RE: [Xen-devel] WRITE_MSR

["Kaushik Barde" <Kaushik_Barde@xxxxxxxxxxx>]

Setting values by default may not be a good coding practice, if you want to do that you find a common place and set it once. Of course, if you are always sure of a result and still want to compare before setting also is quite unnecessary.

 

-Kaushik

 

---

From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Dong, Eddie
Sent: Thursday, May 10, 2007 8:12 AM
To: xen-devel
Subject: [Xen-devel] WRITE_MSR

Not sure why we do test_bit and then set_bit rather than set_bit directly. Any comments?

 

 

 

 

diff -r 3ef0510e44d0 xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c        Tue May 08 10:21:23 2007 +0100
+++ b/xen/arch/x86/hvm/vmx/vmx.c        Thu May 10 23:09:19 2007 +0800
@@ -103,8 +103,7 @@ static void vmx_save_host_msrs(void)

 

 #define WRITE_MSR(address)                                                  \
         guest_msr_state->msrs[VMX_INDEX_MSR_ ## address] = msr_content;     \
-        if ( !test_bit(VMX_INDEX_MSR_ ## address, &guest_msr_state->flags) )\
-            set_bit(VMX_INDEX_MSR_ ## address, &guest_msr_state->flags);    \
+        set_bit(VMX_INDEX_MSR_ ## address, &guest_msr_state->flags);    \
         wrmsrl(MSR_ ## address, msr_content);                               \
         set_bit(VMX_INDEX_MSR_ ## address, &host_msr_state->flags);         \
         break

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel