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Diffstat (limited to 'arch/x86/kvm/mmu/tdp_mmu.c')
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c215
1 files changed, 72 insertions, 143 deletions
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 7c25dbf32ecc..b2fca11b91ff 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -334,35 +334,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
u64 old_spte, u64 new_spte, int level,
bool shared);
-static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
-{
- if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
- return;
-
- if (is_accessed_spte(old_spte) &&
- (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
- spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
- kvm_set_pfn_accessed(spte_to_pfn(old_spte));
-}
-
-static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
- u64 old_spte, u64 new_spte, int level)
-{
- bool pfn_changed;
- struct kvm_memory_slot *slot;
-
- if (level > PG_LEVEL_4K)
- return;
-
- pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
-
- if ((!is_writable_pte(old_spte) || pfn_changed) &&
- is_writable_pte(new_spte)) {
- slot = __gfn_to_memslot(__kvm_memslots(kvm, as_id), gfn);
- mark_page_dirty_in_slot(kvm, slot, gfn);
- }
-}
-
static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
{
kvm_account_pgtable_pages((void *)sp->spt, +1);
@@ -505,7 +476,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
}
/**
- * __handle_changed_spte - handle bookkeeping associated with an SPTE change
+ * handle_changed_spte - handle bookkeeping associated with an SPTE change
* @kvm: kvm instance
* @as_id: the address space of the paging structure the SPTE was a part of
* @gfn: the base GFN that was mapped by the SPTE
@@ -516,12 +487,13 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
* the MMU lock and the operation must synchronize with other
* threads that might be modifying SPTEs.
*
- * Handle bookkeeping that might result from the modification of a SPTE.
- * This function must be called for all TDP SPTE modifications.
+ * Handle bookkeeping that might result from the modification of a SPTE. Note,
+ * dirty logging updates are handled in common code, not here (see make_spte()
+ * and fast_pf_fix_direct_spte()).
*/
-static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
- u64 old_spte, u64 new_spte, int level,
- bool shared)
+static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
+ u64 old_spte, u64 new_spte, int level,
+ bool shared)
{
bool was_present = is_shadow_present_pte(old_spte);
bool is_present = is_shadow_present_pte(new_spte);
@@ -605,17 +577,10 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
if (was_present && !was_leaf &&
(is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
-}
-static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
- u64 old_spte, u64 new_spte, int level,
- bool shared)
-{
- __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
- shared);
- handle_changed_spte_acc_track(old_spte, new_spte, level);
- handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
- new_spte, level);
+ if (was_leaf && is_accessed_spte(old_spte) &&
+ (!is_present || !is_accessed_spte(new_spte) || pfn_changed))
+ kvm_set_pfn_accessed(spte_to_pfn(old_spte));
}
/*
@@ -658,9 +623,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte))
return -EBUSY;
- __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
- new_spte, iter->level, true);
- handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
+ handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+ new_spte, iter->level, true);
return 0;
}
@@ -696,7 +660,7 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *kvm,
/*
- * __tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookkeeping
+ * tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookkeeping
* @kvm: KVM instance
* @as_id: Address space ID, i.e. regular vs. SMM
* @sptep: Pointer to the SPTE
@@ -704,23 +668,12 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *kvm,
* @new_spte: The new value that will be set for the SPTE
* @gfn: The base GFN that was (or will be) mapped by the SPTE
* @level: The level _containing_ the SPTE (its parent PT's level)
- * @record_acc_track: Notify the MM subsystem of changes to the accessed state
- * of the page. Should be set unless handling an MMU
- * notifier for access tracking. Leaving record_acc_track
- * unset in that case prevents page accesses from being
- * double counted.
- * @record_dirty_log: Record the page as dirty in the dirty bitmap if
- * appropriate for the change being made. Should be set
- * unless performing certain dirty logging operations.
- * Leaving record_dirty_log unset in that case prevents page
- * writes from being double counted.
*
* Returns the old SPTE value, which _may_ be different than @old_spte if the
* SPTE had voldatile bits.
