Medium term goal is to eliminate the i915->engine[] array and to get there
we have recently introduced equivalent array in intel_gt. Now we need to
migrate the code further towards this state.

This next step is to eliminate usage of i915->engines[] from the
for_each_engine_masked iterator.

For this to work we also need to use engine->id as index when populating
the gt->engine[] array and adjust the default engine set indexing to use
engine->legacy_idx instead of assuming gt->engines[] indexing.

v2:
  * Populate gt->engine[] earlier.
  * Check that we don't duplicate engine->legacy_idx

v3:
  * Work around the initialization order issue between default_engines()
    and intel_engines_driver_register() which sets engine->legacy_idx for
    now. It will be fixed properly later.

v4:
  * Merge with forgotten v2.5.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191017161852.8836-1-tvrtko.ursulin@linux.intel.com

Keep track of the GEM contexts underneath i915->gem.contexts and assign
them their own lock for the purposes of list management.

v2: Focus on lock tracking; ctx->vm is protected by ctx->mutex
v3: Correct split with removal of logical HW ID
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-15-chris@chris-wilson.co.uk

Forgo the struct_mutex serialisation for i915_active, and interpose its
own mutex handling for active/retire.

This is a multi-layered sleight-of-hand. First, we had to ensure that no
active/retire callbacks accidentally inverted the mutex ordering rules,
nor assumed that they were themselves serialised by struct_mutex. More
challenging though, is the rule over updating elements of the active
rbtree. Instead of the whole i915_active now being serialised by
struct_mutex, allocations/rotations of the tree are serialised by the
i915_active.mutex and individual nodes are serialised by the caller
using the i915_timeline.mutex (we need to use nested spinlocks to
interact with the dma_fence callback lists).

The pain point here is that instead of a single mutex around execbuf, we
now have to take a mutex for active tracker (one for each vma, context,
etc) and a couple of spinlocks for each fence update. The improvement in
fine grained locking allowing for multiple concurrent clients
(eventually!) should be worth it in typical loads.

v2: Add some comments that barely elucidate anything :(
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-6-chris@chris-wilson.co.uk

The guest may use this register to identify the running state of one
context. Emulate it as the value in context image as if the context runs
on the GPU hardware.
Signed-off-by: NWeinan Li <weinan.z.li@intel.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

when creating a vGPU workload, the guest context head pointer should
be updated correctly by comparing with the exsiting workload in the
guest worklod queue including the current running context.

in some situation, there is a running context A and then received 2 new
vGPU workload context B and A. in the new workload context A, it's head
pointer should be updated with the running context A's tail.

v2: walk through guest workload list in backward way.

Cc: stable@vger.kernel.org
Signed-off-by: NXiaolin Zhang <xiaolin.zhang@intel.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Push the ring creation flags from the outer GEM context to the inner
intel_context to avoid an unsightly back-reference from inside the
backend.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809182518.20486-3-chris@chris-wilson.co.uk

As we are phasing out using the GEM context for internal clients that
need to manipulate logical context state directly, remove the
constructor for the GVT context. We are not using it for anything other
than default setup and allocation of an i915_ppgtt.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809182518.20486-1-chris@chris-wilson.co.uk

We can't free "workload" until after the printk or it's a use after
free.

Fixes: 2089a76a ("drm/i915/gvt: Checking workload's gma earlier")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Ignore the central i915->kernel_context for allocating an engine, as
that GEM context is being phased out. For internal clients, we just need
the per-engine logical state, so allocate it at the point of use.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808110612.23539-1-chris@chris-wilson.co.uk

The oa object manages the oa buffer and must be allocated when the user
intends to read performance counter snapshots. This can be achieved by
making the oa object part of the stream object which is allocated when a
stream is opened by the user.

Attributes in the oa object that are gen-specific are moved to the perf
object so that they can be initialized on driver load.

The split provides a better separation of the objects used in perf
implementation of i915 driver so that resources are allocated and
initialized only when needed.

v2: Fix checkpatch warnings
v3: Addressed Lionel's review comment
v4: Rebase
v5: Fix rebase/merge issue with ratelimit_state_init
Signed-off-by: NUmesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806233002.984-1-umesh.nerlige.ramappa@intel.com

We only compute the lrc_descriptor() on pinning the context, i.e.
infrequently, so we do not benefit from storing the template as the
addressing mode is also fixed for the lifetime of the intel_context.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NPrathap Kumar Valsan <prathap.kumar.valsan@intel.com>
Acked-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730133035.1977-9-chris@chris-wilson.co.uk

Track the currently bound address space used by the HW context. Minor
conversions to use the local intel_context.vm are made, leaving behind
some more surgery required to make intel_context the primary through the
selftests.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730143209.4549-2-chris@chris-wilson.co.uk

Windows guest can't run after force-TDR with host log:
...
gvt: vgpu 1: workload shadow ppgtt isn't ready
gvt: vgpu 1: fail to dispatch workload, skip
...

