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Commit 2f4f3372 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: move audit to a separate file 



Move the audit code from arch/x86/kvm/mmu.c to arch/x86/kvm/mmu_audit.c

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 8b1fe17c

arch/x86/kvm/mmu.c

+1 −278
Original line number Diff line number Diff line
@@ -3490,282 +3490,5 @@ int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]) 
EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);



#ifdef CONFIG_KVM_MMU_AUDIT

static const char *audit_msg;



typedef void (*inspect_spte_fn) (struct kvm *kvm, u64 *sptep);



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

			    inspect_spte_fn fn)

{

	int i;



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

		u64 ent = sp->spt[i];



		if (is_shadow_present_pte(ent)) {

			if (!is_last_spte(ent, sp->role.level)) {

				struct kvm_mmu_page *child;

				child = page_header(ent & PT64_BASE_ADDR_MASK);

				__mmu_spte_walk(kvm, child, fn);

			} else

				fn(kvm, &sp->spt[i]);

		}

	}

}



static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)

{

	int i;

	struct kvm_mmu_page *sp;



	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))

		return;

	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {

		hpa_t root = vcpu->arch.mmu.root_hpa;

		sp = page_header(root);

		__mmu_spte_walk(vcpu->kvm, sp, fn);

		return;

	}

	for (i = 0; i < 4; ++i) {

		hpa_t root = vcpu->arch.mmu.pae_root[i];



		if (root && VALID_PAGE(root)) {

			root &= PT64_BASE_ADDR_MASK;

			sp = page_header(root);

			__mmu_spte_walk(vcpu->kvm, sp, fn);

		}

	}

	return;

}



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

				gva_t va, int level)

{

	u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);

	int i;

	gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));



	for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {

		u64 *sptep = pt + i;

		struct kvm_mmu_page *sp;

		gfn_t gfn;

		pfn_t pfn;

		hpa_t hpa;



		sp = page_header(__pa(sptep));



		if (sp->unsync) {

			if (level != PT_PAGE_TABLE_LEVEL) {

				printk(KERN_ERR "audit: (%s) error: unsync sp: %p level = %d\n",

						audit_msg, sp, level);

				return;

			}



			if (*sptep == shadow_notrap_nonpresent_pte) {

				printk(KERN_ERR "audit: (%s) error: notrap spte in unsync sp: %p\n",

						audit_msg, sp);

				return;

			}

		}



		if (sp->role.direct && *sptep == shadow_notrap_nonpresent_pte) {

			printk(KERN_ERR "audit: (%s) error: notrap spte in direct sp: %p\n",

					audit_msg, sp);

			return;

		}



		if (!is_shadow_present_pte(*sptep) ||

		      !is_last_spte(*sptep, level))

			return;



		gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt);

		pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn);



		if (is_error_pfn(pfn)) {

			kvm_release_pfn_clean(pfn);

			return;

		}



		hpa =  pfn << PAGE_SHIFT;



		if ((*sptep & PT64_BASE_ADDR_MASK) != hpa)

			printk(KERN_ERR "xx audit error: (%s) levels %d"

					   " gva %lx pfn %llx hpa %llx ent %llxn",

					   audit_msg, vcpu->arch.mmu.root_level,

					   va, pfn, hpa, *sptep);

	}

}



static void audit_mappings(struct kvm_vcpu *vcpu)

{

	unsigned i;



	if (vcpu->arch.mmu.root_level == 4)

		audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);

	else

		for (i = 0; i < 4; ++i)

			if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)

				audit_mappings_page(vcpu,

						    vcpu->arch.mmu.pae_root[i],

						    i << 30,

						    2);

}



void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)

{

	unsigned long *rmapp;

	struct kvm_mmu_page *rev_sp;

	gfn_t gfn;





	rev_sp = page_header(__pa(sptep));

	gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);



	if (!gfn_to_memslot(kvm, gfn)) {

		if (!printk_ratelimit())

			return;

		printk(KERN_ERR "%s: no memslot for gfn %llx\n",

				 audit_msg, gfn);

		printk(KERN_ERR "%s: index %ld of sp (gfn=%llx)\n",

		       audit_msg, (long int)(sptep - rev_sp->spt),

				rev_sp->gfn);

		dump_stack();

		return;

