i915/gem_ctx_persistence: Check precision of hostile cancellation

Check that if we have to remove a hostile request from a non-persistent
context, we do so without harming any other concurrent users.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

1 files changed, 72 insertions, 0 deletions

diff --git a/tests/i915/gem_ctx_persistence.c b/tests/i915/gem_ctx_persistence.c
index 20007f5c..5e6e7f30 100644
--- a/tests/i915/gem_ctx_persistence.c
+++ b/tests/i915/gem_ctx_persistence.c
@@ -613,6 +613,71 @@ static void test_process_mixed(int pfd, unsigned int engine)
 	gem_quiescent_gpu(pfd);
 }
 
+static void
+test_saturated_hostile(int i915, const struct intel_execution_engine2 *engine)
+{
+	const struct intel_execution_engine2 *other;
+	igt_spin_t *spin;
+	uint32_t ctx;
+	int fence = -1;
+
+	/*
+	 * Check that if we have to remove a hostile request from a
+	 * non-persistent context, we do so without harming any other
+	 * concurrent users.
+	 *
+	 * We only allow non-persistent contexts if we can perform a
+	 * per-engine reset, that is removal of the hostile context without
+	 * impacting other users on the system. [Consider the problem of
+	 * allowing the user to create a context with which they can arbitrarily
+	 * reset other users whenever they chose.]
+	 */
+
+	__for_each_physical_engine(i915, other) {
+		if (other->flags == engine->flags)
+			continue;
+
+		spin = igt_spin_new(i915,
+				   .engine = other->flags,
+				   .flags = (IGT_SPIN_NO_PREEMPTION |
+					     IGT_SPIN_FENCE_OUT));
+
+		if (fence < 0) {
+			fence = spin->out_fence;
+		} else {
+			int tmp;
+
+			tmp = sync_fence_merge(fence, spin->out_fence);
+			close(fence);
+			close(spin->out_fence);
+
+			fence = tmp;
+		}
+		spin->out_fence = -1;
+	}
+	igt_require(fence != -1);
+
+	ctx = gem_context_clone_with_engines(i915, 0);
+	gem_context_set_persistence(i915, ctx, false);
+	spin = igt_spin_new(i915, ctx,
+			    .engine = engine->flags,
+			    .flags = (IGT_SPIN_NO_PREEMPTION |
+				      IGT_SPIN_POLL_RUN |
+				      IGT_SPIN_FENCE_OUT));
+	igt_spin_busywait_until_started(spin);
+	gem_context_destroy(i915, ctx);
+
+	/* Hostile request requires a GPU reset to terminate */
+	igt_assert_eq(sync_fence_wait(spin->out_fence, reset_timeout_ms), 0);
+	igt_assert_eq(sync_fence_status(spin->out_fence), -EIO);
+
+	/* All other spinners should be left unharmed */
+	gem_quiescent_gpu(i915);
+	igt_assert_eq(sync_fence_wait(fence, reset_timeout_ms), 0);
+	igt_assert_eq(sync_fence_status(fence), 1);
+	close(fence);
+}
+
 static void test_processes(int i915)
 {
 	struct {
@@ -1041,6 +1106,13 @@ igt_main
 			}
 		}
 
+		igt_subtest_with_dynamic_f("saturated-hostile") {
+			__for_each_physical_engine(i915, e) {
+				igt_dynamic_f("%s", e->name)
+					test_saturated_hostile(i915, e);
+			}
+		}
+
 		igt_subtest("smoketest")
 			smoketest(i915);
 	}