KVM: Use kmem cache for allocating vcpus

Avi wants the allocations of vcpus centralized again.  The easiest way
is to add a "size" arg to kvm_init_arch, and expose the thus-prepared
cache to the modules.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 030b93b..b362e8f 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -141,6 +141,7 @@
 };
 
 struct kvm_vcpu;
+extern struct kmem_cache *kvm_vcpu_cache;
 
 /*
  * x86 supports 3 paging modes (4-level 64-bit, 3-level 64-bit, and 2-level
@@ -483,7 +484,8 @@
 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id);
 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu);
 
-int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module);
+int kvm_init_arch(struct kvm_arch_ops *ops, unsigned int vcpu_size,
+		  struct module *module);
 void kvm_exit_arch(void);
 
 int kvm_mmu_module_init(void);