vfio: selftests: update DMA map/unmap helpers to support more test kinds

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.

Reviewed-by: David Matlack <[e-mail]>
Signed-off-by: Alex Mastro <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alex Williamson <[e-mail]>

tools/testing/selftests/vfio/lib/include/vfio_util.h

···
 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);

tools/testing/selftests/vfio/lib/vfio_pci_device.c

···
 #include <dirent.h>
 #include <fcntl.h>
 #include <libgen.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
···
 	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 = {
···
 		.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 = {
···
 		.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)
 {
-	if (device->iommufd)
-		iommufd_dma_unmap(device, region);
-	else
-		vfio_iommu_dma_unmap(device, region);
+	int ret;
 
-	list_del(&region->link);
+	if (device->iommufd)
+		ret = iommufd_dma_unmap(device->iommufd, region->iova,
+					region->size, device->ioas_id,
+					unmapped);
+	else
+		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);
+
+	return 0;
 }
 
 static void vfio_pci_region_get(struct vfio_pci_device *device, int index,

tools/testing/selftests/vfio/vfio_dma_mapping_test.c

···
 	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);
···
 	}
 
 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));