diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 0f8bfa57d7..742f68afca 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1706,11 +1706,11 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
 
     mc->init = machvirt_init;
-    /* Start max_cpus at the maximum QEMU supports. We'll further restrict
-     * it later in machvirt_init, where we have more information about the
+    /* Start with max_cpus set to 512, which is the maximum supported by KVM.
+     * The value may be reduced later when we have more information about the
      * configuration of the particular instance.
      */
-    mc->max_cpus = 255;
+    mc->max_cpus = 512;
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_CALXEDA_XGMAC);
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_AMD_XGBE);
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
@@ -1837,6 +1837,7 @@ static void virt_machine_2_12_options(MachineClass *mc)
     virt_machine_3_0_options(mc);
     SET_MACHINE_COMPAT(mc, VIRT_COMPAT_2_12);
     vmc->no_highmem_ecam = true;
+    mc->max_cpus = 255;
 }
 DEFINE_VIRT_MACHINE(2, 12)