Throws a #GP when it should throw a #SS
Description of problem:
When stacks are switched as part of a 64-bit mode privilege-level change (resulting from an interrupt), IA-32e mode loads only an inner-level RSP from the TSS. If the value of rsp from tss is a non-canonical form. It will trigger #SS. But when I test it in qemu it throws #GP instead of #SS
Steps to reproduce:
In order to confirm that it is the #SS triggered by the non-canonical address, We can verify on a real machine.  
1. Set the value of the current core's `TSS.IST7` to the the non-canonical address.
2. Set the `ist` field of the interrupt 4 (Overflow Exception) descriptor to 7.
3. Execute the `INT 4` instruction in Ring 3 and it will be taken over by the #SS handler.

Repeat the above steps in qemu this exception will be taken over by #GP
Additional information: