Re: [Intel-gfx] [PATCH 19/51] drm/i915/guc: GuC virtual engines

Daniele Ceraolo Spurio
2021-07-19T23:43:03Z

On 7/19/2021 4:27 PM, Matthew Brost wrote:
> On Mon, Jul 19, 2021 at 04:33:56PM -0700, Daniele Ceraolo Spurio wrote:
>>
>> On 7/16/2021 1:16 PM, Matthew Brost wrote:
>>> Implement GuC virtual engines. Rather simple implementation, basically
>>> just allocate an engine, setup context enter / exit function to virtual
>>> engine specific functions, set all other variables / functions to guc
>>> versions, and set the engine mask to that of all the siblings.
>>>
>>> v2: Update to work with proto-ctx
>>>
>>> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
>>> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>>> ---
>>> drivers/gpu/drm/i915/gem/i915_gem_context.c | 8 +-
>>> drivers/gpu/drm/i915/gem/i915_gem_context.h | 1 +
>>> drivers/gpu/drm/i915/gt/intel_context_types.h | 6 +
>>> drivers/gpu/drm/i915/gt/intel_engine.h | 27 +-
>>> drivers/gpu/drm/i915/gt/intel_engine_cs.c | 14 +
>>> .../drm/i915/gt/intel_execlists_submission.c | 29 ++-
>>> .../drm/i915/gt/intel_execlists_submission.h | 4 -
>>> drivers/gpu/drm/i915/gt/selftest_execlists.c | 12 +-
>>> .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 240 +++++++++++++++++-
>>> .../gpu/drm/i915/gt/uc/intel_guc_submission.h | 2 +
>>> 10 files changed, 308 insertions(+), 35 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>>> index 64659802d4df..edefe299bd76 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>>> @@ -74,7 +74,6 @@
>>> #include "gt/intel_context_param.h"
>>> #include "gt/intel_engine_heartbeat.h"
>>> #include "gt/intel_engine_user.h"
>>> -#include "gt/intel_execlists_submission.h" /* virtual_engine */
>>> #include "gt/intel_gpu_commands.h"
>>> #include "gt/intel_ring.h"
>>> @@ -363,9 +362,6 @@ set_proto_ctx_engines_balance(struct i915_user_extension __user *base,
>>> if (!HAS_EXECLISTS(i915))
>>> return -ENODEV;
>>> - if (intel_uc_uses_guc_submission(&i915->gt.uc))
>>> - return -ENODEV; /* not implement yet */
>>> -
>>> if (get_user(idx, &ext->engine_index))
>>> return -EFAULT;
>>> @@ -950,8 +946,8 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
>>> break;
>>> case I915_GEM_ENGINE_TYPE_BALANCED:
>>> - ce = intel_execlists_create_virtual(pe[n].siblings,
>>> - pe[n].num_siblings);
>>> + ce = intel_engine_create_virtual(pe[n].siblings,
>>> + pe[n].num_siblings);
>>> break;
>>> case I915_GEM_ENGINE_TYPE_INVALID:
>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
>>> index 20411db84914..2639c719a7a6 100644
>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
>>> @@ -10,6 +10,7 @@
>>> #include "i915_gem_context_types.h"
>>> #include "gt/intel_context.h"
>>> +#include "gt/intel_engine.h"
>> Apologies for the late question, but why do you need this include in this
>> header? nothing else is changing within the file.
>>
> It likely doesn't need to be included. Let me see what the build / CI
> says if I remove it.
>
>>> #include "i915_drv.h"
>>> #include "i915_gem.h"
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
>>> index 4a5518d295c2..542c98418771 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_context_types.h
>>> +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
>>> @@ -47,6 +47,12 @@ struct intel_context_ops {
>>> void (*reset)(struct intel_context *ce);
>>> void (*destroy)(struct kref *kref);
>>> +
>>> + /* virtual engine/context interface */
>>> + struct intel_context *(*create_virtual)(struct intel_engine_cs **engine,
>>> + unsigned int count);
>>> + struct intel_engine_cs *(*get_sibling)(struct intel_engine_cs *engine,
>>> + unsigned int sibling);
>>> };
>>> struct intel_context {
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
>>> index f911c1224ab2..9fec0aca5f4b 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_engine.h
>>> +++ b/drivers/gpu/drm/i915/gt/intel_engine.h
>>> @@ -273,13 +273,38 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
>>> return intel_engine_has_preemption(engine);
>>> }
>>> +struct intel_context *
>>> +intel_engine_create_virtual(struct intel_engine_cs **siblings,
>>> + unsigned int count);
>>> +
>>> +static inline bool
>>> +intel_virtual_engine_has_heartbeat(const struct intel_engine_cs *engine)
>>> +{
>>> + if (intel_engine_uses_guc(engine))
>>> + return intel_guc_virtual_engine_has_heartbeat(engine);
>>> + else
>>> + GEM_BUG_ON("Only should be called in GuC submission");
>> I insist that this needs a better explanation, as I've commented on the
>> previous rev. Given that this is a shared file, it is not immediately
>> evident why this call shouldn't be called with the execlists backend.
