Commit 24157aaf authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: MMU: Eliminate redundant temporaries in FNAME(fetch) 



'level' and 'sptep' are aliases for 'interator.level' and 'iterator.sptep', no
need for them.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 5991b332

arch/x86/kvm/paging_tmpl.h

+24 −35
Original line number Diff line number Diff line
@@ -320,12 +320,10 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, 
{

	unsigned access = gw->pt_access;

	struct kvm_mmu_page *sp = NULL;

	u64 *sptep = NULL;

	int uninitialized_var(level);

	bool dirty = is_dirty_gpte(gw->ptes[gw->level - 1]);

	int top_level;

	unsigned direct_access;

	struct kvm_shadow_walk_iterator iterator;

	struct kvm_shadow_walk_iterator it;



	if (!is_present_gpte(gw->ptes[gw->level - 1]))

		return NULL;
@@ -346,68 +344,59 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, 
	if (FNAME(gpte_changed)(vcpu, gw, top_level))

		goto out_gpte_changed;



	for (shadow_walk_init(&iterator, vcpu, addr);

	     shadow_walk_okay(&iterator) && iterator.level > gw->level;

	     shadow_walk_next(&iterator)) {

	for (shadow_walk_init(&it, vcpu, addr);

	     shadow_walk_okay(&it) && it.level > gw->level;

	     shadow_walk_next(&it)) {

		gfn_t table_gfn;



		level = iterator.level;

		sptep = iterator.sptep;



		drop_large_spte(vcpu, sptep);

		drop_large_spte(vcpu, it.sptep);



		sp = NULL;

		if (!is_shadow_present_pte(*sptep)) {

			table_gfn = gw->table_gfn[level - 2];

			sp = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,

					      false, access, sptep);

		if (!is_shadow_present_pte(*it.sptep)) {

			table_gfn = gw->table_gfn[it.level - 2];

			sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,

					      false, access, it.sptep);

		}



		/*

		 * Verify that the gpte in the page we've just write

		 * protected is still there.

		 */

		if (FNAME(gpte_changed)(vcpu, gw, level - 1))

		if (FNAME(gpte_changed)(vcpu, gw, it.level - 1))

			goto out_gpte_changed;



		if (sp)

			link_shadow_page(sptep, sp);

			link_shadow_page(it.sptep, sp);

	}



	for (;

	     shadow_walk_okay(&iterator) && iterator.level > hlevel;

	     shadow_walk_next(&iterator)) {

	     shadow_walk_okay(&it) && it.level > hlevel;

	     shadow_walk_next(&it)) {

		gfn_t direct_gfn;



		level = iterator.level;

		sptep = iterator.sptep;



		validate_direct_spte(vcpu, sptep, direct_access);

		validate_direct_spte(vcpu, it.sptep, direct_access);



		drop_large_spte(vcpu, sptep);

		drop_large_spte(vcpu, it.sptep);



		if (is_shadow_present_pte(*sptep))

		if (is_shadow_present_pte(*it.sptep))

			continue;



		direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);

		direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);



		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, level-1,

				      true, direct_access, sptep);

		link_shadow_page(sptep, sp);

		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,

				      true, direct_access, it.sptep);

		link_shadow_page(it.sptep, sp);

	}



	sptep = iterator.sptep;

	level = iterator.level;



	mmu_set_spte(vcpu, sptep, access, gw->pte_access & access,

		     user_fault, write_fault, dirty, ptwrite, level,

	mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,

		     user_fault, write_fault, dirty, ptwrite, it.level,

		     gw->gfn, pfn, false, true);



	return sptep;

	return it.sptep;



out_gpte_changed:

	if (sp)

		kvm_mmu_put_page(sp, sptep);

		kvm_mmu_put_page(sp, it.sptep);

	kvm_release_pfn_clean(pfn);

	return NULL;

}