Changes between Version 2 and Version 3 of VirtualBox_architecture

Timestamp:

Feb 9, 2007 1:19:50 PM (17 years ago)

Author:

umoeller

Comment:

--

VirtualBox_architecture

@@ -66 +66 @@
  * '''Host context (HC)''' means that the host OS is in control of everything including virtual memory. In the !VirtualBox sources, the term "HC" will normally refer to the host's ring-3 context only. We only use host ring-0 (R0) context with our new Intel VT-x (Vanderpool) support, which we'll leave out of the picture for now (but see below).
 
- * '''Guest context (GC)''' means that !VirtualBox has set up CPU & memory exactly the way the guest expects, but has inserted itself at the "bottom" of the picture, so that !VirtualBox gains control ''first'' for any privileged instructions executed, guest trap or external interrupts, before !VirtualBox may then possibly delegate handling such things to the host OS. So, in the guest context, we have 
+ * '''Guest context (GC)''' means that basically the guest OS in control, but with !VirtualBox keeping a watch on things in the background. Here, !VirtualBox has set up CPU & memory exactly the way the guest expects, but it has inserted itself at the "bottom" of the picture. It can then assume control when nasty things happen -- if a privileged instruction is executed, the guest traps or external interrupts occur. !VirtualBox may then possibly delegate handling such things to the host OS. So, in the guest context, we have 
    * ring 3 (hopefully executed in "raw mode" all the time);
    * ring 1 (of which the guest thinks it's ring 0, see above), and