Re: QEMU PIC indirection patch for in-kernel APIC work

Dor Laor
2007-04-04T15:47:58Z

>>> This is for the TPR right? VT has special logic to handle TPR
>>> virtualization doesn't it? I thought SVM did too...
>>>
>>
>> Yes, the TPR. Both VT and SVM virtualize CR8 in 64-bit mode. SVM
>> also supports CR8 in 32-bit mode through a nwe instruction encoding,
>> but
>> nobody uses that to my knowledge. Maybe some brave soul can hack kvm
>> to patch the new instruction in place of the mmio instruction Windows
>> uses
>> to bang on the tpr.
>
>Actually VT has virtual TPR support that does not require CR8. We
>submitted a patch for Xen. Please see
>http://lists.xensource.com/archives/html/xen-devel/2007-03/msg00993.htm
l
>The spec should be available soon. We are working on a patch for KVM.
>
>Jun

That's superb! Windows gives us really bad time with all of those TPR
accesses. Because of that we currently prefer of using the non-acpi HAL.

On what version on chip is this feature supported?

This pushes towards in kernel apic too. Can't see how we avoid it.