[PATCH 2/2] drm/i915: Support replaying GPU hangs with captured context image
Santa, Carlos
carlos.santa at intel.com
Mon Feb 26 14:39:07 UTC 2024
> -----Original Message-----
> From: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Sent: Monday, February 26, 2024 1:56 AM
> To: Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Cc: Intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org; Ursulin,
> Tvrtko <tvrtko.ursulin at intel.com>; Landwerlin, Lionel G
> <lionel.g.landwerlin at intel.com>; Santa, Carlos <carlos.santa at intel.com>
> Subject: Re: [PATCH 2/2] drm/i915: Support replaying GPU hangs with
> captured context image
>
>
>
> On 22/02/2024 21:07, Rodrigo Vivi wrote:
> > On Wed, Feb 21, 2024 at 02:22:45PM +0000, Tvrtko Ursulin wrote:
> >> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >> 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 we 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
> >>
> >> v2:
> >> * Fix whitespace alignment as per checkpatch.
> >> * Added warning on userspace misuse.
> >> * Rebase for extracting ce->default_state shadowing.
> >>
> >> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> >> Cc: Carlos Santa <carlos.santa at intel.com>
> >> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> >> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com> # v1
> >
> > still valid for v2. Thanks for splitting the patch.
>
> Great, thanks!
>
> Now we need to hear from Lionel if he is still keen to have this. In which case
> some acks or tested by would be good.
>
> Regards,
>
> Tvrtko
I tested a setup at my end and it reproduces the GPU hang. I am on a TGL based NUC system running Ubuntu 22.04.
There's a one-liner change that's needed in the corresponding Mesa but I've communicated that to Lionel already.
You can use my Tested-by: Carlos Santa <carlos.santa at intel.com>
>
> >> ---
> >> drivers/gpu/drm/i915/Kconfig.debug | 17 +++
> >> drivers/gpu/drm/i915/gem/i915_gem_context.c | 113
> ++++++++++++++++++
> >> 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 | 1 +
> >> drivers/gpu/drm/i915/gt/intel_lrc.c | 3 +-
> >> .../gpu/drm/i915/gt/intel_ring_submission.c | 3 +-
> >> 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, 193 insertions(+), 3 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..481aacbc1772 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 +2094,95 @@ 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 (drm_WARN_ON_ONCE(&ctx->i915->drm,
> >> + test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
> >> + /*
> >> + * This is racy but for a debug only API, if userspace is keen
> >> + * to create and configure contexts, while simultaneously
> using
> >> + * them from a second thread, let them suffer by potentially
> not
> >> + * executing with the context image they just raced to apply.
> >> + */
> >> + 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 +2235,10 @@
> >> 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 +2583,7 @@ 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 +2696,22 @@ 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 b179178680a5..d91b33c3664c 100644
> >> --- a/drivers/gpu/drm/i915/gt/intel_context_types.h
> >> +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
> >> @@ -132,6 +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 d4eb822d20ae..1038659754f8 100644
> >> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> >> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> >> @@ -1173,7 +1173,8 @@ int lrc_alloc(struct intel_context *ce, struct
> >> intel_engine_cs *engine)
> >>
> >> GEM_BUG_ON(ce->state);
> >>
> >> - ce->default_state = engine->default_state;
> >> + if (!intel_context_has_own_state(ce))
> >> + ce->default_state = engine->default_state;
> >>
> >> vma = __lrc_alloc_state(ce, engine);
> >> if (IS_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 8625e88e785f..72277bc8322e 100644
> >> --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> >> +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> >> @@ -569,7 +569,8 @@ static int ring_context_alloc(struct intel_context
> *ce)
> >> {
> >> struct intel_engine_cs *engine = ce->engine;
> >>
> >> - ce->default_state = engine->default_state;
> >> + 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);
> >> diff --git a/drivers/gpu/drm/i915/i915_params.c
> >> b/drivers/gpu/drm/i915/i915_params.c
> >> index de43048543e8..afd95b2b7e4b 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 2ee338860b7e..e194d17c3568
> 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
> >>
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