	}



	rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);

	if (!*rmapp) {

		if (!printk_ratelimit())

			return;

		printk(KERN_ERR "%s: no rmap for writable spte %llx\n",

				 audit_msg, *sptep);

		dump_stack();

	}

}



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)

{

	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;



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

			if (!is_rmap_spte(pt[i]))

				continue;



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

		}

	}

	return;

}



static void audit_rmap(struct kvm_vcpu *vcpu)

{

	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;



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

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



		spte = rmap_next(vcpu->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);

		}

	}

}



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);

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

		audit_mappings(vcpu);

	audit_sptes_have_rmaps(vcpu);

}



static bool mmu_audit;



static void mmu_audit_enable(void)

{

	int ret;



	if (mmu_audit)

		return;



	ret = register_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);

	WARN_ON(ret);



	mmu_audit = true;

}



static void mmu_audit_disable(void)

{

	if (!mmu_audit)

		return;



	unregister_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);

	tracepoint_synchronize_unregister();

	mmu_audit = false;

}



static int mmu_audit_set(const char *val, const struct kernel_param *kp)

{

	int ret;

	unsigned long enable;



	ret = strict_strtoul(val, 10, &enable);

	if (ret < 0)

		return -EINVAL;



	switch (enable) {

	case 0:

		mmu_audit_disable();

		break;

	case 1:

		mmu_audit_enable();

		break;

	default:

		return -EINVAL;

	}



	return 0;

}



static struct kernel_param_ops audit_param_ops = {

	.set = mmu_audit_set,

	.get = param_get_bool,

};



module_param_cb(mmu_audit, &audit_param_ops, &mmu_audit, 0644);

#include "mmu_audit.c"

#endif

arch/x86/kvm/mmu_audit.c

0 → 100644
+297 −0
Original line number Diff line number Diff line 
/*

 * mmu_audit.c:

 *

 * Audit code for KVM MMU

 *

 * Copyright (C) 2006 Qumranet, Inc.

 * Copyright 2010 Red Hat, Inc. and/or its affilates.

 *

 * Authors:

 *   Yaniv Kamay  <yaniv@qumranet.com>

 *   Avi Kivity   <avi@qumranet.com>

 *   Marcelo Tosatti <mtosatti@redhat.com>

 *   Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 *

 */



static const char *audit_msg;



typedef void (*inspect_spte_fn) (struct kvm *kvm, u64 *sptep);



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

			    inspect_spte_fn fn)

{

	int i;



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

		u64 ent = sp->spt[i];



		if (is_shadow_present_pte(ent)) {

			if (!is_last_spte(ent, sp->role.level)) {

				struct kvm_mmu_page *child;

				child = page_header(ent & PT64_BASE_ADDR_MASK);

				__mmu_spte_walk(kvm, child, fn);

			} else

				fn(kvm, &sp->spt[i]);

		}

	}

}



static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)

{

	int i;

	struct kvm_mmu_page *sp;



	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))

		return;

	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {

		hpa_t root = vcpu->arch.mmu.root_hpa;

		sp = page_header(root);

		__mmu_spte_walk(vcpu->kvm, sp, fn);

		return;

	}

	for (i = 0; i < 4; ++i) {

		hpa_t root = vcpu->arch.mmu.pae_root[i];



		if (root && VALID_PAGE(root)) {

			root &= PT64_BASE_ADDR_MASK;

			sp = page_header(root);

			__mmu_spte_walk(vcpu->kvm, sp, fn);

		}

	}

	return;

}



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

				gva_t va, int level)

