KVM: x86 emulator: inject #UD on access to non-existing CR

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index fa4604e..836e97b 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2520,6 +2520,13 @@ twobyte_insn:
                c->dst.type = OP_NONE;
                break;
        case 0x20: /* mov cr, reg */
+               switch (c->modrm_reg) {
+               case 1:
+               case 5 ... 7:
+               case 9 ... 15:
+                       kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+                       goto done;
+               }
                c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu);
                c->dst.type = OP_NONE;  /* no writeback */
                break;