ARM: KVM: trap VM system registers until MMU and caches are ON

In order to be able to detect the point where the guest enables
its MMU and caches, trap all the VM related system registers.

Once we see the guest enabling both the MMU and the caches, we
can go back to a saner mode of operation, which is to leave these
registers in complete control of the guest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm/kvm/coproc.h

@@ -153,4 +153,8 @@ static inline int cmp_reg(const struct coproc_reg *i1,
 #define is64		.is_64 = true
 #define is32		.is_64 = false
 
+bool access_sctlr(struct kvm_vcpu *vcpu,
+		  const struct coproc_params *p,
+		  const struct coproc_reg *r);
+
 #endif /* __ARM_KVM_COPROC_LOCAL_H__ */