Commit 56ca57f9 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Paolo Bonzini
Browse files

KVM: MMU: use page track for non-leaf shadow pages 



non-leaf shadow pages are always write protected, it can be the user
of page track

Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0eb05bf2

arch/x86/kvm/mmu.c

+21 −5
Original line number Diff line number Diff line
@@ -806,11 +806,17 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 
	struct kvm_memory_slot *slot;

	gfn_t gfn;



	kvm->arch.indirect_shadow_pages++;

	gfn = sp->gfn;

	slots = kvm_memslots_for_spte_role(kvm, sp->role);

	slot = __gfn_to_memslot(slots, gfn);



	/* the non-leaf shadow pages are keeping readonly. */

	if (sp->role.level > PT_PAGE_TABLE_LEVEL)

		return kvm_slot_page_track_add_page(kvm, slot, gfn,

						    KVM_PAGE_TRACK_WRITE);



	kvm_mmu_gfn_disallow_lpage(slot, gfn);

	kvm->arch.indirect_shadow_pages++;

}



static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
@@ -819,11 +825,15 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) 
	struct kvm_memory_slot *slot;

	gfn_t gfn;



	kvm->arch.indirect_shadow_pages--;

	gfn = sp->gfn;

	slots = kvm_memslots_for_spte_role(kvm, sp->role);

	slot = __gfn_to_memslot(slots, gfn);

	if (sp->role.level > PT_PAGE_TABLE_LEVEL)

		return kvm_slot_page_track_remove_page(kvm, slot, gfn,

						       KVM_PAGE_TRACK_WRITE);



	kvm_mmu_gfn_allow_lpage(slot, gfn);

	kvm->arch.indirect_shadow_pages--;

}



static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
@@ -2132,12 +2142,18 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, 
	hlist_add_head(&sp->hash_link,

		&vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]);

	if (!direct) {

		if (rmap_write_protect(vcpu, gfn))

		/*

		 * we should do write protection before syncing pages

		 * otherwise the content of the synced shadow page may

		 * be inconsistent with guest page table.

		 */

		account_shadowed(vcpu->kvm, sp);

		if (level == PT_PAGE_TABLE_LEVEL &&

		      rmap_write_protect(vcpu, gfn))

			kvm_flush_remote_tlbs(vcpu->kvm);



		if (level > PT_PAGE_TABLE_LEVEL && need_sync)

			kvm_sync_pages(vcpu, gfn);



		account_shadowed(vcpu->kvm, sp);

	}

	sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;

	clear_page(sp->spt);