References: bnc#835896

# Commit 69962e19ed432570f6cdcfdb5f6f22d6e3c54e6c
# Date 2013-08-22 11:24:00 +0200
# Author Juergen Gross <juergen.gross@ts.fujitsu.com>
# Committer Jan Beulich <jbeulich@suse.com>
Correct X2-APIC HVM emulation

commit 6859874b61d5ddaf5289e72ed2b2157739b72ca5 ("x86/HVM: fix x2APIC
APIC_ID read emulation") introduced an error for the hvm emulation of
x2apic. Any try to write to APIC_ICR MSR will result in a GP fault.

Signed-off-by: Juergen Gross <juergen.gross@ts.fujitsu.com>

--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -868,6 +868,7 @@ int hvm_x2apic_msr_write(struct vcpu *v,
         rc = vlapic_reg_write(v, APIC_ICR2, (uint32_t)(msr_content >> 32));
         if ( rc )
             return rc;
+        break;
 
     case APIC_ICR2:
         return X86EMUL_UNHANDLEABLE;