In VDUSE_GET_RECONNECT_INFO, the Userspace App can get the map size
and The number of mapping memory pages from the kernel. The userspace
App can use this information to map the pages.
Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 15 +++++++++++++++
include/uapi/linux/vduse.h | 15 +++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 680b23dbdde2..c99f99892b5c 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1368,6 +1368,21 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
ret = 0;
break;
}
+ case VDUSE_GET_RECONNECT_INFO: {
+ struct vduse_reconnect_mmap_info info;
+
+ ret = -EFAULT;
+ if (copy_from_user(&info, argp, sizeof(info)))
+ break;
+
+ info.size = PAGE_SIZE;
+ info.max_index = dev->vq_num + 1;
+
+ if (copy_to_user(argp, &info, sizeof(info)))
+ break;
+ ret = 0;
+ break;
+ }
default:
ret = -ENOIOCTLCMD;
break;
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index d585425803fd..ce55e34f63d7 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -356,4 +356,19 @@ struct vhost_reconnect_vring {
_Bool avail_wrap_counter;
};
+/**
+ * struct vduse_reconnect_mmap_info
+ * @size: mapping memory size, always page_size here
+ * @max_index: the number of pages allocated in kernel,just
+ * use for check
+ */
+
+struct vduse_reconnect_mmap_info {
+ __u32 size;
+ __u32 max_index;
+};
+
+#define VDUSE_GET_RECONNECT_INFO \
+ _IOWR(VDUSE_BASE, 0x1b, struct vduse_reconnect_mmap_info)
+
#endif /* _UAPI_VDUSE_H_ */
--
2.34.3
