KVM: Directly return result from kvm_arch_check_processor_compat()

Add a wrapper to invoke kvm_arch_check_processor_compat() so that the
boilerplate ugliness of checking virtualization support on all CPUs is
hidden from the arch specific code.  x86's implementation in particular
is quite heinous, as it unnecessarily propagates the out-param pattern
into kvm_x86_ops.

While the x86 specific issue could be resolved solely by changing
kvm_x86_ops, make the change for all architectures as returning a value
directly is prettier and technically more robust, e.g. s390 doesn't set
the out param, which could lead to subtle breakage in the (highly
unlikely) scenario where the out-param was not pre-initialized by the
caller.

Opportunistically annotate svm_check_processor_compat() with __init.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index aa3a678711be..628d3c791ad7 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -425,9 +425,9 @@ int kvm_arch_hardware_setup(void)
 	return 0;
 }
 
-void kvm_arch_check_processor_compat(void *rtn)
+int kvm_arch_check_processor_compat(void)
 {
-	*(int *)rtn = kvmppc_core_check_processor_compat();
+	return kvmppc_core_check_processor_compat();
 }
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)