A pinned dma mapping may include reserved pages, which are not included
in the task's locked_vm count. Maintain a count of reserved pages, for
iommu capable devices, so that locked_vm can be restored after fork or
exec in a subsequent patch.
Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index cd49b656..add87cd 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -101,6 +101,7 @@ struct vfio_dma {
struct rb_root pfn_list; /* Ex-user pinned pfn list */
unsigned long *bitmap;
struct mm_struct *mm;
+ long reserved_pages;
};
struct vfio_batch {
@@ -662,7 +663,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
{
unsigned long pfn;
struct mm_struct *mm = current->mm;
- long ret, pinned = 0, lock_acct = 0;
+ long ret, pinned = 0, lock_acct = 0, reserved_pages = 0;
bool rsvd;
dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
@@ -716,7 +717,9 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
* externally pinned pages are already counted against
* the user.
*/
- if (!rsvd && !vfio_find_vpfn(dma, iova)) {
+ if (rsvd) {
+ reserved_pages++;
+ } else if (!vfio_find_vpfn(dma, iova)) {
if (!dma->lock_cap &&
mm->locked_vm + lock_acct + 1 > limit) {
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
@@ -746,6 +749,8 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
out:
ret = vfio_lock_acct(dma, lock_acct, false);
+ if (!ret)
+ dma->reserved_pages += reserved_pages;
unpin_out:
if (batch->size == 1 && !batch->offset) {
@@ -771,7 +776,7 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
unsigned long pfn, long npage,
bool do_accounting)
{
- long unlocked = 0, locked = 0;
+ long unlocked = 0, locked = 0, reserved_pages = 0;
long i;
for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
@@ -779,9 +784,12 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
unlocked++;
if (vfio_find_vpfn(dma, iova))
locked++;
+ } else {
+ reserved_pages++;
}
}
+ dma->reserved_pages -= reserved_pages;
if (do_accounting)
vfio_lock_acct(dma, locked - unlocked, true);
--
1.8.3.1
