*/
bool tdp_enabled = false;
-#undef MMU_DEBUG
+enum {
+ AUDIT_PRE_PAGE_FAULT,
+ AUDIT_POST_PAGE_FAULT,
+ AUDIT_PRE_PTE_WRITE,
+ AUDIT_POST_PTE_WRITE
+};
-#undef AUDIT
+char *audit_point_name[] = {
+ "pre page fault",
+ "post page fault",
+ "pre pte write",
+ "post pte write"
+};
-#ifdef AUDIT
-static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
-#else
-static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
-#endif
+#undef MMU_DEBUG
#ifdef MMU_DEBUG
#endif
-#if defined(MMU_DEBUG) || defined(AUDIT)
+#ifdef MMU_DEBUG
static int dbg = 0;
module_param(dbg, bool, 0644);
#endif
}
#endif
+#define PTE_PREFETCH_NUM 8
+
#define PT_FIRST_AVAIL_BITS_SHIFT 9
#define PT64_SECOND_AVAIL_BITS_SHIFT 52
static struct kmem_cache *pte_chain_cache;
static struct kmem_cache *rmap_desc_cache;
static struct kmem_cache *mmu_page_header_cache;
+static struct percpu_counter kvm_total_used_mmu_pages;
static u64 __read_mostly shadow_trap_nonpresent_pte;
static u64 __read_mostly shadow_notrap_nonpresent_pte;
#endif
}
+static bool spte_has_volatile_bits(u64 spte)
+{
+ if (!shadow_accessed_mask)
+ return false;
+
+ if (!is_shadow_present_pte(spte))
+ return false;
+
+ if ((spte & shadow_accessed_mask) &&
+ (!is_writable_pte(spte) || (spte & shadow_dirty_mask)))
+ return false;
+
+ return true;
+}
+
+static bool spte_is_bit_cleared(u64 old_spte, u64 new_spte, u64 bit_mask)
+{
+ return (old_spte & bit_mask) && !(new_spte & bit_mask);
+}
+
static void update_spte(u64 *sptep, u64 new_spte)
{
- u64 old_spte;
+ u64 mask, old_spte = *sptep;
+
+ WARN_ON(!is_rmap_spte(new_spte));
- if (!shadow_accessed_mask || (new_spte & shadow_accessed_mask) ||
- !is_rmap_spte(*sptep))
+ new_spte |= old_spte & shadow_dirty_mask;
+
+ mask = shadow_accessed_mask;
+ if (is_writable_pte(old_spte))
+ mask |= shadow_dirty_mask;
+
+ if (!spte_has_volatile_bits(old_spte) || (new_spte & mask) == mask)
__set_spte(sptep, new_spte);
- else {
+ else
old_spte = __xchg_spte(sptep, new_spte);
- if (old_spte & shadow_accessed_mask)
- mark_page_accessed(pfn_to_page(spte_to_pfn(old_spte)));
- }
+
+ if (!shadow_accessed_mask)
+ return;
+
+ if (spte_is_bit_cleared(old_spte, new_spte, shadow_accessed_mask))
+ kvm_set_pfn_accessed(spte_to_pfn(old_spte));
+ if (spte_is_bit_cleared(old_spte, new_spte, shadow_dirty_mask))
+ kvm_set_pfn_dirty(spte_to_pfn(old_spte));
}
static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
if (r)
goto out;
r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
- rmap_desc_cache, 4);
+ rmap_desc_cache, 4 + PTE_PREFETCH_NUM);
if (r)
goto out;
r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt);
rmapp = gfn_to_rmap(kvm, gfn, sp->role.level);
if (!*rmapp) {
- printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
+ printk(KERN_ERR "rmap_remove: %p 0->BUG\n", spte);
BUG();
} else if (!(*rmapp & 1)) {
- rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
+ rmap_printk("rmap_remove: %p 1->0\n", spte);
if ((u64 *)*rmapp != spte) {
- printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
- spte, *spte);
+ printk(KERN_ERR "rmap_remove: %p 1->BUG\n", spte);
BUG();
}
*rmapp = 0;
} else {
- rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
+ rmap_printk("rmap_remove: %p many->many\n", spte);
desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
prev_desc = NULL;
while (desc) {
prev_desc = desc;
desc = desc->more;
}
- pr_err("rmap_remove: %p %llx many->many\n", spte, *spte);
+ pr_err("rmap_remove: %p many->many\n", spte);
BUG();
}
}
pfn_t pfn;
u64 old_spte = *sptep;
- if (!shadow_accessed_mask || !is_shadow_present_pte(old_spte) ||
- old_spte & shadow_accessed_mask) {
+ if (!spte_has_volatile_bits(old_spte))
__set_spte(sptep, new_spte);
- } else
+ else
old_spte = __xchg_spte(sptep, new_spte);
if (!is_rmap_spte(old_spte))
return;
+
pfn = spte_to_pfn(old_spte);
if (!shadow_accessed_mask || old_spte & shadow_accessed_mask)
