VFIO fix v4.17

- Revert a pfn page mapping optimization identified as introducing
    a bad page state regression (Alex Williamson)
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Merge tag 'vfio-v4.17' of git://github.com/awilliam/linux-vfio

Pull VFIO fix from Alex Williamson:
 "Revert a pfn page mapping optimization identified as introducing a bad
  page state regression (Alex Williamson)"

* tag 'vfio-v4.17' of git://github.com/awilliam/linux-vfio:
  Revert "vfio/type1: Improve memory pinning process for raw PFN mapping"
This commit is contained in:
Linus Torvalds 2018-06-02 10:08:45 -07:00
commit 7172a69c10
1 changed files with 10 additions and 15 deletions

View File

@ -404,6 +404,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
{
unsigned long pfn = 0;
long ret, pinned = 0, lock_acct = 0;
bool rsvd;
dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
/* This code path is only user initiated */
@ -414,23 +415,14 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
if (ret)
return ret;
if (is_invalid_reserved_pfn(*pfn_base)) {
struct vm_area_struct *vma;
down_read(&current->mm->mmap_sem);
vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
pinned = min_t(long, npage, vma_pages(vma));
up_read(&current->mm->mmap_sem);
return pinned;
}
pinned++;
rsvd = is_invalid_reserved_pfn(*pfn_base);
/*
* Reserved pages aren't counted against the user, externally pinned
* pages are already counted against the user.
*/
if (!vfio_find_vpfn(dma, iova)) {
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
if (!lock_cap && current->mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
@ -450,12 +442,13 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
if (ret)
break;
if (pfn != *pfn_base + pinned) {
if (pfn != *pfn_base + pinned ||
rsvd != is_invalid_reserved_pfn(pfn)) {
put_pfn(pfn, dma->prot);
break;
}
if (!vfio_find_vpfn(dma, iova)) {
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
if (!lock_cap &&
current->mm->locked_vm + lock_acct + 1 > limit) {
put_pfn(pfn, dma->prot);
@ -473,8 +466,10 @@ out:
unpin_out:
if (ret) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
if (!rsvd) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
}
return ret;
}