drivers/vhost/vdpa.c | 80
++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 62 insertions(+), 18 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index b6d9016..5b13dfd 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -560,6 +560,8 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
if (r)
vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
+ else
+ atomic64_add(size >> PAGE_SHIFT, &dev->mm->pinned_vm);
return r;
}
@@ -591,14 +593,16 @@ static int
vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
unsigned int gup_flags = FOLL_LONGTERM;
unsigned long npages, cur_base, map_pfn, last_pfn = 0;
- unsigned long locked, lock_limit, pinned, i;
+ unsigned long lock_limit, sz2pin, nchunks, i;
u64 iova = msg->iova;
+ long pinned;
int ret = 0;
if (vhost_iotlb_itree_first(iotlb, msg->iova,
msg->iova + msg->size - 1))
return -EEXIST;
+ /* Limit the use of memory for bookkeeping */
page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list)
return -ENOMEM;
@@ -607,52 +611,75 @@ static int
vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
gup_flags |= FOLL_WRITE;
npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >>
PAGE_SHIFT;
- if (!npages)
- return -EINVAL;
+ if (!npages) {
+ ret = -EINVAL;
+ goto free;
+ }
mmap_read_lock(dev->mm);
- locked = atomic64_add_return(npages, &dev->mm->pinned_vm);
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- if (locked > lock_limit) {
+ if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
ret = -ENOMEM;
- goto out;
+ goto unlock;
}
cur_base = msg->uaddr & PAGE_MASK;
iova &= PAGE_MASK;
+ nchunks = 0;
while (npages) {
- pinned = min_t(unsigned long, npages, list_size);
- ret = pin_user_pages(cur_base, pinned,
- gup_flags, page_list, NULL);
- if (ret != pinned)
+ sz2pin = min_t(unsigned long, npages, list_size);
+ pinned = pin_user_pages(cur_base, sz2pin,
+ gup_flags, page_list, NULL);
+ if (sz2pin != pinned) {
+ if (pinned < 0) {
+ ret = pinned;
+ } else {
+ unpin_user_pages(page_list, pinned);
+ ret = -ENOMEM;
+ }
goto out;
+ }
+ nchunks++;
if (!last_pfn)
map_pfn = page_to_pfn(page_list[0]);
- for (i = 0; i < ret; i++) {
+ for (i = 0; i < pinned; i++) {
unsigned long this_pfn = page_to_pfn(page_list[i]);
u64 csize;
if (last_pfn && (this_pfn != last_pfn + 1)) {
/* Pin a contiguous chunk of memory */
csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
- if (vhost_vdpa_map(v, iova, csize,
- map_pfn << PAGE_SHIFT,
- msg->perm))
+ ret = vhost_vdpa_map(v, iova, csize,
+ map_pfn << PAGE_SHIFT,
+ msg->perm);
+ if (ret) {
+ /*
+ * Unpin the pages that are left unmapped
+ * from this point on in the current
+ * page_list. The remaining outstanding
+ * ones which may stride across several
+ * chunks will be covered in the common
+ * error path subsequently.
+ */
+ unpin_user_pages(&page_list[i],
+ pinned - i);
goto out;
+ }
+
map_pfn = this_pfn;
iova += csize;
+ nchunks = 0;
}
last_pfn = this_pfn;
}
- cur_base += ret << PAGE_SHIFT;
- npages -= ret;
+ cur_base += pinned << PAGE_SHIFT;
+ npages -= pinned;
}
/* Pin the rest chunk */
@@ -660,10 +687,27 @@ static int
vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
map_pfn << PAGE_SHIFT, msg->perm);
out:
if (ret) {
+ if (nchunks) {
+ unsigned long pfn;
+
+ /*
+ * Unpin the outstanding pages which are yet to be
+ * mapped but haven't due to vdpa_map() or
+ * pin_user_pages() failure.
+ *
+ * Mapped pages are accounted in vdpa_map(), hence
+ * the corresponding unpinning will be handled by
+ * vdpa_unmap().
+ */
+ WARN_ON(!last_pfn);
+ for (pfn = map_pfn; pfn <= last_pfn; pfn++)
+ unpin_user_page(pfn_to_page(pfn));
+ }
vhost_vdpa_unmap(v, msg->iova, msg->size);
- atomic64_sub(npages, &dev->mm->pinned_vm);
}
+unlock:
mmap_read_unlock(dev->mm);
+free:
free_page((unsigned long)page_list);
return ret;
}