>>
> Sure, can add a comment. Basically it comes down to it is always called
> an active request which in execlists mode is always a physical engine.

I had added a sample comment in the previous review in case you want to
copy it. I remember you explaining this to me a while back, but it
always takes me a moment to recall it when I look at this code and I
expect someone not familiar with the backend implementation would be
even more confused.

Daniele

>
> Matt
>
>> Daniele
>>
>>> +
>>> + return false;
>>> +}
>>> +
>>> static inline bool
>>> intel_engine_has_heartbeat(const struct intel_engine_cs *engine)
>>> {
>>> if (!IS_ACTIVE(CONFIG_DRM_I915_HEARTBEAT_INTERVAL))
>>> return false;
>>> - return READ_ONCE(engine->props.heartbeat_interval_ms);
>>> + if (intel_engine_is_virtual(engine))
>>> + return intel_virtual_engine_has_heartbeat(engine);
>>> + else
>>> + return READ_ONCE(engine->props.heartbeat_interval_ms);
>>> +}
>>> +
>>> +static inline struct intel_engine_cs *
>>> +intel_engine_get_sibling(struct intel_engine_cs *engine, unsigned int sibling)
>>> +{
>>> + GEM_BUG_ON(!intel_engine_is_virtual(engine));
>>> + return engine->cops->get_sibling(engine, sibling);
>>> }
>>> #endif /* _INTEL_RINGBUFFER_H_ */
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>> index d561573ed98c..b7292d5cb7da 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>> @@ -1737,6 +1737,20 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
>>> return total;
>>> }
>>> +struct intel_context *
>>> +intel_engine_create_virtual(struct intel_engine_cs **siblings,
>>> + unsigned int count)
>>> +{
>>> + if (count == 0)
>>> + return ERR_PTR(-EINVAL);
>>> +
>>> + if (count == 1)
>>> + return intel_context_create(siblings[0]);
>>> +
>>> + GEM_BUG_ON(!siblings[0]->cops->create_virtual);
>>> + return siblings[0]->cops->create_virtual(siblings, count);
>>> +}
>>> +
>>> static bool match_ring(struct i915_request *rq)
>>> {
>>> u32 ring = ENGINE_READ(rq->engine, RING_START);
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> index 56e25090da67..28492cdce706 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
>>> @@ -193,6 +193,9 @@ static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
>>> return container_of(engine, struct virtual_engine, base);
>>> }
>>> +static struct intel_context *
>>> +execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
>>> +
>>> static struct i915_request *
>>> __active_request(const struct intel_timeline * const tl,
>>> struct i915_request *rq,
>>> @@ -2548,6 +2551,8 @@ static const struct intel_context_ops execlists_context_ops = {
>>> .reset = lrc_reset,
>>> .destroy = lrc_destroy,
>>> +
>>> + .create_virtual = execlists_create_virtual,
>>> };
>>> static int emit_pdps(struct i915_request *rq)
>>> @@ -3493,6 +3498,17 @@ static void virtual_context_exit(struct intel_context *ce)
>>> intel_engine_pm_put(ve->siblings[n]);
>>> }
>>> +static struct intel_engine_cs *
>>> +virtual_get_sibling(struct intel_engine_cs *engine, unsigned int sibling)
>>> +{
>>> + struct virtual_engine *ve = to_virtual_engine(engine);
>>> +
>>> + if (sibling >= ve->num_siblings)
>>> + return NULL;
>>> +
>>> + return ve->siblings[sibling];
>>> +}
>>> +
>>> static const struct intel_context_ops virtual_context_ops = {
>>> .flags = COPS_HAS_INFLIGHT,
>>> @@ -3507,6 +3523,8 @@ static const struct intel_context_ops virtual_context_ops = {
