KVM: x86: define SVM/VMX specific kvm_arch_[alloc|free]_vm

Define kvm_arch_[alloc|free]_vm in x86 as pass through functions
to new kvm_x86_ops vm_alloc and vm_free, and move the current
allocation logic as-is to SVM and VMX.  Vendor specific alloc/free
functions set the stage for SVM/VMX wrappers of 'struct kvm',
which will allow us to move the growing number of SVM/VMX specific
member variables out of 'struct kvm_arch'.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c72891d..94dcc55 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -948,6 +948,8 @@ struct kvm_x86_ops {
 	bool (*cpu_has_high_real_mode_segbase)(void);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
+	struct kvm *(*vm_alloc)(void);
+	void (*vm_free)(struct kvm *);
 	int (*vm_init)(struct kvm *kvm);
 	void (*vm_destroy)(struct kvm *kvm);
 
@@ -1121,6 +1123,17 @@ struct kvm_arch_async_pf {
 
 extern struct kvm_x86_ops *kvm_x86_ops;
 
+#define __KVM_HAVE_ARCH_VM_ALLOC
+static inline struct kvm *kvm_arch_alloc_vm(void)
+{
+	return kvm_x86_ops->vm_alloc();
+}
+
+static inline void kvm_arch_free_vm(struct kvm *kvm)
+{
+	return kvm_x86_ops->vm_free(kvm);
+}
+
 int kvm_mmu_module_init(void);
 void kvm_mmu_module_exit(void);