#include <asm/cmpxchg.h>
#include <asm/io.h>
#include <asm/vmx.h>
+#include <asm/kvm_page_track.h>
/*
* When setting this variable to true it enables Two-Dimensional-Paging
return &slot->arch.lpage_info[level - 2][idx];
}
+static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
+ gfn_t gfn, int count)
+{
+ struct kvm_lpage_info *linfo;
+ int i;
+
+ for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
+ linfo = lpage_info_slot(gfn, slot, i);
+ linfo->disallow_lpage += count;
+ WARN_ON(linfo->disallow_lpage < 0);
+ }
+}
+
+void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+{
+ update_gfn_disallow_lpage_count(slot, gfn, 1);
+}
+
+void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
+{
+ update_gfn_disallow_lpage_count(slot, gfn, -1);
+}
+
static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *slot;
- struct kvm_lpage_info *linfo;
gfn_t gfn;
- int i;
+ kvm->arch.indirect_shadow_pages++;
gfn = sp->gfn;
slots = kvm_memslots_for_spte_role(kvm, sp->role);
slot = __gfn_to_memslot(slots, gfn);
- for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
- linfo = lpage_info_slot(gfn, slot, i);
- linfo->write_count += 1;
- }
- kvm->arch.indirect_shadow_pages++;
+
+ /* 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);
}
static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *slot;
- struct kvm_lpage_info *linfo;
gfn_t gfn;
- int i;
+ kvm->arch.indirect_shadow_pages--;
gfn = sp->gfn;
slots = kvm_memslots_for_spte_role(kvm, sp->role);
slot = __gfn_to_memslot(slots, gfn);
- for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
- linfo = lpage_info_slot(gfn, slot, i);
- linfo->write_count -= 1;
- WARN_ON(linfo->write_count < 0);
- }
- kvm->arch.indirect_shadow_pages--;
+ 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);
}
-static int __has_wrprotected_page(gfn_t gfn, int level,
- struct kvm_memory_slot *slot)
+static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
+ struct kvm_memory_slot *slot)
{
struct kvm_lpage_info *linfo;
if (slot) {
linfo = lpage_info_slot(gfn, slot, level);
- return linfo->write_count;
+ return !!linfo->disallow_lpage;
}
- return 1;
+ return true;
}
-static int has_wrprotected_page(struct kvm_vcpu *vcpu, gfn_t gfn, int level)
+static bool mmu_gfn_lpage_is_disallowed(struct kvm_vcpu *vcpu, gfn_t gfn,
+ int level)
{
struct kvm_memory_slot *slot;
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
- return __has_wrprotected_page(gfn, level, slot);
+ return __mmu_gfn_lpage_is_disallowed(gfn, level, slot);
}
static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
max_level = min(kvm_x86_ops->get_lpage_level(), host_level);
for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
- if (__has_wrprotected_page(large_gfn, level, slot))
+ if (__mmu_gfn_lpage_is_disallowed(large_gfn, level, slot))
break;
return level - 1;
kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
}
-static bool rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
+bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
+ struct kvm_memory_slot *slot, u64 gfn)
{
- struct kvm_memory_slot *slot;
struct kvm_rmap_head *rmap_head;
int i;
bool write_protected = false;
- slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
-
for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
rmap_head = __gfn_to_rmap(gfn, i, slot);
- write_protected |= __rmap_write_protect(vcpu->kvm, rmap_head, true);
+ write_protected |= __rmap_write_protect(kvm, rmap_head, true);
}
return write_protected;
}
+static bool rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
+{
+ struct kvm_memory_slot *slot;
+
+ slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
+ return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn);
+}
+
static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head)
{
u64 *sptep;
return nr_unsync_leaf;
}
+#define INVALID_INDEX (-1)
+
static int mmu_unsync_walk(struct kvm_mmu_page *sp,
struct kvm_mmu_pages *pvec)
{
+ pvec->nr = 0;
if (!sp->unsync_children)
return 0;
- mmu_pages_add(pvec, sp, 0);
+ mmu_pages_add(pvec, sp, INVALID_INDEX);
return __mmu_unsync_walk(sp, pvec);
}
}
struct mmu_page_path {
- struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
- unsigned int idx[PT64_ROOT_LEVEL-1];
+ struct kvm_mmu_page *parent[PT64_ROOT_LEVEL];
+ unsigned int idx[PT64_ROOT_LEVEL];
};
#define for_each_sp(pvec, sp, parents, i) \
