Add the support of x2apic logical cluster mode.

Add a xen boolean parameter 'x2apic'.
Add a xen boolean parameter 'x2apic_phys'(by default, we use logical
cluster mode).

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>

1 files changed, 25 insertions, 10 deletions

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index 47d614269e..ba6b0dbb3d 100644
--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -848,8 +848,31 @@ void enable_x2apic(void)
 {
     u32 lo, hi;
 
-    if ( !iommu_supports_eim() )
-        return;
+    if ( smp_processor_id() == 0 )
+    {
+        if ( !iommu_supports_eim() )
+        {
+            printk("x2APIC would not be enabled without EIM.\n");
+            return;
+        }
+
+        if ( apic_x2apic_phys.probe() )
+            genapic = &apic_x2apic_phys;
+        else if ( apic_x2apic_cluster.probe() )
+            genapic = &apic_x2apic_cluster;
+        else
+        {
+            printk("x2APIC would not be enabled due to x2apic=off.\n");
+            return;
+        }
+
+        x2apic_enabled = 1;
+        printk("Switched to APIC driver %s.\n", genapic->name);
+    }
+    else
+    {
+        BUG_ON(!x2apic_enabled); /* APs only enable x2apic when BSP did so. */
+    }
 
     rdmsr(MSR_IA32_APICBASE, lo, hi);
     if ( !(lo & MSR_IA32_APICBASE_EXTD) )
@@ -860,14 +883,6 @@ void enable_x2apic(void)
     }
     else
         printk("x2APIC mode enabled by BIOS.\n");
-
-    if ( !x2apic_enabled )
-    {
-        x2apic_enabled = 1;
-        genapic = &apic_x2apic;
-        printk(KERN_INFO "Switched to APIC driver %s.\n",
-                       genapic->name);
-    }
 }
 
 void __init init_apic_mappings(void)