The error is raised by set_context_ppgtt_from_shadow(), when it checks
and found the shadow_mm isn't marked as shadowed.

In work thread before each submission, a shadow_mm is set to shadowed in:
shadow_ppgtt_mm()
<-intel_vgpu_pin_mm()
<-prepare_workload()
<-dispatch_workload()
<-workload_thread()
However checking whether or not shadow_mm is shadowed is prior to it:
set_context_ppgtt_from_shadow()
<-dispatch_workload()
<-workload_thread()

In normal case, create workload will check the existence of shadow_mm,
if not it will create a new one and marked as shadowed. If already exist
it will reuse the old one. Since shadow_mm is reused, checking of shadowed
in set_context_ppgtt_from_shadow() actually always see the state set in
creation, but not the state set in intel_vgpu_pin_mm().

When force-TDR, all engines are reset, since it's not dmlr level, all
ppgtt_mm are invalidated but not destroyed. Invalidation will mark all
reused shadow_mm as not shadowed but still keeps in ppgtt_mm_list_head.
If workload submission phase those shadow_mm are reused with shadowed
not set, then set_context_ppgtt_from_shadow() will report error.

Pin for context after shadow_mm pinned and shadow pdps settled.

v2:
Move set_context_ppgtt_from_shadow() after prepare_workload(). (zhenyu)
v3:
Move set_context_ppgtt_from_shadow() after shadow pdps updated.(zhenyu)

Fixes: 4f15665c ("drm/i915: Add ppgtt to GVT GEM context")
Cc: stable@vger.kernel.org
Signed-off-by: NColin Xu <colin.xu@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

in workload_thread, it should grab runtime pm wakelock and later
uncore forcewake get will check rpm wakelock held successfully.
otherwise, sometimes, rpm wakelock not hold and print call trace below:

 Call Trace:
  intel_uncore_forcewake_get+0x15/0x20 [i915]
  workload_thread+0x5f9/0x16f0 [i915]
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to+0x85/0x3f0
  ? __switch_to_asm+0x40/0x70
  ? do_wait_intr_irq+0x90/0x90
  kthread+0x121/0x140
  ? intel_vgpu_clean_workloads+0x100/0x100 [i915]
  ? kthread_park+0x90/0x90
  ret_from_fork+0x35/0x40
 --[ end trace 86525f742a02e12c ]--

v2: adapted to use rpm structure.

Fixes: 251d46b0 ("drm/i915/gvt: Pin the per-engine GVT shadow contexts")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NXiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Workload contains RB and WA_CTX which are in ggtt space,
if they aren't in valid ggtt space, the workload shouldn't be
shadowed and scanned. So checking them earlier to avoid shadow
them.
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

All page directories are identical in function, only the position in the
hierarchy differ. Use same base type for directory functionality.

v2: cleanup, size always 512, init to null

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190614164350.30415-2-mika.kuoppala@linux.intel.com

The functions where internally already only using the structure, so we
need to just flip the interface.

v2: rebase
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613232156.34940-7-daniele.ceraolospurio@intel.com

Keeping the _hw_ in there does not help to distinguish it from its
only brethren i915_ggtt, so drop it.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611091238.15808-2-chris@chris-wilson.co.uk

Make the kref common to both derived structs (i915_ggtt and i915_ppgtt)
so that we can safely reference count an abstract ctx->vm address space.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611091238.15808-1-chris@chris-wilson.co.uk

Save RING_HEAD into vgpu reg when vgpu switched out and report
it's value back to guest.

v6: addressed comment for ring head wrap count support. (Zhenyu)
v5: ring head wrap count support.
v4: updated HEAD/TAIL with guest value, not host value. (Yan Zhao)
v3: save RING HEAD/TAIL vgpu reg in save_ring_hw_state. (Zhenyu Wang)
v2: save RING_TAIL as well during vgpu mmio switch to meet ring_is_idle
condition. (Fred Gao)
v1: based on input from Weinan. (Weinan Li)

