On Tue, Feb 13, 2024 at 01:14:34PM +0000, Tvrtko Ursulin wrote: > From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > When debugging GPU hangs Mesa developers are finding it useful to replay > the captured error state against the simulator. But due various simulator > limitations which prevent replicating all hangs, one step further is being > able to replay against a real GPU. > > This is almost doable today with the missing part being able to upload the > captured context image into the driver state prior to executing the > uploaded hanging batch and all the buffers. > > To enable this last part we add a new context parameter called > I915_CONTEXT_PARAM_CONTEXT_IMAGE. It follows the existing SSEU > configuration pattern of being able to select which context to apply > against, paired with the actual image and its size. > > Since this is adding a new concept of debug only uapi, we hide it behind > a new kconfig option and also require activation with a module parameter. > Together with a warning banner printed at driver load, all those combined > should be sufficient to guard against inadvertently enabling the feature. > > In terms of implementation the only trivial change is shadowing of the > default state from engine to context. We also allow the legacy context > set param to be used since that removes the need to record the per context > data in the proto context, while still allowing flexibility of specifying > context images for any context. > > Mesa MR using the uapi can be seen at: > https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27594 I just wonder if it would be better to split the default_state in a separate patch.... but from what I could see it looks correct. Also, I have to say that this approach is nice, clean and well protected. And much simpler then I imagined when I saw the idea around. Feel free to use: Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx> > Cc: Carlos Santa <carlos.santa@xxxxxxxxx> > --- > drivers/gpu/drm/i915/Kconfig.debug | 17 +++ > drivers/gpu/drm/i915/gem/i915_gem_context.c | 106 ++++++++++++++++++ > drivers/gpu/drm/i915/gt/intel_context.c | 2 + > drivers/gpu/drm/i915/gt/intel_context.h | 22 ++++ > drivers/gpu/drm/i915/gt/intel_context_types.h | 3 + > drivers/gpu/drm/i915/gt/intel_lrc.c | 8 +- > .../gpu/drm/i915/gt/intel_ring_submission.c | 8 +- > drivers/gpu/drm/i915/i915_params.c | 5 + > drivers/gpu/drm/i915/i915_params.h | 3 +- > include/uapi/drm/i915_drm.h | 27 +++++ > 10 files changed, 194 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug > index 5b7162076850..32e9f70e91ed 100644 > --- a/drivers/gpu/drm/i915/Kconfig.debug > +++ b/drivers/gpu/drm/i915/Kconfig.debug > @@ -16,6 +16,23 @@ config DRM_I915_WERROR > > If in doubt, say "N". > > +config DRM_I915_REPLAY_GPU_HANGS_API > + bool "Enable GPU hang replay userspace API" > + depends on DRM_I915 > + depends on EXPERT > + default n > + help > + Choose this option if you want to enable special and unstable > + userspace API used for replaying GPU hangs on a running system. > + > + This API is intended to be used by userspace graphics stack developers > + and provides no stability guarantees. > + > + The API needs to be activated at boot time using the > + enable_debug_only_api module parameter. > + > + If in doubt, say "N". > + > config DRM_I915_DEBUG > bool "Enable additional driver debugging" > depends on DRM_I915 > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > index dcbfe32fd30c..1cfd624bd978 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > @@ -78,6 +78,7 @@ > #include "gt/intel_engine_user.h" > #include "gt/intel_gpu_commands.h" > #include "gt/intel_ring.h" > +#include "gt/shmem_utils.h" > > #include "pxp/intel_pxp.h" > > @@ -949,6 +950,7 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv, > case I915_CONTEXT_PARAM_NO_ZEROMAP: > case I915_CONTEXT_PARAM_BAN_PERIOD: > case I915_CONTEXT_PARAM_RINGSIZE: > + case I915_CONTEXT_PARAM_CONTEXT_IMAGE: > default: > ret = -EINVAL; > break; > @@ -2092,6 +2094,88 @@ static int get_protected(struct i915_gem_context *ctx, > return 0; > } > > +static int set_context_image(struct i915_gem_context *ctx, > + struct drm_i915_gem_context_param *args) > +{ > + struct i915_gem_context_param_context_image user; > + struct intel_context *ce; > + struct file *shmem_state; > + unsigned long lookup; > + void *state; > + int ret = 0; > + > + if (!IS_ENABLED(CONFIG_DRM_I915_REPLAY_GPU_HANGS_API)) > + return -EINVAL; > + > + if (!ctx->i915->params.enable_debug_only_api) > + return -EINVAL; > + > + if (args->size < sizeof(user)) > + return -EINVAL; > + > + if (copy_from_user(&user, u64_to_user_ptr(args->value), sizeof(user))) > + return -EFAULT; > + > + if (user.mbz) > + return -EINVAL; > + > + if (user.flags & ~(I915_CONTEXT_IMAGE_FLAG_ENGINE_INDEX)) > + return -EINVAL; > + > + lookup = 0; > + if (user.flags & I915_CONTEXT_IMAGE_FLAG_ENGINE_INDEX) > + lookup |= LOOKUP_USER_INDEX; > + > + ce = lookup_user_engine(ctx, lookup, &user.engine); > + if (IS_ERR(ce)) > + return PTR_ERR(ce); > + > + if (user.size < ce->engine->context_size) { > + ret = -EINVAL; > + goto out_ce; > + } > + > + if (test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) { > + ret = -EBUSY; > + goto out_ce; > + } > + > + state = kmalloc(ce->engine->context_size, GFP_KERNEL); > + if (!state) { > + ret = -ENOMEM; > + goto out_ce; > + } > + > + if (copy_from_user(state, u64_to_user_ptr(user.image), > + ce->engine->context_size)) { > + ret = -EFAULT; > + goto out_state; > + } > + > + shmem_state = shmem_create_from_data(ce->engine->name, > + state, ce->engine->context_size); > + if (IS_ERR(shmem_state)) { > + ret = PTR_ERR(shmem_state); > + goto out_state; > + } > + > + if (intel_context_set_own_state(ce)) { > + ret = -EBUSY; > + fput(shmem_state); > + goto out_state; > + } > + > + ce->default_state = shmem_state; > + > + args->size = sizeof(user); > + > +out_state: > + kfree(state); > +out_ce: > + intel_context_put(ce); > + return ret; > +} > + > static int ctx_setparam(struct drm_i915_file_private *fpriv, > struct i915_gem_context *ctx, > struct drm_i915_gem_context_param *args) > @@ -2144,6 +2228,10 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv, > ret = set_persistence(ctx, args); > break; > > + case I915_CONTEXT_PARAM_CONTEXT_IMAGE: > + ret = set_context_image(ctx, args); > + break; > + > case I915_CONTEXT_PARAM_PROTECTED_CONTENT: > case I915_CONTEXT_PARAM_NO_ZEROMAP: > case I915_CONTEXT_PARAM_BAN_PERIOD: > @@ -2488,6 +2576,7 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data, > case I915_CONTEXT_PARAM_BAN_PERIOD: > case I915_CONTEXT_PARAM_ENGINES: > case I915_CONTEXT_PARAM_RINGSIZE: > + case I915_CONTEXT_PARAM_CONTEXT_IMAGE: > default: > ret = -EINVAL; > break; > @@ -2600,5 +2689,22 @@ int __init i915_gem_context_module_init(void) > if (!slab_luts) > return -ENOMEM; > > + if (IS_ENABLED(CONFIG_DRM_I915_REPLAY_GPU_HANGS_API)) { > + pr_notice("**************************************************************\n"); > + pr_notice("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); > + pr_notice("** **\n"); > + if (i915_modparams.enable_debug_only_api) > + pr_notice("** i915.enable_debug_only_api is intended to be set **\n"); > + else > + pr_notice("** CONFIG_DRM_I915_REPLAY_GPU_HANGS_API builds are intended **\n"); > + pr_notice("** for specific userspace graphics stack