[PATCH v5 4/5] vfio: selftests: update DMA map/unmap helpers to support more test kinds

Alex Mastro
2025-10-27T17:34:23Z

Add __vfio_pci_dma_* helpers which return -errno from the underlying
ioctls.

Add __vfio_pci_dma_unmap_all to test more unmapping code paths. Add an
out unmapped arg to report the unmapped byte size.

The existing vfio_pci_dma_* functions, which are intended for happy-path
usage (assert on failure) are now thin wrappers on top of the
double-underscore helpers.

Signed-off-by: Alex Mastro <amastro@fb.com>
---
.../testing/selftests/vfio/lib/include/vfio_util.h | 27 +++++-
tools/testing/selftests/vfio/lib/vfio_pci_device.c | 105 ++++++++++++++++-----
.../testing/selftests/vfio/vfio_dma_mapping_test.c | 5 +-
3 files changed, 109 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h
index ed31606e01b7..240409bf5f8a 100644
--- a/tools/testing/selftests/vfio/lib/include/vfio_util.h
+++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h
@@ -206,10 +206,29 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, const char *iommu_
void vfio_pci_device_cleanup(struct vfio_pci_device *device);
void vfio_pci_device_reset(struct vfio_pci_device *device);

-void vfio_pci_dma_map(struct vfio_pci_device *device,
- struct vfio_dma_region *region);
-void vfio_pci_dma_unmap(struct vfio_pci_device *device,
- struct vfio_dma_region *region);
+int __vfio_pci_dma_map(struct vfio_pci_device *device,
+ struct vfio_dma_region *region);
+int __vfio_pci_dma_unmap(struct vfio_pci_device *device,
+ struct vfio_dma_region *region,
+ u64 *unmapped);
+int __vfio_pci_dma_unmap_all(struct vfio_pci_device *device, u64 *unmapped);
+
+static inline void vfio_pci_dma_map(struct vfio_pci_device *device,
+ struct vfio_dma_region *region)
+{
+ VFIO_ASSERT_EQ(__vfio_pci_dma_map(device, region), 0);
+}
+
+static inline void vfio_pci_dma_unmap(struct vfio_pci_device *device,
+ struct vfio_dma_region *region)
+{
+ VFIO_ASSERT_EQ(__vfio_pci_dma_unmap(device, region, NULL), 0);
+}
+
+static inline void vfio_pci_dma_unmap_all(struct vfio_pci_device *device)
+{
+ VFIO_ASSERT_EQ(__vfio_pci_dma_unmap_all(device, NULL), 0);
+}

void vfio_pci_config_access(struct vfio_pci_device *device, bool write,
size_t config, size_t size, void *data);
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 0921b2451ba5..af43d8c07199 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -2,6 +2,7 @@
#include <dirent.h>
#include <fcntl.h>
#include <libgen.h>
+#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
@@ -141,7 +142,7 @@ static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,
ioctl_assert(device->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info);
}

-static void vfio_iommu_dma_map(struct vfio_pci_device *device,
+static int vfio_iommu_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct vfio_iommu_type1_dma_map args = {
@@ -152,10 +153,13 @@ static void vfio_iommu_dma_map(struct vfio_pci_device *device,
.size = region->size,
};

- ioctl_assert(device->container_fd, VFIO_IOMMU_MAP_DMA, &args);
+ if (ioctl(device->container_fd, VFIO_IOMMU_MAP_DMA, &args))
+ return -errno;
+
+ return 0;
}

-static void iommufd_dma_map(struct vfio_pci_device *device,
+static int iommufd_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
struct iommu_ioas_map args = {
@@ -169,54 +173,109 @@ static void iommufd_dma_map(struct vfio_pci_device *device,
.ioas_id = device->ioas_id,
};

- ioctl_assert(device->iommufd, IOMMU_IOAS_MAP, &args);
+ if (ioctl(device->iommufd, IOMMU_IOAS_MAP, &args))
+ return -errno;
+
+ return 0;
}

