vfio: selftests: Move vfio dma mapping test to their own file

Move the dma_map_unmap test from vfio_pci_device_test to a new test:
vfio_dma_mapping_test. We are going to add more complex dma mapping
tests, so it makes sense to separate this from the vfio pci device
test which is more of a sanity check for vfio pci functionality.

Signed-off-by: Josh Hilke <jrhilke@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-6-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

tools/testing/selftests/vfio/Makefile

@@ -1,4 +1,5 @@
 CFLAGS = $(KHDR_INCLUDES)
+TEST_GEN_PROGS += vfio_dma_mapping_test
 TEST_GEN_PROGS += vfio_iommufd_setup_test
 TEST_GEN_PROGS += vfio_pci_device_test
 include ../lib.mk

tools/testing/selftests/vfio/vfio_dma_mapping_test.c

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <fcntl.h>
+
+#include <sys/mman.h>
+
+#include <linux/sizes.h>
+#include <linux/vfio.h>
+
+#include <vfio_util.h>
+
+#include "../kselftest_harness.h"
+
+static const char *device_bdf;
+
+FIXTURE(vfio_dma_mapping_test) {
+	struct vfio_pci_device *device;
+};
+
+FIXTURE_SETUP(vfio_dma_mapping_test)
+{
+	self->device = vfio_pci_device_init(device_bdf, VFIO_TYPE1_IOMMU);
+}
+
+FIXTURE_TEARDOWN(vfio_dma_mapping_test)
+{
+	vfio_pci_device_cleanup(self->device);
+}
+
+TEST_F(vfio_dma_mapping_test, dma_map_unmap)
+{
+	const u64 size = SZ_2M;
+	void *mem;
+	u64 iova;
+
+	mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	ASSERT_NE(mem, MAP_FAILED);
+
+	iova = (u64)mem;
+
+	vfio_pci_dma_map(self->device, iova, size, mem);
+	printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", mem, size, iova);
+	vfio_pci_dma_unmap(self->device, iova, size);
+
+	ASSERT_TRUE(!munmap(mem, size));
+}
+
+int main(int argc, char *argv[])
+{
+	device_bdf = vfio_selftests_get_bdf(&argc, argv);
+	return test_harness_run(argc, argv);
+}

tools/testing/selftests/vfio/vfio_pci_device_test.c

@@ -36,24 +36,6 @@ FIXTURE_TEARDOWN(vfio_pci_device_test)
 	vfio_pci_device_cleanup(self->device);
 }
 
-TEST_F(vfio_pci_device_test, dma_map_unmap)
-{
-	const u64 size = SZ_2M;
-	void *mem;
-	u64 iova;
-
-	mem = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
-	ASSERT_NE(mem, MAP_FAILED);
-
-	iova = (u64)mem;
-
-	vfio_pci_dma_map(self->device, iova, size, mem);
-	printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", mem, size, iova);
-	vfio_pci_dma_unmap(self->device, iova, size);
-
-	ASSERT_TRUE(!munmap(mem, SZ_2M));
-}
-
 #define read_pci_id_from_sysfs(_file) ({							\
 	char __sysfs_path[PATH_MAX];								\
 	char __buf[32];										\