KVM: x86: Remove useless regs_page pointer from kvm_lapic

Access to this page is mostly done through the regs member which holds
the address to this page.  The exceptions are in vmx_vcpu_reset() and
kvm_free_lapic() and these both can easily be converted to using regs.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/lapic.c

@@ -871,8 +871,8 @@ void kvm_free_lapic(struct kvm_vcpu *vcpu)
 
 	hrtimer_cancel(&vcpu->arch.apic->lapic_timer.timer);
 
-	if (vcpu->arch.apic->regs_page)
-		__free_page(vcpu->arch.apic->regs_page);
+	if (vcpu->arch.apic->regs)
+		free_page((unsigned long)vcpu->arch.apic->regs);
 
 	kfree(vcpu->arch.apic);
 }
@@ -1061,13 +1061,12 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.apic = apic;
 
-	apic->regs_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
-	if (apic->regs_page == NULL) {
+	apic->regs = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!apic->regs) {
 		printk(KERN_ERR "malloc apic regs error for vcpu %x\n",
 		       vcpu->vcpu_id);
 		goto nomem_free_apic;
 	}
-	apic->regs = page_address(apic->regs_page);
 	apic->vcpu = vcpu;
 
 	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,

arch/x86/kvm/lapic.h

@@ -13,7 +13,6 @@ struct kvm_lapic {
 	u32 divide_count;
 	struct kvm_vcpu *vcpu;
 	bool irr_pending;
-	struct page *regs_page;
 	void *regs;
 	gpa_t vapic_addr;
 	struct page *vapic_page;

arch/x86/kvm/vmx.c

@@ -2821,7 +2821,7 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
 		vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
 		if (vm_need_tpr_shadow(vmx->vcpu.kvm))
 			vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
-				page_to_phys(vmx->vcpu.arch.apic->regs_page));
+				     __pa(vmx->vcpu.arch.apic->regs));
 		vmcs_write32(TPR_THRESHOLD, 0);
 	}