[zhenyuw: Include this fix for possible future guest kernel that
would utilize RING_HEAD for hangcheck.]
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NXiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

An old optimisation to reduce the number of atomics per batch sadly
relies on struct_mutex for coordination. In order to remove struct_mutex
from serialising object/context closing, always taking and releasing an
active reference on first use / last use greatly simplifies the locking.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-15-chris@chris-wilson.co.uk

Use the per-object local lock to control the cache domain of the
individual GEM objects, not struct_mutex. This is a huge leap forward
for us in terms of object-level synchronisation; execbuffers are
coordinated using the ww_mutex and pread/pwrite is finally fully
serialised again.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-10-chris@chris-wilson.co.uk

Continuing the theme of separating out the GEM clutter.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-8-chris@chris-wilson.co.uk

Continuing the decluttering of i915_gem.c, that of the read/write
domains, perhaps the biggest of GEM's follies?
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-7-chris@chris-wilson.co.uk

for restore-inhibit context, hardware will not load in-context mmios
(engine context part) to hardware, but hardware will save the mmio
values in hardware back to context image. So, in order to save correct
values of vGPU back to context image, values of vGPU mmios have to be
loaded into hardware first for restore-inhibit context.

In this patch, the mechanism is applied to all gen9 platform.

The reason excluding gen8 platforms is only because of lacking of testing
on those platforms.

v3: for mocs registers, goto in-context mmios save-restore path for skl
platform as well (weinan li)
v2: update vreg when scanning indirect context for inhibit context for
gen9

Cc: Weinan Li <weinan.z.li@intel.com>
Acked-by: NWeinan Li <weinan.z.li@intel.com>
Signed-off-by: NYan Zhao <yan.y.zhao@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

"To track whether a request has started on HW, we can emit a breadcrumb at
the beginning of the request and check its timeline's HWSP to see if the
breadcrumb has advanced past the start of this request." It means all the
request which timeline's has_init_breadcrumb is true, then the
emit_init_breadcrumb process must have before emitting the real commands,
otherwise, the scheduler might get a wrong state of this request during
reset. If the request is exactly the guilty one, the scheduler won't
terminate it with the wrong state. To avoid this, do emit_init_breadcrumb
for all the requests from gvt.

v2: cc to stable kernel

Fixes: 85474441 ("drm/i915: Identify active requests")
Cc: stable@vger.kernel.org
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NWeinan <weinan.z.li@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

We switched to a tree of per-engine HW context to accommodate the
introduction of virtual engines. However, we plan to also support
multiple instances of the same engine within the GEM context, defeating
our use of the engine as a key to looking up the HW context. Just
allocate a logical per-engine instance and always use an index into the
ctx->engines[]. Later on, this ctx->engines[] may be replaced by a user
specified map.

v2: Add for_each_gem_engine() helper to iterator within the engines lock
v3: intel_context_create_request() helper
v4: s/unsigned long/unsigned int/ 4 billion engines is quite enough.
v5: Push iterator locking to caller
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-7-chris@chris-wilson.co.uk

We want to pass in a intel_context into intel_context_pin() and that
requires us to first be able to lookup the intel_context!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-2-chris@chris-wilson.co.uk

Our eventual goal is to rid request construction of struct_mutex, with
the short term step of lifting the struct_mutex requirements into the
higher levels (i.e. the caller must ensure that the context is already
pinned into the GTT). In this patch, we pin GVT's shadow context upon
allocation and so keep them pinned into the GGTT for as long as the
virtual machine is alive, and so we can use the simpler request
construction path safe in the knowledge that the hard work is already
done.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-1-chris@chris-wilson.co.uk

Typedef is not recommended in the Linux kernel.The klocwork static code
analyzer takes the enumeration as the full range of intel_gvt_gtt_type_t.
But the intel_gvt_gtt_type_t will never be used in full range. For
example, the GTT_TYPE_INVALID will never be used as an index of an array.
Remove the typedef and let the enumeration starts from zero to pass
klocwork analysis.

