KVM: PPC: Add sanity checking to vcpu_run

There are multiple features in PowerPC KVM that can now be enabled
depending on the user's wishes. Some of the combinations don't make
sense or don't work though.

So this patch adds a way to check if the executing environment would
actually be able to run the guest properly. It also adds sanity
checks if PVR is set (should always be true given the current code
flow), if PAPR is only used with book3s_64 where it works and that
HV KVM is only used in PAPR mode.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index d121f49..46efd1a 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -66,6 +66,7 @@
 extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
 extern void kvmppc_emulate_dec(struct kvm_vcpu *vcpu);
 extern u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb);
+extern int kvmppc_sanity_check(struct kvm_vcpu *vcpu);
 
 /* Core-specific hooks */