KVM: MMU: rewrite audit_mappings_page() function

[cascardo/linux.git] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5186e72..c7a57b4 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -927,35 +927,46 @@ int memslot_id(struct kvm *kvm, gfn_t gfn)
        return memslot - slots->memslots;
 }
 
-static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
-{
-       return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE;
-}
-
-unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
+static unsigned long gfn_to_hva_many(struct kvm *kvm, gfn_t gfn,
+                                    gfn_t *nr_pages)
 {
        struct kvm_memory_slot *slot;
 
        slot = gfn_to_memslot(kvm, gfn);
        if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
                return bad_hva();
+
+       if (nr_pages)
+               *nr_pages = slot->npages - (gfn - slot->base_gfn);
+
        return gfn_to_hva_memslot(slot, gfn);
 }
+
+unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
+{
+       return gfn_to_hva_many(kvm, gfn, NULL);
+}
 EXPORT_SYMBOL_GPL(gfn_to_hva);
 
-static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
+static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic)
 {
        struct page *page[1];
        int npages;
        pfn_t pfn;
 
-       might_sleep();
-
-       npages = get_user_pages_fast(addr, 1, 1, page);
+       if (atomic)
+               npages = __get_user_pages_fast(addr, 1, 1, page);
+       else {
+               might_sleep();
+               npages = get_user_pages_fast(addr, 1, 1, page);
+       }
 
        if (unlikely(npages != 1)) {
                struct vm_area_struct *vma;
 
+               if (atomic)
+                       goto return_fault_page;
+
                down_read(&current->mm->mmap_sem);
                if (is_hwpoison_address(addr)) {
                        up_read(&current->mm->mmap_sem);
@@ -968,6 +979,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
                if (vma == NULL || addr < vma->vm_start ||
                    !(vma->vm_flags & VM_PFNMAP)) {
                        up_read(&current->mm->mmap_sem);
+return_fault_page:
                        get_page(fault_page);
                        return page_to_pfn(fault_page);
                }
@@ -981,7 +993,13 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
        return pfn;
 }
 
-pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
+{
+       return hva_to_pfn(kvm, addr, true);
+}
+EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
+
+static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic)
 {
        unsigned long addr;
 
@@ -991,7 +1009,18 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
                return page_to_pfn(bad_page);
        }
 
-       return hva_to_pfn(kvm, addr);
+       return hva_to_pfn(kvm, addr, atomic);
+}
+
+pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
+{
+       return __gfn_to_pfn(kvm, gfn, true);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
+
+pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
+{
+       return __gfn_to_pfn(kvm, gfn, false);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn);
 
@@ -999,9 +1028,26 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
                         struct kvm_memory_slot *slot, gfn_t gfn)
 {
        unsigned long addr = gfn_to_hva_memslot(slot, gfn);
-       return hva_to_pfn(kvm, addr);
+       return hva_to_pfn(kvm, addr, false);
 }
 
+int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
+                                                                 int nr_pages)
+{
+       unsigned long addr;
+       gfn_t entry;
+
+       addr = gfn_to_hva_many(kvm, gfn, &entry);
+       if (kvm_is_error_hva(addr))
+               return -1;
+
+       if (entry < nr_pages)
+               return 0;
+
+       return __get_user_pages_fast(addr, nr_pages, 1, pages);
+}
+EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
+
 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 {
        pfn_t pfn;
@@ -1961,7 +2007,9 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
        case CPU_STARTING:
                printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
                       cpu);
+               spin_lock(&kvm_lock);
                hardware_enable(NULL);
+               spin_unlock(&kvm_lock);
                break;
        }
        return NOTIFY_OK;
@@ -2168,8 +2216,10 @@ static int kvm_suspend(struct sys_device *dev, pm_message_t state)
 
 static int kvm_resume(struct sys_device *dev)
 {
-       if (kvm_usage_count)
+       if (kvm_usage_count) {
+               WARN_ON(spin_is_locked(&kvm_lock));
                hardware_enable(NULL);
+       }
        return 0;
 }