File 26254-VMX-nested-dr.patch of Package xen

# HG changeset patch
# User Dongxiao Xu <dongxiao.xu@intel.com>
# Date 1354813009 0
# Node ID e6eb1e52da7cfcb1a7697b35b4d842f35107d1ed
# Parent  a09150b57ace2fa786dcaefa958f0b197b1b6d4c
nested vmx: fix DR access VM exit

For DR register, we use lazy restore mechanism when access
it. Therefore when receiving such VM exit, L0 should be responsible to
switch to the right DR values, then inject to L1 hypervisor.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Committed-by: Keir Fraser <keir@xen.org>

--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -1585,7 +1585,8 @@ int nvmx_n2_vmexit_handler(struct cpu_us
         break;
     case EXIT_REASON_DR_ACCESS:
         ctrl = __n2_exec_control(v);
-        if ( ctrl & CPU_BASED_MOV_DR_EXITING )
+        if ( (ctrl & CPU_BASED_MOV_DR_EXITING) &&
+            v->arch.hvm_vcpu.flag_dr_dirty )
             nvcpu->nv_vmexit_pending = 1;
         break;
     case EXIT_REASON_INVLPG: