What should I do when handle task switch, but the new TSS is not in current virtual address space?
Shoud I inject a Page Fault Exception to the guest directly?
The article, Stack switching mechanism in a computer, may provide some insights for you.
Another place is the review the Xen source code.
A new blog was created to provide resources for sw developers: Resources for Software Developers: Intel® Virtualization Technology (Intel® VT)