Can struct statx be used inside kernel?

I'm trying to get a particular process' creation time. In order to do that I use vfs_statx() method which takes struct kstat as an argument. But the problem is that does the struct kstat has struct statx_timestamp field inside it? I know that struct statx does have it, but can it be used within kernel?

Shortly:

Can I define a variable like struct statx my_stat; inside kernel and then use its statx_timestamp field?

Thanks in advance.