Commit b034cf01 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: audit: allow audit more guests at the same time 



It only allows to audit one guest in the system since:
- 'audit_point' is a glob variable
- mmu_audit_disable() is called in kvm_mmu_destroy(), so audit is disabled
  after a guest exited

this patch fix those issues then allow to audit more guests at the same time

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent aff48baa

arch/x86/include/asm/kvm_host.h

+4 −0
Original line number Diff line number Diff line
@@ -461,6 +461,10 @@ struct kvm_arch { 
	/* fields used by HYPER-V emulation */

	u64 hv_guest_os_id;

	u64 hv_hypercall;



	#ifdef CONFIG_KVM_MMU_AUDIT

	int audit_point;

	#endif

};



struct kvm_vm_stat {

arch/x86/kvm/mmu.c

+13 −13
Original line number Diff line number Diff line
@@ -3534,13 +3534,6 @@ static void mmu_destroy_caches(void) 
		kmem_cache_destroy(mmu_page_header_cache);

}



void kvm_mmu_module_exit(void)

{

	mmu_destroy_caches();

	percpu_counter_destroy(&kvm_total_used_mmu_pages);

	unregister_shrinker(&mmu_shrinker);

}



int kvm_mmu_module_init(void)

{

	pte_chain_cache = kmem_cache_create("kvm_pte_chain",
@@ -3733,12 +3726,6 @@ 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

#include "mmu_audit.c"

#else

static void mmu_audit_disable(void) { }

#endif



void kvm_mmu_destroy(struct kvm_vcpu *vcpu)

{

	ASSERT(vcpu);
@@ -3746,5 +3733,18 @@ void kvm_mmu_destroy(struct kvm_vcpu *vcpu) 
	destroy_kvm_mmu(vcpu);

	free_mmu_pages(vcpu);

	mmu_free_memory_caches(vcpu);

}



#ifdef CONFIG_KVM_MMU_AUDIT

#include "mmu_audit.c"

#else

static void mmu_audit_disable(void) { }

#endif



void kvm_mmu_module_exit(void)

{

	mmu_destroy_caches();

	percpu_counter_destroy(&kvm_total_used_mmu_pages);

	unregister_shrinker(&mmu_shrinker);

	mmu_audit_disable();

}

arch/x86/kvm/mmu_audit.c

+22 −17
Original line number Diff line number Diff line
@@ -19,11 +19,9 @@ 


#include <linux/ratelimit.h>



static int audit_point;



#define audit_printk(fmt, args...)		\

#define audit_printk(kvm, fmt, args...)		\

	printk(KERN_ERR "audit: (%s) error: "	\

		fmt, audit_point_name[audit_point], ##args)

		fmt, audit_point_name[kvm->arch.audit_point], ##args)



typedef void (*inspect_spte_fn) (struct kvm_vcpu *vcpu, u64 *sptep, int level);
@@ -97,18 +95,21 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level) 


	if (sp->unsync) {

		if (level != PT_PAGE_TABLE_LEVEL) {

			audit_printk("unsync sp: %p level = %d\n", sp, level);

			audit_printk(vcpu->kvm, "unsync sp: %p "

				     "level = %d\n", sp, level);

			return;

		}



		if (*sptep == shadow_notrap_nonpresent_pte) {

			audit_printk("notrap spte in unsync sp: %p\n", sp);

			audit_printk(vcpu->kvm, "notrap spte in unsync "

				     "sp: %p\n", sp);

			return;

		}

	}



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

		audit_printk("notrap spte in direct sp: %p\n", sp);

		audit_printk(vcpu->kvm, "notrap spte in direct sp: %p\n",

			     sp);

		return;

	}
@@ -125,8 +126,9 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level) 


	hpa =  pfn << PAGE_SHIFT;

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

		audit_printk("levels %d pfn %llx hpa %llx ent %llxn",

				   vcpu->arch.mmu.root_level, pfn, hpa, *sptep);

		audit_printk(vcpu->kvm, "levels %d pfn %llx hpa %llx "

			     "ent %llxn", vcpu->arch.mmu.root_level, pfn,

			     hpa, *sptep);

}



static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
@@ -142,8 +144,8 @@ static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep) 
	if (!gfn_to_memslot(kvm, gfn)) {

		if (!printk_ratelimit())

			return;

		audit_printk("no memslot for gfn %llx\n", gfn);

		audit_printk("index %ld of sp (gfn=%llx)\n",

		audit_printk(kvm, "no memslot for gfn %llx\n", gfn);

		audit_printk(kvm, "index %ld of sp (gfn=%llx)\n",

		       (long int)(sptep - rev_sp->spt), rev_sp->gfn);

		dump_stack();

		return;
@@ -153,7 +155,8 @@ static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep) 
	if (!*rmapp) {

		if (!printk_ratelimit())

			return;

		audit_printk("no rmap for writable spte %llx\n", *sptep);

		audit_printk(kvm, "no rmap for writable spte %llx\n",

			     *sptep);

		dump_stack();

	}

}
@@ -168,8 +171,9 @@ static void audit_spte_after_sync(struct kvm_vcpu *vcpu, u64 *sptep, int level) 
{

	struct kvm_mmu_page *sp = page_header(__pa(sptep));



	if (audit_point == AUDIT_POST_SYNC && sp->unsync)

		audit_printk("meet unsync sp(%p) after sync root.\n", sp);

	if (vcpu->kvm->arch.audit_point == AUDIT_POST_SYNC && sp->unsync)

		audit_printk(vcpu->kvm, "meet unsync sp(%p) after sync "

			     "root.\n", sp);

}



static void check_mappings_rmap(struct kvm *kvm, struct kvm_mmu_page *sp)
@@ -202,8 +206,9 @@ static void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp) 
	spte = rmap_next(kvm, rmapp, NULL);

	while (spte) {

		if (is_writable_pte(*spte))

			audit_printk("shadow page has writable mappings: gfn "

				     "%llx role %x\n", sp->gfn, sp->role.word);

			audit_printk(kvm, "shadow page has writable "

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

				     sp->gfn, sp->role.word);

		spte = rmap_next(kvm, rmapp, spte);

	}

}
@@ -238,7 +243,7 @@ static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int point) 
	if (!__ratelimit(&ratelimit_state))

		return;



	audit_point = point;

	vcpu->kvm->arch.audit_point = point;

	audit_all_active_sps(vcpu->kvm);

	audit_vcpu_spte(vcpu);

}

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