Add 'notifier' to memslot to make it a memfile_notifier node and then register it to memory backing store via memfile_register_notifier() when memslot gets created. When memslot is deleted, do the reverse with memfile_unregister_notifier(). Note each KVM memslot can be registered to different memory backing stores (or the same backing store but at different offset) independently. Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx> Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx> --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 75 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 70 insertions(+), 6 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6e1d770d6bf8..9b175aeca63f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -567,6 +567,7 @@ struct kvm_memory_slot { struct file *private_file; loff_t private_offset; struct memfile_pfn_ops *pfn_ops; + struct memfile_notifier notifier; }; static inline bool kvm_slot_is_private(const struct kvm_memory_slot *slot) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d11a2628b548..67349421eae3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -840,6 +840,37 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +#ifdef CONFIG_MEMFILE_NOTIFIER +static inline int kvm_memfile_register(struct kvm_memory_slot *slot) +{ + return memfile_register_notifier(file_inode(slot->private_file), + &slot->notifier, + &slot->pfn_ops); +} + +static inline void kvm_memfile_unregister(struct kvm_memory_slot *slot) +{ + if (slot->private_file) { + memfile_unregister_notifier(file_inode(slot->private_file), + &slot->notifier); + fput(slot->private_file); + slot->private_file = NULL; + } +} + +#else /* !CONFIG_MEMFILE_NOTIFIER */ + +static inline int kvm_memfile_register(struct kvm_memory_slot *slot) +{ + return -EOPNOTSUPP; +} + +static inline void kvm_memfile_unregister(struct kvm_memory_slot *slot) +{ +} + +#endif /* CONFIG_MEMFILE_NOTIFIER */ + #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, @@ -884,6 +915,9 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) /* This does not remove the slot from struct kvm_memslots data structures */ static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { + if (slot->flags & KVM_MEM_PRIVATE) + kvm_memfile_unregister(slot); + kvm_destroy_dirty_bitmap(slot); kvm_arch_free_memslot(kvm, slot); @@ -1738,6 +1772,12 @@ static int kvm_set_memslot(struct kvm *kvm, kvm_invalidate_memslot(kvm, old, invalid_slot); } + if (new->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) { + r = kvm_memfile_register(new); + if (r) + return r; + } + r = kvm_prepare_memory_region(kvm, old, new, change); if (r) { /* @@ -1752,6 +1792,10 @@ static int kvm_set_memslot(struct kvm *kvm, } else { mutex_unlock(&kvm->slots_arch_lock); } + + if (new->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) + kvm_memfile_unregister(new); + return r; } @@ -1817,6 +1861,7 @@ int __kvm_set_memory_region(struct kvm *kvm, enum kvm_mr_change change; unsigned long npages; gfn_t base_gfn; + struct file *file = NULL; int as_id, id; int r; @@ -1890,14 +1935,24 @@ int __kvm_set_memory_region(struct kvm *kvm, return 0; } + if (mem->flags & KVM_MEM_PRIVATE) { + file = fdget(region_ext->private_fd).file; + if (!file) + return -EINVAL; + } + if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) && - kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) - return -EEXIST; + kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) { + r = -EEXIST; + goto out; + } /* Allocate a slot that will persist in the memslot. */ new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT); - if (!new) - return -ENOMEM; + if (!new) { + r = -ENOMEM; + goto out; + } new->as_id = as_id; new->id = id; @@ -1905,10 +1960,18 @@ int __kvm_set_memory_region(struct kvm *kvm, new->npages = npages; new->flags = mem->flags; new->userspace_addr = mem->userspace_addr; + new->private_file = file; + new->private_offset = mem->flags & KVM_MEM_PRIVATE ? + region_ext->private_offset : 0; r = kvm_set_memslot(kvm, old, new, change); - if (r) - kfree(new); + if (!r) + return r; + + kfree(new); +out: + if (file) + fput(file); return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); -- 2.17.1