KVM: PPC: Book3S: Allow only implemented hcalls to be enabled or disabled

This adds code to check that when the KVM_CAP_PPC_ENABLE_HCALL
capability is used to enable or disable in-kernel handling of an
hcall, that the hcall is actually implemented by the kernel.
If not an EINVAL error is returned.

This also checks the default-enabled list of hcalls and prints a
warning if any hcall there is not actually implemented.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index eacaa6e..6d0143f 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -309,6 +309,27 @@
 	return EMULATE_FAIL;
 }
 
+int kvmppc_hcall_impl_pr(unsigned long cmd)
+{
+	switch (cmd) {
+	case H_ENTER:
+	case H_REMOVE:
+	case H_PROTECT:
+	case H_BULK_REMOVE:
+	case H_PUT_TCE:
+	case H_CEDE:
+#ifdef CONFIG_KVM_XICS
+	case H_XIRR:
+	case H_CPPR:
+	case H_EOI:
+	case H_IPI:
+	case H_IPOLL:
+	case H_XIRR_X:
+#endif
+		return 1;
+	}
+	return 0;
+}
 
 /*
  * List of hcall numbers to enable by default.
@@ -337,7 +358,11 @@
 void kvmppc_pr_init_default_hcalls(struct kvm *kvm)
 {
 	int i;
+	unsigned int hcall;
 
-	for (i = 0; default_hcall_list[i]; ++i)
-		__set_bit(default_hcall_list[i] / 4, kvm->arch.enabled_hcalls);
+	for (i = 0; default_hcall_list[i]; ++i) {
+		hcall = default_hcall_list[i];
+		WARN_ON(!kvmppc_hcall_impl_pr(hcall));
+		__set_bit(hcall / 4, kvm->arch.enabled_hcalls);
+	}
 }