On 2026-05-05 10:14 PM, Samiullah Khawaja wrote:
> Add a test for iommufd to verify creation of multiple iommus using an
> already setup iommufd and switch between them.
>
> Signed-off-by: Samiullah Khawaja <[email protected]>
> ---
> tools/testing/selftests/vfio/Makefile | 1 +
> .../vfio/vfio_iommufd_multi_iommu_test.c | 203 ++++++++++++++++++
> 2 files changed, 204 insertions(+)
> create mode 100644
> tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c
>
> diff --git a/tools/testing/selftests/vfio/Makefile
> b/tools/testing/selftests/vfio/Makefile
> index 0684932d91bf..24bdeaad590f 100644
> --- a/tools/testing/selftests/vfio/Makefile
> +++ b/tools/testing/selftests/vfio/Makefile
> @@ -8,6 +8,7 @@ else
> CFLAGS = $(KHDR_INCLUDES)
> TEST_GEN_PROGS += vfio_dma_mapping_test
> TEST_GEN_PROGS += vfio_dma_mapping_mmio_test
> +TEST_GEN_PROGS += vfio_iommufd_multi_iommu_test
> TEST_GEN_PROGS += vfio_iommufd_setup_test
> TEST_GEN_PROGS += vfio_pci_device_test
> TEST_GEN_PROGS += vfio_pci_device_init_perf_test
> diff --git a/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c
> b/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c
> new file mode 100644
> index 000000000000..7199c662637c
> --- /dev/null
> +++ b/tools/testing/selftests/vfio/vfio_iommufd_multi_iommu_test.c
> @@ -0,0 +1,203 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <sys/ioctl.h>
> +#include <sys/mman.h>
> +
> +#include <linux/sizes.h>
> +#include <linux/vfio.h>
> +
> +#include <libvfio.h>
> +
> +#include "kselftest_harness.h"
> +
> +static const char *device_bdf;
> +
> +#define IOMMU_DEFAULT 0
> +#define IOMMU_WITH_PT 1
> +#define IOMMU_WITHOUT_PT 2
> +
> +static void region_setup(struct iommu *iommu,
> + struct iova_allocator *iova_allocator,
> + struct dma_region *region, u64 size)
> +{
> + const int flags = MAP_SHARED | MAP_ANONYMOUS;
> + const int prot = PROT_READ | PROT_WRITE;
> + void *vaddr;
> +
> + vaddr = mmap(NULL, size, prot, flags, -1, 0);
> + VFIO_ASSERT_NE(vaddr, MAP_FAILED);
> +
> + region->vaddr = vaddr;
> + region->iova = iova_allocator_alloc(iova_allocator, size);
> + region->size = size;
> +
> + iommu_map(iommu, region);
> +}
> +
> +static void region_teardown(struct iommu *iommu, struct dma_region *region)
> +{
> + iommu_unmap(iommu, region);
> + VFIO_ASSERT_EQ(munmap(region->vaddr, region->size), 0);
> +}
Can you create library helpers in the library to share with
vfio_pci_driver_test.c?
dma_region_setup()
dma_region_teardown()
> +
> +FIXTURE(vfio_iommufd_multi_iommu_test) {
> + struct iommu *iommu;
> + struct vfio_pci_device *device;
> + struct iova_allocator *iova_allocator;
> + struct dma_region memcpy_region;
> + void *vaddr;
> +
> + u64 size;
> + void *src;
> + void *dst;
> + iova_t src_iova;
> + iova_t dst_iova;
> +};
> +
> +FIXTURE_SETUP(vfio_iommufd_multi_iommu_test)
> +{
> + struct vfio_pci_driver *driver;
> +
> + self->iommu = iommu_init("iommufd");
MODE_IOMMUFD
> + self->device = vfio_pci_device_init(device_bdf, self->iommu);
> + self->iova_allocator = iova_allocator_init(self->iommu);
> +
> + driver = &self->device->driver;
> +
> + region_setup(self->iommu, self->iova_allocator, &self->memcpy_region,
> SZ_1G);
> + region_setup(self->iommu, self->iova_allocator, &driver->region, SZ_2M);
> +
> + if (driver->ops)
> + vfio_pci_driver_init(self->device);
> +
> + self->size = self->memcpy_region.size / 2;
> + self->src = self->memcpy_region.vaddr;
> + self->dst = self->src + self->size;
> +
> + self->src_iova = to_iova(self->device, self->src);
> + self->dst_iova = to_iova(self->device, self->dst);
> +}
> +
> +FIXTURE_TEARDOWN(vfio_iommufd_multi_iommu_test)
> +{
> + struct vfio_pci_driver *driver = &self->device->driver;
> +
> + if (driver->ops)
> + vfio_pci_driver_remove(self->device);
> +
> + region_teardown(self->iommu, &self->memcpy_region);
> + region_teardown(self->iommu, &driver->region);
> +
> + iova_allocator_cleanup(self->iova_allocator);
