@@ -70,6 +70,7 @@
#include <drm/i915_drm.h>
#include "gt/intel_lrc_reg.h"
+#include "gt/intel_engine_heartbeat.h"
#include "gt/intel_engine_user.h"
#include "i915_gem_context.h"
@@ -269,6 +270,78 @@ void i915_gem_context_release(struct kref *ref)
schedule_work(&gc->free_work);
}
+static inline struct i915_gem_engines *
+__context_engines_static(struct i915_gem_context *ctx)
+{
+ return rcu_dereference_protected(ctx->engines, true);
+}
+
+static void kill_context(struct i915_gem_context *ctx)
+{
+ intel_engine_mask_t tmp, active, reset;
+ struct intel_gt *gt = &ctx->i915->gt;
+ struct i915_gem_engines_iter it;
+ struct intel_engine_cs *engine;
+ struct intel_context *ce;
+
+ /*
+ * If we are already banned, it was due to a guilty request causing
+ * a reset and the entire context being evicted from the GPU.
+ */
+ if (i915_gem_context_is_banned(ctx))
+ return;
+
+ i915_gem_context_set_banned(ctx);
+
+ /*
+ * Map the user's engine back to the actual engines; one virtual
+ * engine will be mapped to multiple engines, and using ctx->engine[]
+ * the same engine may be have multiple instances in the user's map.
+ * However, we only care about pending requests, so only include
+ * engines on which there are incomplete requests.
+ */
+ active = 0;
+ for_each_gem_engine(ce, __context_engines_static(ctx), it) {
+ struct dma_fence *fence;
+
+ if (!ce->timeline)
+ continue;
+
+ fence = i915_active_fence_get(&ce->timeline->last_request);
+ if (!fence)
+ continue;
+
+ engine = to_request(fence)->engine;
+ if (HAS_EXECLISTS(gt->i915))
+ engine = intel_context_inflight(ce);
+ if (engine)
+ active |= engine->mask;
+
+ dma_fence_put(fence);
+ }
+
+ /*
+ * Send a "high priority pulse" down the engine to cause the
+ * current request to be momentarily preempted. (If it fails to
+ * be preempted, it will be reset). As we have marked our context
+ * as banned, any incomplete request, including any running, will
+ * be skipped following the preemption.
+ */
+ reset = 0;
+ for_each_engine_masked(engine, gt->i915, active, tmp)
+ if (intel_engine_pulse(engine))
+ reset |= engine->mask;
+
+ /*
+ * If we are unable to send a preemptive pulse to bump
+ * the context from the GPU, we have to resort to a full
+ * reset. We hope the collateral damage is worth it.
+ */
+ if (reset)
+ intel_gt_handle_error(gt, reset, 0,
+ "context closure in %s", ctx->name);
+}
+
static void context_close(struct i915_gem_context *ctx)
{
struct i915_address_space *vm;
@@ -291,9 +364,47 @@ static void context_close(struct i915_gem_context *ctx)
lut_close(ctx);
mutex_unlock(&ctx->mutex);
+
+ /*
+ * If the user has disabled hangchecking, we can not be sure that
+ * the batches will ever complete after the context is closed,
+ * keep the context and all resources pinned forever. So in this
+ * case we opt to forcibly kill off all remaining requests on
+ * context close.
+ */
+ if (!i915_gem_context_is_persistent(ctx) ||
+ !i915_modparams.enable_hangcheck)
+ kill_context(ctx);
+
i915_gem_context_put(ctx);
}
+static int __context_set_persistence(struct i915_gem_context *ctx, bool state)
+{
+ if (i915_gem_context_is_persistent(ctx) == state)
+ return 0;
+
+ if (state) {
+ /*
+ * Only contexts that are short-lived [that will expire or be
+ * reset] are allowed to survive past termination. We require
+ * hangcheck to ensure that the persistent requests are healthy.
