summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/mmu/mmu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/mmu/mmu.c')
-rw-r--r--arch/x86/kvm/mmu/mmu.c474
1 files changed, 343 insertions, 131 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8160870398b9..7b3f1783ab3c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -110,6 +110,7 @@ static bool __ro_after_init tdp_mmu_allowed;
#ifdef CONFIG_X86_64
bool __read_mostly tdp_mmu_enabled = true;
module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444);
+EXPORT_SYMBOL_GPL(tdp_mmu_enabled);
#endif
static int max_huge_page_level __read_mostly;
@@ -501,7 +502,7 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte)
return false;
}
- if (!spte_has_volatile_bits(old_spte))
+ if (!spte_needs_atomic_update(old_spte))
__update_clear_spte_fast(sptep, new_spte);
else
old_spte = __update_clear_spte_slow(sptep, new_spte);
@@ -524,7 +525,7 @@ static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep)
int level = sptep_to_sp(sptep)->role.level;
if (!is_shadow_present_pte(old_spte) ||
- !spte_has_volatile_bits(old_spte))
+ !spte_needs_atomic_update(old_spte))
__update_clear_spte_fast(sptep, SHADOW_NONPRESENT_VALUE);
else
old_spte = __update_clear_spte_slow(sptep, SHADOW_NONPRESENT_VALUE);
@@ -853,32 +854,173 @@ static struct kvm_memory_slot *gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu
* About rmap_head encoding:
*
* If the bit zero of rmap_head->val is clear, then it points to the only spte
- * in this rmap chain. Otherwise, (rmap_head->val & ~1) points to a struct
+ * in this rmap chain. Otherwise, (rmap_head->val & ~3) points to a struct
* pte_list_desc containing more mappings.
*/
#define KVM_RMAP_MANY BIT(0)
/*
+ * rmaps and PTE lists are mostly protected by mmu_lock (the shadow MMU always
+ * operates with mmu_lock held for write), but rmaps can be walked without
+ * holding mmu_lock so long as the caller can tolerate SPTEs in the rmap chain
+ * being zapped/dropped _while the rmap is locked_.
+ *
+ * Other than the KVM_RMAP_LOCKED flag, modifications to rmap entries must be
+ * done while holding mmu_lock for write. This allows a task walking rmaps
+ * without holding mmu_lock to concurrently walk the same entries as a task
+ * that is holding mmu_lock but _not_ the rmap lock. Neither task will modify
+ * the rmaps, thus the walks are stable.
+ *
+ * As alluded to above, SPTEs in rmaps are _not_ protected by KVM_RMAP_LOCKED,
+ * only the rmap chains themselves are protected. E.g. holding an rmap's lock
+ * ensures all "struct pte_list_desc" fields are stable.
+ */
+#define KVM_RMAP_LOCKED BIT(1)
+
+static unsigned long __kvm_rmap_lock(struct kvm_rmap_head *rmap_head)
+{
+ unsigned long old_val, new_val;
+
+ lockdep_assert_preemption_disabled();
+
+ /*
+ * Elide the lock if the rmap is empty, as lockless walkers (read-only
+ * mode) don't need to (and can't) walk an empty rmap, nor can they add
+ * entries to the rmap. I.e. the only paths that process empty rmaps
+ * do so while holding mmu_lock for write, and are mutually exclusive.
+ */
+ old_val = atomic_long_read(&rmap_head->val);
+ if (!old_val)
+ return 0;
+
+ do {
+ /*
+ * If the rmap is locked, wait for it to be unlocked before
+ * trying acquire the lock, e.g. to avoid bouncing the cache
+ * line.
+ */
+ while (old_val & KVM_RMAP_LOCKED) {
+ cpu_relax();
+ old_val = atomic_long_read(&rmap_head->val);
+ }
+
+ /*
+ * Recheck for an empty rmap, it may have been purged by the
+ * task that held the lock.
+ */
+ if (!old_val)
+ return 0;
+
+ new_val = old_val | KVM_RMAP_LOCKED;
+ /*
+ * Use try_cmpxchg_acquire() to prevent reads and writes to the rmap
+ * from being reordered outside of the critical section created by
+ * __kvm_rmap_lock().
+ *
+ * Pairs with the atomic_long_set_release() in kvm_rmap_unlock().
+ *
+ * For the !old_val case, no ordering is needed, as there is no rmap
+ * to walk.
