From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Subject: Re: [PATCH 6/7] KVM: MMU: Simplify spte fetch() function
Date: Mon, 12 Jul 2010 13:08:41 +0800
Message-ID: <4C3AA359.6020305@cn.fujitsu.com>
References: <1278862955-6890-1-git-send-email-avi@redhat.com> <1278862955-6890-7-git-send-email-avi@redhat.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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Avi Kivity wrote:

> -		if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep)
> -		    && level == gw->level)
> -			validate_direct_spte(vcpu, sptep, direct_access);

......

> +		link_shadow_page(sptep, sp);
> +	}
> +
> +	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);

Need validate_direct_spte() only when 'level == gw->level'