[PATCH v4 i-g-t 2/2] tests/intel/xe_sriov_flr: Add flr-twice subtest

[Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>]

Introduce the `flr-twice` subtest, which initiates FLR twice in parallel
on the same VF. This subtest covers a use case where two FLRs can occur
within a short time frame, such as when starting a QEMU VM with
a passed VF.

Example log showing the behavior:
[  241.906514] vfio-pci 0000:00:02.1: resetting
[  241.907123] xe 0000:00:02.0: [drm] GT1: PF: VF1 FLR
[  241.907204] xe 0000:00:02.0: [drm] GT0: PF: VF1 FLR
[  242.013441] vfio-pci 0000:00:02.1: reset done
[  242.040918] vfio-pci 0000:00:02.1: resetting
[  242.041794] xe 0000:00:02.0: [drm] GT1: PF: VF1 FLR
[  242.041803] xe 0000:00:02.0: [drm:pf_enter_vf_flr_wip [xe]] GT1: PF:
VF1 FLR is already in progress
[  242.042207] xe 0000:00:02.0: [drm] GT0: PF: VF1 FLR
[  242.042214] xe 0000:00:02.0: [drm:pf_enter_vf_flr_wip [xe]] GT0: PF:
VF1 FLR is already in progress
[  242.149432] vfio-pci 0000:00:02.1: reset done

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Reviewed-by: Lukasz Laguna <lukasz.laguna@intel.com>
Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
Cc: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Narasimha C V <narasimha.c.v@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
---
 tests/intel/xe_sriov_flr.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/intel/xe_sriov_flr.c b/tests/intel/xe_sriov_flr.c
index 3b42aa637..a98d6ce70 100644
--- a/tests/intel/xe_sriov_flr.c
+++ b/tests/intel/xe_sriov_flr.c
@@ -41,6 +41,13 @@
  * Run type: FULL
  * Description:
  *   Executes FLR on all VFs simultaneously to validate correct behavior during parallel resets.
+ *
+ * SUBTEST: flr-twice
+ * Run type: FULL
+ * Description:
+ *   Initiates FLR twice in parallel on the same VF to validate behavior
+ *   when multiple resets occur within a short time frame, as seen in some
+ *   real-world scenarios (e.g., when starting a QEMU VM with a passed VF).
  */
 
 IGT_TEST_DESCRIPTION("Xe tests for SR-IOV VF FLR (Functional Level Reset)");
@@ -449,6 +456,14 @@ static int execute_parallel_flr(int pf_fd, int num_vfs, struct subcheck *checks,
 				     wait_flr_ms, 1);
 }
 
+static int execute_parallel_flr_twice(int pf_fd, int num_vfs,
+				      struct subcheck *checks, int num_checks,
+				      const int wait_flr_ms)
+{
+	return execute_parallel_flr_(pf_fd, num_vfs, checks, num_checks,
+				     wait_flr_ms, 2);
+}
+
 #define GEN12_VF_CAP_REG			0x1901f8
 #define GGTT_PTE_TEST_FIELD_MASK		GENMASK_ULL(19, 12)
 #define GGTT_PTE_ADDR_SHIFT			12
@@ -1073,6 +1088,11 @@ igt_main
 		clear_tests(pf_fd, total_vfs, execute_parallel_flr);
 	}
 
+	igt_describe("Initiate FLR twice in parallel on same VF.");
+	igt_subtest("flr-twice") {
+		clear_tests(pf_fd, 1, execute_parallel_flr_twice);
+	}
+
 	igt_fixture {
 		igt_sriov_disable_vfs(pf_fd);
 		/* abort to avoid execution of next tests with enabled VFs */
-- 
2.31.1