+ */
+ } while (!atomic_long_try_cmpxchg_acquire(&rmap_head->val, &old_val, new_val));
+
+ /*
+ * Return the old value, i.e. _without_ the LOCKED bit set. It's
+ * impossible for the return value to be 0 (see above), i.e. the read-
+ * only unlock flow can't get a false positive and fail to unlock.
+ */
+ return old_val;
+}
+
+static unsigned long kvm_rmap_lock(struct kvm *kvm,
+ struct kvm_rmap_head *rmap_head)
+{
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ return __kvm_rmap_lock(rmap_head);
+}
+
+static void __kvm_rmap_unlock(struct kvm_rmap_head *rmap_head,
+ unsigned long val)
+{
+ KVM_MMU_WARN_ON(val & KVM_RMAP_LOCKED);
+ /*
+ * Ensure that all accesses to the rmap have completed before unlocking
+ * the rmap.
+ *
+ * Pairs with the atomic_long_try_cmpxchg_acquire() in __kvm_rmap_lock().
+ */
+ atomic_long_set_release(&rmap_head->val, val);
+}
+
+static void kvm_rmap_unlock(struct kvm *kvm,
+ struct kvm_rmap_head *rmap_head,
+ unsigned long new_val)
+{
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ __kvm_rmap_unlock(rmap_head, new_val);
+}
+
+static unsigned long kvm_rmap_get(struct kvm_rmap_head *rmap_head)
+{
+ return atomic_long_read(&rmap_head->val) & ~KVM_RMAP_LOCKED;
+}
+
+/*
+ * If mmu_lock isn't held, rmaps can only be locked in read-only mode. The
+ * actual locking is the same, but the caller is disallowed from modifying the
+ * rmap, and so the unlock flow is a nop if the rmap is/was empty.
+ */
+static unsigned long kvm_rmap_lock_readonly(struct kvm_rmap_head *rmap_head)
+{
+ unsigned long rmap_val;
+
+ preempt_disable();
+ rmap_val = __kvm_rmap_lock(rmap_head);
+
+ if (!rmap_val)
+ preempt_enable();
+
+ return rmap_val;
+}
+
+static void kvm_rmap_unlock_readonly(struct kvm_rmap_head *rmap_head,
+ unsigned long old_val)
+{
+ if (!old_val)
+ return;
+
+ KVM_MMU_WARN_ON(old_val != kvm_rmap_get(rmap_head));
+
+ __kvm_rmap_unlock(rmap_head, old_val);
+ preempt_enable();
+}
+
+/*
* Returns the number of pointers in the rmap chain, not counting the new one.
*/
-static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte,
- struct kvm_rmap_head *rmap_head)
+static int pte_list_add(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+ u64 *spte, struct kvm_rmap_head *rmap_head)
{
+ unsigned long old_val, new_val;
struct pte_list_desc *desc;
int count = 0;
- if (!rmap_head->val) {
- rmap_head->val = (unsigned long)spte;
- } else if (!(rmap_head->val & KVM_RMAP_MANY)) {
+ old_val = kvm_rmap_lock(kvm, rmap_head);
+
+ if (!old_val) {
+ new_val = (unsigned long)spte;
+ } else if (!(old_val & KVM_RMAP_MANY)) {
desc = kvm_mmu_memory_cache_alloc(cache);
- desc->sptes[0] = (u64 *)rmap_head->val;
+ desc->sptes[0] = (u64 *)old_val;
desc->sptes[1] = spte;
desc->spte_count = 2;
desc->tail_count = 0;
- rmap_head->val = (unsigned long)desc | KVM_RMAP_MANY;
+ new_val = (unsigned long)desc | KVM_RMAP_MANY;
++count;
} else {
- desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ desc = (struct pte_list_desc *)(old_val & ~KVM_RMAP_MANY);
count = desc->tail_count + desc->spte_count;
/*
@@ -887,21 +1029,25 @@ static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte,
*/
if (desc->spte_count == PTE_LIST_EXT) {
desc = kvm_mmu_memory_cache_alloc(cache);
- desc->more = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ desc->more = (struct pte_list_desc *)(old_val & ~KVM_RMAP_MANY);
desc->spte_count = 0;
desc->tail_count = count;
- rmap_head->val = (unsigned long)desc | KVM_RMAP_MANY;
+ new_val = (unsigned long)desc | KVM_RMAP_MANY;
+ } else {
+ new_val = old_val;
}
desc->sptes[desc->spte_count++] = spte;
}
+
+ kvm_rmap_unlock(kvm, rmap_head, new_val);
+
return count;
}
-static void pte_list_desc_remove_entry(struct kvm *kvm,
- struct kvm_rmap_head *rmap_head,
+static void pte_list_desc_remove_entry(struct kvm *kvm, unsigned long *rmap_val,
struct pte_list_desc *desc, int i)
{
- struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ struct pte_list_desc *head_desc = (struct pte_list_desc *)(*rmap_val & ~KVM_RMAP_MANY);
int j = head_desc->spte_count - 1;
/*
@@ -928,9 +1074,9 @@ static void pte_list_desc_remove_entry(struct kvm *kvm,
* head at the next descriptor, i.e. the new head.
