Merge tag 'kvm-arm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm...

[karo-tx-linux.git] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bd2eb92c5d0eb3800c9fb5f7aa437d4a89a70672..61b31a5f76c856f2d7e7f09c6b68ff5ac2fea526 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1442,6 +1442,52 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
        return true;
 }
 
+static int hva_to_pfn_remapped(struct vm_area_struct *vma,
+                              unsigned long addr, bool *async,
+                              bool write_fault, kvm_pfn_t *p_pfn)
+{
+       unsigned long pfn;
+       int r;
+
+       r = follow_pfn(vma, addr, &pfn);
+       if (r) {
+               /*
+                * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
+                * not call the fault handler, so do it here.
+                */
+               bool unlocked = false;
+               r = fixup_user_fault(current, current->mm, addr,
+                                    (write_fault ? FAULT_FLAG_WRITE : 0),
+                                    &unlocked);
+               if (unlocked)
+                       return -EAGAIN;
+               if (r)
+                       return r;
+
+               r = follow_pfn(vma, addr, &pfn);
+               if (r)
+                       return r;
+
+       }
+
+
+       /*
+        * Get a reference here because callers of *hva_to_pfn* and
+        * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
+        * returned pfn.  This is only needed if the VMA has VM_MIXEDMAP
+        * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will
+        * simply do nothing for reserved pfns.
+        *
+        * Whoever called remap_pfn_range is also going to call e.g.
+        * unmap_mapping_range before the underlying pages are freed,
+        * causing a call to our MMU notifier.
+        */ 
+       kvm_get_pfn(pfn);
+
+       *p_pfn = pfn;
+       return 0;
+}
+
 /*
  * Pin guest page in memory and return its pfn.
  * @addr: host virtual address which maps memory to the guest
@@ -1461,7 +1507,7 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
 {
        struct vm_area_struct *vma;
        kvm_pfn_t pfn = 0;
-       int npages;
+       int npages, r;
 
        /* we can do it either atomically or asynchronously, not both */
        BUG_ON(atomic && async);
@@ -1483,14 +1529,17 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
                goto exit;
        }
 
+retry:
        vma = find_vma_intersection(current->mm, addr, addr + 1);
 
        if (vma == NULL)
                pfn = KVM_PFN_ERR_FAULT;
-       else if ((vma->vm_flags & VM_PFNMAP)) {
-               pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
-                       vma->vm_pgoff;
-               BUG_ON(!kvm_is_reserved_pfn(pfn));
+       else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
+               r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn);
+               if (r == -EAGAIN)
+                       goto retry;
+               if (r < 0)
+                       pfn = KVM_PFN_ERR_FAULT;
        } else {
                if (async && vma_is_valid(vma, write_fault))
                        *async = true;