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>

arch/powerpc/kvm/book3s_pr.c

@@ -153,6 +153,7 @@ void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
 		if (!to_book3s(vcpu)->hior_sregs)
 			to_book3s(vcpu)->hior = 0xfff00000;
 		to_book3s(vcpu)->msr_mask = 0xffffffffffffffffULL;
+		vcpu->arch.cpu_type = KVM_CPU_3S_64;
 	} else
 #endif
 	{
@@ -160,8 +161,11 @@ void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
 		if (!to_book3s(vcpu)->hior_sregs)
 			to_book3s(vcpu)->hior = 0;
 		to_book3s(vcpu)->msr_mask = 0xffffffffULL;
+		vcpu->arch.cpu_type = KVM_CPU_3S_32;
 	}
 
+	kvmppc_sanity_check(vcpu);
+
 	/* If we are in hypervisor level on 970, we can tell the CPU to
 	 * treat DCBZ as 32 bytes store */
 	vcpu->arch.hflags &= ~BOOK3S_HFLAG_DCBZ32;
@@ -938,6 +942,12 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 #endif
 	ulong ext_msr;
 
+	/* Check if we can run the vcpu at all */
+	if (!vcpu->arch.sane) {
+		kvm_run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return -EINVAL;
+	}
+
 	/* No need to go into the guest when all we do is going out */
 	if (signal_pending(current)) {
 		kvm_run->exit_reason = KVM_EXIT_INTR;