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>

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 13bc798a444..a8000ce562b 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -95,6 +95,31 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
         return r;
 }
 
+int kvmppc_sanity_check(struct kvm_vcpu *vcpu)
+{
+        int r = false;
+
+        /* We have to know what CPU to virtualize */
+        if (!vcpu->arch.pvr)
+                goto out;
+
+        /* PAPR only works with book3s_64 */
+        if ((vcpu->arch.cpu_type != KVM_CPU_3S_64) && vcpu->arch.papr_enabled)
+                goto out;
+
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+        /* HV KVM can only do PAPR mode for now */
+        if (!vcpu->arch.papr_enabled)
+                goto out;
+#endif
+
+        r = true;
+
+out:
+        vcpu->arch.sane = r;
+        return r ? 0 : -EINVAL;
+}
+
 int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
         enum emulation_result er;
@@ -582,6 +607,9 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
                 break;
         }
 
+        if (!r)
+                r = kvmppc_sanity_check(vcpu);
+
         return r;
 }