Chris Wilson <ch...@chris-wilson.co.uk> writes:
> Keep scrubbing the kernel_context image with poison before we reset it
> in order to demonstrate that we will be resilient in the case where it
> is accidentally overwritten on idle.
>
> Suggested-by: Imre Deak <imre.d...@intel.com>
> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
> Cc: Imre Deak <imre.d...@intel.com>
> ---
> drivers/gpu/drm/i915/gt/intel_context_types.h | 2 ++
> drivers/gpu/drm/i915/gt/intel_engine_pm.c | 18 +++++++++++++++++-
> drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++--
> 3 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h
> b/drivers/gpu/drm/i915/gt/intel_context_types.h
> index 9527a659546c..ca1420fb8b53 100644
> --- a/drivers/gpu/drm/i915/gt/intel_context_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
> @@ -17,6 +17,8 @@
> #include "intel_engine_types.h"
> #include "intel_sseu.h"
>
> +#define CONTEXT_REDZONE POISON_INUSE
> +
> struct i915_gem_context;
> struct i915_vma;
> struct intel_context;
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> index 1b9f73948f22..ea90ab3e396e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
> @@ -37,8 +37,24 @@ static int __engine_unpark(struct intel_wakeref *wf)
>
> /* Discard stale context state from across idling */
> ce = engine->kernel_context;
> - if (ce)
> + if (ce) {
> + GEM_BUG_ON(test_bit(CONTEXT_VALID_BIT, &ce->flags));
> +
> + /* First poison the image to verify we never fully trust it */
> + if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && ce->state) {
> + struct drm_i915_gem_object *obj = ce->state->obj;
> + int type = i915_coherent_map_type(engine->i915);
> +
> + map = i915_gem_object_pin_map(obj, type);
> + if (!IS_ERR(map)) {
> + memset(map, CONTEXT_REDZONE, obj->base.size);
Just pondering if the dword granularity would suffice.
Reviewed-by: Mika Kuoppala <mika.kuopp...@linux.intel.com>
> + i915_gem_object_flush_map(obj);
> + i915_gem_object_unpin_map(obj);
> + }
> + }
> +
> ce->ops->reset(ce);
> + }
>
> if (engine->unpark)
> engine->unpark(engine);
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c
> b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 6d26d84812b6..f81e70cfd194 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -2409,7 +2409,7 @@ set_redzone(void *vaddr, const struct intel_engine_cs
> *engine)
>
> vaddr += engine->context_size;
>
> - memset(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE);
> + memset(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE);
> }
>
> static void
> @@ -2420,7 +2420,7 @@ check_redzone(const void *vaddr, const struct
> intel_engine_cs *engine)
>
> vaddr += engine->context_size;
>
> - if (memchr_inv(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE))
> + if (memchr_inv(vaddr, CONTEXT_REDZONE, I915_GTT_PAGE_SIZE))
> dev_err_once(engine->i915->drm.dev,
> "%s context redzone overwritten!\n",
> engine->name);
> --
> 2.25.0.rc0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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