x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info

shared_info page has space for 32 vcpu info slots for first 32 vCPUs
but these are the first 32 vCPUs from Xen's perspective and we should
map them accordingly with the newly introduced xen_vcpu_id mapping.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

arch/x86/xen/enlighten.c

@@ -207,8 +207,9 @@ static void xen_vcpu_setup(int cpu)
 		if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
 			return;
 	}
-	if (cpu < MAX_VIRT_CPUS)
-		per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+	if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
+		per_cpu(xen_vcpu, cpu) =
+			&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
 
 	if (!have_vcpu_info_placement) {
 		if (cpu >= MAX_VIRT_CPUS)
@@ -1783,9 +1784,10 @@ void __ref xen_hvm_init_shared_info(void)
 	 * in that case multiple vcpus might be online. */
 	for_each_online_cpu(cpu) {
 		/* Leave it to be NULL. */
-		if (cpu >= MAX_VIRT_CPUS)
+		if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
 			continue;
-		per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+		per_cpu(xen_vcpu, cpu) =
+			&HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
 	}
 }