KVM: VMX: Use direct vcpu pointer during vCPU create/free

Capture the vcpu pointer in a local varaible and replace '&vmx->vcpu'
references with a direct reference to the pointer in anticipation of
moving bits of the code to common x86 and passing the vcpu pointer into
vmx_create_vcpu(), i.e. eliminate unnecessary noise from future patches.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

@@ -6682,17 +6682,17 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
 	nested_vmx_free_vcpu(vcpu);
 	free_loaded_vmcs(vmx->loaded_vmcs);
 	kvm_vcpu_uninit(vcpu);
-	kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu);
-	kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu);
+	kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
+	kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
 	kmem_cache_free(kvm_vcpu_cache, vmx);
 }
 
 static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 {
-	int err;
+	struct kvm_vcpu *vcpu;
 	struct vcpu_vmx *vmx;
 	unsigned long *msr_bitmap;
-	int i, cpu;
+	int i, cpu, err;
 
 	BUILD_BUG_ON_MSG(offsetof(struct vcpu_vmx, vcpu) != 0,
 		"struct kvm_vcpu must be at offset 0 for arch usercopy region");
@@ -6701,23 +6701,25 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 	if (!vmx)
 		return ERR_PTR(-ENOMEM);
 
-	vmx->vcpu.arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache,
-			GFP_KERNEL_ACCOUNT);
-	if (!vmx->vcpu.arch.user_fpu) {
+	vcpu = &vmx->vcpu;
+
+	vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache,
+						GFP_KERNEL_ACCOUNT);
+	if (!vcpu->arch.user_fpu) {
 		printk(KERN_ERR "kvm: failed to allocate kvm userspace's fpu\n");
 		err = -ENOMEM;
 		goto free_partial_vcpu;
 	}
 
-	vmx->vcpu.arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
-			GFP_KERNEL_ACCOUNT);
-	if (!vmx->vcpu.arch.guest_fpu) {
+	vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
+						 GFP_KERNEL_ACCOUNT);
+	if (!vcpu->arch.guest_fpu) {
 		printk(KERN_ERR "kvm: failed to allocate vcpu's fpu\n");
 		err = -ENOMEM;
 		goto free_user_fpu;
 	}
 
-	err = kvm_vcpu_init(&vmx->vcpu, kvm, id);
+	err = kvm_vcpu_init(vcpu, kvm, id);
 	if (err)
 		goto free_vcpu;
 
@@ -6789,12 +6791,12 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 
 	vmx->loaded_vmcs = &vmx->vmcs01;
 	cpu = get_cpu();
-	vmx_vcpu_load(&vmx->vcpu, cpu);
-	vmx->vcpu.cpu = cpu;
+	vmx_vcpu_load(vcpu, cpu);
+	vcpu->cpu = cpu;
 	init_vmcs(vmx);
-	vmx_vcpu_put(&vmx->vcpu);
+	vmx_vcpu_put(vcpu);
 	put_cpu();
-	if (cpu_need_virtualize_apic_accesses(&vmx->vcpu)) {
+	if (cpu_need_virtualize_apic_accesses(vcpu)) {
 		err = alloc_apic_access_page(kvm);
 		if (err)
 			goto free_vmcs;
@@ -6809,7 +6811,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 	if (nested)
 		nested_vmx_setup_ctls_msrs(&vmx->nested.msrs,
 					   vmx_capability.ept,
-					   kvm_vcpu_apicv_active(&vmx->vcpu));
+					   kvm_vcpu_apicv_active(vcpu));
 	else
 		memset(&vmx->nested.msrs, 0, sizeof(vmx->nested.msrs));
 
@@ -6827,19 +6829,19 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 
 	vmx->ept_pointer = INVALID_PAGE;
 
-	return &vmx->vcpu;
+	return vcpu;
 
 free_vmcs:
 	free_loaded_vmcs(vmx->loaded_vmcs);
 free_pml:
 	vmx_destroy_pml_buffer(vmx);
 uninit_vcpu:
-	kvm_vcpu_uninit(&vmx->vcpu);
+	kvm_vcpu_uninit(vcpu);
 	free_vpid(vmx->vpid);
 free_vcpu:
-	kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu);
+	kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu);
 free_user_fpu:
-	kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu);
+	kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu);
 free_partial_vcpu:
 	kmem_cache_free(kvm_vcpu_cache, vmx);
 	return ERR_PTR(err);