drm/i915: Cancel outstanding work after disabling heartbeats on an engine

We only allow persistent requests to remain on the GPU past the closure
of their containing context (and process) so long as they are continuously
checked for hangs or allow other requests to preempt them, as we need to
ensure forward progress of the system. If we allow persistent contexts
to remain on the system after the the hangcheck mechanism is disabled,
the system may grind to a halt. On disabling the mechanism, we sent a
pulse along the engine to remove all executing contexts from the engine
which would check for hung contexts -- but we did not prevent those
contexts from being resubmitted if they survived the final hangcheck.

Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs")
Testcase: igt/gem_ctx_persistence/heartbeat-stop
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200928221510.26044-1-chris@chris-wilson.co.uk
(cherry picked from commit 7a991cd3e3da9a56d5616b62d425db000a3242f2)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 08e2c000dcc3bc8121e49b7a8b7a7eaa74bf371c..7c3a1012e702046de696e82191ab1bef23bb9009 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -337,4 +337,13 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
        return intel_engine_has_preemption(engine);
 }
 
+static inline bool
+intel_engine_has_heartbeat(const struct intel_engine_cs *engine)
+{
+       if (!IS_ACTIVE(CONFIG_DRM_I915_HEARTBEAT_INTERVAL))
+               return false;
+
+       return READ_ONCE(engine->props.heartbeat_interval_ms);
+}
+
 #endif /* _INTEL_RINGBUFFER_H_ */

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 436ce368ddaaa214c22fda621ddfa3132501db95..0e813819b041b5ed7f15648333676c521e7049a9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -542,8 +542,13 @@ bool __i915_request_submit(struct i915_request *request)
        if (i915_request_completed(request))
                goto xfer;
 
+       if (unlikely(intel_context_is_closed(request->context) &&
+                    !intel_engine_has_heartbeat(engine)))
+               intel_context_set_banned(request->context);
+
        if (unlikely(intel_context_is_banned(request->context)))
                i915_request_set_error_once(request, -EIO);
+
        if (unlikely(fatal_error(request->fence.error)))
                __i915_request_skip(request);