>>> .exit = virtual_context_exit,
>>> .destroy = virtual_context_destroy,
>>> +
>>> + .get_sibling = virtual_get_sibling,
>>> };
>>> static intel_engine_mask_t virtual_submission_mask(struct virtual_engine *ve)
>>> @@ -3655,20 +3673,13 @@ static void virtual_submit_request(struct i915_request *rq)
>>> spin_unlock_irqrestore(&ve->base.sched_engine->lock, flags);
>>> }
>>> -struct intel_context *
>>> -intel_execlists_create_virtual(struct intel_engine_cs **siblings,
>>> - unsigned int count)
>>> +static struct intel_context *
>>> +execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
>>> {
>>> struct virtual_engine *ve;
>>> unsigned int n;
>>> int err;
>>> - if (count == 0)
>>> - return ERR_PTR(-EINVAL);
>>> -
>>> - if (count == 1)
>>> - return intel_context_create(siblings[0]);
>>> -
>>> ve = kzalloc(struct_size(ve, siblings, count), GFP_KERNEL);
>>> if (!ve)
>>> return ERR_PTR(-ENOMEM);
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.h b/drivers/gpu/drm/i915/gt/intel_execlists_submission.h
>>> index ad4f3e1a0fde..a1aa92c983a5 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.h
>>> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.h
>>> @@ -32,10 +32,6 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
>>> int indent),
>>> unsigned int max);
>>> -struct intel_context *
>>> -intel_execlists_create_virtual(struct intel_engine_cs **siblings,
>>> - unsigned int count);
>>> -
>>> bool
>>> intel_engine_in_execlists_submission_mode(const struct intel_engine_cs *engine);
>>> diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c
>>> index 73ddc6e14730..59cf8afc6d6f 100644
>>> --- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
>>> +++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
>>> @@ -3727,7 +3727,7 @@ static int nop_virtual_engine(struct intel_gt *gt,
>>> GEM_BUG_ON(!nctx || nctx > ARRAY_SIZE(ve));
>>> for (n = 0; n < nctx; n++) {
>>> - ve[n] = intel_execlists_create_virtual(siblings, nsibling);
>>> + ve[n] = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ve[n])) {
>>> err = PTR_ERR(ve[n]);
>>> nctx = n;
>>> @@ -3923,7 +3923,7 @@ static int mask_virtual_engine(struct intel_gt *gt,
>>> * restrict it to our desired engine within the virtual engine.
>>> */
>>> - ve = intel_execlists_create_virtual(siblings, nsibling);
>>> + ve = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ve)) {
>>> err = PTR_ERR(ve);
>>> goto out_close;
>>> @@ -4054,7 +4054,7 @@ static int slicein_virtual_engine(struct intel_gt *gt,
>>> i915_request_add(rq);
>>> }
>>> - ce = intel_execlists_create_virtual(siblings, nsibling);
>>> + ce = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ce)) {
>>> err = PTR_ERR(ce);
>>> goto out;
>>> @@ -4106,7 +4106,7 @@ static int sliceout_virtual_engine(struct intel_gt *gt,
>>> /* XXX We do not handle oversubscription and fairness with normal rq */
>>> for (n = 0; n < nsibling; n++) {
>>> - ce = intel_execlists_create_virtual(siblings, nsibling);
>>> + ce = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ce)) {
>>> err = PTR_ERR(ce);
>>> goto out;
>>> @@ -4208,7 +4208,7 @@ static int preserved_virtual_engine(struct intel_gt *gt,
>>> if (err)
>>> goto out_scratch;
>>> - ve = intel_execlists_create_virtual(siblings, nsibling);
>>> + ve = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ve)) {
>>> err = PTR_ERR(ve);
>>> goto out_scratch;
>>> @@ -4348,7 +4348,7 @@ static int reset_virtual_engine(struct intel_gt *gt,