+ */
+ if (!i915_modparams.enable_hangcheck)
+ return -EINVAL;
+
+ i915_gem_context_set_persistence(ctx);
+ } else {
+ /* To cancel a context we use "preempt-to-idle" */
+ if (!(ctx->i915->caps.scheduler & I915_SCHEDULER_CAP_PREEMPTION))
+ return -ENODEV;
+
+ i915_gem_context_clear_persistence(ctx);
+ }
+
+ return 0;
+}
+
static struct i915_gem_context *
__create_context(struct drm_i915_private *i915)
{
@@ -328,6 +439,7 @@ __create_context(struct drm_i915_private *i915)
i915_gem_context_set_bannable(ctx);
i915_gem_context_set_recoverable(ctx);
+ __context_set_persistence(ctx, true /* cgroup hook? */);
for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp); i++)
ctx->hang_timestamp[i] = jiffies - CONTEXT_FAST_HANG_JIFFIES;
@@ -484,6 +596,7 @@ i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio)
return ctx;
i915_gem_context_clear_bannable(ctx);
+ i915_gem_context_set_persistence(ctx);
ctx->sched.priority = I915_USER_PRIORITY(prio);
GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
@@ -1594,6 +1707,16 @@ get_engines(struct i915_gem_context *ctx,
return err;
}
+static int
+set_persistence(struct i915_gem_context *ctx,
+ const struct drm_i915_gem_context_param *args)
+{
+ if (args->size)
+ return -EINVAL;
+
+ return __context_set_persistence(ctx, args->value);
+}
+
static int ctx_setparam(struct drm_i915_file_private *fpriv,
struct i915_gem_context *ctx,
struct drm_i915_gem_context_param *args)
@@ -1671,6 +1794,10 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
ret = set_engines(ctx, args);
break;
+ case I915_CONTEXT_PARAM_PERSISTENCE:
+ ret = set_persistence(ctx, args);
+ break;
+
case I915_CONTEXT_PARAM_BAN_PERIOD:
default:
ret = -EINVAL;
@@ -2123,6 +2250,11 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
ret = get_engines(ctx, args);
break;
+ case I915_CONTEXT_PARAM_PERSISTENCE:
+ args->size = 0;
+ args->value = i915_gem_context_is_persistent(ctx);
+ break;
+
case I915_CONTEXT_PARAM_BAN_PERIOD:
default:
ret = -EINVAL;
@@ -76,6 +76,21 @@ static inline void i915_gem_context_clear_recoverable(struct i915_gem_context *c
clear_bit(UCONTEXT_RECOVERABLE, &ctx->user_flags);
}
+static inline bool i915_gem_context_is_persistent(const struct i915_gem_context *ctx)
+{
+ return test_bit(UCONTEXT_PERSISTENCE, &ctx->user_flags);
+}
+
+static inline void i915_gem_context_set_persistence(struct i915_gem_context *ctx)
+{
+ set_bit(UCONTEXT_PERSISTENCE, &ctx->user_flags);
+}
+
+static inline void i915_gem_context_clear_persistence(struct i915_gem_context *ctx)
+{
+ clear_bit(UCONTEXT_PERSISTENCE, &ctx->user_flags);
+}
+
static inline bool i915_gem_context_is_banned(const struct i915_gem_context *ctx)
{
return test_bit(CONTEXT_BANNED, &ctx->flags);
@@ -137,6 +137,7 @@ struct i915_gem_context {
#define UCONTEXT_NO_ERROR_CAPTURE 1
#define UCONTEXT_BANNABLE 2
#define UCONTEXT_RECOVERABLE 3
+#define UCONTEXT_PERSISTENCE 4
/**
* @flags: small set of booleans
@@ -22,6 +22,8 @@ mock_context(struct drm_i915_private *i915,
INIT_LIST_HEAD(&ctx->link);
ctx->i915 = i915;
+ i915_gem_context_set_persistence(ctx);
+
mutex_init(&ctx->engines_mutex);
e = default_engines(ctx);
if (IS_ERR(e))
@@ -1565,6 +1565,21 @@ struct drm_i915_gem_context_param {
* i915_context_engines_bond (I915_CONTEXT_ENGINES_EXT_BOND)
*/
#define I915_CONTEXT_PARAM_ENGINES 0xa
+
+/*
+ * I915_CONTEXT_PARAM_PERSISTENCE:
+ *
+ * Allow the context and active rendering to survive the process until
+ * completion. Persistence allows fire-and-forget clients to queue up a
+ * bunch of work, hand the output over to a display server and the quit.
+ * If the context is not marked as persistent, upon closing (either via
+ * an explicit DRM_I915_GEM_CONTEXT_DESTROY or implicitly from file closure
+ * or process termination), the context and any outstanding requests will be
+ * cancelled (and exported fences for cancelled requests marked as -EIO).
+ *
+ * By default, new contexts allow persistence.
+ */
+#define I915_CONTEXT_PARAM_PERSISTENCE 0xb
/* Must be kept compact -- no holes and well documented */
__u64 value;