Re: [PATCH 6/7] KVM: MMU: Simplify spte fetch() function

[Avi Kivity <avi@redhat.com>]

On 07/11/2010 06:42 PM, Avi Kivity wrote:
> Paritition the function into three sections:
>
> - fetching indirect shadow pages (host_level>  guest_level)
> - fetching direct shadow pages (page_level<  host_level<= guest_level)
> - the final spte (page_level == host_level)
>
> Instead of the current spaghetti.
>    

> +
> +	for (;
> +	     shadow_walk_okay(&iterator)&&  iterator.level>  hlevel;
> +	     shadow_walk_next(&iterator)) {
> +		gfn_t direct_gfn;
> +
> +		level = iterator.level;
> +		sptep = iterator.sptep;
>
>   		drop_spte_if_large(vcpu, sptep);
>
>   		if (is_shadow_present_pte(*sptep))
>   			continue;
>
> -		if (level<= gw->level) {
> -			direct = 1;
> -			access = direct_access;
> -
> -			/*
> -			 * It is a large guest pages backed by small host pages,
> -			 * So we set @direct(@sp->role.direct)=1, and set
> -			 * @table_gfn(@sp->gfn)=the base page frame for linear
> -			 * translations.
> -			 */
> -			table_gfn = gw->gfn&  ~(KVM_PAGES_PER_HPAGE(level) - 1);
> -		} else {
> -			direct = 0;
> -			table_gfn = gw->table_gfn[level - 2];
> -		}
> -		sp = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
> -					       direct, access, sptep);
> -		if (!direct)
> -			if (!FNAME(validate_indirect_spte)(vcpu, sptep, sp,
> -							   gw, level)) {
> -				kvm_release_pfn_clean(pfn);
> -				sptep = NULL;
> -				break;
> -			}
> +		validate_direct_spte(vcpu, sptep, direct_access);
> +
> +		direct_gfn = gw->gfn&  ~(KVM_PAGES_PER_HPAGE(level) - 1);
>
> +		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, level-1,
> +				      true, direct_access, sptep);
>   		link_shadow_page(sptep, sp);
>   	}
>
>    

validate_direct_spte() should be before the 'continue' above, probably.

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