>>> if (igt_spinner_init(&spin, gt))
>>> return -ENOMEM;
>>> - ve = intel_execlists_create_virtual(siblings, nsibling);
>>> + ve = intel_engine_create_virtual(siblings, nsibling);
>>> if (IS_ERR(ve)) {
>>> err = PTR_ERR(ve);
>>> goto out_spin;
>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>>> index 05958260e849..7b3e1c91e689 100644
>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>>> @@ -60,6 +60,15 @@
>>> *
>>> */
>>> +/* GuC Virtual Engine */
>>> +struct guc_virtual_engine {
>>> + struct intel_engine_cs base;
>>> + struct intel_context context;
>>> +};
>>> +
>>> +static struct intel_context *
>>> +guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
>>> +
>>> #define GUC_REQUEST_SIZE 64 /* bytes */
>>> /*
>>> @@ -925,20 +934,35 @@ static int guc_lrc_desc_pin(struct intel_context *ce)
>>> return ret;
>>> }
>>> -static int guc_context_pre_pin(struct intel_context *ce,
>>> - struct i915_gem_ww_ctx *ww,
>>> - void **vaddr)
>>> +static int __guc_context_pre_pin(struct intel_context *ce,
>>> + struct intel_engine_cs *engine,
>>> + struct i915_gem_ww_ctx *ww,
>>> + void **vaddr)
>>> {
>>> - return lrc_pre_pin(ce, ce->engine, ww, vaddr);
>>> + return lrc_pre_pin(ce, engine, ww, vaddr);
>>> }
>>> -static int guc_context_pin(struct intel_context *ce, void *vaddr)
>>> +static int __guc_context_pin(struct intel_context *ce,
>>> + struct intel_engine_cs *engine,
>>> + void *vaddr)
>>> {
>>> if (i915_ggtt_offset(ce->state) !=
>>> (ce->lrc.lrca & CTX_GTT_ADDRESS_MASK))
>>> set_bit(CONTEXT_LRCA_DIRTY, &ce->flags);
>>> - return lrc_pin(ce, ce->engine, vaddr);
>>> + return lrc_pin(ce, engine, vaddr);
>>> +}
>>> +
>>> +static int guc_context_pre_pin(struct intel_context *ce,
>>> + struct i915_gem_ww_ctx *ww,
>>> + void **vaddr)
>>> +{
>>> + return __guc_context_pre_pin(ce, ce->engine, ww, vaddr);
>>> +}
>>> +
>>> +static int guc_context_pin(struct intel_context *ce, void *vaddr)
>>> +{
>>> + return __guc_context_pin(ce, ce->engine, vaddr);
>>> }
>>> static void guc_context_unpin(struct intel_context *ce)
>>> @@ -1043,6 +1067,21 @@ static inline void guc_lrc_desc_unpin(struct intel_context *ce)
>>> deregister_context(ce, ce->guc_id);
>>> }
>>> +static void __guc_context_destroy(struct intel_context *ce)
>>> +{
>>> + lrc_fini(ce);
>>> + intel_context_fini(ce);
>>> +
>>> + if (intel_engine_is_virtual(ce->engine)) {
>>> + struct guc_virtual_engine *ve =
>>> + container_of(ce, typeof(*ve), context);
>>> +
>>> + kfree(ve);
>>> + } else {
>>> + intel_context_free(ce);
>>> + }
>>> +}
>>> +
>>> static void guc_context_destroy(struct kref *kref)
>>> {
>>> struct intel_context *ce = container_of(kref, typeof(*ce), ref);
>>> @@ -1059,7 +1098,7 @@ static void guc_context_destroy(struct kref *kref)
>>> if (context_guc_id_invalid(ce) ||
>>> !lrc_desc_registered(guc, ce->guc_id)) {
>>> release_guc_id(guc, ce);
>>> - lrc_destroy(kref);
>>> + __guc_context_destroy(ce);
>>> return;
>>> }
>>> @@ -1075,7 +1114,7 @@ static void guc_context_destroy(struct kref *kref)
>>> if (context_guc_id_invalid(ce)) {
>>> __release_guc_id(guc, ce);
>>> spin_unlock_irqrestore(&guc->contexts_lock, flags);
>>> - lrc_destroy(kref);
>>> + __guc_context_destroy(ce);
>>> return;
>>> }
>>> @@ -1120,6 +1159,8 @@ static const struct intel_context_ops guc_context_ops = {
>>> .reset = lrc_reset,
>>> .destroy = guc_context_destroy,
>>> +
