guest reports cpu usage of the host system when it shouldn't

[simulacrum111]

I am running an XP Home guest on a Kubuntu host.

SMP is enabled on the guest. Guest additions are installed.

The XP guest reports the cpu usage of the host machine when it shouldn't.

The XP guest itself is idle in that it is not running any user applications.

High cpu usage is reported by the guest when cpu intensive tasks are run in the host OS e.g. a parallel build of a large library.

The XP guest is extremely prone to crashes under high cpu load for applications it is running. It happens regardless of the particular application or set of applications.

It is my suspicion that the crashes and my asserted improper cpu usage reporting are linked somehow. This appears to be a major bug as the guest shoud not know what the host OS is doing. However this is my best guess since I don't yet understand why the guest OS would be affected "directly" by the host OS cpu usage - indirectly of course - directly...I don't understand.

A set of processes always spike in their cpu usage when the host OS begins a CPU intensive task: From most cpu intensive to least cpu intensive: csrss.exe System lsass.exe

Other processes spike in cpu use but not as much where csrss.exe and System often take turns in being most cpu intensive during the hosts cpu intensive work - again the guest itself is idle in that it is running no user space applications.

[simulacrum111]

The following link on the virtualbox forums discusses the bug and has other pertinent information.

​http://forums.virtualbox.org/viewtopic.php?f=2&t=22084

[Sander van Leeuwen]

3.0.10 contains guest SMP fixes to address such issues. Reopen if necessary please.

As for the guest noticing high cpu usage on the host; I'd say that's quite normal.