kvm_set_pfn_accessed(pfn);
- if (is_writable_pte(old_spte))
+ if (!shadow_dirty_mask || (old_spte & shadow_dirty_mask))
kvm_set_pfn_dirty(pfn);
}
}
spte = rmap_next(kvm, rmapp, spte);
}
- if (write_protected) {
- pfn_t pfn;
-
- spte = rmap_next(kvm, rmapp, NULL);
- pfn = spte_to_pfn(*spte);
- kvm_set_pfn_dirty(pfn);
- }
/* check for huge page mappings */
for (i = PT_DIRECTORY_LEVEL;
}
#endif
+/*
+ * This value is the sum of all of the kvm instances's
+ * kvm->arch.n_used_mmu_pages values. We need a global,
+ * aggregate version in order to make the slab shrinker
+ * faster
+ */
+static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr)
+{
+ kvm->arch.n_used_mmu_pages += nr;
+ percpu_counter_add(&kvm_total_used_mmu_pages, nr);
+}
+
static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
{
ASSERT(is_empty_shadow_page(sp->spt));
if (!sp->role.direct)
__free_page(virt_to_page(sp->gfns));
kmem_cache_free(mmu_page_header_cache, sp);
- ++kvm->arch.n_free_mmu_pages;
+ kvm_mod_used_mmu_pages(kvm, -1);
}
static unsigned kvm_page_table_hashfn(gfn_t gfn)
bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
sp->multimapped = 0;
sp->parent_pte = parent_pte;
- --vcpu->kvm->arch.n_free_mmu_pages;
+ kvm_mod_used_mmu_pages(vcpu->kvm, +1);
return sp;
}
if (role.direct)
role.cr4_pae = 0;
role.access = access;
- if (!tdp_enabled && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
+ if (!vcpu->arch.mmu.direct_map
+ && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
role.quadrant = quadrant;
/*
* Changing the number of mmu pages allocated to the vm
- * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
+ * Note: if goal_nr_mmu_pages is too small, you will get dead lock
*/
-void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
+void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int goal_nr_mmu_pages)
{
- int used_pages;
LIST_HEAD(invalid_list);
-
- used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
- used_pages = max(0, used_pages);
-
/*
* If we set the number of mmu pages to be smaller be than the
* number of actived pages , we must to free some mmu pages before we
* change the value
*/
- if (used_pages > kvm_nr_mmu_pages) {
- while (used_pages > kvm_nr_mmu_pages &&
+ if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) {
+ while (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages &&
!list_empty(&kvm->arch.active_mmu_pages)) {
struct kvm_mmu_page *page;
page = container_of(kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
- used_pages -= kvm_mmu_prepare_zap_page(kvm, page,
- &invalid_list);
+ kvm_mmu_prepare_zap_page(kvm, page, &invalid_list);
+ kvm_mmu_commit_zap_page(kvm, &invalid_list);
}
- kvm_mmu_commit_zap_page(kvm, &invalid_list);
- kvm_nr_mmu_pages = used_pages;
- kvm->arch.n_free_mmu_pages = 0;
+ goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages;
}
- else
- kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
- - kvm->arch.n_alloc_mmu_pages;
- kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
+ kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages;
}
static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
LIST_HEAD(invalid_list);
int r;
- pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
+ pgprintk("%s: looking for gfn %llx\n", __func__, gfn);
r = 0;
for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
- pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
+ pgprintk("%s: gfn %llx role %x\n", __func__, gfn,
sp->role.word);
r = 1;
kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
LIST_HEAD(invalid_list);
for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
- pgprintk("%s: zap %lx %x\n",
+ pgprintk("%s: zap %llx %x\n",
__func__, gfn, sp->role.word);
kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
}
* whether the guest actually used the pte (in order to detect
* demand paging).