>>> + .create_virtual = guc_create_virtual,
>>> };
>>> static void __guc_signal_context_fence(struct intel_context *ce)
>>> @@ -1248,6 +1289,83 @@ static int guc_request_alloc(struct i915_request *rq)
>>> return 0;
>>> }
>>> +static struct intel_engine_cs *
>>> +guc_virtual_get_sibling(struct intel_engine_cs *ve, unsigned int sibling)
>>> +{
>>> + struct intel_engine_cs *engine;
>>> + intel_engine_mask_t tmp, mask = ve->mask;
>>> + unsigned int num_siblings = 0;
>>> +
>>> + for_each_engine_masked(engine, ve->gt, mask, tmp)
>>> + if (num_siblings++ == sibling)
>>> + return engine;
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +static int guc_virtual_context_pre_pin(struct intel_context *ce,
>>> + struct i915_gem_ww_ctx *ww,
>>> + void **vaddr)
>>> +{
>>> + struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
>>> +
>>> + return __guc_context_pre_pin(ce, engine, ww, vaddr);
>>> +}
>>> +
>>> +static int guc_virtual_context_pin(struct intel_context *ce, void *vaddr)
>>> +{
>>> + struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
>>> +
>>> + return __guc_context_pin(ce, engine, vaddr);
>>> +}
>>> +
>>> +static void guc_virtual_context_enter(struct intel_context *ce)
>>> +{
>>> + intel_engine_mask_t tmp, mask = ce->engine->mask;
>>> + struct intel_engine_cs *engine;
>>> +
>>> + for_each_engine_masked(engine, ce->engine->gt, mask, tmp)
>>> + intel_engine_pm_get(engine);
>>> +
>>> + intel_timeline_enter(ce->timeline);
>>> +}
>>> +
>>> +static void guc_virtual_context_exit(struct intel_context *ce)
>>> +{
>>> + intel_engine_mask_t tmp, mask = ce->engine->mask;
>>> + struct intel_engine_cs *engine;
>>> +
>>> + for_each_engine_masked(engine, ce->engine->gt, mask, tmp)
>>> + intel_engine_pm_put(engine);
>>> +
>>> + intel_timeline_exit(ce->timeline);
>>> +}
>>> +
>>> +static int guc_virtual_context_alloc(struct intel_context *ce)
>>> +{
>>> + struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
>>> +
>>> + return lrc_alloc(ce, engine);
>>> +}
>>> +
>>> +static const struct intel_context_ops virtual_guc_context_ops = {
>>> + .alloc = guc_virtual_context_alloc,
>>> +
>>> + .pre_pin = guc_virtual_context_pre_pin,
>>> + .pin = guc_virtual_context_pin,
>>> + .unpin = guc_context_unpin,
>>> + .post_unpin = guc_context_post_unpin,
>>> +
>>> + .enter = guc_virtual_context_enter,
>>> + .exit = guc_virtual_context_exit,
>>> +
>>> + .sched_disable = guc_context_sched_disable,
>>> +
>>> + .destroy = guc_context_destroy,
>>> +
>>> + .get_sibling = guc_virtual_get_sibling,
>>> +};
>>> +
>>> static void sanitize_hwsp(struct intel_engine_cs *engine)
>>> {
>>> struct intel_timeline *tl;
>>> @@ -1559,7 +1677,7 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
>>> } else if (context_destroyed(ce)) {
>>> /* Context has been destroyed */
>>> release_guc_id(guc, ce);
>>> - lrc_destroy(&ce->ref);
>>> + __guc_context_destroy(ce);
>>> }
>>> decr_outstanding_submission_g2h(guc);
>>> @@ -1674,3 +1792,107 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc,
>>> atomic_read(&ce->guc_sched_state_no_lock));
>>> }
>>> }
>>> +
>>> +static struct intel_context *
>>> +guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
>>> +{
>>> + struct guc_virtual_engine *ve;
>>> + struct intel_guc *guc;
>>> + unsigned int n;
>>> + int err;
>>> +
>>> + ve = kzalloc(sizeof(*ve), GFP_KERNEL);
>>> + if (!ve)
>>> + return ERR_PTR(-ENOMEM);
>>> +
>>> + guc = &siblings[0]->gt->uc.guc;
