[PATCH 2/6] drm/i915/gvt: Add error handling for intel_gvt_scan_and_shadow_workload

[fred gao]

When an error occurs after shadow_indirect_ctx, this patch is to do the
proper cleanup and rollback to the original states for shadowed indirect
context before the workload is abandoned.

v2:
- split the mixed several error paths for better review. (Zhenyu)

v3:
- no return check for clean up functions. (Changbin)

v4:
- expose and reuse the existing release_shadow_wa_ctx. (Zhenyu)

Signed-off-by: fred gao <fred.gao at intel.com>
---
 drivers/gpu/drm/i915/gvt/execlist.c  |  2 +-
 drivers/gpu/drm/i915/gvt/execlist.h  |  3 +++
 drivers/gpu/drm/i915/gvt/scheduler.c | 10 ++++++----
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/execlist.c b/drivers/gpu/drm/i915/gvt/execlist.c
index 1e2c277..930768a 100644
--- a/drivers/gpu/drm/i915/gvt/execlist.c
+++ b/drivers/gpu/drm/i915/gvt/execlist.c
@@ -489,7 +489,7 @@ static void release_shadow_batch_buffer(struct intel_vgpu_workload *workload)
 	}
 }
 
-static void release_shadow_wa_ctx(struct intel_shadow_wa_ctx *wa_ctx)
+void release_shadow_wa_ctx(struct intel_shadow_wa_ctx *wa_ctx)
 {
 	if (!wa_ctx->indirect_ctx.obj)
 		return;
diff --git a/drivers/gpu/drm/i915/gvt/execlist.h b/drivers/gpu/drm/i915/gvt/execlist.h
index 7eced40..c7a9a29 100644
--- a/drivers/gpu/drm/i915/gvt/execlist.h
+++ b/drivers/gpu/drm/i915/gvt/execlist.h
@@ -176,6 +176,9 @@ struct intel_vgpu_execlist {
 	struct intel_vgpu_elsp_dwords elsp_dwords;
 };
 
+struct intel_shadow_wa_ctx;
+void release_shadow_wa_ctx(struct intel_shadow_wa_ctx *wa_ctx);
+
 void intel_vgpu_clean_execlist(struct intel_vgpu *vgpu);
 
 int intel_vgpu_init_execlist(struct intel_vgpu *vgpu);
diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 43022d3..aeb99cdac 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -283,18 +283,18 @@ int intel_gvt_scan_and_shadow_workload(struct intel_vgpu_workload *workload)
 	if (IS_ERR(ring)) {
 		ret = PTR_ERR(ring);
 		gvt_vgpu_err("fail to pin shadow context\n");
-		goto out;
+		goto err_shadow;
 	}
 
 	ret = populate_shadow_context(workload);
 	if (ret)
-		goto out;
+		goto err_shadow;
 
 	rq = i915_gem_request_alloc(dev_priv->engine[ring_id], shadow_ctx);
 	if (IS_ERR(rq)) {
 		gvt_vgpu_err("fail to allocate gem request\n");
 		ret = PTR_ERR(rq);
-		goto out;
+		goto err_shadow;
 	}
 
 	gvt_dbg_sched("ring id %d get i915 gem request %p\n", ring_id, rq);
@@ -302,9 +302,11 @@ int intel_gvt_scan_and_shadow_workload(struct intel_vgpu_workload *workload)
 	workload->req = i915_gem_request_get(rq);
 	ret = copy_workload_to_ring_buffer(workload);
 	if (ret)
-		goto out;
+		goto err_shadow;
 	workload->shadowed = true;
 
+err_shadow:
+	release_shadow_wa_ctx(&workload->wa_ctx);
 out:
 	return ret;
 }
-- 
2.7.4