*/
-static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
- u64 old_spte, u64 new_spte, gfn_t gfn, int level,
- bool record_acc_track, bool record_dirty_log)
+static u64 tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
+ u64 old_spte, u64 new_spte, gfn_t gfn, int level)
{
lockdep_assert_held_write(&kvm->mmu_lock);
@@ -735,46 +688,17 @@ static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
old_spte = kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level);
- __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
-
- if (record_acc_track)
- handle_changed_spte_acc_track(old_spte, new_spte, level);
- if (record_dirty_log)
- handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
- new_spte, level);
+ handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
return old_spte;
}
-static inline void _tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
- u64 new_spte, bool record_acc_track,
- bool record_dirty_log)
+static inline void tdp_mmu_iter_set_spte(struct kvm *kvm, struct tdp_iter *iter,
+ u64 new_spte)
{
WARN_ON_ONCE(iter->yielded);
-
- iter->old_spte = __tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep,
- iter->old_spte, new_spte,
- iter->gfn, iter->level,
- record_acc_track, record_dirty_log);
-}
-
-static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
- u64 new_spte)
-{
- _tdp_mmu_set_spte(kvm, iter, new_spte, true, true);
-}
-
-static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm,
- struct tdp_iter *iter,
- u64 new_spte)
-{
- _tdp_mmu_set_spte(kvm, iter, new_spte, false, true);
-}
-
-static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
- struct tdp_iter *iter,
- u64 new_spte)
-{
- _tdp_mmu_set_spte(kvm, iter, new_spte, true, false);
+ iter->old_spte = tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep,
+ iter->old_spte, new_spte,
+ iter->gfn, iter->level);
}
#define tdp_root_for_each_pte(_iter, _root, _start, _end) \
@@ -866,7 +790,7 @@ retry:
continue;
if (!shared)
- tdp_mmu_set_spte(kvm, &iter, 0);
+ tdp_mmu_iter_set_spte(kvm, &iter, 0);
else if (tdp_mmu_set_spte_atomic(kvm, &iter, 0))
goto retry;
}
@@ -923,8 +847,8 @@ bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
if (WARN_ON_ONCE(!is_shadow_present_pte(old_spte)))
return false;
- __tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte, 0,
- sp->gfn, sp->role.level + 1, true, true);
+ tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte, 0,
+ sp->gfn, sp->role.level + 1);
return true;
}
@@ -958,7 +882,7 @@ static bool tdp_mmu_zap_leafs(struct kvm *kvm, struct kvm_mmu_page *root,
!is_last_spte(iter.old_spte, iter.level))
continue;
- tdp_mmu_set_spte(kvm, &iter, 0);
+ tdp_mmu_iter_set_spte(kvm, &iter, 0);
flush = true;
}
@@ -1128,7 +1052,7 @@ static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter,
if (ret)
return ret;
} else {
- tdp_mmu_set_spte(kvm, iter, spte);
+ tdp_mmu_iter_set_spte(kvm, iter, spte);
}
tdp_account_mmu_page(kvm, sp);
@@ -1262,33 +1186,42 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm,
/*
* Mark the SPTEs range of GFNs [start, end) unaccessed and return non-zero
* if any of the GFNs in the range have been accessed.
+ *
+ * No need to mark the corresponding PFN as accessed as this call is coming
+ * from the clear_young() or clear_flush_young() notifier, which uses the
+ * return value to determine if the page has been accessed.
*/
static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter,
struct kvm_gfn_range *range)
{
- u64 new_spte = 0;
+ u64 new_spte;
/* If we have a non-accessed entry we don't need to change the pte. */
if (!is_accessed_spte(iter->old_spte))
return false;
- new_spte = iter->old_spte;
-
- if (spte_ad_enabled(new_spte)) {
- new_spte &= ~shadow_accessed_mask;
+ if (spte_ad_enabled(iter->old_spte)) {
+ iter->old_spte = tdp_mmu_clear_spte_bits(iter->sptep,
+ iter->old_spte,
+ shadow_accessed_mask,
+ iter->level);
+ new_spte = iter->old_spte & ~shadow_accessed_mask;
} else {
/*
* Capture the dirty status of the page, so that it doesn't get
* lost when the SPTE is marked for access tracking.
*/
- if (is_writable_pte(new_spte))
- kvm_set_pfn_dirty(spte_to_pfn(new_spte));
+ if (is_writable_pte(iter->old_spte))
+ kvm_set_pfn_dirty(spte_to_pfn(iter->old_spte));
- new_spte = mark_spte_for_access_track(new_spte);
+ new_spte = mark_spte_for_access_track(iter->old_spte);
+ iter->old_spte = kvm_tdp_mmu_write_spte(iter->sptep,
+ iter->old_spte, new_spte,
+ iter->level);
}
- tdp_mmu_set_spte_no_acc_track(kvm, iter, new_spte);
-
+ trace_kvm_tdp_mmu_spte_changed(iter->as_id, iter->gfn, iter->level,
+ iter->old_spte, new_spte);
return true;
}
@@ -1324,15 +1257,15 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
* Note, when changing a read-only SPTE, it's not strictly necessary to
* zero the SPTE before setting the new PFN, but doing so preserves the
* invariant that the PFN of a present * leaf SPTE can never change.
