From: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
[ Upstream commit be16c1fd99f41abebc0bf965d5d29cd18c9d271e ]
vaddr_get_pfn() simply returns 0 on success. Have it report the number
of pfns successfully gotten instead, whether from page pinning or
follow_fault_pfn(), which will be used later when batching pinning.
Change the last check in vfio_pin_pages_remote() for consistency with
the other two.
Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Stable-dep-of: 873aefb376bb ("vfio/type1: Unpin zero pages")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index fbd438e9b9b0..2d26244f9c32 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -464,6 +464,10 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
return ret;
}
+/*
+ * Returns the positive number of pfns successfully obtained or a negative
+ * error code.
+ */
static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
int prot, unsigned long *pfn)
{
@@ -480,7 +484,6 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
page, NULL, NULL);
if (ret == 1) {
*pfn = page_to_pfn(page[0]);
- ret = 0;
goto done;
}
@@ -494,8 +497,12 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
if (ret == -EAGAIN)
goto retry;
- if (!ret && !is_invalid_reserved_pfn(*pfn))
- ret = -EFAULT;
+ if (!ret) {
+ if (is_invalid_reserved_pfn(*pfn))
+ ret = 1;
+ else
+ ret = -EFAULT;
+ }
}
done:
mmap_read_unlock(mm);
@@ -521,7 +528,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
return -ENODEV;
ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, pfn_base);
- if (ret)
+ if (ret < 0)
return ret;
pinned++;
@@ -548,7 +555,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage;
pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn);
- if (ret)
+ if (ret < 0)
break;
if (pfn != *pfn_base + pinned ||
@@ -574,7 +581,7 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
ret = vfio_lock_acct(dma, lock_acct, false);
unpin_out:
- if (ret) {
+ if (ret < 0) {
if (!rsvd) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
@@ -618,7 +625,7 @@ static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
return -ENODEV;
ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
- if (!ret && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
+ if (ret == 1 && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
ret = vfio_lock_acct(dma, 1, true);
if (ret) {
put_pfn(*pfn_base, dma->prot);
--
2.35.1
