[PATCH 07/11] vfio: selftests: Allow drivers to specify required region size

[Jason Gunthorpe <jgg@nvidia.com>]

Add a region_size field to struct vfio_pci_driver_ops so drivers can
declare how much DMA-mapped region they need. The mlx5 driver will
need ~18MB for firmware pages. Existing drivers leave region_size as
0 and get the current default of SZ_2M.

Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 .../selftests/vfio/lib/include/libvfio/vfio_pci_driver.h       | 3 +++
 tools/testing/selftests/vfio/vfio_pci_driver_test.c            | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_driver.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_driver.h
index e5ada209b1d102..fa172635632453 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_driver.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_driver.h
@@ -9,6 +9,9 @@ struct vfio_pci_device;
 struct vfio_pci_driver_ops {
 	const char *name;
 
+	/* Minimum driver region size, 0 = default SZ_2M */
+	u64 region_size;
+
 	/**
 	 * @probe() - Check if the driver supports the given device.
 	 *
diff --git a/tools/testing/selftests/vfio/vfio_pci_driver_test.c b/tools/testing/selftests/vfio/vfio_pci_driver_test.c
index 761bf117d624f8..97eea34825f88b 100644
--- a/tools/testing/selftests/vfio/vfio_pci_driver_test.c
+++ b/tools/testing/selftests/vfio/vfio_pci_driver_test.c
@@ -87,7 +87,8 @@ FIXTURE_SETUP(vfio_pci_driver_test)
 	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);
+	region_setup(self->iommu, self->iova_allocator, &driver->region,
+		     driver->ops->region_size ?: SZ_2M);
 
 	/* Any IOVA that doesn't overlap memcpy_region and driver->region. */
 	self->unmapped_iova = iova_allocator_alloc(self->iova_allocator, SZ_1G);
-- 
2.43.0