id	summary	reporter	owner	description	type	status	component	version	resolution	keywords	cc	guest	host
9667	Cannot read TPR	confusedsushi		"I recently upgraded to VirtualBox 4.1.2, unfortunately I having some trouble with it.

Reading of the TPR does not seem to function, I tracked the problem down to the fact that reading the TPR just not return anything.

Reading is done by:

mov	 eax, DWORD PTR [ecx+edx]

with ecx holding the mapped APIC base address and edx the offset to the TPR. After the Instruction which seemed to be replaced by a vmmcall the eax register is not modified at all.

I remembered that my old virtual system which was set up with a Version of VirtualBox 3 running in VirtualBox 4.0.10 I don't had the problem, so I downgraded to 4.0.10, but still the problem, but the interesting thing is, that when i start the old virtual system I don't experience the problem.

 "	defect	closed	other	VirtualBox 4.1.2	fixed			other	Windows