- for (i = mmu_pages_next(&pvec, &parents, -1), \
- sp = pvec.page[i].sp; \
+ for (i = mmu_pages_first(&pvec, &parents); \
i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
i = mmu_pages_next(&pvec, &parents, i))
for (n = i+1; n < pvec->nr; n++) {
struct kvm_mmu_page *sp = pvec->page[n].sp;
+ unsigned idx = pvec->page[n].idx;
+ int level = sp->role.level;
- if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
- parents->idx[0] = pvec->page[n].idx;
- return n;
- }
+ parents->idx[level-1] = idx;
+ if (level == PT_PAGE_TABLE_LEVEL)
+ break;
- parents->parent[sp->role.level-2] = sp;
- parents->idx[sp->role.level-1] = pvec->page[n].idx;
+ parents->parent[level-2] = sp;
}
return n;
}
+static int mmu_pages_first(struct kvm_mmu_pages *pvec,
+ struct mmu_page_path *parents)
+{
+ struct kvm_mmu_page *sp;
+ int level;
+
+ if (pvec->nr == 0)
+ return 0;
+
+ WARN_ON(pvec->page[0].idx != INVALID_INDEX);
+
+ sp = pvec->page[0].sp;
+ level = sp->role.level;
+ WARN_ON(level == PT_PAGE_TABLE_LEVEL);
+
+ parents->parent[level-2] = sp;
+
+ /* Also set up a sentinel. Further entries in pvec are all
+ * children of sp, so this element is never overwritten.
+ */
+ parents->parent[level-1] = NULL;
+ return mmu_pages_next(pvec, parents, 0);
+}
+
static void mmu_pages_clear_parents(struct mmu_page_path *parents)
{
struct kvm_mmu_page *sp;
do {
unsigned int idx = parents->idx[level];
-
sp = parents->parent[level];
if (!sp)
return;
+ WARN_ON(idx == INVALID_INDEX);
clear_unsync_child_bit(sp, idx);
level++;
- } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
-}
-
-static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
- struct mmu_page_path *parents,
- struct kvm_mmu_pages *pvec)
-{
- parents->parent[parent->role.level-1] = NULL;
- pvec->nr = 0;
+ } while (!sp->unsync_children);
}
static void mmu_sync_children(struct kvm_vcpu *vcpu,
struct kvm_mmu_pages pages;
LIST_HEAD(invalid_list);
- kvm_mmu_pages_init(parent, &parents, &pages);
while (mmu_unsync_walk(parent, &pages)) {
bool protected = false;
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
cond_resched_lock(&vcpu->kvm->mmu_lock);
- kvm_mmu_pages_init(parent, &parents, &pages);
}
}
static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp)
{
- sp->write_flooding_count = 0;
+ atomic_set(&sp->write_flooding_count, 0);
}
static void clear_sp_write_flooding_count(u64 *spte)
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);
if (parent->role.level == PT_PAGE_TABLE_LEVEL)
return 0;
- kvm_mmu_pages_init(parent, &parents, &pages);
while (mmu_unsync_walk(parent, &pages)) {
struct kvm_mmu_page *sp;
mmu_pages_clear_parents(&parents);
zapped++;
}
- kvm_mmu_pages_init(parent, &parents, &pages);
}
return zapped;
if (list_empty(&kvm->arch.active_mmu_pages))
return false;
- sp = list_entry(kvm->arch.active_mmu_pages.prev,
- struct kvm_mmu_page, link);
+ sp = list_last_entry(&kvm->arch.active_mmu_pages,
+ struct kvm_mmu_page, link);
kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
return true;
}
EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page);
-static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+static void kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
trace_kvm_mmu_unsync_page(sp);
++vcpu->kvm->stat.mmu_unsync;
kvm_mmu_mark_parents_unsync(sp);
}
-static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
+static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
+ bool can_unsync)
{
- struct kvm_mmu_page *s;
-
- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) {
- if (s->unsync)
- continue;
- WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
- __kvm_unsync_page(vcpu, s);
- }
-}
+ struct kvm_mmu_page *sp;
-static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
- bool can_unsync)
-{
- struct kvm_mmu_page *s;
- bool need_unsync = false;
+ if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+ return true;
- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
if (!can_unsync)
- return 1;
+ return true;
- if (s->role.level != PT_PAGE_TABLE_LEVEL)
- return 1;
+ if (sp->unsync)
+ continue;
- if (!s->unsync)
- need_unsync = true;
+ WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL);
+ kvm_unsync_page(vcpu, sp);
}
- if (need_unsync)
- kvm_unsync_pages(vcpu, gfn);
- return 0;
+
+ return false;
}
static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
* be fixed if guest refault.