{

	u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);

	int i;

	gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));



	for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {

		u64 *sptep = pt + i;

		struct kvm_mmu_page *sp;

		gfn_t gfn;

		pfn_t pfn;

		hpa_t hpa;



		sp = page_header(__pa(sptep));



		if (sp->unsync) {

			if (level != PT_PAGE_TABLE_LEVEL) {

				printk(KERN_ERR "audit: (%s) error: unsync sp: %p level = %d\n",

						audit_msg, sp, level);

				return;

			}



			if (*sptep == shadow_notrap_nonpresent_pte) {

				printk(KERN_ERR "audit: (%s) error: notrap spte in unsync sp: %p\n",

						audit_msg, sp);

				return;

			}

		}



		if (sp->role.direct && *sptep == shadow_notrap_nonpresent_pte) {

			printk(KERN_ERR "audit: (%s) error: notrap spte in direct sp: %p\n",

					audit_msg, sp);

			return;

		}



		if (!is_shadow_present_pte(*sptep) ||

		      !is_last_spte(*sptep, level))

			return;



		gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt);

		pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn);



		if (is_error_pfn(pfn)) {

			kvm_release_pfn_clean(pfn);

			return;

		}



		hpa =  pfn << PAGE_SHIFT;



		if ((*sptep & PT64_BASE_ADDR_MASK) != hpa)

			printk(KERN_ERR "xx audit error: (%s) levels %d"

					   " gva %lx pfn %llx hpa %llx ent %llxn",

					   audit_msg, vcpu->arch.mmu.root_level,

					   va, pfn, hpa, *sptep);

	}

}



static void audit_mappings(struct kvm_vcpu *vcpu)

{

	unsigned i;



	if (vcpu->arch.mmu.root_level == 4)

		audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);

	else

		for (i = 0; i < 4; ++i)

			if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)

				audit_mappings_page(vcpu,

						    vcpu->arch.mmu.pae_root[i],

						    i << 30,

						    2);

}



void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)

{

	unsigned long *rmapp;

	struct kvm_mmu_page *rev_sp;

	gfn_t gfn;





	rev_sp = page_header(__pa(sptep));

	gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);



	if (!gfn_to_memslot(kvm, gfn)) {

		if (!printk_ratelimit())

			return;

		printk(KERN_ERR "%s: no memslot for gfn %llx\n",

				 audit_msg, gfn);

		printk(KERN_ERR "%s: index %ld of sp (gfn=%llx)\n",

		       audit_msg, (long int)(sptep - rev_sp->spt),

				rev_sp->gfn);

		dump_stack();

		return;

	}



	rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);

	if (!*rmapp) {

		if (!printk_ratelimit())

			return;

		printk(KERN_ERR "%s: no rmap for writable spte %llx\n",

				 audit_msg, *sptep);

		dump_stack();

	}

}



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)

{

	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;



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

			if (!is_rmap_spte(pt[i]))

				continue;



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

		}

	}

	return;

}



static void audit_rmap(struct kvm_vcpu *vcpu)

{

	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;



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

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



		spte = rmap_next(vcpu->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);

		}

	}

}



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);

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

		audit_mappings(vcpu);

	audit_sptes_have_rmaps(vcpu);

}



static bool mmu_audit;



static void mmu_audit_enable(void)

{

	int ret;



	if (mmu_audit)

		return;



	ret = register_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);

	WARN_ON(ret);



	mmu_audit = true;

}



static void mmu_audit_disable(void)

{

	if (!mmu_audit)

		return;



	unregister_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);

	tracepoint_synchronize_unregister();

	mmu_audit = false;

}



static int mmu_audit_set(const char *val, const struct kernel_param *kp)

{

	int ret;

	unsigned long enable;



	ret = strict_strtoul(val, 10, &enable);

	if (ret < 0)

		return -EINVAL;



	switch (enable) {

	case 0:

		mmu_audit_disable();

		break;

	case 1:

		mmu_audit_enable();

		break;

	default:

		return -EINVAL;

	}



	return 0;

}



static struct kernel_param_ops audit_param_ops = {

	.set = mmu_audit_set,

	.get = param_get_bool,

};



module_param_cb(mmu_audit, &audit_param_ops, &mmu_audit, 0644);