*/
- spte = shadow_base_present_pte | shadow_dirty_mask;
+ spte = shadow_base_present_pte;
if (!speculative)
spte |= shadow_accessed_mask;
if (!dirty)
spte |= shadow_user_mask;
if (level > PT_PAGE_TABLE_LEVEL)
spte |= PT_PAGE_SIZE_MASK;
- if (tdp_enabled)
+ if (vcpu->arch.mmu.direct_map)
spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
kvm_is_mmio_pfn(pfn));
spte |= (u64)pfn << PAGE_SHIFT;
if ((pte_access & ACC_WRITE_MASK)
- || (!tdp_enabled && write_fault && !is_write_protection(vcpu)
- && !user_fault)) {
+ || (!vcpu->arch.mmu.direct_map && write_fault
+ && !is_write_protection(vcpu) && !user_fault)) {
if (level > PT_PAGE_TABLE_LEVEL &&
has_wrprotected_page(vcpu->kvm, gfn, level)) {
spte |= PT_WRITABLE_MASK;
- if (!tdp_enabled && !(pte_access & ACC_WRITE_MASK))
+ if (!vcpu->arch.mmu.direct_map
+ && !(pte_access & ACC_WRITE_MASK))
spte &= ~PT_USER_MASK;
/*
goto set_pte;
if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
- pgprintk("%s: found shadow page for %lx, marking ro\n",
+ pgprintk("%s: found shadow page for %llx, marking ro\n",
__func__, gfn);
ret = 1;
pte_access &= ~ACC_WRITE_MASK;
mark_page_dirty(vcpu->kvm, gfn);
set_pte:
- if (is_writable_pte(*sptep) && !is_writable_pte(spte))
- kvm_set_pfn_dirty(pfn);
update_spte(sptep, spte);
done:
return ret;
int rmap_count;
pgprintk("%s: spte %llx access %x write_fault %d"
- " user_fault %d gfn %lx\n",
+ " user_fault %d gfn %llx\n",
__func__, *sptep, pt_access,
write_fault, user_fault, gfn);
__set_spte(sptep, shadow_trap_nonpresent_pte);
kvm_flush_remote_tlbs(vcpu->kvm);
} else if (pfn != spte_to_pfn(*sptep)) {
- pgprintk("hfn old %lx new %lx\n",
+ pgprintk("hfn old %llx new %llx\n",
spte_to_pfn(*sptep), pfn);
drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte);
kvm_flush_remote_tlbs(vcpu->kvm);
}
pgprintk("%s: setting spte %llx\n", __func__, *sptep);
- pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
+ pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
is_large_pte(*sptep)? "2MB" : "4kB",
*sptep & PT_PRESENT_MASK ?"RW":"R", gfn,
*sptep, sptep);
{
}
+static struct kvm_memory_slot *
+pte_prefetch_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn, bool no_dirty_log)
+{
+ struct kvm_memory_slot *slot;
+
+ slot = gfn_to_memslot(vcpu->kvm, gfn);
+ if (!slot || slot->flags & KVM_MEMSLOT_INVALID ||
+ (no_dirty_log && slot->dirty_bitmap))
+ slot = NULL;
+
+ return slot;
+}
+
+static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn,
+ bool no_dirty_log)
+{
+ struct kvm_memory_slot *slot;
+ unsigned long hva;
+
+ slot = pte_prefetch_gfn_to_memslot(vcpu, gfn, no_dirty_log);
+ if (!slot) {
+ get_page(bad_page);
+ return page_to_pfn(bad_page);
+ }
+
+ hva = gfn_to_hva_memslot(slot, gfn);
+
+ return hva_to_pfn_atomic(vcpu->kvm, hva);
+}
+
+static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *sp,
+ u64 *start, u64 *end)
+{
+ struct page *pages[PTE_PREFETCH_NUM];
+ unsigned access = sp->role.access;
+ int i, ret;
+ gfn_t gfn;
+
+ gfn = kvm_mmu_page_get_gfn(sp, start - sp->spt);
+ if (!pte_prefetch_gfn_to_memslot(vcpu, gfn, access & ACC_WRITE_MASK))
+ return -1;
+
+ ret = gfn_to_page_many_atomic(vcpu->kvm, gfn, pages, end - start);
+ if (ret <= 0)
+ return -1;
