On Wed, Jan 28, 2015 at 9:06 PM, Zhang, Yang Z <yang.z.zhang@xxxxxxxxx> wrote:
>>>> __clear_bit(msr, msr_bitmap_nested + 0x000 / f);
>>>
>>>
>>> Anyway, this is not necessary for your current patch. We can consider
>>> it later if there really have other features will use it.
>>>
>>
>> Yep, I know what you mean now, for other msrs which are not forwarded
>> access by a mechanism like virtual-apic page, we should intercept it
>> unconditionally. I think we should ensure the msr can be allowed
>> before call nested_vmx_disable_intercept_for_msr, if L0 want to
>> intercept it, just do not call nested_vmx_disable_intercept_for_msr.
>
> Yes, this is a solution. But I prefer to handle it in nested code path since others may not familiar with nested and may block it by mistake.
>
>>
>> !test_bit(msr, vmcs01_msr_bitmap) will introduce a problem that some
>> of the msrs will be affcted by vmcs01_msr_bitmap, TMCCT and TPR, for example.
>> Intercept reading for these msrs is okay, but it is not efficient.
>
> TMCCT is always trapped by most VMM. I don't think TPR is trapped in KVM.
>
Oooops. This piece of code made me confused and I was not think about
that words, just forget it.
( * ^ _ ^ * )
vmx_enable_intercept_msr_read_x2apic(0x802);
/* TMCCT */
vmx_enable_intercept_msr_read_x2apic(0x839);
/* TPR */
If there are any features use it in the future, let's consider about
this, thank you for your patience.
Thanks,
Wincy
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