*/
if (!head_desc->more)
- rmap_head->val = 0;
+ *rmap_val = 0;
else
- rmap_head->val = (unsigned long)head_desc->more | KVM_RMAP_MANY;
+ *rmap_val = (unsigned long)head_desc->more | KVM_RMAP_MANY;
mmu_free_pte_list_desc(head_desc);
}
@@ -938,24 +1084,26 @@ static void pte_list_remove(struct kvm *kvm, u64 *spte,
struct kvm_rmap_head *rmap_head)
{
struct pte_list_desc *desc;
+ unsigned long rmap_val;
int i;
- if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_head->val, kvm))
- return;
+ rmap_val = kvm_rmap_lock(kvm, rmap_head);
+ if (KVM_BUG_ON_DATA_CORRUPTION(!rmap_val, kvm))
+ goto out;
- if (!(rmap_head->val & KVM_RMAP_MANY)) {
- if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_head->val != spte, kvm))
- return;
+ if (!(rmap_val & KVM_RMAP_MANY)) {
+ if (KVM_BUG_ON_DATA_CORRUPTION((u64 *)rmap_val != spte, kvm))
+ goto out;
- rmap_head->val = 0;
+ rmap_val = 0;
} else {
- desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ desc = (struct pte_list_desc *)(rmap_val & ~KVM_RMAP_MANY);
while (desc) {
for (i = 0; i < desc->spte_count; ++i) {
if (desc->sptes[i] == spte) {
- pte_list_desc_remove_entry(kvm, rmap_head,
+ pte_list_desc_remove_entry(kvm, &rmap_val,
desc, i);
- return;
+ goto out;
}
}
desc = desc->more;
@@ -963,6 +1111,9 @@ static void pte_list_remove(struct kvm *kvm, u64 *spte,
KVM_BUG_ON_DATA_CORRUPTION(true, kvm);
}
+
+out:
+ kvm_rmap_unlock(kvm, rmap_head, rmap_val);
}
static void kvm_zap_one_rmap_spte(struct kvm *kvm,
@@ -977,17 +1128,19 @@ static bool kvm_zap_all_rmap_sptes(struct kvm *kvm,
struct kvm_rmap_head *rmap_head)
{
struct pte_list_desc *desc, *next;
+ unsigned long rmap_val;
int i;
- if (!rmap_head->val)
+ rmap_val = kvm_rmap_lock(kvm, rmap_head);
+ if (!rmap_val)
return false;
- if (!(rmap_head->val & KVM_RMAP_MANY)) {
- mmu_spte_clear_track_bits(kvm, (u64 *)rmap_head->val);
+ if (!(rmap_val & KVM_RMAP_MANY)) {
+ mmu_spte_clear_track_bits(kvm, (u64 *)rmap_val);
goto out;
}
- desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ desc = (struct pte_list_desc *)(rmap_val & ~KVM_RMAP_MANY);
for (; desc; desc = next) {
for (i = 0; i < desc->spte_count; i++)
@@ -997,20 +1150,21 @@ static bool kvm_zap_all_rmap_sptes(struct kvm *kvm,
}
out:
/* rmap_head is meaningless now, remember to reset it */
- rmap_head->val = 0;
+ kvm_rmap_unlock(kvm, rmap_head, 0);
return true;
}
unsigned int pte_list_count(struct kvm_rmap_head *rmap_head)
{
+ unsigned long rmap_val = kvm_rmap_get(rmap_head);
struct pte_list_desc *desc;
- if (!rmap_head->val)
+ if (!rmap_val)
return 0;
- else if (!(rmap_head->val & KVM_RMAP_MANY))
+ else if (!(rmap_val & KVM_RMAP_MANY))
return 1;
- desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ desc = (struct pte_list_desc *)(rmap_val & ~KVM_RMAP_MANY);
return desc->tail_count + desc->spte_count;
}
@@ -1053,6 +1207,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
*/