- * See __handle_changed_spte().
+ * See handle_changed_spte().
*/
- tdp_mmu_set_spte(kvm, iter, 0);
+ tdp_mmu_iter_set_spte(kvm, iter, 0);
if (!pte_write(range->pte)) {
new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte,
pte_pfn(range->pte));
- tdp_mmu_set_spte(kvm, iter, new_spte);
+ tdp_mmu_iter_set_spte(kvm, iter, new_spte);
}
return true;
@@ -1349,7 +1282,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
/*
* No need to handle the remote TLB flush under RCU protection, the
* target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
- * shadow page. See the WARN on pfn_changed in __handle_changed_spte().
+ * shadow page. See the WARN on pfn_changed in handle_changed_spte().
*/
return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
}
@@ -1607,8 +1540,8 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm,
static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
gfn_t start, gfn_t end)
{
+ u64 dbit = kvm_ad_enabled() ? shadow_dirty_mask : PT_WRITABLE_MASK;
struct tdp_iter iter;
- u64 new_spte;
bool spte_set = false;
rcu_read_lock();
@@ -1621,19 +1554,13 @@ retry:
if (!is_shadow_present_pte(iter.old_spte))
continue;
- if (spte_ad_need_write_protect(iter.old_spte)) {
- if (is_writable_pte(iter.old_spte))
- new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
- else
- continue;
- } else {
- if (iter.old_spte & shadow_dirty_mask)
- new_spte = iter.old_spte & ~shadow_dirty_mask;
- else
- continue;
- }
+ MMU_WARN_ON(kvm_ad_enabled() &&
+ spte_ad_need_write_protect(iter.old_spte));
- if (tdp_mmu_set_spte_atomic(kvm, &iter, new_spte))
+ if (!(iter.old_spte & dbit))
+ continue;
+
+ if (tdp_mmu_set_spte_atomic(kvm, &iter, iter.old_spte & ~dbit))
goto retry;
spte_set = true;
@@ -1675,8 +1602,9 @@ bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root,
gfn_t gfn, unsigned long mask, bool wrprot)
{
+ u64 dbit = (wrprot || !kvm_ad_enabled()) ? PT_WRITABLE_MASK :
+ shadow_dirty_mask;
struct tdp_iter iter;
- u64 new_spte;
rcu_read_lock();
@@ -1685,25 +1613,26 @@ static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root,
if (!mask)
break;
+ MMU_WARN_ON(kvm_ad_enabled() &&
+ spte_ad_need_write_protect(iter.old_spte));
+
if (iter.level > PG_LEVEL_4K ||
!(mask & (1UL << (iter.gfn - gfn))))
continue;
mask &= ~(1UL << (iter.gfn - gfn));
- if (wrprot || spte_ad_need_write_protect(iter.old_spte)) {
- if (is_writable_pte(iter.old_spte))
- new_spte = iter.old_spte & ~PT_WRITABLE_MASK;
- else
- continue;
- } else {
- if (iter.old_spte & shadow_dirty_mask)
- new_spte = iter.old_spte & ~shadow_dirty_mask;
- else
- continue;
- }
+ if (!(iter.old_spte & dbit))
+ continue;
+
+ iter.old_spte = tdp_mmu_clear_spte_bits(iter.sptep,
+ iter.old_spte, dbit,
+ iter.level);
- tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte);
+ trace_kvm_tdp_mmu_spte_changed(iter.as_id, iter.gfn, iter.level,
+ iter.old_spte,
+ iter.old_spte & ~dbit);
+ kvm_set_pfn_dirty(spte_to_pfn(iter.old_spte));
}
rcu_read_unlock();
@@ -1821,7 +1750,7 @@ static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root,
if (new_spte == iter.old_spte)
break;
- tdp_mmu_set_spte(kvm, &iter, new_spte);
+ tdp_mmu_iter_set_spte(kvm, &iter, new_spte);
spte_set = true;
}