diff -r 7abb25095de0 xen/arch/x86/cpu/mcheck/mce.c
--- a/xen/arch/x86/cpu/mcheck/mce.c	Thu Oct 25 13:15:19 2012 +0200
+++ b/xen/arch/x86/cpu/mcheck/mce.c	Thu Oct 25 15:13:24 2012 +0200
@@ -560,30 +560,6 @@ void mcheck_mca_clearbanks(struct mca_ba
     }
 }
 
-static enum mcheck_type amd_mcheck_init(struct cpuinfo_x86 *ci)
-{
-    enum mcheck_type rc = mcheck_none;
-
-    switch (ci->x86) {
-    case 6:
-        rc = amd_k7_mcheck_init(ci);
-        break;
-
-    default:
-        /* Assume that machine check support is available.
-         * The minimum provided support is at least the K8. */
-    case 0xf:
-        rc = amd_k8_mcheck_init(ci);
-        break;
-
-    case 0x10 ... 0x17:
-        rc = amd_f10_mcheck_init(ci);
-        break;
-    }
-
-    return rc;
-}
-
 /*check the existence of Machine Check*/
 int mce_available(struct cpuinfo_x86 *c)
 {
@@ -774,7 +750,7 @@ void mcheck_init(struct cpuinfo_x86 *c, 
 
     switch (c->x86_vendor) {
     case X86_VENDOR_AMD:
-        inited = amd_mcheck_init(c);
+        inited = amd_mcheck_init(c, bsp);
         break;
 
     case X86_VENDOR_INTEL:
diff -r 7abb25095de0 xen/arch/x86/cpu/mcheck/mce.h
--- a/xen/arch/x86/cpu/mcheck/mce.h	Thu Oct 25 13:15:19 2012 +0200
+++ b/xen/arch/x86/cpu/mcheck/mce.h	Thu Oct 25 15:13:24 2012 +0200
@@ -39,10 +39,7 @@ enum mcheck_type {
 };
 
 /* Init functions */
-enum mcheck_type amd_k7_mcheck_init(struct cpuinfo_x86 *c);
-enum mcheck_type amd_k8_mcheck_init(struct cpuinfo_x86 *c);
-enum mcheck_type amd_f10_mcheck_init(struct cpuinfo_x86 *c);
-
+enum mcheck_type amd_mcheck_init(struct cpuinfo_x86 *c, bool_t bsp);
 enum mcheck_type intel_mcheck_init(struct cpuinfo_x86 *c, bool_t bsp);
 
 void intel_mcheck_timer(struct cpuinfo_x86 *c);
diff -r 7abb25095de0 xen/arch/x86/cpu/mcheck/mce_amd.c
--- a/xen/arch/x86/cpu/mcheck/mce_amd.c	Thu Oct 25 13:15:19 2012 +0200
+++ b/xen/arch/x86/cpu/mcheck/mce_amd.c	Thu Oct 25 15:13:24 2012 +0200
@@ -19,6 +19,7 @@
 
 #include <xen/init.h>
 #include <xen/types.h>
+#include <xen/cpu.h>
 
 #include <asm/msr.h>
 
@@ -98,3 +99,53 @@ mc_amd_addrcheck(uint64_t status, uint64
     BUG();
     return 0;
 }
+
+static int
+amd_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+    int rc = 0;
+
+    switch (action) {
+    case CPU_DYING:
+        clear_in_cr4(X86_CR4_MCE);
+        break;
+    default:
+        break;
+    }
+
+    return notifier_from_errno(rc);
+}
+
+static struct notifier_block cpu_nfb = {
+    .notifier_call = amd_cpu_callback
+};
+
+enum mcheck_type
+amd_mcheck_init(struct cpuinfo_x86 *ci, bool_t bsp)
+{
+    enum mcheck_type rc = mcheck_none;
+
+    if (bsp) {
+        /* Early MCE initialization for BSP. */
+        register_cpu_notifier(&cpu_nfb);
+    }
+
+    switch (ci->x86) {
+    case 6:
+        rc = amd_k7_mcheck_init(ci);
+        break;
+
+    default:
+        /* Assume that machine check support is available.
+         * The minimum provided support is at least the K8. */
+    case 0xf:
+        rc = amd_k8_mcheck_init(ci);
+        break;
+
+    case 0x10 ... 0x17:
+        rc = amd_f10_mcheck_init(ci);
+        break;
+    }
+
+    return rc;
+}
diff -r 7abb25095de0 xen/arch/x86/cpu/mcheck/mce_amd.h
--- a/xen/arch/x86/cpu/mcheck/mce_amd.h	Thu Oct 25 13:15:19 2012 +0200
+++ b/xen/arch/x86/cpu/mcheck/mce_amd.h	Thu Oct 25 15:13:24 2012 +0200
@@ -1,6 +1,10 @@
 #ifndef _MCHECK_AMD_H
 #define _MCHECK_AMD_H
 
+enum mcheck_type amd_k7_mcheck_init(struct cpuinfo_x86 *c);
+enum mcheck_type amd_k8_mcheck_init(struct cpuinfo_x86 *c);
+enum mcheck_type amd_f10_mcheck_init(struct cpuinfo_x86 *c);
+
 int mc_amd_recoverable_scan(uint64_t status);
 int mc_amd_addrcheck(uint64_t status, uint64_t misc, int addrtype);