-void vfio_pci_dma_map(struct vfio_pci_device *device,
+int __vfio_pci_dma_map(struct vfio_pci_device *device,
struct vfio_dma_region *region)
{
+ int ret;
+
if (device->iommufd)
- iommufd_dma_map(device, region);
+ ret = iommufd_dma_map(device, region);
else
- vfio_iommu_dma_map(device, region);
+ ret = vfio_iommu_dma_map(device, region);
+
+ if (ret)
+ return ret;

list_add(&region->link, &device->dma_regions);
+
+ return 0;
}

-static void vfio_iommu_dma_unmap(struct vfio_pci_device *device,
- struct vfio_dma_region *region)
+static int vfio_iommu_dma_unmap(int fd, u64 iova, u64 size, u32 flags,
+ u64 *unmapped)
{
struct vfio_iommu_type1_dma_unmap args = {
.argsz = sizeof(args),
- .iova = region->iova,
- .size = region->size,
+ .iova = iova,
+ .size = size,
+ .flags = flags,
};

- ioctl_assert(device->container_fd, VFIO_IOMMU_UNMAP_DMA, &args);
+ if (ioctl(fd, VFIO_IOMMU_UNMAP_DMA, &args))
+ return -errno;
+
+ if (unmapped)
+ *unmapped = args.size;
+
+ return 0;
}

-static void iommufd_dma_unmap(struct vfio_pci_device *device,
- struct vfio_dma_region *region)
+static int iommufd_dma_unmap(int fd, u64 iova, u64 length, u32 ioas_id,
+ u64 *unmapped)
{
struct iommu_ioas_unmap args = {
.size = sizeof(args),
- .iova = region->iova,
- .length = region->size,
- .ioas_id = device->ioas_id,
+ .iova = iova,
+ .length = length,
+ .ioas_id = ioas_id,
};

- ioctl_assert(device->iommufd, IOMMU_IOAS_UNMAP, &args);
+ if (ioctl(fd, IOMMU_IOAS_UNMAP, &args))
+ return -errno;
+
+ if (unmapped)
+ *unmapped = args.length;
+
+ return 0;
}

-void vfio_pci_dma_unmap(struct vfio_pci_device *device,
- struct vfio_dma_region *region)
+int __vfio_pci_dma_unmap(struct vfio_pci_device *device,
+ struct vfio_dma_region *region, u64 *unmapped)
{
+ int ret;
+
if (device->iommufd)
- iommufd_dma_unmap(device, region);
+ ret = iommufd_dma_unmap(device->iommufd, region->iova,
+ region->size, device->ioas_id,
+ unmapped);
else
- vfio_iommu_dma_unmap(device, region);
+ ret = vfio_iommu_dma_unmap(device->container_fd, region->iova,
+ region->size, 0, unmapped);
+
+ if (ret)
+ return ret;
+
+ list_del_init(&region->link);
+
+ return 0;
+}
+
+int __vfio_pci_dma_unmap_all(struct vfio_pci_device *device, u64 *unmapped)
+{
+ int ret;
+ struct vfio_dma_region *curr, *next;
+
+ if (device->iommufd)
+ ret = iommufd_dma_unmap(device->iommufd, 0, UINT64_MAX,
+ device->ioas_id, unmapped);
+ else
+ ret = vfio_iommu_dma_unmap(device->container_fd, 0, 0,
+ VFIO_DMA_UNMAP_FLAG_ALL, unmapped);
+
+ if (ret)
+ return ret;
+
+ list_for_each_entry_safe(curr, next, &device->dma_regions, link) {
+ list_del_init(&curr->link);
+ }

- list_del(&region->link);
+ return 0;
}

static void vfio_pci_region_get(struct vfio_pci_device *device, int index,
diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
index ab19c54a774d..a38966e8e5a6 100644
--- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
+++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
@@ -129,6 +129,7 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap)
struct vfio_dma_region region;
struct iommu_mapping mapping;
u64 mapping_size = size;
+ u64 unmapped;
int rc;

region.vaddr = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
@@ -184,7 +185,9 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap)
}

unmap:
- vfio_pci_dma_unmap(self->device, &region);
+ rc = __vfio_pci_dma_unmap(self->device, &region, &unmapped);
+ ASSERT_EQ(rc, 0);
+ ASSERT_EQ(unmapped, region.size);
printf("Unmapped IOVA 0x%lx\n", region.iova);
ASSERT_EQ(INVALID_IOVA, __to_iova(self->device, region.vaddr));
ASSERT_NE(0, iommu_mapping_get(device_bdf, region.iova, &mapping));

--
2.47.3