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/vmx.c b/drivers/kvm/vmx.c
index f770f55..2b30274 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -2365,7 +2365,7 @@
 static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 {
 	int err;
-	struct vcpu_vmx *vmx = kzalloc(sizeof(*vmx), GFP_KERNEL);
+	struct vcpu_vmx *vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
 	int cpu;
 
 	if (!vmx)
@@ -2490,7 +2490,7 @@
 	memset(iova, 0xff, PAGE_SIZE);
 	kunmap(vmx_io_bitmap_b);
 
-	r = kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
+	r = kvm_init_arch(&vmx_arch_ops, sizeof(struct vcpu_vmx), THIS_MODULE);
 	if (r)
 		goto out1;