Re: [PATCH v3 2/5] KVM: MMU: check guest CR3 reserved bits based on its physical address width.

From: Paolo Bonzini
Date: Thu Aug 24 2017 - 12:51:51 EST


On 24/08/2017 18:21, Yu Zhang wrote:
>
>
> On 8/25/2017 12:27 AM, Paolo Bonzini wrote:
>> On 24/08/2017 17:38, Yu Zhang wrote:
>>>>
>>>> In practice, MAXPHYADDR will never be 59 even because the PKRU bits are
>>>> at bits 59..62.
>>> Thanks, Paolo.
>>> I see. I had made an assumption that MAXPHYADDR shall not exceed the
>>> physical one,
>>> which is 52 I believe. But I'm not sure there's any place to check this.
>>> Maybe we should make sure the vcpu->arch.maxphyaddr will not be greater
>>> than the value of the host?
>> That's a separate change anyway. In any case, since currently the
>> MAXPHYADDR is not validated, your change to rsvd_bits makes sense.
>
> Thanks, Paolo.
> As to this patch series, any change I need do?

No, it's fine.

> BTW, I have written a patch for kvm-unit-test access test, but the test
> failed.
> Not sure if my patch is erroneous or due to a simulator error. I'll send
> out the
> test patch after it works.:-)

Try to send it. I can also test it with QEMU TCG.

Paolo