Changes between Version 14 and Version 15 of VirtualBox architecture

Timestamp:

Nov 16, 2006 5:20:07 PM (17 years ago)

Author:

jose

Comment:

--

VirtualBox architecture

@@ -48 +48 @@
     * for execution of certain single instructions; this typically happens when a nasty guest instruction such as `LIDT` has caused a trap and needs to be emulated;
     * for any real-mode code (e.g. BIOS code, a DOS guest, or any operating system startup).
- 3. Your CPU  can be '''running guest ring-3 code natively''' (within the ring-3 host VM process). In !VirtualBox, this is called "raw ring 3". This is, of course, the most efficient way to run the guest, and hopefully we don't leave this mode too often. The more we do, the slower the VM is compared to a native OS, because all context switches are very expensive.
+ 3. Your CPU  can be '''running guest ring-3 code natively''' (within the ring-3 host VM process). With !VirtualBox, we call this "raw ring 3". This is, of course, the most efficient way to run the guest, and hopefully we don't leave this mode too often. The more we do, the slower the VM is compared to a native OS, because all context switches are very expensive.
  4. Your CPU  can be '''running guest ring-0 code natively.''' Here is where things get hairy: The guest only ''thinks'' it's running ring-0 code, but !VirtualBox has patched the guest OS to instead enter ring 1 (which is normally unused with x86 operating systems).