developers only! **\n"); > + pr_notice("** **\n"); > + pr_notice("** If you are seeing this message please report this to the **\n"); > + pr_notice("** provider of your kernel build. **\n"); > + pr_notice("** **\n"); > + pr_notice("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); > + pr_notice("**************************************************************\n"); > + } > + > return 0; > } > diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c > index a2f1245741bb..b1b8695ba7c9 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context.c > +++ b/drivers/gpu/drm/i915/gt/intel_context.c > @@ -27,6 +27,8 @@ static void rcu_context_free(struct rcu_head *rcu) > struct intel_context *ce = container_of(rcu, typeof(*ce), rcu); > > trace_intel_context_free(ce); > + if (intel_context_has_own_state(ce)) > + fput(ce->default_state); > kmem_cache_free(slab_ce, ce); > } > > diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h > index 25564c01507e..9f523999acd1 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context.h > +++ b/drivers/gpu/drm/i915/gt/intel_context.h > @@ -375,6 +375,28 @@ intel_context_clear_nopreempt(struct intel_context *ce) > clear_bit(CONTEXT_NOPREEMPT, &ce->flags); > } > > +#if IS_ENABLED(CONFIG_DRM_I915_REPLAY_GPU_HANGS_API) > +static inline bool intel_context_has_own_state(const struct intel_context *ce) > +{ > + return test_bit(CONTEXT_OWN_STATE, &ce->flags); > +} > + > +static inline bool intel_context_set_own_state(struct intel_context *ce) > +{ > + return test_and_set_bit(CONTEXT_OWN_STATE, &ce->flags); > +} > +#else > +static inline bool intel_context_has_own_state(const struct intel_context *ce) > +{ > + return false; > +} > + > +static inline bool intel_context_set_own_state(struct intel_context *ce) > +{ > + return true; > +} > +#endif > + > u64 intel_context_get_total_runtime_ns(struct intel_context *ce); > u64 intel_context_get_avg_runtime_ns(struct intel_context *ce); > > diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h > index 7eccbd70d89f..b2ea14155ff0 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context_types.h > +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h > @@ -87,6 +87,8 @@ struct intel_context { > struct rcu_head rcu; > }; > > + struct file *default_state; > + > struct intel_engine_cs *engine; > struct intel_engine_cs *inflight; > #define __intel_context_inflight(engine) ptr_mask_bits(engine, 3) > @@ -130,6 +132,7 @@ struct intel_context { > #define CONTEXT_PERMA_PIN 11 > #define CONTEXT_IS_PARKING 12 > #define CONTEXT_EXITING 13 > +#define CONTEXT_OWN_STATE 14 > > struct { > u64 timeout_us; > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 7c367ba8d9dc..1038659754f8 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -1060,9 +1060,8 @@ void lrc_init_state(struct intel_context *ce, > > set_redzone(state, engine); > > - if (engine->default_state) { > - shmem_read(engine->default_state, 0, > - state, engine->context_size); > + if (ce->default_state) { > + shmem_read(ce->default_state, 0, state, engine->context_size); > __set_bit(CONTEXT_VALID_BIT, &ce->flags); > inhibit = false; > } > @@ -1174,6 +1173,9 @@ int lrc_alloc(struct intel_context *ce, struct intel_engine_cs *engine) > > GEM_BUG_ON(ce->state); > > + if (!intel_context_has_own_state(ce)) > + ce->default_state = engine->default_state; > + > vma = __lrc_alloc_state(ce, engine); > if (IS_ERR(vma)) > return PTR_ERR(vma); > diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c > index 92085ffd23de..72277bc8322e 100644 > --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c > +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c > @@ -474,8 +474,7 @@ static int ring_context_init_default_state(struct