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vfio/ccw: Add length to DMA_UNMAP checks

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As pointed out with the simplification of the
VFIO_IOMMU_NOTIFY_DMA_UNMAP notifier [1], the length
parameter was never used to check against the pinned
pages.

Let's correct that, and see if a page is within the
affected range instead of simply the first page of
the range.

[1] https://lore.kernel.org/kvm/20220720170457.39cda0d0.alex.williamson@redhat.com/

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220728204914.2420989-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Eric Farman 2022-07-28 22:49:12 +02:00 committed by Alex Williamson
parent 34a255e676
commit 5a4fe7c41b
3 changed files with 13 additions and 7 deletions
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16
drivers/s390/cio/vfio_ccw_cp.c
View File

@ -170,13 +170,18 @@ static void page_array_unpin_free(struct page_array *pa, struct vfio_device *vde
kfree(pa->pa_iova);
}
static bool page_array_iova_pinned(struct page_array *pa, unsigned long iova)
static bool page_array_iova_pinned(struct page_array *pa, u64 iova, u64 length)
{
u64 iova_pfn_start = iova >> PAGE_SHIFT;
u64 iova_pfn_end = (iova + length - 1) >> PAGE_SHIFT;
u64 pfn;
int i;
for (i = 0; i < pa->pa_nr; i++)
if (pa->pa_iova[i] == iova)
for (i = 0; i < pa->pa_nr; i++) {
pfn = pa->pa_iova[i] >> PAGE_SHIFT;
if (pfn >= iova_pfn_start && pfn <= iova_pfn_end)
return true;
}
return false;
}
@ -899,11 +904,12 @@ void cp_update_scsw(struct channel_program *cp, union scsw *scsw)
* cp_iova_pinned() - check if an iova is pinned for a ccw chain.
* @cp: channel_program on which to perform the operation
* @iova: the iova to check
* @length: the length to check from @iova
*
* If the @iova is currently pinned for the ccw chain, return true;
* else return false.
*/
bool cp_iova_pinned(struct channel_program *cp, u64 iova)
bool cp_iova_pinned(struct channel_program *cp, u64 iova, u64 length)
{
struct ccwchain *chain;
int i;
@ -913,7 +919,7 @@ bool cp_iova_pinned(struct channel_program *cp, u64 iova)
list_for_each_entry(chain, &cp->ccwchain_list, next) {
for (i = 0; i < chain->ch_len; i++)
if (page_array_iova_pinned(chain->ch_pa + i, iova))
if (page_array_iova_pinned(chain->ch_pa + i, iova, length))
return true;
}

2
drivers/s390/cio/vfio_ccw_cp.h
View File

@ -46,6 +46,6 @@ void cp_free(struct channel_program *cp);
int cp_prefetch(struct channel_program *cp);
union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm);
void cp_update_scsw(struct channel_program *cp, union scsw *scsw);
bool cp_iova_pinned(struct channel_program *cp, u64 iova);
bool cp_iova_pinned(struct channel_program *cp, u64 iova, u64 length);
#endif

2
drivers/s390/cio/vfio_ccw_ops.c
View File

@ -39,7 +39,7 @@ static void vfio_ccw_dma_unmap(struct vfio_device *vdev, u64 iova, u64 length)
container_of(vdev, struct vfio_ccw_private, vdev);
/* Drivers MUST unpin pages in response to an invalidation. */
if (!cp_iova_pinned(&private->cp, iova))
if (!cp_iova_pinned(&private->cp, iova, length))
return;
vfio_ccw_mdev_reset(private);