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Commit 49edf878 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: improve active sp audit 



Both audit_rmap() and audit_write_protection() need to walk all active sp, so
we can do these checking in a sp walking

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 2f4f3372

arch/x86/kvm/mmu_audit.c

+38 −36
Original line number Diff line number Diff line
@@ -65,6 +65,16 @@ static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn) 
	return;

}



typedef void (*sp_handler) (struct kvm *kvm, struct kvm_mmu_page *sp);



static void walk_all_active_sps(struct kvm *kvm, sp_handler fn)

{

	struct kvm_mmu_page *sp;



	list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link)

		fn(kvm, sp);

}



static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,

				gva_t va, int level)

{
@@ -175,67 +185,59 @@ void audit_sptes_have_rmaps(struct kvm_vcpu *vcpu) 
	mmu_spte_walk(vcpu, inspect_spte_has_rmap);

}



static void check_mappings_rmap(struct kvm_vcpu *vcpu)

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

{

	struct kvm_mmu_page *sp;

	int i;



	list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {

		u64 *pt = sp->spt;



	if (sp->role.level != PT_PAGE_TABLE_LEVEL)

			continue;

		return;



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

			if (!is_rmap_spte(pt[i]))

		if (!is_rmap_spte(sp->spt[i]))

			continue;



			inspect_spte_has_rmap(vcpu->kvm, &pt[i]);

		inspect_spte_has_rmap(kvm, sp->spt + i);

	}

}

	return;

}



static void audit_rmap(struct kvm_vcpu *vcpu)

void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)

{

	check_mappings_rmap(vcpu);

}



static void audit_write_protection(struct kvm_vcpu *vcpu)

{

	struct kvm_mmu_page *sp;

	struct kvm_memory_slot *slot;

	unsigned long *rmapp;

	u64 *spte;



	list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {

		if (sp->role.direct)

			continue;

		if (sp->unsync)

			continue;

		if (sp->role.invalid)

			continue;

	if (sp->role.direct || sp->unsync || sp->role.invalid)

		return;



		slot = gfn_to_memslot(vcpu->kvm, sp->gfn);

	slot = gfn_to_memslot(kvm, sp->gfn);

	rmapp = &slot->rmap[sp->gfn - slot->base_gfn];



		spte = rmap_next(vcpu->kvm, rmapp, NULL);

	spte = rmap_next(kvm, rmapp, NULL);

	while (spte) {

		if (is_writable_pte(*spte))

			printk(KERN_ERR "%s: (%s) shadow page has "

				"writable mappings: gfn %llx role %x\n",

			       __func__, audit_msg, sp->gfn,

			       sp->role.word);

			spte = rmap_next(vcpu->kvm, rmapp, spte);

		spte = rmap_next(kvm, rmapp, spte);

	}

}



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

{

	check_mappings_rmap(kvm, sp);

	audit_write_protection(kvm, sp);

}



static void audit_all_active_sps(struct kvm *kvm)

{

	walk_all_active_sps(kvm, audit_sp);

}



static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int audit_point)

{

	audit_msg = audit_point_name[audit_point];

	audit_rmap(vcpu);

	audit_write_protection(vcpu);

	audit_all_active_sps(vcpu->kvm);

	if (strcmp("pre pte write", audit_msg) != 0)

		audit_mappings(vcpu);

	audit_sptes_have_rmaps(vcpu);