This patch fixed the critial issues #483, #551, #665 reported by
klockwork.

v3:
- Remove the typedef and let the enumeration starts from zero.
Signed-off-by: NAleksei Gimbitskii <aleksei.gimbitskii@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
CC: Colin Xu <colin.xu@intel.com>
Reviewed-by: NColin Xu <colin.xu@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

We want to use intel_engine_mask_t inside i915_request.h, which means
extracting it from the general header file mess and placing it inside a
types.h. A knock on effect is that the compiler wants to warn about
type-contraction of ALL_ENGINES into intel_engine_maskt_t, so prepare
for the worst.

v2: Use intel_engine_mask_t consistently
v3: Move I915_NUM_ENGINES to its natural home at the end of the enum
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190401162641.10963-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

in workload creation routine, if any failure occurs, do not queue this
workload for delivery. if this failure is fatal, enter into failsafe
mode.

Fixes: 6d763035 ("drm/i915/gvt: Move common vGPU workload creation into scheduler.c")
Cc: stable@vger.kernel.org #4.19+
Cc: zhenyuw@linux.intel.com
Signed-off-by: NYan Zhao <yan.y.zhao@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Now that the internal code all works on intel_uncore, flip the
external-facing interface.

v2: fix GVT.
Signed-off-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190319183543.13679-4-daniele.ceraolospurio@intel.com

Large ppGTT are differentiated by the requirement to go to four levels
to address more than 32b. Given the introduction of more 4 level ppGTT
with different sizes of addressable bits, rename i915_vm_is_48b() to
better reflect the commonality of using 4 levels.

Based on a patch by Bob Paauwe.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190314223839.28258-4-chris@chris-wilson.co.uk

In the next patch, we are introducing a broad virtual engine to encompass
multiple physical engines, losing the 1:1 nature of BIT(engine->id). To
reflect the broader set of engines implied by the virtual instance, lets
store the full bitmask.

v2: Use intel_engine_mask_t (s/ring_mask/engine_mask/)
v3: Tvrtko voted for moah churn so teach everyone to not mention ring
and use $class$instance throughout.
v4: Comment upon the disparity in bspec for using VCS1,VCS2 in gen8 and
VCS[0-4] in later gen. We opt to keep the code consistent and use
0-index naming throughout.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190305180332.30900-1-chris@chris-wilson.co.uk

This moves ppgtt root hook out of scan and shadow function,
as it's only required at dispatch time. Also make sure this
checks against shadow mm to be ready, otherwise bail to fail
earlier.
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Cc: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

As vGPU shadow ctx is loaded with guest context state, arbitrarily
submitting request in error workload dispatch path would cause trouble.
So don't try to submit in error path now like in previous code.
This is to fix VM failure when GPU hang happens.

Fixes: f0e99437 ("drm/i915/gvt: Fix workload request allocation before request add")
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

There is one corner case that workload_thread may pick and dispatch one
workload of vgpu after it's already deactivated. Below is the scenario:

1. deactive_vgpu got the vgpu_lock, it found pending workload was
submitted, then it released the vgpu_lock and wait for vgpu idle.
2. before deactive_vgpu got the vgpu_lock back, workload_thread might pick
one new valid workload, then it was blocked by the vgpu_lock.
3. deactive_vgpu got the vgpu_lock again, finished the last processes of
deactivating, then release the vgpu_lock.
4. workload_thread got the vgpu_lock, then it will try to dispatch the
fetched workload. It's not expected one workload of deactivated vgpu is
dispatched.

The solution is to add condition check of the vgpu's active flag and stop
to schedule when it's inactive.
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NWeinan Li <weinan.z.li@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

GVT-g will shadow the privilege batch buffer and the indirect context
during command scan, move the release process into
intel_vgpu_destroy_workload() to ensure the resources are recycled
properly.

Fixes: 0cce2823 ("drm/i915/gvt/kvmgt:Refine error handling for prepare_execlist_workload")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NWeinan Li <weinan.z.li@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The majority of runtime-pm operations are bounded and scoped within a
function; these are easy to verify that the wakeref are handled
correctly. We can employ the compiler to help us, and reduce the number
of wakerefs tracked when debugging, by passing around cookies provided
by the various rpm_get functions to their rpm_put counterpart. This
makes the pairing explicit, and given the required wakeref cookie the
compiler can verify that we pass an initialised value to the rpm_put
(quite handy for double checking error paths).

For regular builds, the compiler should be able to eliminate the unused
local variables and the program growth should be minimal. Fwiw, it came
out as a net improvement as gcc was able to refactor rpm_get and
rpm_get_if_in_use together,

v2: Just s/rpm_put/rpm_put_unchecked/ everywhere, leaving the manual
mark up for smaller more targeted patches.
v3: Mention the cookie in Returns
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-2-chris@chris-wilson.co.uk