KVM: SMP: Add vcpu_id field in struct vcpu

This patch adds a `vcpu_id' field in `struct vcpu', so we can
differentiate BSP and APs without pointer comparison or arithmetic.
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/kvm.h

@@ -328,6 +328,7 @@ void kvm_io_bus_register_dev(struct kvm_io_bus *bus,
 
 struct kvm_vcpu {
 	struct kvm *kvm;
+	int vcpu_id;
 	union {
 		struct vmcs *vmcs;
 		struct vcpu_svm *svm;

drivers/kvm/kvm_main.c

@@ -2355,6 +2355,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 		goto out;
 
 	vcpu = &kvm->vcpus[n];
+	vcpu->vcpu_id = n;
 
 	mutex_lock(&vcpu->mutex);
 

drivers/kvm/svm.c

@@ -591,7 +591,7 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
 	fx_init(vcpu);
 	vcpu->fpu_active = 1;
 	vcpu->apic_base = 0xfee00000 | MSR_IA32_APICBASE_ENABLE;
-	if (vcpu == &vcpu->kvm->vcpus[0])
+	if (vcpu->vcpu_id == 0)
 		vcpu->apic_base |= MSR_IA32_APICBASE_BSP;
 
 	return 0;

drivers/kvm/vmx.c

@@ -1253,7 +1253,7 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 	vcpu->regs[VCPU_REGS_RDX] = get_rdx_init_val();
 	vcpu->cr8 = 0;
 	vcpu->apic_base = 0xfee00000 | MSR_IA32_APICBASE_ENABLE;
-	if (vcpu == &vcpu->kvm->vcpus[0])
+	if (vcpu->vcpu_id == 0)
 		vcpu->apic_base |= MSR_IA32_APICBASE_BSP;
 
 	fx_init(vcpu);