[Qemu-devel] [PATCH] vfio: Align iova also to IOMMU page size

[Pavel Fedin]

On some architectures TARGET_PAGE_ALIGN() is not enough to get the right
alignment. For example on ARM TARGET_PAGE_BITS is 10 because some old CPUs
support 1K page size, while minimum SMMU page size is 4K.

This fixes problems like:

2015-11-17T07:37:42.892265Z qemu-system-aarch64: VFIO_MAP_DMA: -22
2015-11-17T07:37:42.892309Z qemu-system-aarch64: vfio_dma_map(0x223da230, 
0x80002f0400, 0x10fc00, 0x7f89b40400) = -22 (Invalid
argument)
qemu: hardware error: vfio: DMA mapping failed, unable to continue

Signed-off-by: Pavel Fedin <address@hidden>
---
 hw/vfio/common.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index ff5a89a..328140c 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -326,7 +326,7 @@ static void vfio_listener_region_add(MemoryListener 
*listener,
                                      MemoryRegionSection *section)
 {
     VFIOContainer *container = container_of(listener, VFIOContainer, listener);
-    hwaddr iova, end;
+    hwaddr iova, end, iommu_page_size;
     Int128 llend;
     void *vaddr;
     int ret;
@@ -346,6 +346,8 @@ static void vfio_listener_region_add(MemoryListener 
*listener,
     }
 
     iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    iommu_page_size = vfio_container_granularity(container);
+    iova = (iova + iommu_page_size - 1) & ~(iommu_page_size - 1);
     llend = int128_make64(section->offset_within_address_space);
     llend = int128_add(llend, section->size);
     llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
@@ -390,8 +392,7 @@ static void vfio_listener_region_add(MemoryListener 
*listener,
         QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next);
 
         memory_region_register_iommu_notifier(giommu->iommu, &giommu->n);
-        memory_region_iommu_replay(giommu->iommu, &giommu->n,
-                                   vfio_container_granularity(container),
+        memory_region_iommu_replay(giommu->iommu, &giommu->n, iommu_page_size,
                                    false);
 
         return;
-- 
1.9.5.msysgit.0