struct rmap_iterator {
/* private fields */
+ struct rmap_head *head;
struct pte_list_desc *desc; /* holds the sptep if not NULL */
int pos; /* index of the sptep */
};
@@ -1067,23 +1222,19 @@ struct rmap_iterator {
static u64 *rmap_get_first(struct kvm_rmap_head *rmap_head,
struct rmap_iterator *iter)
{
- u64 *sptep;
+ unsigned long rmap_val = kvm_rmap_get(rmap_head);
- if (!rmap_head->val)
+ if (!rmap_val)
return NULL;
- if (!(rmap_head->val & KVM_RMAP_MANY)) {
+ if (!(rmap_val & KVM_RMAP_MANY)) {
iter->desc = NULL;
- sptep = (u64 *)rmap_head->val;
- goto out;
+ return (u64 *)rmap_val;
}
- iter->desc = (struct pte_list_desc *)(rmap_head->val & ~KVM_RMAP_MANY);
+ iter->desc = (struct pte_list_desc *)(rmap_val & ~KVM_RMAP_MANY);
iter->pos = 0;
- sptep = iter->desc->sptes[iter->pos];
-out:
- BUG_ON(!is_shadow_present_pte(*sptep));
- return sptep;
+ return iter->desc->sptes[iter->pos];
}
/*
@@ -1093,14 +1244,11 @@ out:
*/
static u64 *rmap_get_next(struct rmap_iterator *iter)
{
- u64 *sptep;
-
if (iter->desc) {
if (iter->pos < PTE_LIST_EXT - 1) {
++iter->pos;
- sptep = iter->desc->sptes[iter->pos];
- if (sptep)
- goto out;
+ if (iter->desc->sptes[iter->pos])
+ return iter->desc->sptes[iter->pos];
}
iter->desc = iter->desc->more;
@@ -1108,20 +1256,24 @@ static u64 *rmap_get_next(struct rmap_iterator *iter)
if (iter->desc) {
iter->pos = 0;
/* desc->sptes[0] cannot be NULL */
- sptep = iter->desc->sptes[iter->pos];
- goto out;
+ return iter->desc->sptes[iter->pos];
}
}
return NULL;
-out:
- BUG_ON(!is_shadow_present_pte(*sptep));
- return sptep;
}
-#define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \
- for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \
- _spte_; _spte_ = rmap_get_next(_iter_))
+#define __for_each_rmap_spte(_rmap_head_, _iter_, _sptep_) \
+ for (_sptep_ = rmap_get_first(_rmap_head_, _iter_); \
+ _sptep_; _sptep_ = rmap_get_next(_iter_))
+
+#define for_each_rmap_spte(_rmap_head_, _iter_, _sptep_) \
+ __for_each_rmap_spte(_rmap_head_, _iter_, _sptep_) \
+ if (!WARN_ON_ONCE(!is_shadow_present_pte(*(_sptep_)))) \
+
+#define for_each_rmap_spte_lockless(_rmap_head_, _iter_, _sptep_, _spte_) \
+ __for_each_rmap_spte(_rmap_head_, _iter_, _sptep_) \
+ if (is_shadow_present_pte(_spte_ = mmu_spte_get_lockless(sptep)))
static void drop_spte(struct kvm *kvm, u64 *sptep)
{
@@ -1207,12 +1359,13 @@ static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
struct rmap_iterator iter;
bool flush = false;
- for_each_rmap_spte(rmap_head, &iter, sptep)
+ for_each_rmap_spte(rmap_head, &iter, sptep) {
if (spte_ad_need_write_protect(*sptep))
flush |= test_and_clear_bit(PT_WRITABLE_SHIFT,
(unsigned long *)sptep);
else
flush |= spte_clear_dirty(sptep);
+ }
return flush;
}
@@ -1304,15 +1457,15 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
* enabled but it chooses between clearing the Dirty bit and Writeable
* bit based on the context.
