KVM: emulate: warn on invalid or uninitialized exception numbers
These were reported when running Jailhouse on AMD processors.
Initialize ctxt->exception.vector with an invalid exception number,
and warn if it remained invalid even though the emulator got
an X86EMUL_PROPAGATE_FAULT return code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 4fbf4b5..e5bf130 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -527,6 +527,7 @@
static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
u32 error, bool valid)
{
+ WARN_ON(vec > 0x1f);
ctxt->exception.vector = vec;
ctxt->exception.error_code = error;
ctxt->exception.error_code_valid = valid;
@@ -4827,8 +4828,10 @@
ctxt->eip = ctxt->_eip;
done:
- if (rc == X86EMUL_PROPAGATE_FAULT)
+ if (rc == X86EMUL_PROPAGATE_FAULT) {
+ WARN_ON(ctxt->exception.vector > 0x1f);
ctxt->have_exception = true;
+ }
if (rc == X86EMUL_INTERCEPTED)
return EMULATION_INTERCEPTED;