Commit 2d11123a authored by Avi Kivity's avatar Avi Kivity
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KVM: MMU: Add for_each_shadow_entry(), a simpler alternative to walk_shadow() 



Using a for_each loop style removes the need to write callback and nasty
casts.

Implement the walk_shadow() using the for_each_shadow_entry().

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 971cc3dc

arch/x86/kvm/mmu.c

+49 −20
Original line number Diff line number Diff line
@@ -150,6 +150,20 @@ struct kvm_shadow_walk { 
		     u64 addr, u64 *spte, int level);

};



struct kvm_shadow_walk_iterator {

	u64 addr;

	hpa_t shadow_addr;

	int level;

	u64 *sptep;

	unsigned index;

};



#define for_each_shadow_entry(_vcpu, _addr, _walker)    \

	for (shadow_walk_init(&(_walker), _vcpu, _addr);	\

	     shadow_walk_okay(&(_walker));			\

	     shadow_walk_next(&(_walker)))





struct kvm_unsync_walk {

	int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk);

};
@@ -1254,33 +1268,48 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 
	return sp;

}



static int walk_shadow(struct kvm_shadow_walk *walker,

static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,

			     struct kvm_vcpu *vcpu, u64 addr)

{

	hpa_t shadow_addr;

	int level;

	int r;

	u64 *sptep;

	unsigned index;

	iterator->addr = addr;

	iterator->shadow_addr = vcpu->arch.mmu.root_hpa;

	iterator->level = vcpu->arch.mmu.shadow_root_level;

	if (iterator->level == PT32E_ROOT_LEVEL) {

		iterator->shadow_addr

			= vcpu->arch.mmu.pae_root[(addr >> 30) & 3];

		iterator->shadow_addr &= PT64_BASE_ADDR_MASK;

		--iterator->level;

		if (!iterator->shadow_addr)

			iterator->level = 0;

	}

}



	shadow_addr = vcpu->arch.mmu.root_hpa;

	level = vcpu->arch.mmu.shadow_root_level;

	if (level == PT32E_ROOT_LEVEL) {

		shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];

		shadow_addr &= PT64_BASE_ADDR_MASK;

		if (!shadow_addr)

			return 1;

		--level;

static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)

{

	if (iterator->level < PT_PAGE_TABLE_LEVEL)

		return false;

	iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);

	iterator->sptep	= ((u64 *)__va(iterator->shadow_addr)) + iterator->index;

	return true;

}



static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)

{

	iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;

	--iterator->level;

}



	while (level >= PT_PAGE_TABLE_LEVEL) {

		index = SHADOW_PT_INDEX(addr, level);

		sptep = ((u64 *)__va(shadow_addr)) + index;

		r = walker->entry(walker, vcpu, addr, sptep, level);

static int walk_shadow(struct kvm_shadow_walk *walker,

		       struct kvm_vcpu *vcpu, u64 addr)

{

	struct kvm_shadow_walk_iterator iterator;

	int r;



	for_each_shadow_entry(vcpu, addr, iterator) {

		r = walker->entry(walker, vcpu, addr,

				  iterator.sptep, iterator.level);

		if (r)

			return r;

		shadow_addr = *sptep & PT64_BASE_ADDR_MASK;

		--level;

	}

	return 0;

}