6 +301,36 @@ static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, 
u16 __user *argp)
        return 0;
 }
 
+static void vhost_vdpa_config_put(struct vhost_vdpa *v)
+{
+       if (v->config_ctx)
+               eventfd_ctx_put(v->config_ctx);
+}
+
+static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
+{
+       struct vdpa_callback cb;
+       int fd;
+       struct eventfd_ctx *ctx;
+
+       cb.callback = vhost_vdpa_config_cb;
+       cb.private = v->vdpa;
+       if (copy_from_user(&fd, argp, sizeof(fd)))
+               return  -EFAULT;
+
+       ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
+       swap(ctx, v->config_ctx);
+
+       if (!IS_ERR_OR_NULL(ctx))
+               eventfd_ctx_put(ctx);
+
+       if (IS_ERR(v->config_ctx))
+               return PTR_ERR(v->config_ctx);
+
+       v->vdpa->config->set_config_cb(v->vdpa, &cb);
+
+       return 0;
+}
 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
                                   void __user *argp)
 {
@@ -395,6 +438,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
        case VHOST_SET_LOG_FD:
                r = -ENOIOCTLCMD;
                break;
+       case VHOST_VDPA_SET_CONFIG_CALL:
+               r = vhost_vdpa_set_config_call(v, argp);
+               break;
        default:
                r = vhost_dev_ioctl(&v->vdev, cmd, argp);
                if (r == -ENOIOCTLCMD)
@@ -729,6 +775,7 @@ static int vhost_vdpa_release(struct inode *inode, struct 
file *filep)
        vhost_dev_stop(&v->vdev);
        vhost_vdpa_iotlb_free(v);
        vhost_vdpa_free_domain(v);
+       vhost_vdpa_config_put(v);
        vhost_dev_cleanup(&v->vdev);
        kfree(v->vdev.vqs);
        mutex_unlock(&d->mutex);
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index 9fe72e4..0c23496 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -15,6 +15,8 @@
 #include <linux/types.h>
 #include <linux/ioctl.h>
 
+#define VHOST_FILE_UNBIND -1
+
 /* ioctls */
 
 #define VHOST_VIRTIO 0xAF
@@ -140,4 +142,6 @@
 /* Get the max ring size. */
 #define VHOST_VDPA_GET_VRING_NUM       _IOR(VHOST_VIRTIO, 0x76, __u16)
 
+/* Set event fd for config interrupt*/
+#define VHOST_VDPA_SET_CONFIG_CALL     _IOW(VHOST_VIRTIO, 0x77, int)
 #endif
-- 
1.8.3.1