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Diffstat (limited to 'arch/x86/kvm/mmu/tdp_mmu.c')
-rw-r--r--arch/x86/kvm/mmu/tdp_mmu.c38
1 files changed, 32 insertions, 6 deletions
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 841feaa48be5..7b9265d67131 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1742,12 +1742,12 @@ static void zap_collapsible_spte_range(struct kvm *kvm,
gfn_t start = slot->base_gfn;
gfn_t end = start + slot->npages;
struct tdp_iter iter;
+ int max_mapping_level;
kvm_pfn_t pfn;
rcu_read_lock();
tdp_root_for_each_pte(iter, root, start, end) {
-retry:
if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true))
continue;
@@ -1755,15 +1755,41 @@ retry:
!is_last_spte(iter.old_spte, iter.level))
continue;
+ /*
+ * This is a leaf SPTE. Check if the PFN it maps can
+ * be mapped at a higher level.
+ */
pfn = spte_to_pfn(iter.old_spte);
- if (kvm_is_reserved_pfn(pfn) ||
- iter.level >= kvm_mmu_max_mapping_level(kvm, slot, iter.gfn,
- pfn, PG_LEVEL_NUM))
+
+ if (kvm_is_reserved_pfn(pfn))
continue;
+ max_mapping_level = kvm_mmu_max_mapping_level(kvm, slot,
+ iter.gfn, pfn, PG_LEVEL_NUM);
+
+ WARN_ON(max_mapping_level < iter.level);
+
+ /*
+ * If this page is already mapped at the highest
+ * viable level, there's nothing more to do.
+ */
+ if (max_mapping_level == iter.level)
+ continue;
+
+ /*
+ * The page can be remapped at a higher level, so step
+ * up to zap the parent SPTE.
+ */
+ while (max_mapping_level > iter.level)
+ tdp_iter_step_up(&iter);
+
/* Note, a successful atomic zap also does a remote TLB flush. */
- if (tdp_mmu_zap_spte_atomic(kvm, &iter))
- goto retry;
+ tdp_mmu_zap_spte_atomic(kvm, &iter);
+
+ /*
+ * If the atomic zap fails, the iter will recurse back into
+ * the same subtree to retry.
+ */
}
rcu_read_unlock();