*/
- if (kvm_x86_ops.cpu_dirty_log_size)
+ if (kvm->arch.cpu_dirty_log_size)
kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask);
else
kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
}
-int kvm_cpu_dirty_log_size(void)
+int kvm_cpu_dirty_log_size(struct kvm *kvm)
{
- return kvm_x86_ops.cpu_dirty_log_size;
+ return kvm->arch.cpu_dirty_log_size;
}
bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
@@ -1401,7 +1554,7 @@ static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator)
while (++iterator->rmap <= iterator->end_rmap) {
iterator->gfn += KVM_PAGES_PER_HPAGE(iterator->level);
- if (iterator->rmap->val)
+ if (atomic_long_read(&iterator->rmap->val))
return;
}
@@ -1533,7 +1686,7 @@ static void __rmap_add(struct kvm *kvm,
kvm_update_page_stats(kvm, sp->role.level, 1);
rmap_head = gfn_to_rmap(gfn, sp->role.level, slot);
- rmap_count = pte_list_add(cache, spte, rmap_head);
+ rmap_count = pte_list_add(kvm, cache, spte, rmap_head);
if (rmap_count > kvm->stat.max_mmu_rmap_size)
kvm->stat.max_mmu_rmap_size = rmap_count;
@@ -1552,51 +1705,67 @@ static void rmap_add(struct kvm_vcpu *vcpu, const struct kvm_memory_slot *slot,
}
static bool kvm_rmap_age_gfn_range(struct kvm *kvm,
- struct kvm_gfn_range *range, bool test_only)
+ struct kvm_gfn_range *range,
+ bool test_only)
{
- struct slot_rmap_walk_iterator iterator;
+ struct kvm_rmap_head *rmap_head;
struct rmap_iterator iter;
+ unsigned long rmap_val;
bool young = false;
u64 *sptep;
+ gfn_t gfn;
+ int level;
+ u64 spte;
- for_each_slot_rmap_range(range->slot, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL,
- range->start, range->end - 1, &iterator) {
- for_each_rmap_spte(iterator.rmap, &iter, sptep) {
- u64 spte = *sptep;
+ for (level = PG_LEVEL_4K; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) {
+ for (gfn = range->start; gfn < range->end;
+ gfn += KVM_PAGES_PER_HPAGE(level)) {
+ rmap_head = gfn_to_rmap(gfn, level, range->slot);
+ rmap_val = kvm_rmap_lock_readonly(rmap_head);
- if (!is_accessed_spte(spte))
- continue;
+ for_each_rmap_spte_lockless(rmap_head, &iter, sptep, spte) {
+ if (!is_accessed_spte(spte))
+ continue;
- if (test_only)
- return true;
-
- if (spte_ad_enabled(spte)) {
- clear_bit((ffs(shadow_accessed_mask) - 1),
- (unsigned long *)sptep);
- } else {
- /*
- * WARN if mmu_spte_update() signals the need
- * for a TLB flush, as Access tracking a SPTE
- * should never trigger an _immediate_ flush.
- */
- spte = mark_spte_for_access_track(spte);
- WARN_ON_ONCE(mmu_spte_update(sptep, spte));
+ if (test_only) {
+ kvm_rmap_unlock_readonly(rmap_head, rmap_val);
+ return true;
+ }
+
+ if (spte_ad_enabled(spte))
+ clear_bit((ffs(shadow_accessed_mask) - 1),
+ (unsigned long *)sptep);
+ else
+ /*
+ * If the following cmpxchg fails, the
+ * spte is being concurrently modified
+ * and should most likely stay young.
