WARN and inject #UD when emulating VMFUNC for L2 if the function is
out-of-bounds or if VMFUNC is not enabled in vmcs12. Neither condition
should occur in practice, as the CPU is supposed to prioritize the #UD
over VM-Exit for out-of-bounds input and KVM is supposed to enable
VMFUNC in vmcs02 if and only if it's enabled in vmcs12, but neither of
those dependencies is obvious.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20210609234235.1244004-15-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
}
vmcs12 = get_vmcs12(vcpu);
+
+ /*
+ * #UD on out-of-bounds function has priority over VM-Exit, and VMFUNC
+ * is enabled in vmcs02 if and only if it's enabled in vmcs12.
+ */
+ if (WARN_ON_ONCE((function > 63) || !nested_cpu_has_vmfunc(vmcs12))) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
+
if (!(vmcs12->vm_function_control & BIT_ULL(function)))
goto fail;