>>> +
>>> + ve->base.i915 = siblings[0]->i915;
>>> + ve->base.gt = siblings[0]->gt;
>>> + ve->base.uncore = siblings[0]->uncore;
>>> + ve->base.id = -1;
>>> +
>>> + ve->base.uabi_class = I915_ENGINE_CLASS_INVALID;
>>> + ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
>>> + ve->base.uabi_instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
>>> + ve->base.saturated = ALL_ENGINES;
>>> + ve->base.breadcrumbs = intel_breadcrumbs_create(&ve->base);
>>> + if (!ve->base.breadcrumbs) {
>>> + kfree(ve);
>>> + return ERR_PTR(-ENOMEM);
>>> + }
>>> +
>>> + snprintf(ve->base.name, sizeof(ve->base.name), "virtual");
>>> +
>>> + ve->base.sched_engine = i915_sched_engine_get(guc->sched_engine);
>>> +
>>> + ve->base.cops = &virtual_guc_context_ops;
>>> + ve->base.request_alloc = guc_request_alloc;
>>> +
>>> + ve->base.submit_request = guc_submit_request;
>>> +
>>> + ve->base.flags = I915_ENGINE_IS_VIRTUAL;
>>> +
>>> + intel_context_init(&ve->context, &ve->base);
>>> +
>>> + for (n = 0; n < count; n++) {
>>> + struct intel_engine_cs *sibling = siblings[n];
>>> +
>>> + GEM_BUG_ON(!is_power_of_2(sibling->mask));
>>> + if (sibling->mask & ve->base.mask) {
>>> + DRM_DEBUG("duplicate %s entry in load balancer\n",
>>> + sibling->name);
>>> + err = -EINVAL;
>>> + goto err_put;
>>> + }
>>> +
>>> + ve->base.mask |= sibling->mask;
>>> +
>>> + if (n != 0 && ve->base.class != sibling->class) {
>>> + DRM_DEBUG("invalid mixing of engine class, sibling %d, already %d\n",
>>> + sibling->class, ve->base.class);
>>> + err = -EINVAL;
>>> + goto err_put;
>>> + } else if (n == 0) {
>>> + ve->base.class = sibling->class;
>>> + ve->base.uabi_class = sibling->uabi_class;
>>> + snprintf(ve->base.name, sizeof(ve->base.name),
>>> + "v%dx%d", ve->base.class, count);
>>> + ve->base.context_size = sibling->context_size;
>>> +
>>> + ve->base.emit_bb_start = sibling->emit_bb_start;
>>> + ve->base.emit_flush = sibling->emit_flush;
>>> + ve->base.emit_init_breadcrumb =
>>> + sibling->emit_init_breadcrumb;
>>> + ve->base.emit_fini_breadcrumb =
>>> + sibling->emit_fini_breadcrumb;
>>> + ve->base.emit_fini_breadcrumb_dw =
>>> + sibling->emit_fini_breadcrumb_dw;
>>> +
>>> + ve->base.flags |= sibling->flags;
>>> +
>>> + ve->base.props.timeslice_duration_ms =
>>> + sibling->props.timeslice_duration_ms;
>>> + }
>>> + }
>>> +
>>> + return &ve->context;
>>> +
>>> +err_put:
>>> + intel_context_put(&ve->context);
>>> + return ERR_PTR(err);
>>> +}
>>> +
>>> +
>>> +
>>> +bool intel_guc_virtual_engine_has_heartbeat(const struct intel_engine_cs *ve)
>>> +{
>>> + struct intel_engine_cs *engine;
>>> + intel_engine_mask_t tmp, mask = ve->mask;
>>> +
>>> + for_each_engine_masked(engine, ve->gt, mask, tmp)
>>> + if (READ_ONCE(engine->props.heartbeat_interval_ms))
>>> + return true;
>>> +
>>> + return false;
>>> +}
>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
>>> index 2b9470c90558..5f263ac4f46a 100644
>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
>>> @@ -26,6 +26,8 @@ void intel_guc_submission_print_info(struct intel_guc *guc,
>>> void intel_guc_submission_print_context_info(struct intel_guc *guc,
>>> struct drm_printer *p);
>>> +bool intel_guc_virtual_engine_has_heartbeat(const struct intel_engine_cs *ve);
>>> +
>>> static inline bool intel_guc_submission_is_supported(struct intel_guc *guc)
>>> {
>>> /* XXX: GuC submission is unavailable for now */