diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index bc3e880f9b82..fcec2f1d34a1 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -44,6 +44,11 @@ static struct apic *apic_probe[] __initdata = {
 	NULL,
 };
 
+static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
+{
+	return hard_smp_processor_id() >> index_msb;
+}
+
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  */
@@ -69,6 +74,11 @@ void __init default_setup_apic_routing(void)
 		printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
 	}
 
+	if (is_vsmp_box()) {
+		/* need to update phys_pkg_id */
+		apic->phys_pkg_id = apicid_phys_pkg_id;
+	}
+
 	/*
 	 * Now that apic routing model is selected, configure the
 	 * fault handling for intr remapping.
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index e90540a46a0b..eb33aaa8415d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -215,6 +215,7 @@ static __init void xen_init_cpuid_mask(void)
 			  (1 << X86_FEATURE_ACPI));  /* disable ACPI */
 
 	ax = 1;
+	cx = 0;
 	xen_cpuid(&ax, &bx, &cx, &dx);
 
 	/* cpuid claims we support xsave; try enabling it to see what happens */
@@ -1059,6 +1060,7 @@ asmlinkage void __init xen_start_kernel(void)
 	/* set up basic CPUID stuff */
 	cpu_detect(&new_cpu_data);
 	new_cpu_data.hard_math = 1;
+	new_cpu_data.wp_works_ok = 1;
 	new_cpu_data.x86_capability[0] = cpuid_edx(1);
 #endif