+
+ for (i = 0; i < ret; i++, gfn++, start++)
+ mmu_set_spte(vcpu, start, ACC_ALL,
+ access, 0, 0, 1, NULL,
+ sp->role.level, gfn,
+ page_to_pfn(pages[i]), true, true);
+
+ return 0;
+}
+
+static void __direct_pte_prefetch(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *sp, u64 *sptep)
+{
+ u64 *spte, *start = NULL;
+ int i;
+
+ WARN_ON(!sp->role.direct);
+
+ i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1);
+ spte = sp->spt + i;
+
+ for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) {
+ if (*spte != shadow_trap_nonpresent_pte || spte == sptep) {
+ if (!start)
+ continue;
+ if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0)
+ break;
+ start = NULL;
+ } else if (!start)
+ start = spte;
+ }
+}
+
+static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
+{
+ struct kvm_mmu_page *sp;
+
+ /*
+ * Since it's no accessed bit on EPT, it's no way to
+ * distinguish between actually accessed translations
+ * and prefetched, so disable pte prefetch if EPT is
+ * enabled.
+ */
+ if (!shadow_accessed_mask)
+ return;
+
+ sp = page_header(__pa(sptep));
+ if (sp->role.level > PT_PAGE_TABLE_LEVEL)
+ return;
+
+ __direct_pte_prefetch(vcpu, sp, sptep);
+}
+
static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
int level, gfn_t gfn, pfn_t pfn)
{
mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
0, write, 1, &pt_write,
level, gfn, pfn, false, true);
+ direct_pte_prefetch(vcpu, iterator.sptep);
++vcpu->stat.pf_fixed;
break;
}
ASSERT(!VALID_PAGE(root));
if (mmu_check_root(vcpu, root_gfn))
return 1;
- if (tdp_enabled) {
+ if (vcpu->arch.mmu.direct_map) {
direct = 1;
root_gfn = 0;
}
return 0;
}
direct = !is_paging(vcpu);
+
+ if (mmu_check_root(vcpu, root_gfn))
+ return 1;
+
for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu.pae_root[i];
continue;
}
root_gfn = pdptr >> PAGE_SHIFT;
+ if (mmu_check_root(vcpu, root_gfn))
+ return 1;
} else if (vcpu->arch.mmu.root_level == 0)
root_gfn = 0;
- if (mmu_check_root(vcpu, root_gfn))
- return 1;
- if (tdp_enabled) {
+ if (vcpu->arch.mmu.direct_map) {
direct = 1;
root_gfn = i << 30;
}
context->root_level = 0;
context->shadow_root_level = PT32E_ROOT_LEVEL;
context->root_hpa = INVALID_PAGE;
+ context->direct_map = true;
return 0;
}
context->root_level = level;
context->shadow_root_level = level;
context->root_hpa = INVALID_PAGE;
+ context->direct_map = false;
return 0;
}
context->root_level = PT32_ROOT_LEVEL;
context->shadow_root_level = PT32E_ROOT_LEVEL;
context->root_hpa = INVALID_PAGE;
+ context->direct_map = false;
return 0;
}
context->invlpg = nonpaging_invlpg;
context->shadow_root_level = kvm_x86_ops->get_tdp_level();
context->root_hpa = INVALID_PAGE;
+ context->direct_map = true;
+ context->set_cr3 = kvm_x86_ops->set_cr3;
if (!is_paging(vcpu)) {
context->gva_to_gpa = nonpaging_gva_to_gpa;
r = paging32_init_context(vcpu);
vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu);
- vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu);
+ vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu);
+ vcpu->arch.mmu.set_cr3 = kvm_x86_ops->set_cr3;
return r;
}
if (r)
goto out;
/* set_cr3() should ensure TLB has been flushed */
- kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
+ vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
out:
return r;
}
kvm_mmu_access_page(vcpu, gfn);
kvm_mmu_free_some_pages(vcpu);
++vcpu->kvm->stat.mmu_pte_write;
- kvm_mmu_audit(vcpu, "pre pte write");
+ trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);
if (guest_initiated) {
if (gfn == vcpu->arch.last_pt_write_gfn
&& !last_updated_pte_accessed(vcpu)) {
}
mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush);
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
- kvm_mmu_audit(vcpu, "post pte write");
+ trace_kvm_mmu_audit(vcpu, AUDIT_POST_PTE_WRITE);
spin_unlock(&vcpu->kvm->mmu_lock);
if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
gpa_t gpa;
int r;
- if (tdp_enabled)
+ if (vcpu->arch.mmu.direct_map)
return 0;
gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
{
- int free_pages;
LIST_HEAD(invalid_list);
- free_pages = vcpu->kvm->arch.n_free_mmu_pages;
- while (free_pages < KVM_REFILL_PAGES &&
+ while (kvm_mmu_available_pages(vcpu->kvm) < KVM_REFILL_PAGES &&
!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
struct kvm_mmu_page *sp;
sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
- free_pages += kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
- &invalid_list);
+ kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
+ kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
++vcpu->kvm->stat.mmu_recycled;
}
- kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
}
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
{
struct kvm *kvm;
struct kvm *kvm_freed = NULL;
- int cache_count = 0;
+
+ if (nr_to_scan == 0)
+ goto out;
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
- int npages, idx, freed_pages;
+ int idx, freed_pages;
LIST_HEAD(invalid_list);
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
- npages = kvm->arch.n_alloc_mmu_pages -
- kvm->arch.n_free_mmu_pages;
- cache_count += npages;
- if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
+ if (!kvm_freed && nr_to_scan > 0 &&
+ kvm->arch.n_used_mmu_pages > 0) {
freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm,
&invalid_list);
- cache_count -= freed_pages;
kvm_freed = kvm;
}
nr_to_scan--;
spin_unlock(&kvm_lock);
- return cache_count;
+out:
+ return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
}
static struct shrinker mmu_shrinker = {
void kvm_mmu_module_exit(void)
{
mmu_destroy_caches();
+ percpu_counter_destroy(&kvm_total_used_mmu_pages);
unregister_shrinker(&mmu_shrinker);
}
if (!mmu_page_header_cache)
goto nomem;
+ if (percpu_counter_init(&kvm_total_used_mmu_pages, 0))
+ goto nomem;
+
register_shrinker(&mmu_shrinker);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
-#ifdef AUDIT
-
-static const char *audit_msg;
-
-static gva_t canonicalize(gva_t gva)
-{
-#ifdef CONFIG_X86_64
- gva = (long long)(gva << 16) >> 16;
-#endif
- return gva;
-}
-
-
-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 ent = pt[i];
-
- if (ent == shadow_trap_nonpresent_pte)
- continue;
-
- va = canonicalize(va);
- if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
- audit_mappings_page(vcpu, ent, va, level - 1);
- else {
- gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL);
