linux-kernel - Re: [PATCH v2 2/5] KVM: MMU: check guest CR3 reserved bits based on its physical address width.

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Message-ID: <8c3819cb-1c1f-5a83-02eb-226aea0f329f@linux.intel.com>
Date:   Thu, 17 Aug 2017 20:25:10 +0800
From:   Yu Zhang <yu.c.zhang@...ux.intel.com>
To:     Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, rkrcmar@...hat.com,
        tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        xiaoguangrong@...cent.com, joro@...tes.org
Subject: Re: [PATCH v2 2/5] KVM: MMU: check guest CR3 reserved bits based on
 its physical address width.



On 8/17/2017 8:31 PM, Paolo Bonzini wrote:
> On 17/08/2017 21:52, Yu Zhang wrote:
>> +		if (efer & EFER_LMA) {
>> +			u64 maxphyaddr;
>> +			u32 eax = 0x80000008;
>> +
>> +			if (ctxt->ops->get_cpuid(ctxt, &eax, NULL, NULL, NULL,
>> +						 NO_CHECK_LIMIT)) {
>> +				maxphyaddr = eax & 0xff;
>> +				rsvd = rsvd_bits(maxphyaddr, 62);
>> +			}
> You should use 36 here if ctxt->ops->get_cpuid returns false, for
> consistency with cpuid_query_maxphyaddr.

Oh, right. Thanks! :-)

Yu