+ */
+ cmpxchg64(sptep, spte,
+ mark_spte_for_access_track(spte));
+ young = true;
}
- young = true;
+
+ kvm_rmap_unlock_readonly(rmap_head, rmap_val);
}
}
return young;
}
+static bool kvm_may_have_shadow_mmu_sptes(struct kvm *kvm)
+{
+ return !tdp_mmu_enabled || READ_ONCE(kvm->arch.indirect_shadow_pages);
+}
+
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
bool young = false;
- if (kvm_memslots_have_rmaps(kvm))
- young = kvm_rmap_age_gfn_range(kvm, range, false);
-
if (tdp_mmu_enabled)
- young |= kvm_tdp_mmu_age_gfn_range(kvm, range);
+ young = kvm_tdp_mmu_age_gfn_range(kvm, range);
+
+ if (kvm_may_have_shadow_mmu_sptes(kvm))
+ young |= kvm_rmap_age_gfn_range(kvm, range, false);
return young;
}
@@ -1605,11 +1774,14 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
{
bool young = false;
- if (kvm_memslots_have_rmaps(kvm))
- young = kvm_rmap_age_gfn_range(kvm, range, true);
-
if (tdp_mmu_enabled)
- young |= kvm_tdp_mmu_test_age_gfn(kvm, range);
+ young = kvm_tdp_mmu_test_age_gfn(kvm, range);
+
+ if (young)
+ return young;
+
+ if (kvm_may_have_shadow_mmu_sptes(kvm))
+ young |= kvm_rmap_age_gfn_range(kvm, range, true);
return young;
}
@@ -1656,13 +1828,14 @@ static unsigned kvm_page_table_hashfn(gfn_t gfn)
return hash_64(gfn, KVM_MMU_HASH_SHIFT);
}
-static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache,
+static void mmu_page_add_parent_pte(struct kvm *kvm,
+ struct kvm_mmu_memory_cache *cache,
struct kvm_mmu_page *sp, u64 *parent_pte)
{
if (!parent_pte)
return;
- pte_list_add(cache, parent_pte, &sp->parent_ptes);
+ pte_list_add(kvm, cache, parent_pte, &sp->parent_ptes);
}
static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
@@ -2352,7 +2525,7 @@ static void __link_shadow_page(struct kvm *kvm,
mmu_spte_set(sptep, spte);
- mmu_page_add_parent_pte(cache, sp, sptep);
+ mmu_page_add_parent_pte(kvm, cache, sp, sptep);
/*
* The non-direct sub-pagetable must be updated before linking. For
@@ -2416,7 +2589,8 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
* avoids retaining a large number of stale nested SPs.
*/
if (tdp_enabled && invalid_list &&
- child->role.guest_mode && !child->parent_ptes.val)
+ child->role.guest_mode &&
+ !atomic_long_read(&child->parent_ptes.val))
return kvm_mmu_prepare_zap_page(kvm, child,
invalid_list);
}
@@ -4662,19 +4836,6 @@ out_unlock:
}
#endif
-bool kvm_mmu_may_ignore_guest_pat(void)
-{
- /*
- * When EPT is enabled (shadow_memtype_mask is non-zero), and the VM
- * has non-coherent DMA (DMA doesn't snoop CPU caches), KVM's ABI is to
- * honor the memtype from the guest's PAT so that guest accesses to
- * memory that is DMA'd aren't cached against the guest's wishes. As a
- * result, KVM _may_ ignore guest PAT, whereas without non-coherent DMA,
- * KVM _always_ ignores guest PAT (when EPT is enabled).
- */
- return shadow_memtype_mask;
-}
-
int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
#ifdef CONFIG_X86_64
@@ -4685,8 +4846,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
return direct_page_fault(vcpu, fault);
}
-static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
- u8 *level)
+int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level)
{
int r;
@@ -4700,6 +4860,10 @@ static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
do {
if (signal_pending(current))
return -EINTR;
+
+ if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu))
+ return -EIO;
+
cond_resched();
r = kvm_mmu_do_page_fault(vcpu, gpa, error_code, true, NULL, level);
} while (r == RET_PF_RETRY);
@@ -4724,6 +4888,7 @@ static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
return -EIO;
}
}
+EXPORT_SYMBOL_GPL(kvm_tdp_map_page);
long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
struct kvm_pre_fault_memory *range)
@@ -5416,12 +5581,19 @@ void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu,
static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu)
{
+ int maxpa;
+
+ if (vcpu->kvm->arch.vm_type == KVM_X86_TDX_VM)
+ maxpa = cpuid_query_maxguestphyaddr(vcpu);
+ else
+ maxpa = cpuid_maxphyaddr(vcpu);
+
/* tdp_root_level is architecture forced level, use it if nonzero */
if (tdp_root_level)
return tdp_root_level;