*/
if (level > PT_PAGE_TABLE_LEVEL &&
- has_wrprotected_page(vcpu, gfn, level))
+ mmu_gfn_lpage_is_disallowed(vcpu, gfn, level))
goto done;
spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
level == PT_PAGE_TABLE_LEVEL &&
PageTransCompound(pfn_to_page(pfn)) &&
- !has_wrprotected_page(vcpu, gfn, PT_DIRECTORY_LEVEL)) {
+ !mmu_gfn_lpage_is_disallowed(vcpu, gfn, PT_DIRECTORY_LEVEL)) {
unsigned long mask;
/*
* mmu_notifier_retry was successful and we hold the
static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
kvm_pfn_t pfn, unsigned access, int *ret_val)
{
- bool ret = true;
-
/* The pfn is invalid, report the error! */
if (unlikely(is_error_pfn(pfn))) {
*ret_val = kvm_handle_bad_page(vcpu, gfn, pfn);
- goto exit;
+ return true;
}
if (unlikely(is_noslot_pfn(pfn)))
vcpu_cache_mmio_info(vcpu, gva, gfn, access);
- ret = false;
-exit:
- return ret;
+ return false;
}
static bool page_fault_can_be_fast(u32 error_code)
return __is_rsvd_bits_set(&mmu->shadow_zero_check, spte, level);
}
-static bool quickly_check_mmio_pf(struct kvm_vcpu *vcpu, u64 addr, bool direct)
+static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct)
{
if (direct)
return vcpu_match_mmio_gpa(vcpu, addr);
u64 spte;
bool reserved;
- if (quickly_check_mmio_pf(vcpu, addr, direct))
+ if (mmio_info_in_cache(vcpu, addr, direct))
return RET_MMIO_PF_EMULATE;
reserved = walk_shadow_page_get_mmio_spte(vcpu, addr, &spte);
}
EXPORT_SYMBOL_GPL(handle_mmio_page_fault);
+static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu,
+ u32 error_code, gfn_t gfn)
+{
+ if (unlikely(error_code & PFERR_RSVD_MASK))
+ return false;
+
+ if (!(error_code & PFERR_PRESENT_MASK) ||
+ !(error_code & PFERR_WRITE_MASK))
+ return false;
+
+ /*
+ * guest is writing the page which is write tracked which can
+ * not be fixed by page fault handler.
