hvm: handle access to MSR_AMD64_NB_CFG

Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 59a835e3b61893f681bcc618aedb46a1d5f735ca..650c29af23dad7db2c8200ee632b5a9c3c57d368 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1842,8 +1842,9 @@ int hvm_msr_read_intercept(struct cpu_user_regs *regs)
         break;
 
     case MSR_K8_ENABLE_C1E:
-         /* There's no point in letting the guest see C-States.
-          * Further, this AMD-only register may be accessed if this HVM guest
+    case MSR_AMD64_NB_CFG:
+         /*
+          * These AMD-only registers may be accessed if this HVM guest
           * has been migrated to an Intel host. This fixes a guest crash
           * in this case.
           */
@@ -1949,6 +1950,10 @@ int hvm_msr_write_intercept(struct cpu_user_regs *regs)
             goto gp_fault;
         break;
 
+    case MSR_AMD64_NB_CFG:
+        /* ignore the write */
+        break;
+
     default:
         ret = mce_wrmsr(ecx, msr_content);
         if ( ret < 0 )