/* Use 5-level TDP if and only if it's useful/necessary. */
- if (max_tdp_level == 5 && cpuid_maxphyaddr(vcpu) <= 48)
+ if (max_tdp_level == 5 && maxpa <= 48)
return 4;
return max_tdp_level;
@@ -5740,6 +5912,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
out:
return r;
}
+EXPORT_SYMBOL_GPL(kvm_mmu_load);
void kvm_mmu_unload(struct kvm_vcpu *vcpu)
{
@@ -5801,6 +5974,7 @@ void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu)
__kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.root_mmu);
__kvm_mmu_free_obsolete_roots(vcpu->kvm, &vcpu->arch.guest_mmu);
}
+EXPORT_SYMBOL_GPL(kvm_mmu_free_obsolete_roots);
static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa,
int *bytes)
@@ -7065,6 +7239,7 @@ static void kvm_mmu_zap_memslot(struct kvm *kvm,
.start = slot->base_gfn,
.end = slot->base_gfn + slot->npages,
.may_block = true,
+ .attr_filter = KVM_FILTER_PRIVATE | KVM_FILTER_SHARED,
};
bool flush;
@@ -7496,9 +7671,30 @@ void kvm_mmu_pre_destroy_vm(struct kvm *kvm)
}
#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
+static bool hugepage_test_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
+ int level)
+{
+ return lpage_info_slot(gfn, slot, level)->disallow_lpage & KVM_LPAGE_MIXED_FLAG;
+}
+
+static void hugepage_clear_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
+ int level)
+{
+ lpage_info_slot(gfn, slot, level)->disallow_lpage &= ~KVM_LPAGE_MIXED_FLAG;
+}
+
+static void hugepage_set_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
+ int level)
+{
+ lpage_info_slot(gfn, slot, level)->disallow_lpage |= KVM_LPAGE_MIXED_FLAG;
+}
+
bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
struct kvm_gfn_range *range)
{
+ struct kvm_memory_slot *slot = range->slot;
+ int level;
+
/*
* Zap SPTEs even if the slot can't be mapped PRIVATE. KVM x86 only
* supports KVM_MEMORY_ATTRIBUTE_PRIVATE, and so it *seems* like KVM
@@ -7513,6 +7709,38 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm)))
return false;
+ if (WARN_ON_ONCE(range->end <= range->start))
+ return false;
+
+ /*
+ * If the head and tail pages of the range currently allow a hugepage,
+ * i.e. reside fully in the slot and don't have mixed attributes, then
+ * add each corresponding hugepage range to the ongoing invalidation,
+ * e.g. to prevent KVM from creating a hugepage in response to a fault
+ * for a gfn whose attributes aren't changing. Note, only the range
+ * of gfns whose attributes are being modified needs to be explicitly
+ * unmapped, as that will unmap any existing hugepages.
+ */
+ for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) {
+ gfn_t start = gfn_round_for_level(range->start, level);
+ gfn_t end = gfn_round_for_level(range->end - 1, level);
+ gfn_t nr_pages = KVM_PAGES_PER_HPAGE(level);
+
+ if ((start != range->start || start + nr_pages > range->end) &&
+ start >= slot->base_gfn &&
+ start + nr_pages <= slot->base_gfn + slot->npages &&
+ !hugepage_test_mixed(slot, start, level))
+ kvm_mmu_invalidate_range_add(kvm, start, start + nr_pages);
+
+ if (end == start)
+ continue;
+
+ if ((end + nr_pages) > range->end &&
+ (end + nr_pages) <= (slot->base_gfn + slot->npages) &&
+ !hugepage_test_mixed(slot, end, level))
+ kvm_mmu_invalidate_range_add(kvm, end, end + nr_pages);
+ }
+
/* Unmap the old attribute page. */
if (range->arg.attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE)
range->attr_filter = KVM_FILTER_SHARED;
@@ -7522,23 +7750,7 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
return kvm_unmap_gfn_range(kvm, range);
}
-static bool hugepage_test_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
- int level)
-{
- return lpage_info_slot(gfn, slot, level)->disallow_lpage & KVM_LPAGE_MIXED_FLAG;
-}
-static void hugepage_clear_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
- int level)
-{
- lpage_info_slot(gfn, slot, level)->disallow_lpage &= ~KVM_LPAGE_MIXED_FLAG;
-}
-
-static void hugepage_set_mixed(struct kvm_memory_slot *slot, gfn_t gfn,
- int level)
-{
- lpage_info_slot(gfn, slot, level)->disallow_lpage |= KVM_LPAGE_MIXED_FLAG;
-}
static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot,
gfn_t gfn, int level, unsigned long attrs)