diff options
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 18 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 7 |
2 files changed, 18 insertions, 7 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 541e199feb99..eadeca9786f6 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7181,13 +7181,19 @@ restart: sp = sptep_to_sp(sptep); /* - * We cannot do huge page mapping for indirect shadow pages, - * which are found on the last rmap (level = 1) when not using - * tdp; such shadow pages are synced with the page table in - * the guest, and the guest page table is using 4K page size - * mapping if the indirect sp has level = 1. + * Direct shadow page can be replaced by a hugepage if the host + * mapping level allows it and the memslot maps all of the host + * hugepage. Note! If the memslot maps only part of the + * hugepage, sp->gfn may be below slot->base_gfn, and querying + * the max mapping level would cause an out-of-bounds lpage_info + * access. So the gfn bounds check *must* be done first. + * + * Indirect shadow pages are created when the guest page tables + * are using 4K pages. Since the host mapping is always + * constrained by the page size in the guest, indirect shadow + * pages are never collapsible. */ - if (sp->role.direct && + if (sp->role.direct && is_gfn_in_memslot(slot, sp->gfn) && sp->role.level < kvm_mmu_max_mapping_level(kvm, NULL, slot, sp->gfn)) { kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 398e5695dc07..3c4e2401de07 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1793,6 +1793,11 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm, struct kvm_irq_ack_notifier *kian); bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args); +static inline bool is_gfn_in_memslot(const struct kvm_memory_slot *slot, gfn_t gfn) +{ + return gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages; +} + /* * Returns a pointer to the memslot if it contains gfn. * Otherwise returns NULL. @@ -1803,7 +1808,7 @@ try_get_memslot(struct kvm_memory_slot *slot, gfn_t gfn) if (!slot) return NULL; - if (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages) + if (is_gfn_in_memslot(slot, gfn)) return slot; else return NULL; |