The current check for the present bit is wrong, since the present bit
is located in the low part of the entry.
Fixes: e8afe1124cc1 ("iommu: elide flushing for higher order map/unmap
operations")
Signed-off-by: Roger Pau Monné <[email protected]>
---
Cc: Suravee Suthikulpanit <[email protected]>
Cc: Brian Woods <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Paul Durrant <[email protected]>
---
xen/drivers/passthrough/amd/iommu_map.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/xen/drivers/passthrough/amd/iommu_map.c
b/xen/drivers/passthrough/amd/iommu_map.c
index 99ac0a6862..67329b0c95 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -39,15 +39,13 @@ static unsigned int clear_iommu_pte_present(unsigned long
l1_mfn,
unsigned long dfn)
{
uint64_t *table, *pte;
- uint32_t entry;
unsigned int flush_flags;
table = map_domain_page(_mfn(l1_mfn));
pte = (table + pfn_to_pde_idx(dfn, 1));
- entry = *pte >> 32;
- flush_flags = get_field_from_reg_u32(entry, IOMMU_PTE_PRESENT_MASK,
+ flush_flags = get_field_from_reg_u32(*pte, IOMMU_PTE_PRESENT_MASK,
IOMMU_PTE_PRESENT_SHIFT) ?
IOMMU_FLUSHF_modified : 0;
--
2.20.1
_______________________________________________
Xen-devel mailing list
[email protected]
https://lists.xenproject.org/mailman/listinfo/xen-devel
