The VMM Communication Exception (#VC, vector 29) pushes an error code onto the stack, similar to exceptions like #PF or #GP.
The generic IDT handler generation macro in the selftests incorrectly assumed that all vectors from 18 to 255 do not have an error code. For new tests (added in subsequent commits) which trigger #VC exception, this incorrect assumption caused the handler to misinterpret the stack frame and the ex_regs fields, leading to stack corruption upon IRET.
Fix this by explicitly defining a handler for vector 29 that correctly accounts for the error code.
This allows selftests to properly catch and handle #VC exceptions, which is a prerequisite for testing features like SEV-ES.
Signed-off-by: Neeraj Upadhyay Neeraj.Upadhyay@amd.com --- tools/testing/selftests/kvm/lib/x86/handlers.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/handlers.S b/tools/testing/selftests/kvm/lib/x86/handlers.S index 7629819734af..19715a58f5d2 100644 --- a/tools/testing/selftests/kvm/lib/x86/handlers.S +++ b/tools/testing/selftests/kvm/lib/x86/handlers.S @@ -76,6 +76,8 @@ idt_handler_code: HANDLERS has_error=1 from=10 to=14 HANDLERS has_error=0 from=15 to=16 HANDLERS has_error=1 from=17 to=17 - HANDLERS has_error=0 from=18 to=255 + HANDLERS has_error=0 from=18 to=28 + HANDLERS has_error=1 from=29 to=29 + HANDLERS has_error=0 from=30 to=255
.section .note.GNU-stack, "", %progbits