+ */
+ if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+ return true;
+
+ return false;
+}
+
+static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr)
+{
+ struct kvm_shadow_walk_iterator iterator;
+ u64 spte;
+
+ if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+ return;
+
+ walk_shadow_page_lockless_begin(vcpu);
+ for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) {
+ clear_sp_write_flooding_count(iterator.sptep);
+ if (!is_shadow_present_pte(spte))
+ break;
+ }
+ walk_shadow_page_lockless_end(vcpu);
+}
+
static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
u32 error_code, bool prefault)
{
- gfn_t gfn;
+ gfn_t gfn = gva >> PAGE_SHIFT;
int r;
pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
- if (unlikely(error_code & PFERR_RSVD_MASK)) {
- r = handle_mmio_page_fault(vcpu, gva, true);
-
- if (likely(r != RET_MMIO_PF_INVALID))
- return r;
- }
+ if (page_fault_handle_page_track(vcpu, error_code, gfn))
+ return 1;
r = mmu_topup_memory_caches(vcpu);
if (r)
MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
- gfn = gva >> PAGE_SHIFT;
return nonpaging_map(vcpu, gva & PAGE_MASK,
error_code, gfn, prefault);
MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
- if (unlikely(error_code & PFERR_RSVD_MASK)) {
- r = handle_mmio_page_fault(vcpu, gpa, true);
-
- if (likely(r != RET_MMIO_PF_INVALID))
- return r;
- }
+ if (page_fault_handle_page_track(vcpu, error_code, gfn))
+ return 1;
r = mmu_topup_memory_caches(vcpu);
if (r)
return (old & ~new & PT64_PERM_MASK) != 0;
}
-static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, bool zap_page,
- bool remote_flush, bool local_flush)
+static void kvm_mmu_flush_or_zap(struct kvm_vcpu *vcpu,
+ struct list_head *invalid_list,
+ bool remote_flush, bool local_flush)
{
- if (zap_page)
+ if (!list_empty(invalid_list)) {
+ kvm_mmu_commit_zap_page(vcpu->kvm, invalid_list);
return;
+ }
if (remote_flush)
kvm_flush_remote_tlbs(vcpu->kvm);
if (sp->role.level == PT_PAGE_TABLE_LEVEL)
return false;
- return ++sp->write_flooding_count >= 3;
+ atomic_inc(&sp->write_flooding_count);
+ return atomic_read(&sp->write_flooding_count) >= 3;
}
/*
return spte;
}
-void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
- const u8 *new, int bytes)
+static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+ const u8 *new, int bytes)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *sp;
LIST_HEAD(invalid_list);
u64 entry, gentry, *spte;
int npte;
- bool remote_flush, local_flush, zap_page;
+ bool remote_flush, local_flush;
union kvm_mmu_page_role mask = { };
mask.cr0_wp = 1;
if (!ACCESS_ONCE(vcpu->kvm->arch.indirect_shadow_pages))
return;
- zap_page = remote_flush = local_flush = false;
+ remote_flush = local_flush = false;
pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
if (detect_write_misaligned(sp, gpa, bytes) ||
detect_write_flooding(sp)) {
- zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
- &invalid_list);
+ kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
++vcpu->kvm->stat.mmu_flooded;
continue;
}
++spte;
}
}
- mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush);
- kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
+ kvm_mmu_flush_or_zap(vcpu, &invalid_list, remote_flush, local_flush);
kvm_mmu_audit(vcpu, AUDIT_POST_PTE_WRITE);
spin_unlock(&vcpu->kvm->mmu_lock);
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
}
-static bool is_mmio_page_fault(struct kvm_vcpu *vcpu, gva_t addr)
-{
- if (vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu))
- return vcpu_match_mmio_gpa(vcpu, addr);
-
- return vcpu_match_mmio_gva(vcpu, addr);
-}
-
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
void *insn, int insn_len)
{
int r, emulation_type = EMULTYPE_RETRY;
enum emulation_result er;
+ bool direct = vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu);
+
+ if (unlikely(error_code & PFERR_RSVD_MASK)) {
+ r = handle_mmio_page_fault(vcpu, cr2, direct);
+ if (r == RET_MMIO_PF_EMULATE) {
+ emulation_type = 0;
+ goto emulate;
+ }
+ if (r == RET_MMIO_PF_RETRY)
+ return 1;
+ if (r < 0)
+ return r;
+ }
r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code, false);
if (r < 0)
- goto out;
-
- if (!r) {
- r = 1;
- goto out;
- }
+ return r;
+ if (!r)
+ return 1;
- if (is_mmio_page_fault(vcpu, cr2))
+ if (mmio_info_in_cache(vcpu, cr2, direct))
emulation_type = 0;
-
+emulate:
er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len);
switch (er) {
default:
BUG();
}
-out:
- return r;
}
EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
init_kvm_mmu(vcpu);
}
+void kvm_mmu_init_vm(struct kvm *kvm)
+{
+ struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
+
+ node->track_write = kvm_mmu_pte_write;
+ kvm_page_track_register_notifier(kvm, node);
+}
+
+void kvm_mmu_uninit_vm(struct kvm *kvm)
+{
+ struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
+
+ kvm_page_track_unregister_notifier(kvm, node);
+}
+
/* The return value indicates if tlb flush on all vcpus is needed. */
typedef bool (*slot_level_handler) (struct kvm *kvm, struct kvm_rmap_head *rmap_head);
projects / cascardo / linux.git / blobdiff