Re: [PATCH] KVM: MMU: Disassociate direct maps from guest levels

[Avi Kivity <avi@redhat.com>]

On 03/17/2010 08:16 PM, Marcelo Tosatti wrote:
> On Sun, Mar 14, 2010 at 10:22:52AM +0200, Avi Kivity wrote:
>    
>> Direct maps are linear translations for a section of memory, used for
>> real mode or with large pages.  As such, they are independent of the guest
>> levels.
>>
>> Teach the mmu about this by making page->role.glevels = 0 for direct maps.
>> This allows direct maps to be shared among real mode and the various paging
>> modes.
>>
>> @@ -1328,6 +1328,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
>>   	role = vcpu->arch.mmu.base_role;
>>   	role.level = level;
>>   	role.direct = direct;
>> +	if (role.direct)
>> +		role.glevels = 0;
>>   	role.access = access;
>>   	if (vcpu->arch.mmu.root_level<= PT32_ROOT_LEVEL) {
>>   		quadrant = gaddr>>  (PAGE_SHIFT + (PT64_PT_BITS * level));
>> -- 
>> 1.7.0.2
>>      
> Isnt this what happens already, since for tdp base_role.glevels is not
> initialized?
>    

Correct.  I was thinking about the nested npt case, which will use 
role.glevels.  Joerg, please incorporate this into your nnpt patchset.

-- 
error compiling committee.c: too many arguments to function