> + vfio_pci_device_cleanup(self->device);
> + iommu_cleanup(self->iommu);
> +}
> +
> +FIXTURE_VARIANT(vfio_iommufd_multi_iommu_test) {
> + u32 start_iommu;
> + u32 end_iommu;
> +};
> +
> +#define ADD_IOMMU_VARIANT(S, E) \
> + FIXTURE_VARIANT_ADD(vfio_iommufd_multi_iommu_test, S##_to_##E) { \
> + .start_iommu = IOMMU_##S, \
> + .end_iommu = IOMMU_##E \
> + };
> +
> +#define ADD_ALL_VARIANTS(S) \
> + ADD_IOMMU_VARIANT(S, DEFAULT) \
> + ADD_IOMMU_VARIANT(S, WITH_PT) \
> + ADD_IOMMU_VARIANT(S, WITHOUT_PT)
> +
> +ADD_ALL_VARIANTS(DEFAULT)
> +ADD_ALL_VARIANTS(WITH_PT)
> +ADD_ALL_VARIANTS(WITHOUT_PT)
> +
> +static struct iommu *setup_variant_iommu(struct iommu *fixture_iommu,
> + u32 dev_id, u32 type)
> +{
> + switch (type) {
> + case IOMMU_WITH_PT:
> + return iommufd_iommu_init(fixture_iommu->iommufd, dev_id,
> + IOMMUFD_IOMMU_INIT_CREATE_PT);
> + case IOMMU_WITHOUT_PT:
> + return iommufd_iommu_init(fixture_iommu->iommufd, dev_id, 0);
> + default:
> + return fixture_iommu;
> + }
> +}
> +
> +static void test_memcpy(struct vfio_pci_device *device, void *src, void *dst,
> + iova_t src_iova, iova_t dst_iova, u64 size, char val)
> +{
> + if (!device->driver.ops)
> + return;
> +
> + memset(src, val, size);
> + memset(dst, 0, size);
> +
> + vfio_pci_driver_memcpy_start(device, src_iova, dst_iova, size, 100);
Why do 100 copies?
> + VFIO_ASSERT_EQ(vfio_pci_driver_memcpy_wait(device), 0);
> + VFIO_ASSERT_EQ(memcmp(src, dst, size), 0);
> +}
> +
> +TEST_F(vfio_iommufd_multi_iommu_test, memcpy)
> +{
> + struct dma_region memcpy_region1, driver_region1;
> + struct dma_region memcpy_region2, driver_region2;
> + struct iommu *iommu1;
> + struct iommu *iommu2;
> +
> + iommu1 = setup_variant_iommu(self->iommu, self->device->dev_id,
> + variant->start_iommu);
> + if (iommu1 != self->iommu) {
> + memcpy_region1 = self->memcpy_region;
> + driver_region1 = self->device->driver.region;
> +
> + iommu_map(iommu1, &memcpy_region1);
Can you make a helper to copy dma_region into a new iommu? It should set
up the new struct dma_region based on the old one, re-initialize the
link field, and then call iommu_map().
> + iommu_map(iommu1, &driver_region1);
> +
> + vfio_pci_device_attach_iommu(self->device, iommu1);
> + }
> +
> + test_memcpy(self->device, self->src, self->dst, self->src_iova,
> + self->dst_iova, self->size, 'x');
nit: You can pass in self to avoid unpacking it in every call to
test_memcpy(). The type would be:
struct _test_data_vfio_iommufd_multi_iommu_test *self
> +
> + iommu2 = setup_variant_iommu(self->iommu, self->device->dev_id,
> + variant->end_iommu);
> + if (iommu2 != self->iommu) {
> + memcpy_region2 = self->memcpy_region;
> + driver_region2 = self->device->driver.region;
> +
> + iommu_map(iommu2, &memcpy_region2);
> + iommu_map(iommu2, &driver_region2);
> + }
> +
> + vfio_pci_device_attach_iommu(self->device, iommu2);
> + test_memcpy(self->device, self->src, self->dst, self->src_iova,
> + self->dst_iova, self->size, 'a');
test_memcpy() zeroes self->dst every time so do you need to use a
different character for each call?
> +
> + vfio_pci_device_attach_iommu(self->device, iommu1);
> + test_memcpy(self->device, self->src, self->dst, self->src_iova,
> + self->dst_iova, self->size, '1');
> +
> + if (iommu1 != self->iommu) {
> + /* attach back to default iommu for cleanup */
> + vfio_pci_device_attach_iommu(self->device, self->iommu);
> + iommu_unmap(iommu1, &memcpy_region1);
> + iommu_unmap(iommu1, &driver_region1);
> + iommu_cleanup(iommu1);
> + }
> +
> + if (iommu2 != self->iommu) {
> + iommu_unmap(iommu2, &memcpy_region2);
> + iommu_unmap(iommu2, &driver_region2);
nit: You don't need to unmap before cleanup. Is this just to exercise
that unmap works on the variant iommus?
> + iommu_cleanup(iommu2);
> + }
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + device_bdf = vfio_selftests_get_bdf(&argc, argv);
> +
> + return test_harness_run(argc, argv);
> +}
> --
> 2.54.0.545.g6539524ca2-goog
>
