Commit a9442f59 authored by Ben Gardon's avatar Ben Gardon Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Factor out functions to add/remove TDP MMU pages 



Move the work of adding and removing TDP MMU pages to/from  "secondary"
data structures to helper functions. These functions will be built on in
future commits to enable MMU operations to proceed (mostly) in parallel.

No functional change expected.

Signed-off-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-20-bgardon@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 531810ca

arch/x86/kvm/mmu/tdp_mmu.c

+39 −8
Original line number Diff line number Diff line
@@ -262,6 +262,39 @@ static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn, 
	}

}



/**

 * tdp_mmu_link_page - Add a new page to the list of pages used by the TDP MMU

 *

 * @kvm: kvm instance

 * @sp: the new page

 * @account_nx: This page replaces a NX large page and should be marked for

 *		eventual reclaim.

 */

static void tdp_mmu_link_page(struct kvm *kvm, struct kvm_mmu_page *sp,

			      bool account_nx)

{

	lockdep_assert_held_write(&kvm->mmu_lock);



	list_add(&sp->link, &kvm->arch.tdp_mmu_pages);

	if (account_nx)

		account_huge_nx_page(kvm, sp);

}



/**

 * tdp_mmu_unlink_page - Remove page from the list of pages used by the TDP MMU

 *

 * @kvm: kvm instance

 * @sp: the page to be removed

 */

static void tdp_mmu_unlink_page(struct kvm *kvm, struct kvm_mmu_page *sp)

{

	lockdep_assert_held_write(&kvm->mmu_lock);



	list_del(&sp->link);

	if (sp->lpage_disallowed)

		unaccount_huge_nx_page(kvm, sp);

}



/**

 * handle_removed_tdp_mmu_page - handle a pt removed from the TDP structure

 *
@@ -281,10 +314,7 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, u64 *pt) 


	trace_kvm_mmu_prepare_zap_page(sp);



	list_del(&sp->link);



	if (sp->lpage_disallowed)

		unaccount_huge_nx_page(kvm, sp);

	tdp_mmu_unlink_page(kvm, sp);



	for (i = 0; i < PT64_ENT_PER_PAGE; i++) {

		old_child_spte = READ_ONCE(*(pt + i));
@@ -705,15 +735,16 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 


		if (!is_shadow_present_pte(iter.old_spte)) {

			sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level);

			list_add(&sp->link, &vcpu->kvm->arch.tdp_mmu_pages);

			child_pt = sp->spt;



			tdp_mmu_link_page(vcpu->kvm, sp,

					  huge_page_disallowed &&

					  req_level >= iter.level);



			new_spte = make_nonleaf_spte(child_pt,

						     !shadow_accessed_mask);



			trace_kvm_mmu_get_page(sp, true);

			if (huge_page_disallowed && req_level >= iter.level)

				account_huge_nx_page(vcpu->kvm, sp);



			tdp_mmu_set_spte(vcpu->kvm, &iter, new_spte);

		}

	}