intel_context *ce, > if (IS_ERR(vaddr)) > return PTR_ERR(vaddr); > > - shmem_read(ce->engine->default_state, 0, > - vaddr, ce->engine->context_size); > + shmem_read(ce->default_state, 0, vaddr, ce->engine->context_size); > > i915_gem_object_flush_map(obj); > __i915_gem_object_release_map(obj); > @@ -491,7 +490,7 @@ static int ring_context_pre_pin(struct intel_context *ce, > struct i915_address_space *vm; > int err = 0; > > - if (ce->engine->default_state && > + if (ce->default_state && > !test_bit(CONTEXT_VALID_BIT, &ce->flags)) { > err = ring_context_init_default_state(ce, ww); > if (err) > @@ -570,6 +569,9 @@ static int ring_context_alloc(struct intel_context *ce) > { > struct intel_engine_cs *engine = ce->engine; > > + if (!intel_context_has_own_state(ce)) > + ce->default_state = engine->default_state; > + > /* One ringbuffer to rule them all */ > GEM_BUG_ON(!engine->legacy.ring); > ce->ring = engine->legacy.ring; > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index de43048543e8..1226af5fd96f 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -134,6 +134,11 @@ i915_param_named_unsafe(lmem_size, uint, 0400, > i915_param_named_unsafe(lmem_bar_size, uint, 0400, > "Set the lmem bar size(in MiB)."); > > +#if IS_ENABLED(CONFIG_DRM_I915_REPLAY_GPU_HANGS_API) > +i915_param_named(enable_debug_only_api, bool, 0400, > + "Enable support for unstable debug only userspace API. (default:false)"); > +#endif > + > static void _param_print_bool(struct drm_printer *p, const char *name, > bool val) > { > diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h > index 1315d7fac850..e2cdf12ce611 100644 > --- a/drivers/gpu/drm/i915/i915_params.h > +++ b/drivers/gpu/drm/i915/i915_params.h > @@ -64,7 +64,8 @@ struct drm_printer; > /* leave bools at the end to not create holes */ \ > param(bool, enable_hangcheck, true, 0600) \ > param(bool, error_capture, true, IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) ? 0600 : 0) \ > - param(bool, enable_gvt, false, IS_ENABLED(CONFIG_DRM_I915_GVT) ? 0400 : 0) > + param(bool, enable_gvt, false, IS_ENABLED(CONFIG_DRM_I915_GVT) ? 0400 : 0) \ > + param(bool, enable_debug_only_api, false, IS_ENABLED(CONFIG_DRM_I915_REPLAY_GPU_HANGS_API) ? 0400 : 0) > > #define MEMBER(T, member, ...) T member; > struct i915_params { > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h > index fd4f9574d177..0af932e61d12 100644 > --- a/include/uapi/drm/i915_drm.h > +++ b/include/uapi/drm/i915_drm.h > @@ -2154,6 +2154,15 @@ struct drm_i915_gem_context_param { > __u64 value; > }; > > +/* > + * I915_CONTEXT_PARAM_CONTEXT_IMAGE: > + * > + * Allows userspace to provide own context images. > + * > + * Note that this is a debug API not available on production kernel builds. > + */ > +#define I915_CONTEXT_PARAM_CONTEXT_IMAGE 0xe > + > /* > * Context SSEU programming > * > @@ -2549,6 +2558,24 @@ struct i915_context_param_engines { > struct i915_engine_class_instance engines[N__]; \ > } __attribute__((packed)) name__ > > +struct i915_gem_context_param_context_image { > + /** @engine: Engine class & instance to be configured. */ > + struct i915_engine_class_instance engine; > + > + /** @flags: One of the supported flags or zero. */ > + __u32 flags; > +#define I915_CONTEXT_IMAGE_FLAG_ENGINE_INDEX (1u << 0) > + > + /** @size: Size of the image blob pointed to by @image. */ > + __u32 size; > + > + /** @mbz: Must be zero. */ > + __u32 mbz; > + > + /** @image: Userspace memory containing the context image. */ > + __u64 image; > +} __attribute__((packed)); > + > /** > * struct drm_i915_gem_context_create_ext_setparam - Context parameter > * to set or query during context creation. > -- > 2.40.1 >
