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Subject: Re: [PATCH v3 2/5] KVM: MMU: check guest CR3 reserved bits based on
 its physical address width.
To: Yu Zhang <yu.c.zhang@linux.intel.com>, kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, rkrcmar@redhat.com, tglx@linutronix.de,
        mingo@redhat.com, hpa@zytor.com, xiaoguangrong@tencent.com,
        joro@8bytes.org
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 <35e285e7-168a-25e6-1053-c005da18c103@redhat.com>
 <f772ea78-12cc-7bde-de3c-19aa8aca6251@linux.intel.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <f199b361-e4ac-74f4-c039-185e19418a15@redhat.com>
Date: Thu, 24 Aug 2017 18:27:41 +0200
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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.

Paolo