From: Dongxiao Xu <dongxiao.xu@intel.com>
Date: Thu, 6 Dec 2012 16:56:49 +0000 (+0000)
Subject: nested vmx: fix DR access VM exit
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~7550
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=4a069acdbdc89bafca1da3c88830d97d5105c296;p=xen.git

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>
---

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index dab9551358..02a7052234 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -1641,7 +1641,8 @@ int nvmx_n2_vmexit_handler(struct cpu_user_regs *regs,
         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: