diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 1993eb1cb2cd..4e60d3695e4e 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -423,6 +423,7 @@ void kvm_arch_flush_shadow(struct kvm *kvm); int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages, int nr_pages); +struct page *get_bad_page(void); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); void kvm_release_page_clean(struct page *page); @@ -576,7 +577,7 @@ void kvm_arch_sync_events(struct kvm *kvm); int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu); void kvm_vcpu_kick(struct kvm_vcpu *vcpu); -int kvm_is_mmio_pfn(pfn_t pfn); +bool kvm_is_mmio_pfn(pfn_t pfn); struct kvm_irq_ack_notifier { struct hlist_node link; diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index ebae24b62c90..79722782d9d7 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -203,8 +203,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu) if (!work) return -ENOMEM; - work->page = bad_page; - get_page(bad_page); + work->page = get_bad_page(); INIT_LIST_HEAD(&work->queue); /* for list_del to work */ spin_lock(&vcpu->async_pf.lock); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0014ee99dc7f..de89497fe4c7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -100,17 +100,11 @@ EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; -struct page *bad_page; -static pfn_t bad_pfn; - -static struct page *hwpoison_page; -static pfn_t hwpoison_pfn; - -static struct page *fault_page; -static pfn_t fault_pfn; - -inline int kvm_is_mmio_pfn(pfn_t pfn) +bool kvm_is_mmio_pfn(pfn_t pfn) { + if (is_error_pfn(pfn)) + return false; + if (pfn_valid(pfn)) { int reserved; struct page *tail = pfn_to_page(pfn); @@ -939,34 +933,55 @@ EXPORT_SYMBOL_GPL(kvm_disable_largepages); int is_error_page(struct page *page) { - return page == bad_page || page == hwpoison_page || page == fault_page; + return IS_ERR(page); } EXPORT_SYMBOL_GPL(is_error_page); int is_error_pfn(pfn_t pfn) { - return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn; + return IS_ERR_VALUE(pfn); } EXPORT_SYMBOL_GPL(is_error_pfn); +static pfn_t get_bad_pfn(void) +{ + return -ENOENT; +} + +pfn_t get_fault_pfn(void) +{ + return -EFAULT; +} +EXPORT_SYMBOL_GPL(get_fault_pfn); + +static pfn_t get_hwpoison_pfn(void) +{ + return -EHWPOISON; +} + int is_hwpoison_pfn(pfn_t pfn) { - return pfn == hwpoison_pfn; + return pfn == -EHWPOISON; } EXPORT_SYMBOL_GPL(is_hwpoison_pfn); int is_noslot_pfn(pfn_t pfn) { - return pfn == bad_pfn; + return pfn == -ENOENT; } EXPORT_SYMBOL_GPL(is_noslot_pfn); int is_invalid_pfn(pfn_t pfn) { - return pfn == hwpoison_pfn || pfn == fault_pfn; + return !is_noslot_pfn(pfn) && is_error_pfn(pfn); } EXPORT_SYMBOL_GPL(is_invalid_pfn); +struct page *get_bad_page(void) +{ + return ERR_PTR(-ENOENT); +} + static inline unsigned long bad_hva(void) { return PAGE_OFFSET; @@ -1038,13 +1053,6 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); -pfn_t get_fault_pfn(void) -{ - get_page(fault_page); - return fault_pfn; -} -EXPORT_SYMBOL_GPL(get_fault_pfn); - int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int write, struct page **page) { @@ -1122,8 +1130,7 @@ static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, if (npages == -EHWPOISON || (!async && check_user_page_hwpoison(addr))) { up_read(¤t->mm->mmap_sem); - get_page(hwpoison_page); - return page_to_pfn(hwpoison_page); + return get_hwpoison_pfn(); } vma = find_vma_intersection(current->mm, addr, addr+1); @@ -1161,10 +1168,8 @@ static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async, *async = false; addr = gfn_to_hva(kvm, gfn); - if (kvm_is_error_hva(addr)) { - get_page(bad_page); - return page_to_pfn(bad_page); - } + if (kvm_is_error_hva(addr)) + return get_bad_pfn(); return hva_to_pfn(addr, atomic, async, write_fault, writable); } @@ -1218,37 +1223,45 @@ int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages, } EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); +static struct page *kvm_pfn_to_page(pfn_t pfn) +{ + WARN_ON(kvm_is_mmio_pfn(pfn)); + + if (is_error_pfn(pfn) || kvm_is_mmio_pfn(pfn)) + return get_bad_page(); + + return pfn_to_page(pfn); +} + struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); - if (!kvm_is_mmio_pfn(pfn)) - return pfn_to_page(pfn); - WARN_ON(kvm_is_mmio_pfn(pfn)); - - get_page(bad_page); - return bad_page; + return kvm_pfn_to_page(pfn); } EXPORT_SYMBOL_GPL(gfn_to_page); void kvm_release_page_clean(struct page *page) { - kvm_release_pfn_clean(page_to_pfn(page)); + if (!is_error_page(page)) + kvm_release_pfn_clean(page_to_pfn(page)); } EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { - if (!kvm_is_mmio_pfn(pfn)) + if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn)) put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); void kvm_release_page_dirty(struct page *page) { + WARN_ON(is_error_page(page)); + kvm_release_pfn_dirty(page_to_pfn(page)); } EXPORT_SYMBOL_GPL(kvm_release_page_dirty); @@ -2771,33 +2784,6 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, if (r) goto out_fail; - bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO); - - if (bad_page == NULL) { - r = -ENOMEM; - goto out; - } - - bad_pfn = page_to_pfn(bad_page); - - hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO); - - if (hwpoison_page == NULL) { - r = -ENOMEM; - goto out_free_0; - } - - hwpoison_pfn = page_to_pfn(hwpoison_page); - - fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO); - - if (fault_page == NULL) { - r = -ENOMEM; - goto out_free_0; - } - - fault_pfn = page_to_pfn(fault_page); - if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) { r = -ENOMEM; goto out_free_0; @@ -2872,12 +2858,6 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, out_free_0a: free_cpumask_var(cpus_hardware_enabled); out_free_0: - if (fault_page) - __free_page(fault_page); - if (hwpoison_page) - __free_page(hwpoison_page); - __free_page(bad_page); -out: kvm_arch_exit(); out_fail: return r; @@ -2897,8 +2877,5 @@ void kvm_exit(void) kvm_arch_hardware_unsetup(); kvm_arch_exit(); free_cpumask_var(cpus_hardware_enabled); - __free_page(fault_page); - __free_page(hwpoison_page); - __free_page(bad_page); } EXPORT_SYMBOL_GPL(kvm_exit);