- gfn_t gfn = gpa >> PAGE_SHIFT;
- pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
- hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
-
- if (is_error_pfn(pfn)) {
- kvm_release_pfn_clean(pfn);
- continue;
- }
-
- if (is_shadow_present_pte(ent)
- && (ent & PT64_BASE_ADDR_MASK) != hpa)
- printk(KERN_ERR "xx audit error: (%s) levels %d"
- " gva %lx gpa %llx hpa %llx ent %llx %d\n",
- audit_msg, vcpu->arch.mmu.root_level,
- va, gpa, hpa, ent,
- is_shadow_present_pte(ent));
- else if (ent == shadow_notrap_nonpresent_pte
- && !is_error_hpa(hpa))
- printk(KERN_ERR "audit: (%s) notrap shadow,"
- " valid guest gva %lx\n", audit_msg, va);
- kvm_release_pfn_clean(pfn);
-
- }
- }
-}
-
-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);
-}
-
-static int count_rmaps(struct kvm_vcpu *vcpu)
-{
- struct kvm *kvm = vcpu->kvm;
- struct kvm_memslots *slots;
- int nmaps = 0;
- int i, j, k, idx;
-
- idx = srcu_read_lock(&kvm->srcu);
- slots = kvm_memslots(kvm);
- for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
- struct kvm_memory_slot *m = &slots->memslots[i];
- struct kvm_rmap_desc *d;
-
- for (j = 0; j < m->npages; ++j) {
- unsigned long *rmapp = &m->rmap[j];
-
- if (!*rmapp)
- continue;
- if (!(*rmapp & 1)) {
- ++nmaps;
- continue;
- }
- d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
- while (d) {
- for (k = 0; k < RMAP_EXT; ++k)
- if (d->sptes[k])
- ++nmaps;
- else
- break;
- d = d->more;
- }
- }
- }
- srcu_read_unlock(&kvm->srcu, idx);
- return nmaps;
-}
-
-void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
-{
- unsigned long *rmapp;
- struct kvm_mmu_page *rev_sp;
- gfn_t gfn;
-
- if (is_writable_pte(*sptep)) {
- 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 %ld\n",
- audit_msg, gfn);
- printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\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_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
-{
- mmu_spte_walk(vcpu, inspect_spte_has_rmap);
-}
-
-static void check_writable_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) {
- u64 ent = pt[i];
-
- if (!(ent & PT_PRESENT_MASK))
- continue;
- if (!is_writable_pte(ent))
- continue;
- inspect_spte_has_rmap(vcpu->kvm, &pt[i]);
- }
- }
- return;
-}
-
-static void audit_rmap(struct kvm_vcpu *vcpu)
-{
- check_writable_mappings_rmap(vcpu);
- count_rmaps(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;
- gfn_t gfn;
-
- list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
- if (sp->role.direct)
- continue;
- if (sp->unsync)
- continue;
-
- slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
- rmapp = &slot->rmap[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 %lx role %x\n",
- __func__, audit_msg, sp->gfn,
- sp->role.word);
- spte = rmap_next(vcpu->kvm, rmapp, spte);
- }
- }
-}
-
-static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
-{
- int olddbg = dbg;
-
- dbg = 0;
- audit_msg = msg;
- audit_rmap(vcpu);
- audit_write_protection(vcpu);
- if (strcmp("pre pte write", audit_msg) != 0)
- audit_mappings(vcpu);
- audit_writable_sptes_have_rmaps(vcpu);
- dbg = olddbg;
-}
-
+#ifdef CONFIG_KVM_MMU_AUDIT
+#include "mmu_audit.c"
#endif
git.openpandora.org / pandora-kernel.git / blobdiff