RE: [PATCH v8 4/5] iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl

From: Liu, Yi L yi.l.liu@intel.com Sent: Wednesday, August 16, 2023 8:14 PM

+TEST_F(iommufd_ioas, get_hw_info) +{

• struct iommu_test_hw_info buffer_exact;
• struct iommu_test_hw_info_buffer {

• struct iommu_test_hw_info info;
  

• uint64_t trailing_bytes;
  

• } buffer_larger;
• if (self->device_id) {

• /* Provide a zero-size user_buffer */
  

• test_cmd_get_hw_info(self->device_id, NULL, 0);
  

• /* Provide a user_buffer with exact size */
  

• test_cmd_get_hw_info(self->device_id, &buffer_exact,
  

sizeof(buffer_exact));

• /*
  

•  * Provide a user_buffer with size larger than the exact size to
  

check if

•  * kernel zero the trailing bytes.
  

•  */
  

• test_cmd_get_hw_info(self->device_id, &buffer_larger,
  

sizeof(buffer_larger));

Do we also want to test a case where size is smaller than the exact size?