id = 870
title = "Throws a #GP when it should throw a #SS"
state = "closed"
created_at = "2022-02-14T04:08:24.583Z"
closed_at = "2022-03-15T16:28:26.904Z"
labels = ["accel: TCG", "target: i386"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/870"
host-os = "Ubuntu 20.04.3 LTS"
host-arch = "x86"
qemu-version = "QEMU emulator version 6.2.0"
guest-os = "Custom"
guest-arch = "x86"
description = """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"""
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 = """"""