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RE: [Xen-devel] [PATCH 06/16] vmx: nest: handling VMX instruction exits



Tim Deegan wrote:
> At 08:05 +0100 on 10 Sep (1284105901), Dong, Eddie wrote:
>> Qing He wrote:
>>> +static int __clear_current_vvmcs(struct vmx_nest_struct *nest) +{
>>> +    int rc;
>>> +
>>> +    if ( nest->svmcs )
>>> +        __vmpclear(virt_to_maddr(nest->svmcs));
>>> +
>>> +#if !CONFIG_VVMCS_MAPPING
>>> +    rc = hvm_copy_to_guest_phys(nest->gvmcs_pa, nest->vvmcs,
>> 
>> 
>> Qing:
>>      Why this may be failure? The only reason may be nest->gvmcs_pa, but
>> I guess we already verified the address. 
>> 
> 
> It was verified at load time, but the guest could have ballooned it
> out in the meantime.

If the L1 guest allocated that GPA as VMCS memory, it can't balloon them out.
If L1 is a mallicious guest and ballooned the VMCS memory out, it is worthy to 
do. Not?

> 
> Cheers,
> 

Thx, Eddie
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