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authorAlex Williamson <alex.williamson@redhat.com>2018-06-02 08:41:44 -0600
committerAlex Williamson <alex.williamson@redhat.com>2018-06-02 08:41:44 -0600
commit89c29def6b0101fff66a3d74d0178b844f88d732 (patch)
tree8da69b007e6652aa4e5a9750b18a52b5e3b4e55c
parent0512e0134582ef85dee77d51aae77dcd1edec495 (diff)
downloadlinux-89c29def6b0101fff66a3d74d0178b844f88d732.tar.gz
Revert "vfio/type1: Improve memory pinning process for raw PFN mapping"
Bisection by Amadeusz Sławiński implicates this commit leading to bad page state issues after VM shutdown, likely due to unbalanced page references. The original commit was intended only as a performance improvement, therefore revert for offline rework. Link: https://lkml.org/lkml/2018/6/2/97 Fixes: 356e88ebe447 ("vfio/type1: Improve memory pinning process for raw PFN mapping") Cc: Jason Cai (Xiang Feng) <jason.cai@linux.alibaba.com> Reported-by: Amadeusz Sławiński <amade@asmblr.net> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-rw-r--r--drivers/vfio/vfio_iommu_type1.c25
1 files changed, 10 insertions, 15 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 5c212bf29640..3c082451ab1a 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -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;
}